"The Obama administration proposed stricter standards to control harmful soot from heavy industry on Friday, a move expected to save lives but which drew criticism from Republicans and industry worried the costs of compliance will hurt the economy."

"Risking an election-year backlash from Republicans, the Obama administration is proposing new air quality standards to lower the amount of soot that can be released into the air.

The move, to be announced Friday, is likely to win support from environmental groups and public health advocates but exposes the president to potential criticism from congressional Republicans and industry officials that the rules are overly strict and could hurt economic growth and cause job losses in political swing states such as Ohio and Pennsylvania.

"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."