Are synthetic chemicals causing hormonal chaos? Pesticides, PCBs, dioxins, plastics can all mimic natural hormones. What does the evidence say, and what should we do about it?

Are air bags dangerous if used properly? How do air bags work, and why are they being used on Mars?

Environmental Protection Agency proposes tighter rules on air pollution; do they make sense? How many people die during an outbreak of air pollution? What is PM 2.5, and why do your lungs care about it?

Why do airplanes crash? Dozing pilots. Planes crashing into the ground. Inexplicable B-737 accidents. This may not make you want to board your next flight!

What does nicotine do to the brain? Why is smoking so addictive? How can we fight that addiction?

What is the future — and hazard — of transplanting organs from animals to humans?