On March 10, atmospheric chemist “Sherry” Rowland of the University of California-Irvine died in the company of his son and his wife of almost 60 years. Rowland became prominent in the 1970s after warning that common chemicals would destroy ozone 10 kilometers above Earth, exposing life to a shower of harmful radiation.

While exploring how chlorofluorocarbons (CFCs) degrade after being released into the atmosphere, Rowland and graduate student Mario Molina realized the CFCs would float to the upper atmosphere, be cleaved by sunlight, and release chlorine that would destroy ozone through a chain reaction.

(Ozone contain three oxygen atoms; most oxygen molecules contain two oxygens.)

By intercepting cancer-causing UV radiation, ozone in the stratosphere allows life to exist on Earth. Significant damage to this ozone would cause an epidemic of human and animal cancer, and likely damage plants as well.

This alarming prospect was not popular in industries that relied on CFCs, but it sparked a long and largely successful effort to restrict and then ban production of the chemicals.

And although Rowland never retreated from his findings, his calm, charismatic personality helped his cause. Ralph Cicerone, now the president of the National Academy of Sciences, recalls collaborating with Rowland on CFCs. “We talked on the phone nearly every day. I considered Sherry to be my best friend, and over time I learned that many people considered him to be their best friend, too. In the midst of the debates over CFCs, he never exaggerated the dangers, always cited the science, and treated other people with dignity and respect.”

What must a scientist do?

According to the University of California-Irvine’s press service, Rowland knew his results mattered far beyond the lab: “Mario and I realized this was not just a scientific question, but a potentially grave environmental problem involving substantial depletion of the stratospheric ozone layer. Entire biological systems, including humans, would be at danger from ultraviolet rays.”

At the time, scientists were studying the health implications of ozone-bearing smog in the lower atmosphere, but few people knew or cared about “good” ozone in the stratosphere.

The sudden notoriety of CFCs had a certain irony: The chemicals were invented in the 1920s at General Motors, maker of Frigidaire brand refrigerators, as a stable, non-toxic alternative to the ammonia and explosive propane used in air-conditioning and refrigeration.

CFCs later were used to expand plastic foam, clean electronic parts, and propel paint and deodorant in the mushrooming aerosol-spray business.

Antarctic ozone hole, 2011

   

Video: NASA

Chlorine and bromine in the upper atmosphere cause rapid ozone destruction in the super-chilled polar winter. Although the ozone “hole” (blue) is declining with the phase-out of CFCs, it still recurs.

They publish lest we perish!

Rowland’s 1974 study¹ ignited a long squabble over CFC production. Aerosol Age, the spray-can industry’s trade journal, implied that Rowland was a member of the Soviet KGB who wanted to destroy capitalism!

CFCs remained a back-burner issue, however, until the British Antarctic Survey discovered an alarming absence of ozone in 1985. The “Antarctic ozone hole” gave the theoretical worry sudden significance, and as the industry gradually found substitutes for CFCs, the ozone hole stopped expanding.

Today, as we watch the faltering response to global warming, it’s comforting to recall that the ozone threat prompted prompt collective action: The Montreal Protocol, a treaty to restrict CFC production, became effective in 1989 and has since been tightened after further alarm over ozone destruction, and 196 nations — essentially all of them — have signed the original Protocol. Production of ozone-depleting substances has fallen by more than 95 percent.

“CFCs were extremely useful compounds and their use was pervasive,” says Rudy Baum, editor in chief of C&EN (Chemical and Engineering News). “Although manufacturers maintained that there would be dire consequences if the use of CFCs were restricted or banned, it became clear pretty quickly that alternatives could be found in most cases.”

And yet ozone is still a problem, as shown by a 40 percent drop in Arctic ozone in the winter of 2010-2011. Continuing destruction is blamed on the stability of CFCs and the fact that the replacements, while less damaging, still destroy ozone. “Ozone can be thought of as a patient in remission, but it’s too early to declare recovery,” said Susan Solomon of the University of Colorado.

Not bounded by the lab walls

Nonetheless, the Montreal protocols are considered an epochal case of planetary preventive medicine, and Rowland, Molina and Paul Crutzen, who also worked on CFCs, were awarded the 1995 Nobel Prize for Chemistry.

But for 10 or 15 years, Rowland had played the role of maverick — speaking outside the laboratory about the importance of what he had found inside it. It’s not a comfortable role for many scientists; many find it safer to stay in the lab and let others figure out what to do with their results.

Jonathan Fink, vice-president of research at Portland State University, says “The culture of science is pretty deep in terms of how we are trained. Most science grad students are taught to focus on being the best at something, rather than thinking about the application of what they do to society.”

All along, Rowland explained the science and gently reminded us of our stake in an intact ozone layer. He continued to study atmospheric chemistry, mentor younger scientists, and show by example how scientists could speak responsibly about what their results mean for the rest of us.

Somehow, Rowland managed to fight his battles without making enemies, at least outside the industries that had inadvertently begun calamitous destruction of ozone.

Why do scientists like Rowland speak out? “Because they’re scientists and scientists are addicted to facts and what facts tell them,” says Baum. “I knew Sherry Rowland pretty well — I was the West Coast correspondent for C&EN from 1991 to 2004 … he was a gracious, dignified, reserved individual, certainly not a rabble-rouser. But he knew that his science was solid and that it told him that humans were doing something that would have catastrophic consequences if they didn’t stop. So he spoke out. Simple as that.”

A new disaster unfolds

Even before the Montreal Protocol was signed, climate scientists were starting to warn that carbon dioxide in the atmosphere would enhance the greenhouse effect and trigger global warming. In testimony to the U.S. Senate in the torrid summer of 1988, NASA climatologist James Hansen linked rising temperatures to rising levels of greenhouse gases from fossil fuels.

The debate over global warming and climate change had begun, and going public put Hansen in much the same position as Rowland had occupied 15 years before. Via email, Hansen credited Rowland and atmospheric scientist Don Hunten as “role models… . They showed that it was possible to do first-rate science and also uphold our responsibility to make clear the implications of our research for society.”

Rowland redux?

Until then, Hansen had been a well-regarded but faintly visible NASA expert in planetary atmospheres. He had studied Venus, where an atmosphere choked with carbon dioxide produces a “runaway greenhouse effect” that raises the surface temperature to 460° C.

After making news in 1988, Hansen retreated from the public discussion of warming, but in the early 2000s, as temperatures continued to rise, he began to speak up again. In 2005, after the Bush White House tried to muzzle him, he went public with a vengeance.

Why? Journalist Mark Hertsgaard, who has written extensively about global warming and repeatedly interviewed Hansen, says he “thinks like a scientist, believes if you find the information, and present it properly, the truth should carry the day. I think he came out of hibernation in 2005 only because he felt he had to. He looked around and saw that the information alone was not carrying the day.”

Hansen’s regular emails combine climate facts with political opinions for a broad audience. For example, a recent commentary argued that “Scientists attempt to communicate, but are flummoxed by the ability of the profiteers to manipulate democracies. The scientific method (objective analysis of all facts) is pitted against the talk-show method (selective citation of anecdotal bits supporting a predetermined position).”

On Aug. 29, 2011, Hansen was arrested at the White House with hundreds of others protesting the Keystone XL tar-sand oil pipeline. Tapping such a vast reservoir of carbon, Hansen believes, will bring us that much closer to a “tipping point” on greenhouse warming. “Now we’ve got the spectacle of one of the world’s foremost climate scientists getting arrested and urging others to get arrested,” says Hertsgaard. “This is way beyond speaking out.”

Hertsgaard, a native of Minnesota, says it’s “very hard for [Iowa native] Jim Hansen the person to speak out.” In the Midwest, Hertsgaard says, “it is just not seemly to draw attention to yourself or bring up a topic that is likely to discomfort others. … but it’s not corny to talk without irony about the importance of doing the right thing.”

The scientific culture

A fully indoctrinated scientist is chary of talking much beyond the lab, Hertsgaard says. “Many scientists very much frown on taking the public agitator role, and that’s another tribute to Hansen’s courage. He was prepared not only to take brickbats from the Exxon-Mobil front groups, but to endure the judgment of his own peers, who said ‘That’s not what scientists do.’ He remembers that he’s not just a scientist, he’s a human being too.”

Despite the successful example of the Montreal Protocol, the global warming problem is vastly harder to solve, says Baum of C&E News. “The scale of fossil fuel use is several orders of magnitude larger …. Humans consume between 80 million and 90 million barrels of petroleum every day, and that represents only about a third of the fossil fuel that is consumed.”

Finally, while the specter of cancer caused by increased UV radiation is unsettling, “people actually like the warmer conditions, at least for now,” Baum wrote. “We didn’t have a winter in Washington, D.C., this year … and people loved it.”

So will the environmental victory over CFCs that started with Rowland and Molina be mirrored by serious action over global warming? Maybe not, says Spencer Weart, a long-time chronicler of warming. Comparing the ozone battle to the fight over global warming “is like comparing a single battle to a world war. Ozone depletion (once the ozone hole was detected) was clearly an urgent problem, with a straightforward solution. But with global warming, it’s hard for people to worry much about something that seems remote in space and time — isn’t it just a problem for polar bears and our grandchildren?”

Slowing warming “will require wholesale changes in our entire world economy,” Weart says. “And that must begin with government regulation of the fossil fuels industry, the largest concentration of economic power the world has ever seen. The pushback has been fierce, beginning with industries that suspected their profits would be restricted, and extending to people who fear governmental threats to their freedom.”

Rowland was once libeled as a Soviet spy, but “Scientists who have put themselves into politics like Jim Hansen … have been subject to ad hominem attacks: crude vilification and direct threats far beyond anything that Rowland experienced.”

Hansen and his colleagues, says Weart, “have persisted nevertheless. For the logic of their scientific understanding forbids them from keeping silent about the dangers they foresee.”

