"With the Obama administration facing a deadline this week to suggest any changes to the national air quality standards for soot, the pressure is building on all sides."

"Diesel engine fumes can cause lung cancer and belong in the same potentially deadly category as asbestos, arsenic and mustard gas, World Health Organisation (WHO) experts said on Tuesday."

"RIO de JANEIRO -- The Rio+20 Secretary-General said today that the absence of such world leaders as U.S. President Barack Obama, German Chancellor Angela Merkel and UK Prime Minister David Cameron will not undermine the sustainable development summit later this month."

"The Environmental Protection Agency and American Lung Association said they’re close to settling a lawsuit filed by the advocacy group to force regulators to issue overdue rules on soot."

"Three conservation organizations today filed legal action challenging the U.S. Environmental Protection Agency's failure to update air quality standards for acid rain."

"A senior Chinese official demanded on Tuesday that foreign embassies stop issuing air pollution readings, saying it was against the law and diplomatic conventions, in pointed criticism of a closely watched U.S. embassy index."

"SEQUOIA NATIONAL PARK, Calif. -- The California forest that is home to the biggest and oldest living things on earth, the giant Sequoia redwoods, also suffers a dubious distinction. It has the worst air pollution of any national park in the U.S."

"BP will spend more than $400 million to significantly reduce noxious air pollution from its massive refinery in northwest Indiana, the company announced today in a settlement with federal authorities and environmental groups that could set a precedent for oil companies nationwide."

"For years, U.S. government agencies have told the public, veterans and Congress that they couldn't draw any connections between the so-called 'burn pits' disposing of trash at the military's biggest bases and veterans' respiratory or cardiopulmonary problems. But a 2011 Army memo obtained by Danger Room flat-out stated that the burn pit at one of Afghanistan's largest bases poses 'long-term adverse health conditions' to troops breathing the air there."

"Kathy Omachi was eating at McDonald's in Reedley [Calif.] recently, and she counted 51 gravel trucks pass by -- all in the time she finished a hamburger and fruit smoothie. The lifelong resident of this farming town, which is southeast of Fresno and within a few miles of three rock quarries, fears that even more trucks, with their dirty exhaust, will be on the road if nearby mining is expanded."