"The contested air permit for the Sithe Global Desert Rock coal-fired power plant on the Navajo Reservation in New Mexico today was sent back to the U.S. Environmental Protection Agency for additional analysis."

"Texas' new plan to improve the Houston area's famously dirty air may not meet federal limits for smog."

"The World Health Organisation (WHO) has drastically cut the maximum amount of radon -- a naturally occurring gas -- that should be permitted in homes because of strong evidence it causes lung cancer."

"About 50 medical waste incinerators nationwide will have to reduce their air pollution under new regulations announced Wednesday by the Environmental Protection Agency."

"The World Meteorological Organisation said Wednesday that the ozone hole is expected to be smaller in 2009 than a year ago."

"The Obama administration signaled Wednesday that it would scrap a controversial Bush-era rule that set stricter limits for smog but fell short of scientific recommendations."

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."