"Black carbon, the soot produced by burning fossil fuels and biomass, is a more potent atmospheric pollutant than previously thought, according to a four-year international study released on Tuesday."

"WEATHERFORD, Texas -- When a man in a Fort Worth suburb reported his family's drinking water had begun "bubbling" like champagne, the federal government sounded an alarm: An oil company may have tainted their wells while drilling for natural gas. At first, the Environmental Protection Agency believed the situation was so serious that it issued a rare emergency order in late 2010 that said at least two homeowners were in immediate danger from a well saturated with flammable methane. More than a year later, the agency rescinded its mandate and refused to explain why."

"BEIJING — The Chinese state news media on Monday published aggressive reports on what they described as the sickening and dangerous air pollution in Beijing and other parts of northern China, indicating that popular anger over air quality had reached a level where Communist Party propaganda officials felt that they had to allow the officially sanctioned press to address the growing concerns of ordinary citizens."

"CHESTER, W.Va. -- The ground here is leaking. Several neighbors have moved away to escape seeps coming out of the hillside. They say the leaks have dampened their backyards and infested their homes with mold. ..."

"Pennsylvania is considering new air pollution limits for diesel- and natural gas-powered engines used in Marcellus Shale development that are stricter than those that exist now but, according to eight environmental groups, not nearly as tough as they could and should be."

"The operator of three coal-fired power plants in Maryland has agreed to pay a total of $2.2 million in penalties and fix long-standing pollution problems at the landfills in Southern Maryland and Montgomery County where it disposes of the ash from those plants, according to court documents."

"GENEVA — Delegates from more than 130 nations began a final round of negotiations on Sunday that are expected to lead to the creation of the first legally binding international treaty to reduce mercury emissions."

KETTLEMAN CITY -- Maria Saucedo cried as she spoke of the two babies she has lost in Kettleman City -- one to birth defects and the other in a miscarriage. There's no proof, but she blames the toxic landscape surrounding her town. She and others who have suffered in Kettleman City say they live in a nasty soup of pollution. They make a compelling case."

"BP and its partners in the Macondo well that released an estimated 4.9 million gallons of oil over three months beginning in April 2010 should be required to inform state officials -- and the public -- of the toxic materials included in the spill, and the potential health effects of those materials, a three-judge appellate panel ruled in New Orleans on Wednesday."

"GENEVA -- Mercury pollution in the top layer of the world's oceans has doubled in the past century, part of a man-made problem that will require international cooperation to fix, the U.N.'s environment agency said Thursday."