Additionally, combinations of chemicals may have different effects. Finally, the effect may only be seen at a certain dose. Sometimes, a high or low dose has no effect, but the middle dose disrupts the hormonal system. Scientists are working to develop a mechanism to screen the tremendous number of chemicals. Additionally, FQPA requires EPA to develop an endocrine screen for pesticides.
Endocrine disruption is a major endpoint of concern for pesticide registrants as well.
Pesticides identified as 'endocrine disruptors' are unlikely to receive or maintain EPA registration. The companies either owned or operated an abandoned DDT plant in Torrance, California. Government scientists report that the DDT travels up the food chain, beginning with algae and small fish. DDT has been identified in white croaker fish and is blamed for reproductive problems in birds. The companies will spend the money to restore wildlife habitat and to remove or cap the DDT on the ocean floor.