Intensified monitoring for toxics in the air around certain schools has only raised more questions about health effects -- and some lawsuits.

"An important opposition deputy this week accused Chile's government of being less than candid with the public about alarming levels of fine particulate pollution found in the nation’s leading cities."

"The United States and Canada are nearing an international agreement to clean up the emissions of ships traveling within 200 nautical miles of shore."

"Government scientists who study the depletion of Earth’s protective ozone layer are pointing to a previously unheralded culprit: nitrous oxide."

The Justice Department and Illinois are suing Midwest Generation, charging the utility company with evading the Clean Air Act by not installing pollution controls when modernizing its plants. The move marks an Obama administration reversal of Bush policies.

An aging fleet of coal-fired power plants continue to pollute many urban areas. They were exempted from pollution-control requirements of the 1977 Clean Air Act. Companies rebuild them over and over to avoid installing pollution-control equipment. "The clunkers of the power-plant world" may once again escape new rules and modern technology.

"In a victory for environmental groups, a Richmond judge on Tuesday invalidated a permit for a coal-burning power plant being built in southwestern Virginia."

"LONG BEACH -- More than a year after California was rebuffed in federal court for pursuing emission rules on freight ships, federal authorities are pushing to adopt similar restrictions that could prevent up to 33,000 premature deaths annually in the U.S. and Canada."