The flame-retardant chemicals known as PBDEs are virtually ubiquitous in U.S. waters. New research shows that when PBDEs are exposed to wastewater treatment, they can generate dioxins.

"Canadian National Railway pleaded guilty on Monday to polluting Canada's wilderness in two train derailments, one of them resulting in the largest inland oil spill in Canada's history."

A May 17 fire at Sunoco's Marcus Hook refinery near Philadelphia underscored its day-in-day-out impact on the environment.

Despite having been banned in most uses for years, carbon tetrachloride, a probable carcinogen, persists in the environment. USA TODAY found it outside 70 of 95 schools in 30 states.

"Railroad companies are pressing federal regulators to cut back on trains carrying hazardous materials through urban areas, saying they fear a catastrophic release of toxic chemicals in a large city."

"Critically ill newborns may help researchers figure out whether children are at risk from plastic additives called phthalates."

EPA has found suspect materials in a small sample of Chinese-made drywall that some believe may be causing corrosion in homes and possibly sickening people.