Reduced birth weight in relation to pesticide mixtures detected in cord blood of full-term infants: Fid-Bau Portal

Reduced birth weight in relation to pesticide mixtures detected in cord blood of full-term infants

Wickerham, Erin L. / Lozoff, Betsy / Shao, Jie / Kaciroti, Niko / Xia, Yankai / Meeker, John D.

Abstract Previous research has shown that prenatal exposure to pesticides may be associated with decreased fetal growth. The specific pesticides investigated and results reported across studies have been inconsistent, and there is a mounting need for the consideration of mixtures rather than individual agents in studies of health outcomes in relation to environmental exposures. There are also many individual pesticides that have not been investigated in human health studies to date. We conducted a pilot study in rural Zhejiang province, China, measuring 20 non-persistent pesticides (10 insecticides, 6 herbicides, 3 fungicides, and 1 repellant) in umbilical cord blood of 112 full term (>37weeks) infants. The pesticides detected with the greatest frequency were diethyltoluamide (DEET) (73%), a repellant, and vinclozolin (49%), a fungicide. The samples had detectable concentrations for a mean of 4.6 pesticides (SD=1.9) with a maximum of 10. Adjusting for potential confounders, newborn birth weight was inversely associated with the number of pesticides detected in cord blood (p=0.04); birth weight decreased by a mean of 37.1g (95% CI, −72.5 to −1.8) for each detected pesticide. When assessing relationships by pesticide type, detection of fungicides was also associated with decreased birth weight (adjusted β=−116g [95% CI, −212 to −19.2]). For individual pesticides analyzed as dichotomous (detect vs. non-detect) variables, only vinclozolin (adjusted β=−174g [95% CI, −312 to −36.3]) and acetochlor (adjusted β=−165g [95% CI, −325 to −5.7]) were significantly associated with reduced birth weight. No significant associations were seen between birth weight and individual pesticides assessed as continuous or 3-level ordinal variables. Our findings from this pilot investigation suggest that exposure to fungicides may adversely impact fetal growth. Exposure to mixtures of multiple pesticides is also of concern and should be explored in addition to individual pesticides. Additional research is needed to establish causality and to understand the function and impact of fungicides and pesticide mixtures on fetal development.

Highlights ► We studied maternal exposure to 20 pesticides and fetal growth in rural China. ► We found high concentrations of several pesticides compared to studies from the US. ► The number of pesticides in cord blood was inversely related to infant birth weight. ► Vinclozolin and acetochlor were the only individual pesticides associated with birth weight. ► Future studies need to consider exposure to mixtures as well as individual agents.