Strategy for studying health effects of pesticides/fertilizer mixtures in groundwater

This paper is a "historical account" of the entire process leading to the final implementation of a toxicology research program on the health-effect studies of pesticide and fertilizer contaminants in groundwater conducted at the National Institute of Environmental Health Sciences/National Toxicology Program (NIEHS/NTP). Starting with the perception of a potential problem area, the program evolved through several stages, including planning and information-gathering, deliberation on experimental designs, formulation of a draft protocol, peer-review and public comments on the protocol, finalization of the protocol, announcement of open bidding to the NTP master agreement laboratories (i.e., a group of laboratories that has been previously evaluated and approved to conduct NTP toxicology contract work), implementation of chemistry developmental work, selection of toxicology laboratories and awarding of contracts, final implementation of toxicology studies, and cultivation of special collaborative efforts among NIEHS in-house scientists as well as colleagues at the neighbouring laboratories in Research Triangle Park. To put things in perspective, the author's present approach, a coupling of physiologically based pharmacokinetics/pharmacodynamics and computer modeling with the toxicology of chemical mixtures at Colorado State University, is used to address the issues of toxicology and risk assessment of chemical mixtures with respect to rationale and reality.