It's the latest second-hand smoke issue: motorized vs. nonmotorized winter sports.

The closure of U.S. airports following the terrorist attacks of Sept. 11, 2001, provides a rare opportunity to gauge the contributions of airports and related activities to a city's air pollution.

A likely upcoming shift in California's strategy to reduce smog from cars could affect new vehicles rolling onto roads nationwide over the next few years.

A freelance journalist is challenging in court the US Department of Agriculture's efforts to keep secret its data on who owns the feedlots Americans can see and smell, but whose pollution the food industry does not want USDA to regulate.

A rule issued April 16, 2008, ostensibly to keep the public safe from shipments of highly hazardous materials by rail, has been little-understood by the public.

When water providers find pharmaceuticals in drinking water, they rarely tell the public.