Hydrofluoric acid is a deadly chemical used in many petroleum refinery operations. When it escapes, it becomes a gas that can race long distances and kill people who inhale it. Safer alternatives are available to refineries. At the urging of petrochemical companies, Congress and the executive branch have kept the dangers largely secret from the at-risk public, so there has been little pressure for refineries to make their operations safer. In a joint investigation the Center for Public Integrity and ABC News found that worst-case scenarios filed by just 50 refineries showed some 16 million Americans at risk from accidental or intentional hydrofluoric acid releases.

"Lawyers for Bayer CropScience are trying to convince a federal judge the company's Institute plant is safe, even as a federal agency that investigated the facility continues to call for more inspections before Bayer's controversial methyl isocyanate unit is allowed to resume production."

Rescuers struggled to reach victims trapped beneath rubble in the aftermath of a February 22 magnitude 6.3 earthquake that killed at least 75 people in Christchurch, New Zealand. Several hundred more are still missing.

"Climate change is a major obstacle to a 2004 global treaty aimed at cutting exposure to 21 highly dangerous chemicals, says a new U.N.-commissioned report issued Monday. The 66-page report says the risks of exposure could increase if more stockpiles and landfills leak due to flooding, or other extreme weather linked to rising temperatures."

"Baby dolphins, some barely three feet in length, are washing up along the Mississippi and Alabama coastlines at 10 times the normal rate of stillborn and infant deaths, researchers are finding."

"BP has reneged on promises made in November to negotiate early payments to Louisiana to help rebuild oyster beds, repair damaged wetlands and build a fish hatchery to allow the state to respond immediately to the collapse of commercial fisheries in the wake of the BP Gulf oil spill, state officials said Monday."

"Oil from the BP spill remains stuck on the bottom of the Gulf of Mexico, according to a top scientist's video and slides that she says demonstrate the oil isn't degrading as hoped and has decimated life on parts of the sea floor."

"WASHINGTON -- Fifty million 'environmental refugees' will flood into the global north by 2020, fleeing food shortages sparked by climate change, experts warned at a major science conference that ended here Monday."

"Lake Isabella Dam is just one acute example of a widespread problem: Of the nation’s 85,000 dams, more than 4,400 are considered susceptible to failure, according to the Association of State Dam Safety Officials. But repairing all those dams would cost billions of dollars, and it is far from clear who would provide all the money in a recessionary era."

"The Nuclear Regulatory Commission released draft staff reports Thursday on the proposed Yucca Mountain repository but omitted any conclusions about whether the site would be safe for storing radioactive waste."