Urinary biomarkers of exposure to insecticides, herbicides, and one insect repellent among pregnant women in Puerto Rico

Abstract

BackgroundThere are potential adverse health risks to the mother and fetus from exposure to pesticides. Thus, studies of exposure to pesticides among pregnant women are of interest as they will assist with understanding the potential burden of exposure globally, identifying sources of exposure, and designing epidemiology studies.MethodsWe measured urinary concentrations of the insect repellent N-N-diethyl-meta-toluamide (DEET) and two of its metabolites [3-diethyl-carbamoyl benzoic acid (DCBA) and N,N-diethyl-3-hydroxymethylbenzamide (DHMB)], four pyrethroid insecticide metabolites [4-fluoro-3-phenoxybenzoic acid (4-F-3-PBA); 3-phenoxybenzoic acid (3-PBA); trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (trans-DCCA); and cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane carboxylic acid (cis-DBCA)], and two chlorophenoxy herbicides [2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T)] in 54 pregnant women from Puerto Rico at three separate time points (20 ± 2 weeks, 24 ± 2 weeks, and 28 ± 2 weeks of gestation). We calculated the distributions of the biomarker concentrations and compared them to those of women of reproductive age from the general U.S. population where available, and estimated the within-subject temporal variability of these repeated measurements. We also collected questionnaire data on demographics, consumption of select fruits, vegetables, and legumes in the past 48-hr, and pest-related issues, and associations between these variables and biomarker concentrations were examined.ResultsWe found that 95th percentile urinary concentrations of DEET, 3-PBA, trans-DCCA, and 2,4-D were lower than women of reproductive age on the U.S. mainland, whereas 95th percentile urinary concentrations of 4-F-3-PBA, cis-DBCA, and 2,4,5-T were similar. DCBA, the only urinary biomarker detected in >50% of the samples, showed fair to good reproducibility across pregnancy (intraclass correlation coefficient: 0.60). Women were more likely (p <0.05) to have greater urinary concentrations of pesticide biomarkers if they were less educated (DCBA and trans-DCCA), unemployed (DHMB), or married (2,4-D), had consumed collards or spinach in past 48-hr (2,4-D) or had been using insect repellent since becoming pregnant (DCBA), or were involved with residential applications of pesticides (trans-DCCA).ConclusionsWe identified concentrations and predictors of several pesticides among pregnant women in Puerto Rico. Further research is needed to understand what aspects of the predictors identified lead to greater exposure, and whether exposure during pregnancy is associated with adverse health.

Critical and systematic evaluation of data for estimating human exposures to 2,4-dichlorophenoxyacetic acid (2,4-D) – quality and generalizability

“…In adults 21 years and older (N = 1,925), the associations between fasting hours and unadjusted and creatinine-adjusted log urinary 2,4-D levels were not statistically significant. This agrees with results of the study of pregnant women (Lewis et al 2014), in which no significant associations were noted between urinary 2,4-D and consumption of nearly all fruits, vegetables, and legumes (except collards or spinach). In contrast, for children participating in NHANES (<21 years of age, N = 822), significant inverse associations between fasting hours and log urinary 2,4-D were observed (unadjusted: slope = −0.001, p-value = 0.00083; creatinine-adjusted: slope = −0.015, p-value = 0.00033).…”

Predictors of urinary levels of 2,4-dichlorophenoxyacetic acid, 3,5,6-trichloro-2-pyridinol, 3-phenoxybenzoic acid, and pentachlorophenol in 121 adults in Ohio

“…Recently, Lewis et al (2014) reported that marital status and the 48-h consumption of collards and spinach were significantly associated (p < 0.05) with ln(urinary 2,4-D) levels in 54 pregnant women in Puerto Rico in 2010-2012; however these data are limited as this biomarker was only detected in 12% of the urine samples. In comparison to this study, results showed that 48-h time spent outside at home, 48-h sweet/salty snack consumption, and ln(creatinine) levels were significant predictors (p < 0.05) and race was a marginally significant predictor (p = 0.093) of the ln(urinary 2,4-D) levels in the CTEPP adults, collectively explaining 20% of the variability of 2,4-D in the urine samples.…”

“…Only one published study was found that has assessed the relationship between any sociodemographic/lifestyle factor and urinary 2,4-D levels in adults in non-occupational settings, globally (Lewis et al, 2014). Recently, Lewis et al (2014) reported that marital status and the 48-h consumption of collards and spinach were significantly associated (p < 0.05) with ln(urinary 2,4-D) levels in 54 pregnant women in Puerto Rico in 2010-2012; however these data are limited as this biomarker was only detected in 12% of the urine samples.…”

Predictors of Urinary 3-Phenoxybenzoic Acid Levels in 50 North Carolina Adults

“…In comparison to our study, the 2009–2010 U.S. NHANES, a population-based study, reported a much lower GM 3-PBA level of 0.42 ng/mL in the (spot) urine samples of 1296 adults aged 20–59 years [25]. Other studies conducted in the Caribbean, China, Japan, Poland, and Puerto Rico have also reported GM 3-PBA concentrations ranging between 0.20 and 1.77 ng/mL in adult (spot) urine samples [26,27,28,29,30]. These data confirm widespread exposure of adults to pyrethroid insecticides worldwide.…”