Should an artificial waterway in Chicago be closed to block two highly destructive fish from entering Lake Michigan and then the other four Great Lakes?

On Feb. 27, the Supreme Court said ‘no’ when it declined to revisit an appeal by the State of Michigan, which wanted to compel closure of the Chicago Ship and Sanitary Canal. The canal, created to drain stormwater and wastewater from Chicago, could allow silver and bighead carp from the nearby Des Plaines River to enter Lake Michigan.

Since the two carp, native to Asia, escaped from fish ponds in the South in the 1970s, they have occupied much of the Mississippi River system, and have become extremely abundant in rivers near the Canal. Biologists, state agencies and the Great Lakes Commission warn that once the fish reach Lake Michigan, they will likely spread through the five lakes, then into the St. Lawrence River.

The Great Lakes hold almost 20 percent of the world’s fresh water and border eight states and two Canadian Provinces. Given the silver carp’s fearful jumping habits, and the potential for both species to steal food from the mouths of sport fish, the invasion could threaten recreational boating and commercial, sport and tribal fishing that gross $16.4 billion per year.¹

Although the Great Lakes already house at least 180 invasive species, ecologists warn about irreparable harm from Asian carp. They say prevention is cheaper and easier than eradication — which may be a practical impossibility.

Originally, the watersheds of the Great Lakes and Mississippi River were separate. The two were united by the Chicago Sanitary and Ship Canal, which drains stormwater and treated wastewater into the Mississippi River system.

Don’t fence me out!

Although three electric “fences” across the canal have apparently managed to block the fish from entering Lake Michigan, many scientists view the barriers as stopgaps at best, and Asian carp DNA has been found several times beyond the fences.

While that DNA suggests that the carp are already in Lake Michigan, the fish have not been found there. Still, ecologists, accustomed to studying the disastrous aftermath of invasives on land and in water, would love to protect the Great Lakes from the carp by closing the canal. That would also protect the Mississippi River from invasion from the Lakes.

“The Asian carp situation is analogous to medicine, where an ounce of prevention is worth a pound of cure,” says Jake Vander Zanden, a professor of zoology at University of Wisconsin-Madison, and an expert on freshwater invasive species. “It makes so much more sense to keep them out, rather that let them in and deal with the consequences forever.”

The shipping industry, reliant on these waterways, wants to keep the Chicago waterways open, said Mark Biel, chairman of UnLock Our Jobs by email. “Nobody wants to see the Asian carp get into the Great Lakes… This is, however, a manageable issue that requires a long-term, comprehensive plan, and separation is simply not a solution. Given the size, scope and complexity of separating the two bodies of water, it’s clear that the costs would be enormous and the timeline — if it’s possible at all — would do nothing to address the immediate threat of Asian carp.”

Invasions can be expensive. The Environmental Protection Agency figured that just the invasives delivered in ballast water cut commercial fish landings by 13 percent to 33 percent in the U.S. Great Lakes, at an annual cost of $200 million. The estimate did not cover Canada’s part of the lakes, or species that arrived by other means.

What’s the problem with carp? What can be done to prevent their entry into the Great Lakes and beyond? Are invasive species always so damaging to ecosystems?

What’s the beef about carp?

Asian carp are heavy-bodied fish native to Asia that have occupied large parts of the Mississippi River watershed, where their rapid reproduction, voracious feeding (up to two or three times their body weight in plant and animal plankton per day), and made-for-home-video jumps are making life miserable for native fish and fishing people alike. The two carp considered most threatening to the Great Lakes — silver and bighead — originated in Southern fish ponds, where they were placed as natural vacuum cleaners to suck plankton from dirty ponds.

Since at least 1980, when the escape of the silver and bighead was detected, that voracious appetite was transformed from selling point to sticking point.

You might observe — correctly — that species have been moving since life began. It’s true that invasions are an old story, but it’s only half the story: the process has been force-fed by commerce and technology. “This is a natural process; it was once a trickle, but the rate at which it happens now is so devastating,” says Vander Zanden. “With globalization, trade, travel, things are moving so fast, it’s a fundamentally different process, and the implications are huge.”

It’s impossible to predict exactly how well Asian carp would fare in the Great Lakes; their abundance will depend on temperature, food supply, the emergence of diseases and predators, and factors that we can’t predict. But the lakes have a wide variety of habitats, and inevitably some would be conducive to the invaders.

The fundamental reason why invasive species reach nuisance levels resides in the predators, diseases or competitors they leave behind in their homeland. In the new habitat, the traveling species often gets an unfair advantage, enabling it to grow to astonishing abundance and crowd out native species.

Asian carp provide a perfect example of the process. They were deliberately imported to work on Southern fish ponds, and their ability to outcompete native fish for food and habitat “has led to the widespread establishment of Asian carp in the Mississippi River, impacting the natural balance of the aquatic ecosystem,”².

Can we keep carp from the greatest lakes?

On January 31, 2012, the Great Lakes Commission, an international body charged with maintaining the environmental and economic vitality of Earth’s largest lakes, issued a report describing three options for physically separating the two giant drainages to block invasions in both directions. The report was greeted by a number of officials from the region, including Michigan Senator Debbie Stabenow and Chicago mayor Rahm Emanuel.

The Obama Administration opposes closure of the Chicago canal, and in February it proposed to spend $51.5 million on Asian carp research. The money will buy more trapping and netting, to assess whether the fish have reached Lake Michigan, research on fish trapping with chemical attractants, and noisemakers to scare carp from entrances to the lake.

The focus on Chicago is misleading, according to Biel, who notes that the Great Lakes and Mississippi River Interbasin Study, from the Army Corps of Engineers, found “18 aquatic pathways throughout the region (not just Chicago alone) by which the Asian carp could get into the Great Lakes. The existence of these other pathways, which cannot simply be closed, demonstrates the importance of a regional solution to control Asian carp populations. That’s why we have to expand our sights beyond Chicago to determine a comprehensive control plan that implements measures in all of the pathways… .”

Philip Moy is a senior scientist at the Aquatic Sciences Center at UW-Madison who previously worked on the issue for the Corps of Engineers. “Electric barriers buy us time, and we need to do two things,” Moy says. “We should look into additional barrier technologies that can be added to augment the electrical approach… . We need to look pretty hard at the Great Lake Commission report suggesting that the lake and river can be re-separated. It would cost a lot of money, a century of infrastructure has built up there, but what’s the logic of waiting another 10 years to get started on a project that can take a generation to complete?”

The “mid-system separation alternative” proposed by the Great Lakes Commission was estimated to cost $3.26 to $4.27 billion. The latest federal appropriation for monitoring and research related to Asian carp will bring the three-year cost for controlling Asian carp in the area to $156.5 million.

Separation, Biel wrote, “would effectively end waterborne commerce through the Chicago Area Waterway System. The Great Lakes Commission report mischaracterizes how vessels could move containers around the Chicago rail gridlock, giving the impression that there would be a way to facilitate both separation and continued cargo movement.”

Muscling in on the mussels

There are good reasons why zebra and quagga mussels are often mentioned in discussions about invasives in the Great Lakes. Since the zebra entered the lakes in ballast water used to stabilize ships a couple of decades ago, it has clogged water intakes at power plants and water utilities.

Along with a later arrival, the quagga mussel, the zebra has eaten enough plankton to change the ecology of the lakes, and the zebra is now spreading to smaller lakes and rivers.

To prevent further hitchhikers in ballast water, ships now must replace their ballast water in the ocean with salt water, which carries organisms that are unlikely to survive in the freshwater lakes. “Every ship coming in is inspected by the Coast Guard before it reaches the Great Lakes,” Moy says, “and we haven’t discovered another ballast-related species since 2006. In the lakes, there is a growing spirit of cooperation between the companies that operate ships and the states.”

p. 74, “Aquatic invasive species in the Rio Bravo/Laguna Madre Ecological Region”

Salt-water invaders are carried in ballast water and through the pet and fishery trades.

Species invasions also plague smaller lakes, which explains the growing push to prevent the movement of invasive fish, mollusks and plants, by requiring boaters to clean and dry their boats and trailers as they leave a lake.

In Wisconsin, at least, that effort seems to be succeeding, even though not every boater complies, Moy says. “Some people say, ‘If this guy didn’t do it, it’s not the end of the world if I don’t also,’ but it usually takes multiple introductions over time to establish a population. If we reduce the number of introductions per year, we reduce the potential for establishment. Every person makes a difference.”

Buying time, but could time be on our side?

As ecologists pursue the science of invasives, what to do about the carp now knocking on the door of the Great Lakes? Biel, of the shipping industry, says, “Despite the uptick in hysteria on this issue, Asian carp populations in Illinois haven’t actually moved up river in six years. That said, we fully support funding the existing electric control barriers because their effectiveness has been demonstrated over and over again.”

Despite “substantial strides” in controlling Asian carp in Illinois and Indiana, including a third electric barrier and physical barriers along the Des Plaines River and the Illinois and Michigan Canal, “there’s simply not enough being done by other Great Lakes states,” Biel says. “Continued calls for lock closure remain a higher priority for our neighbors and other like-minded groups than actually implementing tactics for prevention.”

During the years it would take to seal the Chicago waterways, control technology may improve, says Moy, who points to fresh ideas from the U.S. Geological Survey. Instead of using the pesticide rotenone as a “big hammer” to kill all fish, he says, the Survey is testing a coating for rotenone that would make a deadly fish feed. Once sprinkled in the water, carp and other filter feeders would eat the feed, but only Asian carp have the enzyme that can dissolve the coating to release the rotenone. “It’s much more specific; an elegant application that takes advantage of the fish’s feeding behavior and internal physiology, using an existing, certified” chemical agent, Moy says.

