• 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.