1.   Another unknown, Brooks said, is whether the chemicals themselves would harm the Everglades somehow, perhaps by removing beneficial chemicals along with the phosphorus.

2.   Both chemicals can harm the nervous system and other organs, and both are suspected of causing cancer.

3.   But environmental groups and many government scientists say the chemicals have harmed wildlife and pose a threat to humans.

4.   But shellfish farmers and environmentalists have long suspected that the chemicals could be harming other marine wildlife.

5.   Government scientists contend that the chemicals have harmed wildlife along the Hudson and are a serious health risk to humans.

6.   Laboratory studies on animals have shown that the chemical can harm the liver, kidneys, and nervous system and, in high concentrations, possibly cause cancer.

7.   Coated onto beet seed, for example, it could be applied to soils where maggot-killing chemicals can harm non-target insects, or endanger groundwater.

8.   The Boston organization said the federal government should start requiring tests to ensure chemicals do not harm human brain development.