"HOUMA, La. -- As thousands attended Grand Isle's biggest tourist event this weekend most of its beaches -- and others close by -- were under advisories for high levels of bacteria in the water. State environmental officials say they don't know the cause because there are too many potential contamination sources."

"The U.S. Environmental Protection Agency is demanding answers to dozens of long-standing questions about the handling of wastes contaminated with polychlorinated biphenyls, PCBs, at U.S. Army ammunition production facilities nationwide."

"The country's top regulator of commodity markets said Tuesday that the government should 'seriously consider' strict limits on the trades of purely financial investors in the futures markets for oil, natural gas and other energy products."

"Silver dental fillings containing mercury are safe for use by adults and children ages 6 and above, the Food and Drug Administration said Tuesday."

"The federal government will not lend $2 billion to USEC, the sole American-owned uranium enrichment company, the Energy Department said on Tuesday."

What do you buy when you buy a carbon offset? Susan Hess follows the $4.50 she paid to offset the CO2 emitted for a train trip to Seattle in Gorge Outdoors, July 24, 2009.

What will happen to all the "clunkers" traded in for gas-sipping new cars under a new federal rebate program?

"In an interview with Yale Environment 360, John Kerry praises the carbon cap-and-trade legislation now being debated in the U.S. Senate, describes its importance to upcoming climate talks in Copenhagen, and explains how he plans to help the landmark legislation clear the Senate and become law."

"The 'dead zone' in the Gulf of Mexico, an area choked by low oxygen levels that threatens marine life, is smaller than expected this year but more deadly, the government said on Monday."