"The Sierra Club launched a system Tuesday to send text message alerts when smog pollution is at a high level in certain areas."

"Even though Maryland has yet to permit any hydraulic fracturing for natural gas, emissions linked to the controversial drilling technique have been detected in the air in Baltimore and Washington, according to a new study."

"Scientists, planes and instruments descend on San Juan Basin to find roots of the massive greenhouse gas hotspot."

"Lawsuit helped force an update of emissions standards for dangerous chemicals that went unchanged nearly 30 years."

"California is suffering from 'second-hand smog' drifting in from Asia and other places, researchers said on Tuesday, even as the state's prolonged drought has made air quality worse."

"A common pollutant in vehicle exhaust, power plant emissions and cigarette smoke can shrink white matter in fetal brains and cause developmental damage during the toddler years, a new study suggests."

"The Supreme Court on Wednesday seemed closely divided over the fate of one of the Obama administration’s most ambitious environmental initiatives."

"The Supreme Court will hear arguments Wednesday in a case that challenges one of the Obama administration's most significant environmental regulations."

"U.S. EPA has agreed to consider clamping down on corrosive dust after watchdogs complained that the current standards failed to protect rescue workers after the Sept. 11, 2001, terrorist attacks."

"The 100 global power companies most at risk from growing pressure to shut highly polluting coal plants have been revealed in a new report from Oxford University. Chinese companies dominate the top of the ranking but US companies, including Warren Buffett’s Berkshire Hathaway, occupy 10 of the top 25 places."