There are benefits to working several angles at once, Moy adds. “These invasions are not inevitable. We can reduce the rate of invasions and the number of introductions per year, and that reduces the likelihood of establishment, and each year we delay introduction to a lake gives research time to come up with a solution.”

Burning of the Alaskan tundra can release massive amounts of carbon dioxide, the major greenhouse gas, according to a study published in Nature this week. The Arctic is warming faster than the rest of the planet, causing scientists to wonder what will happen to the carbon that plants have stored in Arctic soils and plant matter, both living and dead.

The new study looked at the aftermath of the Anaktuvuk River wildfire, which burned more than 1,000 square kilometers of tundra on Alaska’s North Slope in 2007. Anaktuvuk burned for almost three months, and by itself, accounted for two-thirds of the total area burned in Alaskan tundra since 1950.

The immediate cause was lightning, but weather played a major role. Between July and September, 2007, the North Slope had the hottest weather in a 129-year record. When the fire was really roaring, daily highs were 5°C to 10°C above average. The Slope also received less than 20 percent of the average rainfall that summer, leaving the tundra abnormally arid.

In 2008, Michelle Mack, an associate professor of biology at the University of Florida and her colleagues visited the area and took samples from 1-square-meter quadrants both inside and outside the fire zone. Mack was in the field in Alaska, alas, and did not answer our emails, but her group calculated that the fire oxidized more than 2 million tons of carbon, which entered the atmosphere as carbon dioxide.

Accounting for carbon

The movement of carbon through soils, ecosystems, waters and the atmosphere is critical to the issue of global warming. Releasing carbon to the atmosphere as carbon dioxide speeds warming; and storing carbon compounds can slow or potentially reverse warming.

The moist acidic tundra under study covers as much as one-third of a billion square kilometers of the global Arctic – making it a major “sink” for carbon dioxide. The 2 million-ton release of carbon was equal to at least 50 percent of the amount of carbon stored annually in the Alaskan tundra, meaning this one fire almost cancelled the anti-warming benefit of photosynthesis in the region.

Chilling news about a burning issue

The link between global warming and fire also appeared in a new analysis of Yellowstone National Park. “Large, severe fires are normal for this ecosystem,” said Monica Turner, a Yellowstone expert and professor of ecology at the University of Wisconsin-Madison. Historically, the entire Yellowstone landscape has burned every 100 to 300 years, but Turner and company calculated that current trends toward hotter, drier summers, mean fires could consume the entire area every 30 years by 2050.

Wildfires are also becoming more common in the normally fire-resistant tundra of Alaska, and for reasons related to permafrost, reflectivity and feedback, the consequences could be dire:

And feedback moves us from the additive realm to the multiplicative one. In the Arctic, feedback also plays a central role related to the release of methane, which has even more warming potential than carbon dioxide. Many warming Arctic habitats have started releasing larger amounts of methane, which could warm the planet, feed back, and stimulate the release of yet more methane.

This feedback, like the one that may be affecting burning tundra, paints a darker picture of what could happen if we ignore the atmosphere and blithely assume that the future will be just like the present.

– David J. Tenenbaum

Uganda is looking for answers as about 20 students and a teacher were killed June 28 by lightning that struck their school in this highland nation in Eastern Africa. With dozens of children also injured by electricity, Ugandans wonder if the serious string of lightning strikes is related to climate changes, or are just the consequence of an unusually heavy stream of moist air coming from the Atlantic.

We can’t answer, but the tragedy did get us Why Filers to thinking about lightning. Although lightning bolts killed “only” an average of 39 Americans over a recent 10-year stretch, the injuries, which concentrate on the vulnerable nervous system, can be severe and lifelong.

Satellites tell us that 1.2 billion lightning flashes occur in the atmosphere each year — although not all reach Earth.

What is lightning? How does it injure and kill? And what has been learned in the past few years from the millions spent studying nature’s electricity?

2003, NASA Johnson Space Center

A string of lightning flashes are seen from space.

Boom-boom room

Thunder — the cracking or rumbling you often hear — is caused by thermal expansion and contraction. Lightning bolts can get far hotter than the sun’s surface — up to 20,000° Celsius. That heats the air, causing it to expand, and starting a shock wave that moves as sound waves — thunder.

If you’re close to the lightning bolt, you’ll hear a cracking; further away, you’ll hear rumbling because that sound has come from several parts of the bolt, and been reflected from buildings and hills.

And yes, if you start counting “one Mississippi,” when you see the flash, you can estimate the distance to the bolt: Light essentially reaches you instantly, but sound takes about five seconds to travel one mile. Divide the number of seconds by five to find miles, or by three for kilometers.

Silence is — mysterious

One of the many lightning mysteries is this: Sometimes you hear the thunder, and sometimes you don’t. For example, “heat lightning” is an eerie, silent flash that often lights clouds in thunderstorms.

The sound has been gobbled by an audio version of the visual mirages that cause trekkers to see water in stone-dry desert. These visual mirages are caused by heat that bends light waves. You look straight ahead, but you actually see the sky, shimmering like a tempting lake.

Similarly, in a thunderstorm, the sharp boundaries between warm and cool air can channel sound waves away from the observer, as you can see from the nifty applet, below.

Much the same phenomenon was noticed during the Civil War, when artillery was visible in the distance but audible only in some parts of the battlefield.

Go play with lightning.

Nature’s lighting foundry

We think of clouds as billowy places, couches for angels in Renaissance paintings. In thunderclouds, however, air and water – liquid, frozen and in between — may be whizzing up and down at a furious clip — up to 100 miles an hour.

That’s a place where angels fear to tread.

The motion in these cumulonimbus clouds is powered by convection, a force that separates fluids based on density. The dense, cold air falls while the warmer air rises. Smaller water droplets hitchhike up on the updrafts, which can’t support the larger droplets.

Because smaller particles tend to carry positive charges, the movement caused by temperature, humidity and density (which can include snow, ice, and water vapor) segregates electrical charges: The top of a cloud becomes positive and the bottom negative.

Regions of different charge can only exist if surrounded by an insulator — namely air. Insulators, however, eventually fail when they are overwhelmed by electric “pressure.” In a thunderstorm, that “failure” results in lightning.

Hangin’-motor blues

Having trouble envisioning this? Imagine a chain holding a greasy V-8 motor above a ’63 Ford Fairlane in a shade-tree auto mechanic’s backyard. If the engine is too heavy, or the chain too weak, the chain will snap as it is overwhelmed by the gravitational attraction between Earth and engine.

Thunk!

Substitute air’s insulation for the chain, and electrical attraction between positive and negative charges for gravity, and you have a greasy-fingered picture of how air can separate electrical charges during a thunderstorm.

To go further, we need one hunk of physical-science jargon: electrical potential is how fast charge changes with distance, and it’s measured in volts per meter. Electrical potential is the “pressure” that’s “trying” to start an electric current between areas of opposite charge.

(Opposite electrical charges are like young lovers: They will do anything to get together.)

Just as an overweight V-8 can snap a skimpy chain, excess electrical potential can “break” air’s insulation. When that happens, an electrical current — in the form of a lightning bolt — neutralizes the opposing charges.

Flash!

Diagram: Encyclopædia Britannica, Inc.

Lightning leaps between separate negative and positive regions during a storm. Most cloud-to-ground flashes originate in the cloud’s negative regions.

In a cloud-to-ground flash, the huge electrical potential — measured in millions of volts — eventually overcomes air’s electrical resistance, and a “streamer” or “leader” begins reaching, about 50 meters at a time, toward ground. The streamer makes an ionized (conducting) pathway of plasma, allowing current to flow.

Where am I safe?

As the current approaches the ground, its electrical potential can cause a surge of oppositely-charged particles to “reach” up toward it. Because this upward current often springs from tall objects, trees and other tall objects make lousy shelter during a storm.

For a 2001 Why File on lightning, David Rust, who was then director of forecast research and development at the National Severe Storms Laboratory, told us that the safety of a building is determined by the degree of grounding. A steel building that’s securely grounded, he said, will be safer than a wooden one that’s not, even if the steel building is taller. Steel and other conductive metals provide an easy pathway to ground for the lightning, and that translates into safety.

Once the ionized pathway is established, electric currents flow back and forth between ground and cloud so quickly that they appear as flickers rather than separate bolts. (More on lightning safety.)

We’ve heard that a big cloud-to-ground bolt carries one trillion watts of electricity. If that estimate is right, during its fraction-of-a-millisecond life, the flash carries about the same current as the total U.S. generating capability. (Watts measure the flow of electric current at any instant. The more familiar watt-hours measures an hour of flow of a given current; 1 kilowatt hour equals 1,000 watt hours.)

But nobody has figured out how to put this energy to work. Though we have heard one proposal, the currents are insanely high and the strikes are too brief and too unpredictable.

Keeping a close watch on lightning

Our understanding of lightning grows with improvements in technology, and a new instrument on trusty weather balloons has pointed to a surprising source for the electric charge. The process involves a small, spongy relative of hail called graupel, says Don MacGorman a physicist at NOAA’s National Severe Storms Laboratory.

“As graupel accumulates tiny, pristine ice particles, and then falls through liquid water, there can be some charge exchange in collisions where the tiny ice particles rebound,” MacGorman says. In the lab, this interaction seems powerful enough to be main source of electricity – and therefore lightning — in large areas of the storm.

Within a few years, a better understanding of lightning formation could improve predictions, MacGorman says. “We will not be able to say lightning will a hit particular location. Lightning is too random for that, but we are getting to the place where it may be possible to say that a storm will produce a little or lot of lightning, and that would be helpful for storm safety.”

Cloudy picture

The graupel explanation, however, raises a question: If the interaction of water and ice creates the electric charge, why is lightning found in dry sectors of the storm, including the large “anvil” structure that exhausts cold, dry air above the storm? “We have seen lightning initiated almost 100 kilometers from the heavy precipitation area, so something else must be going on in the anvil,” says MacGorman. “This does not accord with how we’d viewed anvils.”

