"President Barack Obama put a stop on Friday to new rules that would limit smog pollution, unexpectedly reversing course on a key policy measure after businesses said it would kill jobs and cost them billions of dollars."

"Significant levels of the world's most-used herbicide have been detected in air and water samples from two U.S. farm states, government scientists said on Wednesday, in groundbreaking research on the active ingredient in Monsanto Co's Roundup."

"The White House is engaged in an intense debate over how much it should tighten national smog standards, an issue that has sparked a battle between business and public health groups.

"Every summer, hordes of beach-goers seeking California sunshine are attracted to the Central Coast. Clad in bikinis and swim shorts, they hit the beach only to be greeted with a sobering surprise: a dense layer of coastal fog rolling off the bay."

"Under Obama, the agency has delayed action repeatedly on a 2010 vow to set tougher smog standards, as critics in industry and the Republican Party argue that regulations kill jobs."

"NASA, the agency best known for exploring space, is trying to answer some urgent questions about air pollution right here on Earth."

"Faced with a natural gas drilling boom that has sullied the air in some parts of the country, the Environmental Protection Agency on Thursday proposed for the first time to control air pollution at oil and gas wells, particularly those drilled using a method called hydraulic fracturing."

"The U.S. Environmental Protection Agency said on Tuesday it would again delay issuing a final limit on smog pollution opposed by manufacturers and many Republican lawmakers until the Obama administration has finished reviewing it."

"Less than half of Pennsylvania's fossil-fueled power plants have pollution controls, a long-tolerated dirty habit that's now getting its comeuppance in tougher, new federal regulations."