The list of health-harming pollutants once considered to be benign at best -- think mercury -- appears to be growing by the day, with the latest being atrazine, one of the more common herbicides used on golf courses, crops and lawns in America.

The major concern: Recent animal studies are showing how atrazine -- among the more common contaminants found in American drinking water sources and reservoirs -- can be harmful in low concentrations, even at levels meeting current federal standards. Among the problems linked to atrazine:

* Menstrual issues.

* Low birth weights.

* Birth defects.

Even worse, animal fetuses briefly exposed to atrazine had an elevated risk of cancer.

The only good news about atrazine: A recent report published in Biology of Reproduction found that hormonal problems experienced by adult rats fed higher amounts of atrazine vanished after exposure to the common herbicide ended, and their recovery was quick (previous studies have shown how atrazine is expelled from the blood and brain of rats within a day).

New York Times August 23, 2009

Environmental Health News August 20, 2009

Atrazine is produced in America by Syngenta.