Scientists are also probing cloud flashes, caused by the flow of current between regions of clouds with opposite charges and does not hit the ground. Formerly dissed because they don’t kill people, cloud flashes are getting some respect.

For one thing, they are the most common type of lightning, accounting for perhaps one-quarter of all lightning flashes. Adding cloud-to-ground and cloud-to-cloud lightning gives a better indicator of total storm intensity than ground flashes alone, “which have very little relationship to storm severity,” says MacGorman. “You can have huge ground flashes in a relatively innocuous storm, but total lightning is well related to things that affect severity and strength: the size of the updraft, the amount of ice in the clouds, and so it gives us clues as to how intense the storm is.”

Positively speaking

The biggest recent discovery on lightning, says MacGorman, concerns storms that produce a large amount of positively charged cloud-to-ground lightning rather than the usual negative currents. During a field research program called STEPS, in a lightning-rich region of the high plains, some storms contained negative charges in places that normally would be positive, and vice versa. In these conditions, instead of dropping the normal negative charge to the ground, the lightning bolts were positive.

The unusual phenomenon could arise in clouds containing a high concentration of liquid water, MacGorman says, and that would also raise the odds of large hail. “Hail typically forms because graupel or another seed particle starts collecting liquid water faster than it can freeze, and the water spreads over the surface, then freezes into a solid layer of ice.”

These dense particles are more likely to happen in an area with a lot of liquid water, and therefore, these positive lightning strikes could be a harbinger of large, destructive, hail.

The view from on high

For the next stage in lightning observations, scientists will go to GOES-R, a series of geostationary satellites scheduled for launch in 2015. These high-orbital spyglasses will carry an optical gadget that should “see” upwards of 90 percent of total lightning activity. “The viewing area will cover pretty much all of the continental United States, and parts of Africa and South America, and eventually, half of the Pacific Ocean,” says MacGorman. “This will allow us to detect thunderstorms over the oceans, which we have not had good way to see in the past.”

That should help airplanes dodge storms, but also aid weather prediction, MacGorman says, since thunderstorms can trigger other thunderstorms. They also add water vapor to the lower atmosphere, which also feeds storms.

Nothing light about lightning

Lightning gathers myths. Whether it’s Zeus throwing thunderbolts from the ancient Greek sky, or the moronic misconception that victims become untouchables because they retain an electric charge, these bolts spark the imagination.

But lightning can change your life, as Steven Marshburn, Sr., of Jacksonville, N.C., told us in 2001. Marshburn was struck in 1969 while working in a bank. Although the sky was blue and no storm was in sight, a bolt entered through a wire from the drive-up window.

Afterwards, Marshburn “suffered from severe headaches, chronic daily pain, grand mal [epileptic] seizures, dizziness, problems with my eyes going blurry. Many health problems persist. I have had 20 lightning-related surgeries…”

In 1989, in response to his brush with death, he formed Lightning Strike & Electric Shock Survivors International to investigate the medical aspects of lightning and to support victims and families. In 2001, he told us that members had talked 13 fellow survivors out of suicide.

A shock to the nervous system

Lightning usually kills by attacking the heart, which runs on electrical impulses. While high-voltage electrical injuries often cause severe burns, they are rare with lightning, likely because the bolts — lasting only 0.1 to 1 millisecond –- are too brief to cause severe burns.

Although burns may result if clothing ignites or sweat boils and steam is trapped under clothing, wet, sweaty clothing may actually conduct a heavy current outside the body and reduce the damage.

Raphael Lee, a professor of surgery and medicine at the University of Chicago, and an expert on the effects of lightning strike, told us that most of the initial current in a lightning strike does not pass through the body. However, two electromagnetic phenomena can produce a strong voltage drop across the body:

Strong electric fields are a problem for nerves and muscles, Lee says, because they “have been structured through evolution to be very sensitive to tiny electric fields.” That, combined with their physical length, which spans a large electrical gradient, “makes them very sensitive to lightning.”

Nerve cells can be a meter long, and by extending into different parts of an electric field, they are exposed to high voltages, Lee says. One focus of concern is the cell membrane which can die if strong voltages poke holes in it. Voltage can also wreak havoc in the pores in the membrane, which regulate the cell’s physiology by controlling how ions enter and leave the cell. Normally, for example, the potassium concentration is 1,000 times higher inside a cell, and damage to the pores can result in malfunction or cell death.

Lightning = thunder in the brain?

Although electricity is the natural focus of lightning damage, Lee suspects that an acoustic pulse, or shock wave, plays a major role, and perhaps a dominant one. A lightning bolt is surrounded by hot, ionized gas that arises in nanoseconds or microseconds and whose temperature may exceed 10,000 ° C. “When you heat something in a small area in such a short period, there are going to be shock waves,” he says.

The power of this acoustic wave is obvious when lightning hits and splits a tree, Lee adds. But inside the brain, the shock can trigger traumatic injuries similar to those caused by a roadside bomb or artillery shell.

Neurological injury: no passing matter

Lightning injury can be severe, long-lasting, and hard to treat, and it “may affect any or all parts of the nervous system,” according to Mary Ann Cooper, an emerita professor of emergency medicine at the University of Illinois-Chicago.

In a 2009 study of survivors of lightning and other electric shocks, 78 percent of the survivors had at least one psychiatric diagnosis; many of the troubles related to learning, memory and executive function.

In 2001, Cooper told The Why Files that confusion, caused by slowed information processing, is a hallmark of lightning injury. Symptoms include “difficulty in short-term memory, coding new information and accessing old information, multitasking, distractibility, irritability and personality change.”

Damage to the frontal lobe, the site of much higher thinking, is common, according to Cooper. “Many suffer personality changes because of frontal lobe damage and become quite irritable and easy to anger. The person who ‘wakes up’ after the injury often does not have the ability to express what is wrong with them…and cannot carry on a conversation, work at their previous job, or do the same activities that they used to handle. As a result, many self-isolate, withdrawing from church, friends, family and other activities.”

Cooper said some cell types continue suffering for weeks after the injury, and that nerve cells seem to “spend a long period trying to heal themselves, until finally the cell body is exhausted” and the cell dies. That process accounts for a delayed disability syndrome among survivors.

Help at hand?

Long-term neurological consequences are a major research area, Lee says, because they also occur in traumatic brain injury. “People are trying to sort out what is the best treatment, and understand why some people are more susceptible to delayed neurological problems. The body is very complicated and … the weight of evidence suggests there are genetic predispositions to complications after a blast causes traumatic injury to the brain, and lightning injury may be no different. Many people recover, but some don’t. What is different about the people who don’t?”

– David J. Tenenbaum

Humans and cats go way back. The relationship sprouted around 2000 BC in Egypt, where humans first domesticated felines. Today, more than 90 million cats in the United States alone enjoy the companionship of humans, while another estimated 90 million are stray or feral.

As in most relationships, there are still secrets between humans and their feline friends. But a recent study published in the Journal of Wildlife Management shed light on one secret that may have been nagging cat owners: what do outdoor cats, otherwise known as “free-roaming,” do all day?

Since there are several cat enthusiasts at The Why Files, we, too, wondered about the answer to that question. And the answer belies a few thorny predicaments peculiar to the cat-human relationship.

A day in the life of a free-roaming cat

Decked with radio collars that tracked their every move, 42 free-roaming cats (18 of them pets, 24 of them owner-less) were the stars of the two-year University of Illinois study. The researchers’ goals were to compare what owned versus un-owned cats did all day, where and how far they wandered, and how likely they were to survive in the often risky outdoors.

Certainly, to no cat owner’s surprise, the felines spent much of their time lounging or sleeping, just like their strictly-indoor counterparts. However, the amount of time pet cats versus owner-less cats spent snoozing differed significantly. Pet cats lazed about for 80 percent of their days, while un-owned cats loafed for “only” 62 percent of the time.

“That alone is very interesting. It could be associated with their requirements. It’s possible that the cats without owners have to spend more time looking for resources to take care of themselves,” speculated Nohra Mateus-Pinilla, study co-author and wildlife veterinary epidemiologist at the Illinois Natural History Survey.

Another important finding, according to Mateus-Pinilla, were the differences in the cats’ ranges. While, not surprisingly, un-owned cats roamed further afield than owned cats, Mateus-Pinilla and her co-authors were surprised by how far the stray cats strayed and by the diversity of habitats they skulked in, as compared to pet cats. While most of the pet cats stuck close to home, the most itinerant stray cat wandered around a 547-hectare (1,351-acre) area.

From original map by Jeff Horn

Despite range differences, un-owned and owned cats’ territories can overlap. The red outline shows the largest range tracked for an un-owned cat in the study, and the yellow dot indicates one pet cat’s range.

“Because of the large home range sizes in the evidence of both cats without ownership and cats that are owned, their home ranges are overlapping. And because of the mortality evidence, these animals could be facing a certain amount of risks that we are unable to measure,” said Mateus-Pinilla.

Indeed, the risks of being a free-range cat are much higher than those of indoor cats, and if the cat has no owner, its fate is almost always bleak. In their study, six stray cats died, while only one owned cat died.

Mateus-Pinilla said their study raises many new questions. To The Why Files, however, it seems that living in the company of humans has its advantages for cats. But keeping this relationship indoors may have advantages for wildlife and people too—-implications that drive the otherwise curious research on free-roaming cats.

Too many kitties on the range

While the indoor-outdoor debate lives on in the cat owner community, and regardless of whether or not cats enjoy the out-of-doors, their secret lives outside entail some dirty secrets that are alarming scientists and laypeople alike.

The sheer number of free-range cats, owned or not, has become a conservation and health concern, some scientists say. Like any species, too many can spell trouble.

