摘要：Background We previously documented significant decreases in chlorpyrifos concentrations in maternal personal and indoor air samples among pregnant African-American and Dominican women from New York City after the 2000–2001 restrictions on its residential use. Objective We undertook a biomarker validation study within the same cohort to evaluate trends over time in multiple biomarkers of prenatal chlorpyrifos exposure. Methods Subjects were enrolled between February 2001 and May 2004 ( n = 102). We measured 3,5,6-trichloro-2-pyridinol (TCPy) in postpartum meconium ( n = 83), repeat prenatal maternal spot urine samples ( n = 253), and postnatal urine from the mothers ( n = 73) and newborns ( n = 59). We measured chlorpyrifos in postnatal maternal ( n = 92) and umbilical cord ( n = 65) blood. Results We did not detect TCPy in infant urine, but all other biomarkers showed a highly significant decrease in detection frequencies (χ2 = 7.8–34.0, p ≤ 0.005) and mean ranks ( p ≤ 0.006, Kruskal–Wallis) among subjects enrolled in 2003–2004 compared with those enrolled in 2001–2002. Chlorpyrifos in maternal personal and indoor air declined 2- to 3-fold over the same period ( p < 0.05). In 2001–2002 samples, TCPy levels in repeat prenatal urine were positively correlated ( r = 0.23–0.56), but within-subject variability exceeded between-subject variability (intraclass correlation coefficient = 0.43); indoor air levels explained 19% of the variance in prenatal urine TCPy ( p = 0.001). Meconium TCPy concentrations were positively correlated with chlorpyrifos in maternal and cord blood ( r = 0.25–0.33, p < 0.05) and with TCPy in maternal urine ( r = 0.31, p < 0.01). Conclusions Results suggest the biomarkers are reliable dosimeters to differentiate between groups with prenatal chlorpyrifos exposures varying by a factor of 2 or more and vividly illustrate the efficacy of residential restriction on chlorpyrifos to reduce the internal dose during pregnancy.
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