A subset of the NHANES III subjects, 20-59 years of age, was selected to participate in the Priority Toxicant Reference Range Study for the purpose of assessing levels of common pesticides (including 2,4-D) and volatile organic compounds (VOC) in blood or urine [ 18].
The team's initial achievements focused on prioritizing reproductive toxicants for further research, promoting the study of high-priority toxicants, and promoting occupational exposure assessment in existing surveillance studies.
Dioxin-like compounds [e.g., non- ortho- substituted polychlorinated biphenyls (PCBs), chlorinated dibenzo- p-dioxins, and chlorinated dibenzofurans] rank among the highest-priority environmental toxicants at Superfund sites (Agency for Toxic Substances and Disease Registry 2007).
To promote the study of high-priority reproductive toxicants, the NORA team established a partnership with the Center for the Evaluation of Risks to Human Reproduction (CERHR).
The focus of the present study was to select seven high-priority toxic metals and/or metalloids on the basis of their presence in the environment and their known or suspected roles as developmental toxicants.
Were parallel reference toxicant toxicity test conducted?
The toxic agents were selected as dissimilarly-acting toxicants from a panel of priority environmental pollutants within the framework of the European Project NoMiRACLE [ 21]: Chlorpyrifos, a broad-spectrum organophosphate insecticide and nickel (Ni), an important heavy metal for its civil and industrial applications.
For example, the currently available ToxCast bioassays have been organized into a global scoring system, called Toxicological Priority Index (ToxPi), to identify potential toxicants by their responses in these assays.
There is no clear explanation for these differences, but given that the differences in NAP concentrations are so substantial, and that NAP is an established FDA HPHC, further investigation should be a priority for future research into STP toxicant chemistry.