Cats, by nature, are superb predators. A cat stalking a bird or squirrel is simply doing what cats do. However, their prowess as hunters, combined with their overpopulation, has wildlife biologists and enthusiasts biting their nails over the potential endangerment or extinction of some prey species.

“There are a growing number of landscapes in which free-ranging cats are not only the most abundant mid-sized mammalian predator, but they can outnumber all of the native mammalian mid-sized predators combined. So they really do become the dominant mid-sized predator in many landscapes,” said Stanley Temple, an emeritus professor of forest and wildlife ecology at the University of Wisconsin-Madison, who was among the first to study the ecological impacts of free-roaming cats.

Because of their impacts on both native predators and prey, conservation scientists consider free-roaming cats invasive species. While not the greatest threat to wildlife, they add to the increasingly complex web of existing threats.

Species most at risk of death-by-kitty are birds that spend a lot of time on the ground, small mammals and reptiles, according to Temple. In fact, cats are second to habitat destruction as the cause of bird extinction. Thirty-three bird species have met their fate to the paws of cats since the 1600s.

The world’s ever-shrinking “islands” of wildlife habitat are hotspots of conservation concern over free-roaming cat populations, since the native species in these areas are the hardest hit by invading cats. For example, birds that live in America’s dwindling grasslands or on the increasingly crowded seashore are finding themselves in a precarious situation.

Open and fragmented landscapes, which also include forest outskirts and farmland, are the territories of choice for cats. And, except in subtropical locales, they tend to stick close to humans. Even if un-owned, most cats are still dependent on people for either food or shelter, or both.

“They are remarkably resourceful at taking advantages of the opportunities that we present,” said Temple, who clarified that free-roaming cats are only truly “feral” if they are completely independent of humans.

Their dependency on humans highlights another dilemma: free-range cats can easily spread diseases and parasites that can jump from cat to cat, cat to wildlife, and even cat to human. The list of contagions includes feline leukemia, feline immunodeficiency virus, worms, rabies and toxoplasmosis, a parasite-caused disease that can damage the developing brains of unborn human babies, if their mothers are infected.

Free-roaming cats’ close proximity to both humans and other animals thus creates a potentially strong reservoir for these diseases. While vaccinating both owned and un-owned cats can help reduce the spread of disease, vaccines are not 100 percent effective and the logistics of vaccinating every single cat may be impossible, especially since many vaccinations are annual.

Photo: Rodrigo Basaure

These street cats certainly benefit from a human handout, but do humans benefit from the cats’ potential disease threat?

It’s complicated

Indeed, solutions to these predicaments aren’t easy. While the science may seem to imply that rounding up every cat on the range may be the best solution, the ubiquity of free-roaming cats and the emotions wrapped up in some people’s relationship with felines complicate the matter.

Studies suggest that many free-range cats are people’s beloved pets that are allowed outside, said Temple. But, while keeping every pet cat indoors would significantly and immediately cut the number of free-range cats, not every cat owner agrees that indoor life is best for kitty.

To further complicate things, one of the often promoted “humane” methods of attempting to reduce un-owned cat populations — trap, treat, neuter, release — repeatedly fails. Not only are there always the cats that get away, but releasing the cats back into the “wild” still does not eliminate the risks to wildlife.

Temple believes that for a cat-control method to work, three criteria must be met: the strategy must actually control cat numbers over large areas, it can’t harm any other part of the ecosystem, and it is socially acceptable. The last criteria can be the trickiest to meet and often creates tension between humans.

Photo: Flickr

Is this outdoor kitty taunting his indoor pal? But who has the better life?

“The divide over how to deal with cat overpopulation, in one way, can be simplified as the group of people who are really concerned about ecological impacts of cats versus those that are really concerned about the welfare of individual animals,” said Temple, based on his years of experience conducting public outreach on the issue. He clarified that he likes cats and is actually the owner of a 21-year-old feline.

Temple believes solutions that meet both factions on common ground do exist. Keeping pet cats inside and trapping, treating, neutering and confining un-owned, free-roaming cats are two strategies that meet his criteria. Though, for some people, it will take some convincing.

Mateus-Pinilla was careful to emphasize that their study did not seek to evaluate management options. They were focused on adding to the science and remaining neutral in the debate about solutions to the issue of free-roaming cats.

– Jenny Seifert

On March 11, a catastrophic earthquake — one of the four largest in the past century — struck in the ocean east of Japan, sending a colossal tsunami against the shore. By March 21, the toll of dead and missing, mainly from the tsunami, was estimated at 22,000.

As Japan confronted what Emperor Akihito called the worst crisis since World War II, we began to hear that the six-reactor complex at the Fukushima Daiichi plant, located directly in the tsunami’s path, had lost electrical power. The emergency generators also failed, apparently due to water damage to them or their fuel supply.

As we focus on the nuclear disaster at Fukushima, we emphasize that as of now, the tsunami itself is the far larger human tragedy. But like the tsunami itself, the nuclear disaster may portend further problems in other places, and is likely to affect a trend toward greater use of nuclear power around the world.

Not cool

Immediately, the arrow of trouble aimed at the most ominous type of nuclear accident: loss of cooling. Fission — splitting of radioactive elements that powers nuclear reactors — can stop when reactor operators flip a switch to insert control rods to absorb neutrons. This stops the chain reaction — the divison of uranium atoms that releases neutrons that split other atoms and generate heat — which is the whole point of building nuclear reactors to boil water and drive turbines.

But once the fission reactions cease, decay heat continues to be released from the unstable atoms that remain after fission, and it is this heat that must be removed by a cooling system after shutdown.

Past accidents have shown that decay heat can build up in seconds; and significant damage to the fuel and potentially reactor equipment can occur within minutes. The danger of such a “meltdown” is a major reason why nuclear designers and engineers focus so much effort on cooling the reactor core.

In the beginning, there was Three Mile Island

Japan, target of the only two atomic bombs used in war, is hardly the first nation to confront a “loss of coolant” emergency at a reactor. That happened on March 28, 1979, in the United States, where Pennsylvania’s Three Mile Island (TMI) reactor #2 began a partial melt-down.

Much later, the Nuclear Regulatory Commission concluded that the accident “was caused by a combination of personnel error, design deficiencies, and component failures.” As hundreds of alarms buzzed in the control room, operators, lacking a direct measurement of the water level inside the reactor, made a bad situation worse, the reactor went at least partly dry, and a large percentage of the fuel melted.

It’s safe to say the public reaction verged on panic as a bubble of explosive hydrogen built up inside the plant and evacuations were ordered.

The slow, dangerous removal of fuel revealed massive heating and damage inside the reactor. According to the book, “TMI 25 Years Later”¹: “A large portion of the core melted and flowed into the lower vessel. Most of the core experienced temperatures of at least 1727° C, with certain parts reaching 2527°C.”

At these temperatures, the essential containment vessel can weaken and fail.

TMI, the above book concluded, neared a complete a meltdown. “No one can say for sure, but some experts say that had the accident continued for another 20 to 45 minutes, the [reactor] vessel would have heated up and the metal would have lost its strength, leading to a rupture,” preventing further cooling and allowing superheated fuel to melt through the reactor vessel and enter – and likely exit — the reactor building.

From there, it’s impossible to speculate how widely the radiation would have spread, the authors wrote, but this is what is called the China Syndrome — a runaway load of reactor fuel melting its way down into the earth. Oddly, “China Syndrome” – the movie — was released 12 days before the TMI meltdown.

TMI #2 has since undergone a major cleanup. Intact and damaged fuel has been moved to storage at Idaho National Engineering Laboratory. Reactor #1 is operating normally, and final removal of the destroyed #2 awaits the decommissioning of its companion.

According to the Nuclear Regulatory Commission: “Estimates are that the average dose to about 2 million people in the area was only about 1 millirem. To put this into context, exposure from a chest X-ray is about 6 millirem.”

Nevertheless, the alarm over TMI sent the U.S. nuclear industry into a tailspin.

 

The meltdown of TMI was the death knell for growth in American nuclear industry — the spate of plants licensed during the 1980s had all been planned or under construction by 1979. Rollover to see a comparison of present dependence on nuclear energy.

Graph 1: U.S. Nuclear Regulatory Commission. Graph 2: International Atomic Energy Association

Chernobyl – the unmitigated disaster

The Lord Voldemort of nuclear accidents started on April 26, 1986, when Chernobyl reactor #4 exploded, burned and melted down in a spectacular fire that spewed an estimated 50 tons of radioactive fuel over a swath of Eastern Europe. Unlike TMI (and the imperiled Japanese reactors) Chernobyl had no vessel to contain its fuel, and a giant fire – consuming the estimated 800 tons of graphite used to slow neutrons in the reactor — burned for more than a week as brave crews tried to damp it with sand, boron and lead.

Chernobyl was located in a part of the Soviet Union that is now in Ukraine.

The meltdown produced some of the worst radiation injuries in history, and hundreds of thousands were force-evacuated from an “exclusion zone” — roughly 30 kilometers in radius — around the smoking, radioactive hulk of #4.

Within months, the cooling reactor was hastily wrapped in a giant concrete “sarcophagus” (stone coffin) to contain further radiation. But the sarcophagus is leaking, says Leon West, a professor of mechanical engineering at the University of Arkansas, who has 40 years of experience in nuclear physics, radiation protection and nuclear engineering. “Chernobyl is still open and is still a threat to the local environment.”
“Construction has already begun on the New Safe Confinement,” says photographer Michael Foster Rothbart, who lived 12 miles from the exclusion zone between 2007 and 2009, “and although it keeps falling behind schedule, target finish date is 2013.”

Japan: Facing Three Mile Island or Chernobyl?

