TitleBiomarker identification and exposure assessment of environmentally toxic substances in a population of pregnant women and newborns
NameYan, Xiaoyong (author), Robson, Mark (chair), Reuhl, Kenneth (internal member), Buckley, Brian (internal member), Ledoux, Thomas (outside member), Rutgers University, Graduate School - New Brunswick,
DescriptionWidespread exposure to environmentally toxic chemicals may adversely affect fetal development and birth outcomes. However, data on prenatal exposure and associated health effects in newborns are very limited. A variety of pesticides, phthalates, and their metabolites were measured in maternal urine, maternal serum, cord serum, amniotic fluid, and meconium samples collected at the time of cesarean delivery from 150 women in central New Jersey. Significantly higher concentrations of dacthal (p=0.007), diethyltoluamide (p=0.043), and phthalimide (p=0.030) in cord serum of pesticide users than non-users suggests that residential use of pesticides may contribute to overall exposure. The concentrations of most pesticides in biological matrices of this study population were either comparable to or lower than the levels reported in previous studies and in the US general population, except for orthophenylphenol. The daily intakes of two representative organophosphorus insecticides (chlorpyrifos and diazinon) were lower than most regulatory protection limits (EPA oral benchmark dose10/100, EPA reference oral dose, or ATSDR minimal risk levels). The urinary concentrations of most phthalate metabolites were comparable to or lower than the U.S. general population, except for mono-(2-ethylhexyl) phthalate, mono-(2-ethyl-5-hydroxyhexyl) phthalate, and mono-(2-ethyl-5-oxohexyl) phthalate, three metabolites of di(2-ethylhexyl) phthalate (DEHP). The median urinary concentrations of mono-(2-ethyl-5-hydroxyhexyl) phthalate (109 ?g/L) and mono-(2-ethyl-5-oxohexyl) phthalate (95.1 ?g/L) were more than 5 times their population-based concentrations, while the median urinary concentration of mono-(2-ethylhexyl) phthalate was over 20 times higher. Calculation of daily phthalate intakes using the urinary biomarker data revealed that none of the pregnant women tested had integrated exposures to DEHP higher than the ATSDR MRLs. High concentrations of DEHP metabolites may indicate a recent exposure to the plastic medical devices containing DEHP in the hospital. However, no abnormal birth outcomes or other adverse clinical reproductive endpoints were noted in those newborns who had higher concentrations of orthophenylphenol and DEHP during the perinatal period. Significantly higher concentrations and detection frequencies in maternal urine than in maternal serum and cord serum suggest that urinary concentrations of the metabolites may be more reliable biomarkers of exposure to the environmental toxicants than the concentrations in other biological specimens.
NoteIncludes bibliographical references (p. 62-72)
Noteby Xiaoyong Yan
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
RightsThe author owns the copyright to this work.