• Another day, another EPA scandal: top Midwest regulator forced out.
• All but five of 500 ducks meet their end in a Canadian oil-sands pond.
• Does artificial turf pose a health threat?
• Economists bash gas-tax holiday idea.
• Arctic sea ice likely to set another record low.
• Shell pulls out of big wind farm.
• Got asthma? Hang out with trees.
• Norway makes first whale kill of the season.