By March 21, 10 days after the tsunami, the owners of the Fukushima power plant reported that it had reconnected electric power to all six reactors. The disaster seems headed toward resolution, says Jeff Geuther, who manages a research reactor at Kansas State University. “My understanding is that the fuel [in the three recently operating reactors and the three spent-fuel pools at other reactors] is all under water. The radiation dose has been falling at the plant, an indication that water level has increased in the spent fuel pools.”

Although it’s not clear how much fuel has melted, Geuther says, “It’s fairly clear that the cladding [a thin sheathing on the fuel rods], at a minimum, had some damage. Iodine and cesium have been detected offsite; these are fission products that would be typically be trapped inside the cladding.”

By March 23, the utility reported that the lights were on in the control room of reactor #3, but work had not yet begun on monitoring equipment and reactor cooling pumps in the three reactors that were operating before the quake. By March 24, smoke was rising from several reactors, three plant employees were being treated for radiation exposure, and the zone of concern about radiation in drinking water had been expanded. The local populace remains under evacuation.

Near-term progress in stabilizing the Fukushima plant will be measured by

A near miss?

Two positive factors helped what looks like a near-miss at Fukushima. First, those reactors (unlike Chernobyl) had thick steel containment vessels, which, despite some reports of damage, seemed to hold up reasonably well.

Second, also unlike Chernobyl, Fukushima used water, not combustible graphite, to slow neutrons.

On the other hand, Fukushima faced systemic difficulties due to the precipitating natural disasters: After the epochal earthquake-towering tsunami sequence shut the reactors down, the electric grid died, killing the emergency cooling pumps.

Then the emergency diesel generators failed, and without cooling, the reactors quickly overheated. But with roads out and the nation tending to survivors and victims of the tsunami, the nuclear emergency festered for days, through a series of explosions, fires, bursts of radiation, and evacuations of plant workers.

At one point, just 50 workers were on hand to deal with multiple emergencies at several reactors and pools of spent fuel. The desperation was on display when helicopters tried to dump buckets of water into the fuel pools and fire trucks sprayed cooling water through explosion-blasted walls.

How many broken reactors?

Despite early fears that Fukushima was mimicking Chernobyl, it seems rather to be headed toward the less malignant TMI precedent, says West. “A big leak [like Fukushima] is not like the open-air nuclear bonfire of Chernobyl that spewed radioactive materials into the upper atmosphere. The extent of the release of radiation and the continuing difficulties with cooling of reactors and spent fuel has clearly put the Daiichi site at the TMI stage.”

As radioactive particles cross the Pacific on the jet streams, “California, Oregon, and Washington should start reporting measurable traces of radioactive materials in air samples,” says West, “but for the United States, this should be more like a Chinese test of a nuclear weapon and of no health consequence.”

Radiation has already been detected on milk and green vegetables near the reactor, and now in drinking water in Tokyo. “The Japanese will need to monitor and control agriculture products to minimize the risk to public health,” says West. “This will be similar to efforts in the United States during the 1950′s, when the U.S. was detonating nuclear weapons in Nevada,” and farmers were prohibited from selling milk for four days afterwards.

Japanese meltdowns, American reverbs

As Japan evacuated neighbors from the Fukushima plant, the U.S. Nuclear Regulatory Commission (NRC) advised American citizens in Japan to move at least 50 miles away. That’s much further than specified American evacuation plans, notes Vicki Bier, a professor of industrial engineering at the University of Wisconsin-Madison. “If the NRC is concerned up to 50 miles in Japan, that certainly calls into question emergency planning here, which is limited to 10 miles.”

On March 16, California Senators Barbara Boxer and Dianne Feinstein asked the NRC to review safety at two California plants located near earthquake faults. “Roughly 424,000 live within 50 miles of the Diablo Canyon and 7.4 million live within 50 miles of San Onofre Nuclear Generating Station,” the senators wrote.

And on Mar. 22, the Nuclear Regulatory Commission agreed to accelerate a safety review at Indian Point, a pair of reactors 30 miles from Manhattan.

Japan: How prepared, in reality?

How did such severe nuclear troubles arise in Japan, where “tsunami” was coined, and which is the world’s leader in earthquake engineering and disaster preparedness?

For starters, the tsunami was much bigger than expected. But we’ve also learned from the Associated Press (on March 24) that Japanese preparations focused on natural disasters.

Was the nuclear emergency made worse because six reactors were at one location? As we saw, radiation vented from one reactor caused the flight of workers trying to tame other reactors. But multiple siting had “always been considered to be a really good idea,” says West. “You have a collection of focused professionals with lots of resources [for example, to fight fires], so if one reactor has difficulties, you could take those excess resources and focus on that situation. … This is the first situation, where [multiple sitings] appears to need to be reexamined.”

Early reports point to a critical design failure at Fukushima, says Bier, an expert on risk assessment at nuclear plants. “They were designing for earthquake and tsunami, but not for this level of damage; you’ve got to give engineers some criteria; they can’t design for anything. They could have designed for what did happen, but they apparently decided it was too unlikely.”

Design: Where are the goalposts?

A specific weakness concerned the emergency diesel generators needed to run the pumps, which apparently were swamped by the tsunami, says Bier. “There is a lot we won’t know for months, but there is reasonable speculation about things that could be done differently at modest cost. You can’t prepare for every eventuality, but probably it would have been possible to get better protection for the diesels in a bunker or on higher ground.”

The systematic disruption and near chaos interfered with tasks like avoiding melt-downs in the pools holding spent fuel, which lack the containment usually found on reactors. As Fukushima proved, accidents can be made worse as effects are compounded: the real-life scenario included a combination of a Japan-record earthquake, massive tsunami damage, regional blackouts and radiation releases.

“The surrounding area was so damaged by earthquake and tsunami that it impeded the emergency response,” says Bier. “We have seen stories about people within the evacuation zone who could not evacuate because the roads are impassable or buildings have collapsed, and they were not sending in rescue teams because the radiation was too high. Certainly it was not anticipated that the damage would be this severe, or the radiation would be too severe to evacuate.”

 

Photo: Japan Red Cross Society

Thousands of Japanese have been evacuated from around the Fukushima Daiichi reactors; masks retard the spread of disease in close quarters. Few experts expect the need for a permanent exclusion zone, like the one in Chernobyl, around Fukushima.

Fukushima: End game

Will the six reactors at Fukushima Daiichi be dismantled, like TMI #2, or wind up inside a Chernobyl-style concrete coffin?

The three reactors that got emergency cooling with sea water are likely finished due to corrosion, not to mention possible explosion damage. “Salt water is a killer,” says Robert Rosner, professor of astronomy, astrophysics and physics at the University of Chicago. Rosner expects these reactors to be taken apart and trucked to long-term storage.

Although the age of the reactors – about 40 years – militates against spending large sums on refurbishment and updating, Japan now faces an electricity shortage, so Rosner expects one or two of the plants to return to service, at least for a while.

West, however, suggests that at least one reactor may wind up encased in concrete. “If I were an engineering manager, I would be looking at the possibility of stabilizing it to deal with all the issues” and then build an outer containment to isolate the reactor but allow service visits.

Credibility at stake

Assessing the long-term impact of Fukushima requires us to look at the technology’s unique place in the popular eye. Whether the nuclear industry likes it or not, nuclear carries plenty of emotional baggage. Nuclear physics produced the mushroom clouds over Hiroshima and Nagasaki long before it was used to make electricity. And because ionizing radiation is invisible, it’s a case where what you don’t know can hurt you.

Nuclear energy also arouses fear because power-plant neighbors cannot control it, says Nathan Hultman, an assistant professor of public policy at the University of Maryland. “A lot of research has looked at why people view risks differently, and both dread and the degree of control in nuclear are nerves that are touched very strongly. We feel safer driving cars than in an airplane, even though statistically, airplanes are much safer, because we feel in control in a car.”

 

Photos: TMI, Cherobyl:Wanrouter.

While TMI today shows the scars of its accident (reactor #2 on left melted down in 1979), Chernobyl’s gravesite (rollover) evokes a much bleaker history and deeper wounds. The thrown-together concrete enclosure may need to be replaced – a hazardous, expensive task.

The Japanese nuclear industry also faces credibility problems, Hultman notes.

“Small nuclear accidents were covered up,” says Hultman. “Often the initial reaction was ‘Everything is just fine, the situation is normal,’ then it came out there was a deeper problem. Now we are in a situation where very bad things are happening, and people are not sure what to believe.”

Hultman adds that these issues are a likely fixture in the coming debate over nuclear power. “Nuclear is not the only way to boil water to generate electricity,” he says, and the discussion of energy sources must be broader than that. “Rather than say, ‘We must have nuclear,’ we need to talk about alternatives as well.”

The Fukushima debacle could further polarize a nuclear debate that was altered by both TMI and Chernobyl, says Hultman. “There is almost a religious division. People who believe it’s good think it will be the answer to all our problems, and people who don’t like it, really really don’t like it.”

An omen for the future?

The Fukushima disaster carries striking ironies. Japan was the only country at the receiving end of atomic bombs, and studies of survivors at Hiroshima and Nagasaki have been the basis for understanding the health effects of low-level radiation.

Historically, the Fukushima disaster occurred as nuclear was gaining so much traction as a low-carbon solution to global warming that some prominent environmentalists had begun to talk nuclear. “This is going to have a big effect on the rebound toward nuclear,” says West, who adds, “We just can’t burn our forests — and coal is an old forest — forever,” due to global warming.

Even technological disasters that loom large in the short run may eventually be seen as lessons, West says. “The crash of a major aircraft … does not mean that air travel should end, it means we need to tighten up our design.”

Rosner, however, suggests that nuclear, with its potential for widespread, long-term contamination, needs to live by different rules. “When you are engineering something where the consequences, if something goes wrong, are devastating, even though the probability is very small, you need to engineer to avoid the devastation. We’ve known how to do that for 50 years, but it was always just a bit too expensive on the front end, so the decision was made: The probability is so low, we are not going to worry about it.”

