Environmental health perspectives
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Environ. Health Perspect. · Mar 2004
Mono(2-ethyl-5-hydroxyhexyl) phthalate and mono-(2-ethyl-5-oxohexyl) phthalate as biomarkers for human exposure assessment to di-(2-ethylhexyl) phthalate.
Exposure to di-(2-ethylhexyl) phthalate (DEHP) is prevalent based on the measurement of its hydrolytic metabolite mono-(2-ethylhexyl) phthalate (MEHP) in the urine of 78% of the general U. S. population studied in the 1999-2000 National Health and Nutrition Examination Survey (NHANES). However, despite the high level of production and use of DEHP, the urinary MEHP levels in the NHANES samples were lower than the monoester metabolites of phthalates less commonly used than DEHP, suggesting metabolic differences between phthalates. ⋯ MEOHP and MEHHP cannot be formed by serum enzymes from the hydrolysis of any contamination from DEHP potentially introduced during blood collection and storage. Therefore, concentrations of MEHHP and MEOHP in serum may be a more selective measure of DEHP exposure than is MEHP. However, additional data on the absorption, distribution, metabolism, and elimination of these oxidative metabolites are needed to completely understand the extent of DEHP exposure from the serum concentrations of oxidative DEHP metabolites.
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Environ. Health Perspect. · Dec 2003
ReviewStrategies for setting a national research agenda that is responsive to community needs.
Setting a national environmental health research agenda requires broad public input, including that from leading scientists, health care professionals, and communities. Contributions from these diverse constituencies are essential to formulating a research and education strategy that both advances our understanding of the causes and mechanisms of environmentally related diseases and translates such findings into effective prevention and clinical applications to protect those most affected by adverse environmental exposures. Given the increasing number of individual researchers working with communities to address environmental health needs during the past decade, it is also essential for research institutions to foster relationships with communities to understand and respond to their unique public health needs, as well as to communicate research advances in a manner that is both understandable and culturally appropriate. ⋯ In particular, the NIEHS finds Town Meetings to be a successful model for bringing academic researchers together with community residents, state and local departments of health, and community-based organizations to foster greater awareness of community needs, public health needs, and environmental health science research. Since 1998, the NIEHS has supported 16 Town Meetings across the country. In this article we highlight the major outcomes of these meetings to demonstrate the effectiveness of this mechanism for enhancing cooperation among researchers, community residents, and public health officials with the goal of improving public health and setting a national research agenda.
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Environ. Health Perspect. · Apr 2003
Fetal chlorpyrifos exposure: adverse effects on brain cell development and cholinergic biomarkers emerge postnatally and continue into adolescence and adulthood.
Fetal and childhood exposures to widely used organophosphate pesticides, especially chlorpyrifos (CPF), have raised concerns about developmental neurotoxicity. Previously, biomarkers for brain cell number, cell packing density, and cell size indicated that neonatal rats were more sensitive to CPF than were fetal rats, yet animals exposed prenatally still developed behavioral deficits in adolescence and adulthood. In the present study, we administered CPF to pregnant rats on gestational days 17-20, using regimens devoid of overt fetal toxicity. ⋯ There was no compensatory up-regulation of cholinergic receptors, as m2-muscarinic cholinergic receptor binding was unchanged. CPF also elicited delayed-onset alterations in biomarkers for general aspects of cell integrity, with reductions in cell packing density, increases in relative cell size, and contraction of neuritic extensions; however, neither the magnitude nor timing of these changes was predictive of the cholinergic defects. The present findings indicate a wide window of vulnerability of cholinergic systems to CPF, extending from prenatal through postnatal periods, occurring independently of adverse effects on general cellular neurotoxicity.