"Hundreds of West Virginia residents who sought emergency-room care in January were treated for symptoms that were 'consistent' with exposure to MCHM, the primary chemical that leaked from the Freedom Industries tank farm into the region’s Elk River drinking-water supply, according to a review made public Wednesday."

"WEST, Texas -- Although the cause of the deadly blast at West Fertilizer Co. remains a mystery, a federal agency on Tuesday said the tragedy was preventable, citing shortcomings in existing regulations and standards at all levels of government."

"The Supreme Court on Monday declined to review a ruling against Exxon Mobil Corp that ordered the company to pay $105 million in damages for polluting New York City's groundwater with a toxic gasoline additive."

"A year after the West Fertilizer explosion, the nation is taking its first steps to repair the failed system for preventing chemical accidents. But whether the fixes will work, or even become reality, remains to be seen. Sen. Barbara Boxer, who chairs the Senate environment and public works committee, noted the disaster’s first anniversary with a call for action."

"Federal scientists have found high amounts of mercury in sport fish caught in remote areas of national parks in the West and Alaska, according to a study released Thursday."

"Evidence of rat poison is found in a sickly puma whose territory includes Griffith Park. Researchers suspect a link between poisons and mange."

"Unpublished research by university scientists is exempt from the Virginia Freedom of Information Act, the Virginia Supreme Court ruled Thursday, rejecting an attempt by skeptics of global warming to view the work of a prominent climate researcher during his years at the University of Virginia."

"In an apparent effort to kickstart agency action on updating permissible exposure limits for hundreds of chemicals, the Occupational Safety and Health Administration asked the White House April 15 to approve a request to gather information on ways to address chemical exposure."

"It is touted as the largest Superfund cleanup ever, one that will remove 4.3 million cubic yards of sediment contaminated with a stew of pollutants from the Passaic River and even make it safe for people to fish there again without significantly raising their risk of cancer."

"The state Department of Public Health is adopting the nation's first-ever drinking water standard for hexavalent chromium, a carcinogen found in water supplies across the state."