Skeptical about global warming? 2010 has just tied 2005, making these the two hottest years on record. And nine of the 10 warmest years on record have occurred since 2001.

Photo: williumbillium

Was New York’s epic blizzard last month related to climate change?

But temperature is only part of the story. After a year that saw epic floods in Pakistan and California, massive floods have swamped Brisbane, Australia, population 2 million. Russia was toasted by a record heat wave last summer. Europe and, of course, New York were smothered by giant snowstorms.

And we just read that 2010 had the heaviest precipitation on records that date to 1880.

So we have to ask: Is this normal weather, or is this climate change in action?

And as greenhouse gases continue to accumulate in the atmosphere, what will happen the day after tomorrow?

There is good theoretical reason to think that an accelerating greenhouse effect will affect weather: Add greenhouse gases like carbon dioxide and methane to the atmosphere, and they trap more heat. In hotter conditions, more water evaporates from the ocean, which eventually falls as precipitation. Heat is energy, and more energy in the ocean and atmosphere provides more power to drive intense storms.

These questions are devilishly difficult to answer. It’s a big planet, and assessing conditions during the past few decades, and making projections for the future, is a gnarly task. Climate models are better at getting the big picture than making regional forecasts for future weather. Data records are incomplete, especially as we delve further in the past.

Graph: Progress Report of the Interagency Climate Change Adaptation Task Force: Recommended Actions in Support of a National Climate Change Adaptation Strategy, October 5, 2010

If you doubt that warming temperatures have anything to do with carbon dioxide, the primary greenhouse gas, here’s something to think about. Horizontal divider shows average temperatures, 1901-2000.

Nevertheless, let’s ask our question about both recent weather data and future forecasts.

Record temperatures

As the climate warms, one easy prediction is that record warm days will become more common, and record colds will be less common. When Gerald Meehl, a senior scientist at the National Center for Atmospheric Research, compared the number of record daily highs to the number of record daily lows in the U.S., he found they were roughly equal in the 1950s.
Today, he says, “for every two record highs, there is only one record low. If there was no warming going on, the ratio would be one to one, so we are shifting the odds toward having a better chance for setting a record high versus a record low.”

Meehl says Australian data show the same thing.

Even though the climate has warmed by only about 0.6° C, he says, “This shows that even with a very small change in average temperature, about 1° Fahrenheit, we can get a pretty noticeable change in the extremes.”

Click here to view the embedded video.

At some point, we may look fondly upon today’s two-to-one ratio, as climate models suggest the ratio will reach 20 to 1 by year 2050 and 50 to 1 in 2100. Yet even then, when the U.S. average temperature may have risen by several degrees C, “We still get some daily record low temperatures,” Meehl says. “We still get extremely cold weather, although it will happen much less frequently.”

Today, he notes, “When there’s a cold snap, people ask, ‘What happened to global warming?’ But even with warming, it will still get cold, but not extremely cold, and not as often.”

Precipitous rise in precipitation?

Rain and snow are two ways that the atmosphere feeds life on the planet. A hotter atmosphere has the ability to hold more moisture because more water evaporates from the ocean, and warmer air can also store more moisture.

Already, says Kevin Trenberth, a senior scientist at the National Center for Atmospheric Research, the water-vapor contained in an imaginary cylinder stretching from Earth to space has been rising 1.3 percent per decade since the 1970s.

And so warming means more potential for precipitation.

“When we review change in the hydrological cycle,” Trenberth says, “not just tropical cyclones [hurricanes and typhoons] but extra-tropical cyclones and individual thunderstorms, the evidence from around the world is that when it rains, it rains harder, when it snows, it snows harder. This is consistent with the understanding we have, the theory.”

That is also happening in the United States, where days with intense rain and snow have been increasing, says Meehl. “When it rains, it pours, we see this in observations, and models show an increase in the future.” For example, a summary published in 2007¹ found that, “Over the last century there was a 50% increase in the frequency of days with precipitation over 101.6 mm (four inches) in the upper Midwestern U.S.”

However, land use plays a role in some observed precipitation changes, says James O’Brien, emeritus professor of meteorology and oceanography at Florida State University. “We studied heavy rainfall over 62 years in Orlando, Fla., and did a simple thing: We divided the time into two periods of 32 years each, and looked at the probability of one or more two-inch rainfalls.”

In the recent period, during almost all non-summer months, Orlando had a big increase in heavy rain, but Gainesville, 40 miles away, did not. “The cause in Orlando is absolutely clear,” says O’Brien. “It’s Disney World. It’s all the roads, the concrete, which act as a heat sink. In winter, a cold fronts hits a bubble of heat caused by this heat island, and it kicks up a storm and you get more rain.”

Heavy rain = heavy drought?

Even if total precipitation does not change, there are consequences to the newer “when-it-rains-it-pours” precip pattern. Heavy rain runs off rather than percolating into the soil, so instead of feeding plants, it can cause soil erosion and floods. If, as some models suggest, extreme precipitation increases in springtime, when the ground is still frozen, “that has a significantly different impact than extreme rainfall during summer,” says Daniel Vimont, an assistant professor at the Center for Climatic Research at the University of Wisconsin-Madison, because the rain cannot enter the soil and must run off.

Heavy rain can also contribute to drought by drying the atmosphere, Meehl says. “We have to take into account the number of days between precipitation events. On a map of North America, almost everywhere intensity shows an increase to date, and a projected increase, but we also see dry days increasing, like in the southern tier of states and especially the Southwest. When it rains, it rains really hard, but there are more days between rainfalls. On average, you are getting less total precipitation, but the risk for floods has increased because of this intensity increase. Over long periods, we are seeing drier conditions, because the number of days between events is also increased.”

Facing a wave of drought

A trend toward drought is already under way, according to a 2004 study by Aiguo Dai of the National Center for Atmospheric Research, which found that the percentage of Earth’s land area stricken by serious drought had more than doubled between the 1970s and the early 2000s.

The future seems no more benign. Last October, Dai published a review, based on 22 computer climate models, that projected a major expansion of drought over the next 30 years. The affected area includes the breadbasket regions of North and South America, most of Africa and Australia, and parts of China and neighboring countries.

According to the study, the western two-thirds of the United States will be significantly drier in the 2030s, after which matters will only get worse.

In general, the only places that will see more precipitation are in the extreme north — Northern Russia, Scandinavia, Canada and Alaska.

So reindeer need raincoats…

But seriously, “We are facing the possibility of widespread drought in the coming decades, but this has yet to be fully recognized by both the public and the climate change research community,” Dai says. “If the projections in this study come even close to being realized, the consequences for society worldwide will be enormous.”

Cyclones, typhoons and hurricanes

In terms of extreme weather, nothing beats the tropical storms variously called typhoons, tropical cyclones or hurricanes — for their winds, high seas and astonishing rainfalls. So hurricanes are the natural focus of study on the past and future effects of global warming.

In 2005, Hurricane Katrina played the starring role in a series of powerful hurricanes that pounded the Gulf of Mexico and Caribbean, and we reported that hurricanes were packing more power in a warmed planet.

Then came a counter-rebellion: scientists began questioning whether hurricanes were really more powerful, and noted that they were not getting more common (although everybody agrees that increasing population and development along the coasts both contribute to greater storm damage).

The chief hindrances to finding real trends in the tropical cyclones are their long-term, natural variation in strength and frequency, and the wobbly nature of data on older cyclones. In the North Atlantic, home of the best hurricane data, the quality of the data jumped when airplanes began flying into hurricanes in 1944, and again when satellite tracking began around 1970. Data on older Pacific and Indian Ocean storms are even more questionable.

To explore how global warming will affect tropical cyclones, the World Meteorological Organization set up a team under the leadership of Thomas Knutson, of the Geophysical Fluid Dynamics Laboratory. Knutson’s group projected that hurricanes, globally, will become 6 percent to 34 percent less common by 2100, despite the warming trends².

The counterintuitive reduction may be due to wind. These storms need a warm ocean to provide energy, “but you also need an atmosphere that cooperates,” explains Charles Conrad, an associate professor of geography at the University of North Carolina and director of the Southeast Regional Climate Center. Wind shear, a change in wind velocity with altitude, can blow a developing storm apart. “Some global climate models suggest that more wind shear over the tropical and sub-tropical Atlantic may inhibit cyclones, so when you put that together with higher sea-surface temperatures, this suggests that when a system can develop, it will be stronger.”

A question of intensity

Given the rickety data on older storms, Knutson’s group concluded that “it remains uncertain whether past changes in tropical cyclone activity have exceeded the variability expected from natural causes.” According to team member Christopher Landsea, science and operations officer at the National Hurricane Center, “Every single paper in the peer reviewed literature, looking at the theoretical side of hurricanes and global warming, or the climate model simulations, says the same thing. The changes today are very, very tiny, maybe 1 percent stronger, due to manmade global warming.”

But another member of the team begs to disagree. “I think the evidence is fairly unequivocal that there has been an increase in intensity,” says Kerry Emanuel, professor of tropical meteorology and climate at Massachusetts Institute of Technology. To gauge intensity, Emanuel used wind speed, measured at six-hour intervals, to calculate a “power dissipation index,” fancy lingo for the amount of energy that enters the hurricane.

Graph: Weather and Climate Extremes in a Changing Climate³

Heat energy from the ocean powers hurricanes, and storm intensity closely follows changes in sea surface temperature in the North Atlantic. “Power dissipation” is a measure of the storm’s total power, based on a cube of maximum wind speed.

The index, he says, shows that recent hurricane intensity is “beautifully correlated with ocean temperature in the tropics,” and those warm seas, in turn, result from accelerating greenhouse warming. Changing levels of greenhouse gases and reflective aerosols in the atmosphere “are the cleanest explanation for what happened with hurricanes,” Emanuel says. “I think there is a strong [human-caused] signal in Atlantic hurricanes over the last 40 years.”

