A new federal study has found that nearly three-fourths of the Chesapeake Bay's waters are "fully or partially impaired" by toxic chemicals.

The report also warns people to limit the number of fish they eat from the bay because of concerns about mercury and polychlorinated biphenyls (PCBs), which were banned years ago but linger in the fish.

Other contaminants from herbicides, pharmaceuticals and personal care products were found in the bay and could pose disputed or unknown health risks.

"Since 2000, new concerns, such as intersex conditions in fish, have arisen," the report says. "Although the causes are undetermined, there is increasing evidence that contaminant exposures may play a role."

The report has prompted environmental and health groups to call for more investigations into the effects of pesticides (Tim Wheeler, Baltimore Sun, Jan. 18). -- MM