Tower of power

And what of the future? The Knutson team projected that average maximum winds would increase 2 percent to 11 percent by 2100, so “a substantial increase in the frequency of the most intense storms is more likely than not globally, although this may not occur in all tropical regions.”

Although the group wrote that intense tropical cyclones, “deserve particular attention, as these storms historically have accounted for an estimated 85 percent of U.S. hurricane damage,” Landsea said, “That’s a very small increase, a long ways in the future,” and it could be offset by a decreasing frequency of storms.

In the world of climate, it’s usually possible to find another voice, and last year, a modeling study⁴ projected that the number of category 4 and 5 storms will almost double by 2100. (Category 5 includes the strongest hurricanes.)

We asked James Kossin, a scientist with the National Oceanic and Atmospheric Administration, who has studied hurricanes since 1987, about those results, and he told us, “There is a lot of uncertainty in our understanding of how tropical cyclones respond to their environment and to changes in their environment.”

Linking changes in hurricanes to human-caused climate changes is “very challenging,” said Kossin. “I have medium confidence that climate change could lead to the strongest storms getting stronger” globally.

Emanuel, however, says the creators of these models “freely admit they will not model intense hurricanes, they don’t have the resolution. What does a 2 percent to 11 percent increase mean if the models are constitutionally incapable of having hurricanes? And this is what the models are telling us, but what does nature say? It tells us that hurricanes intensity is changing much more rapidly.”

Emanuel reminds us that storm destruction equates to at least the cube of wind speed, and therefore, a small increase in maximum wind can mask a much larger increase in intensity and damage.

From here, gentle reader, the arguments devolve from murky to truly obscure. We promise to report back in a few years, but we’re happy to note that this dispute, however contentious, is being fought in print by civil scientists who can cooperatively ponder on our climatic future.

Easy questions can be tough to answer

We’d love to know if warming is affecting wind, but the records do not support such a comparison, says Dan Vimont. In a study on climate change in Wisconsin, for example, “We started to look at wind, but there is not as much observational data. There are 200-odd temperature-precipitation gauges around Wisconsin reporting daily, but … it’s difficult to find a continuous record from a gauge that is monitored well.”

The reality is that as much as we’d like to attribute particular events like the floods in Pakistan and Australia to climate change, we may never know. “For any given event, it’s really hard to gauge how much climate change has contributed,” says Claudia Tebaldi, a climate statistician with the non-profit Climate Central. “Even for heat waves, where it’s obvious that as climate warms you would expect more intense heat waves, [you have to acknowledge that] a given heat wave may have happened anyway without climate change.”

Hangover: Getting to the root of pain

You survived Christmas. Next up: the annual guzzl-a-thon — New Year’s Eve. Will you start the new year with a massive hangover?

Hangovers are an aftershock of acute alcohol intoxication, meaning you get them while recovering from a serious bout of drinking. The symptoms, including headache, nausea, sensitivity to light and noise, lethargy, diarrhea and thirst, often strike people who are already wallowing in self-pity.

Physiology offers explanations: Alcohol causes dehydration. Liver enzymes convert ethanol to the more toxic acetaldehyde. Less glucose reaches the brain, adding to lethargy.

A preventable condition

Short of abstinence, there are ways to reduce hangover. Food, especially fats, slow alcohol absorption, if the food enters the stomach first. James Garbutt, a professor of psychiatry and alcoholism specialist at the University of North Carolina at Chapel Hill, suggests eating a meal before your first drink, and then nibbling through the evening.

Drinking a glass of water between each drink can also cut consumption.

The next morning, Garbutt advises treating the headache with ibuprofen (not aspirin or acetaminophen), and drinking water or a sports drink to restore fluids and electrolytes.
Beyond that, you are on your own: According to a 2005 review¹: “No compelling evidence exists to suggest that any conventional or complementary intervention is effective for preventing or treating alcohol hangover.”

Photo: As Heard From Mars

Think this bloke’s head will be on fire when he wakes from his stupor?

The science of the hangover

Still, The Why Files did track down some cool hangover science:

A good teaching tool? Because that morning of misery is a built-in disincentive to drink, hangovers seldom attract research funding. But a recent survey² of 303 college students chilled the notion that hangover is a good preventative like ice in a shot glass: “The students significantly overestimated the number of drinks it would take to vomit, have unwanted sexual experiences, experience hangovers, and black out in comparison with the actual self-reported number of drinks consumed the last time identical consequences were experienced.” If you tossed your cookies after five drinks, but thought you could absorb 10 next time, what have you learned?

Image from: Innocorp

Cops and health educators use these goggles to dissuade teens from drinking and driving.

Hangover scale: Filling a scientific gap, in 2007, researchers from Brown University³ crafted the “acute hangover scale” to measure the next-morning blues in American college students, recent graduates, and Swedish marine officers (all folks who know which way the bottle tilts). The researchers found that “Do you have a hangover?” was the best single question for identifying hangover, even better than questions about thirst and headache. Why bother? The new scale could help distinguish hangover from other addictive effects of alcohol, the authors explained.

Take the asparagus cure: In 2009, Korean scientists reported that components of asparagus can protect the liver against oxidative stress of alcohol. According to B.Y. Kim of Jeju National University, “These results provide evidence of how the biological functions of asparagus can help alleviate alcohol hangover and protect liver cells.” No word on whether asparagus has a drinking problem … and unfortunately, the leaves, not the shoots that we eat, offered the best protection.

You can’t detect a drunken fruitfly with a breathalyzer, but an inebriometer works just dandy.

Hangover is stupid! A large study⁴ from Scotland found that dumb kids — okay, 11-year-olds with a lower IQ — were more likely to have hangovers in middle age. So, you wonder? Because hangover is a good measure of binge drinking, “This finding may at least partially explain the link between early life IQ and adult risk of mortality ascribed to all causes, cardiovascular disease and, particularly, alcohol related morbidity,” the authors say.

Drunken fruitflies:

A recently discovered⁵ “hangover” gene in fruitflies increases their tolerance to alcohol (when measured, you can’t make this up, in the “inebriometer.”) Because alcohol tolerance is a risk factor for alcoholism, the gene may do something more than just cause headache. Do fruitflies feel queasy the morning after the night before?

The final word

If you drink, drink safe and drink smart. And never, ever overindulge and drive.

And happy New Year from The Why Files!

Urp.

– David J. Tenenbaum

The endocrine system is a marvel of subtlety and complexity. Through the life of the animal (human or otherwise), waves of hormones control reproduction, development, behavior, even other hormones. What happens when this natural system gets bollixed up?

We’ve known for decades that endocrine disruptors sourced in pesticides and plastics can operate at the parts-per-billion level. Disruptors in common body-care products ranging from birth-control pills to shampoo are washing down toilets and drains, then causing deformations in the animals that live downstream.

In 2006, for example, David Norris of the University of Colorado caged fathead minnows in the outflow from Boulder’s wastewater treatment plant. Within seven days, adult males were “feminized,” showing female anatomy and behavior.

Water leaving the treatment plant contained a regular toiletful of hormonally active crud, including ethinylestradiol, a chemical used in most contraceptives, and natural estrogens made and excreted by people. Other endocrine disruptors in the water included two common plastic compounds, bisphenyl A and phthalates. Detergents and pesticides had contributed (is that the right word?) a further group of endocrine suspects called nonylphenols.

Diagram courtesy Renewable Water Resources

Hormones run amok

To compare their ability to trigger the estrogen receptor on cells, estrogen disruptors are measured in units called estradiol equivalents per liter. In 2006, Boulder Creek contained 30 to 40 units, most of it artificial, Norris says.

A few trillionths of a gram in a liter of water may not sound like much, Norris realizes. “At first, people thought, ‘That’s such a small quantity, it can’t be meaningful,’ but biological systems can see it and respond to it. In lab studies, as little as 1 estradiol unit is enough to feminize a fish, so there was plenty of stuff there.”

All the estrogens, artificial and natural, work through same receptor, he says, “so the effects are additive. Even if any single one is not high enough, they add up.”

Ending the endocrine monster?

After the 2006 study (and for reasons unrelated to hormone disruption), Boulder’s treatment plant was upgraded. The newly installed “activated sludge process” transfers most of the estrogen disruptors from the liquid to the solid material, called sludge or biosolid, that remains after treatment.

“Bacteria are eating the estrogen disruptors to some extent, but the vast majority of the chemicals that come into the sewage are trapped in the biosolids,” says Norris. “It’s not a mechanism that was planned to deal with these chemicals at these concentrations, but the procedures are pretty efficient at getting the endocrine disruptors out of the water.”

For the study he just presented at the Endocrine Society, Norris repeated his 2006 study, and found no feminization in fish after 28 days, even among fish that lived in pure treated wastewater.

That finding accords with tests performed at the Wisconsin State Laboratory of Hygiene, says Jocelyn Hemming, a research environmental toxicologist at the lab. “Activated sludge really helps a lot,” she says. In tests using both ultra-sensitive chemical analysis and living cells, “there was definitely good removal of endocrine disruptors, although it wasn’t complete at all facilities.”

The activated sludge process did transfer some unwanted hormone to the sludge, but Hemming says the bacteria likely ate some of the troublesome compounds. “I think there is a pretty good chance of destruction from the microbial community in the activated sludge; it would not all go into the solids.”

In Boulder, the chemists are not ready to release the numbers, but “preliminary chemistry shows that the levels of endocrine disruptors in the effluent have gone way down,” Norris says. “When you are dealing with nanograms per liter [parts per trillion, by weight], you have to be really careful.”

Most of the endocrine disruptors in the Boulder sewer system are artificial, Norris says, coming from plastics, solvents and drugs. About 5 percent comes from birth control pills, and about 10 percent is natural, human estrogen.

– David J. Tenenbaum