Early lifestage exposure and potential developmental susceptibility to tetrachloroethylene

Occupational exposure to organic solvents during pregnancy and child behavior from early childhood to adolescence

BACKGROUND

Organic solvents are used in formulating an extensive range of products for professional use. Animal and human studies suggest that in utero solvent exposure may affect neurodevelopment. Our objective was to assess the association between occupational exposure to solvents during pregnancy and child behavior aged 2-12 years.

METHODS

The French mother-child cohort PELAGIE (2002-2006) included 3,421 women recruited in early pregnancy. Occupational exposure to solvents was self-reported. For 459 children, parents used a questionnaire derived from the Child Behavior Checklist and the Preschool Social Behavior Questionnaire to assess their child's behavior, at age 2, and the Strengths and Difficulties Questionnaire at ages 6 and 12. A cross-lagged structural equation modeling approach was used to assess direct and indirect associations between exposure and child behavior.

RESULTS

At age 2, an increased externalizing behavior score was suggested with prenatal exposure to solvents (mean change in standardized score (95%CI): 0.28 (-0.01, 0.57) for occasional exposure and 0.23 (-0.05, 0.51) for regular exposure). At ages 6 and 12, distinct sex-specific patterns were observed: among boys, no association with externalizing behavior was observed, while among girls, an association was seen for both occasional and regular exposure (total effect at age 12: 0.45 (0.06,0.83) and 0.40 (0.03, 0.76), respectively). For both sexes, occasional exposure may be associated with internalizing behavior at ages 6 and 12 (total effect at age 6: 0.37 (0.06, 0.68) and at age 12: 0.27 (-0.08, 0.62)).

CONCLUSIONS

Occupational exposure to solvents during pregnancy may impact child behavior through either direct or cumulative effects during childhood; these associations may persist until early adolescence, especially among girls.

Maternal residential exposure to solvents from industrial sources during pregnancy and childhood cancer risk in California

BACKGROUND

Maternal solvent exposure has been suspected to increase offspring cancer risk. The study aimed to evaluate the associations between maternal residential exposure to solvents from industrial pollution during pregnancy and childhood cancer.

METHODS

The present study included 15,744 cancer cases (aged 0-19 years at diagnosis) identified from California Cancer Registry and 283,141 controls randomly selected from California Birth Registry (20:1 frequency-matched by birth year: 1998-2016). We examined industrial releases of tetrachloroethylene and 1,1,1-trichloroethane within 3 km of the birth address, while we used a 5 km buffer for carbon disulfide. We calculated the total exposure from all linked Toxic Release Inventory sites during each index pregnancy and assigned "ever/never" and "high/low exposed/unexposed" exposure, using median values. We performed quadratic decay models to estimate cancer risks associated with maternal solvent exposure in pregnancy.

RESULTS

1,1,1-Trichloroethane was associated with rhabdomyosarcoma (adjusted Odds Ratio (aOR): 1.96; 95% Confidence Interval (CI): 1.16, 3.32) in the "ever exposed" group. Ever exposure to carbon disulfide was associated with increased risks of medulloblastoma (OR = 1.85, 95% CI 1.01, 3.40) and ependymoma (OR = 1.63, 95% CI 0.97, 2.74).

CONCLUSIONS

Overall, our findings suggested maternal residential exposure to solvents from industrial sources might be associated with elevated childhood cancer risks.

Occupational exposure to organic solvents during pregnancy and childhood behavior: findings from the PELAGIE birth cohort (France, 2002-2013)

BACKGROUND

Numerous industries use organic solvents, and many workers from various occupational sectors are exposed to these known neurotoxicants, including pregnant women. Our objective is to explore whether occupational exposure of pregnant women to solvents may impair the neurodevelopment of their babies and consequently affect their behavior in childhood.

METHODS

Within the French birth cohort PELAGIE, parents assessed their children's internalizing and externalizing behaviors using items from the Child Behavior Checklist and the Preschool Social Behavior Questionnaire at age 2, and the Strength and Difficulties Questionnaire at age 6. The occupational exposure to solvents of the pregnant women was self-reported prospectively at the beginning of their pregnancy (N = 715). We applied structural equation modeling to capture the longitudinal association of prenatal exposure to solvents with children's behavioral traits at 2 and 6 years.

RESULTS

Increased externalizing behavior score at age 2 was associated with prenatal exposure to solvents (standardized score: 0.34 (95% CI = 0.11, 0.57) for occasional exposure and 0.26 (0.05, 0.48) for regular exposure). This association was attenuated at age 6 (0.22 (- 0.02, 0.47) for occasional exposure and 0.07 (- 0.14, 0.28) for regular exposure). No association was observed for internalizing behavior.

CONCLUSIONS

Pregnant women's occupational exposure to solvents may affect their children's behavior in early childhood. This effect may be attenuated with aging or diluted by the effects of other postnatal predictors.

Structural Magnetic Resonance Imaging in an adult cohort following prenatal and early postnatal exposure to tetrachloroethylene (PCE)-contaminated drinking water

This population-based retrospective cohort study examined Structural Magnetic Resonance Imaging (MRI) of the brain in relation to prenatal and early postnatal exposure to tetrachloroethylene (PCE)-contaminated drinking water on Cape Cod, Massachusetts. Subjects were identified through birth records from 1969 through 1983. Exposure was modeled using pipe network information from town water departments, a PCE leaching and transport algorithm, EPANet water flow modeling software, and Geographic Information System (GIS) methodology. Brain imaging was performed on 26 exposed and 16 unexposed subjects. Scans were acquired on a Philips 3T whole body scanner using the ADNI T1-weighted MP-RAGE scan. The scans were processed by FreeSurfer version 4.3.1 software to obtain measurements of specific brain regions. There were no statistically significant differences between exposed and unexposed subjects on the measures of white matter hypointensities (β: 127.5mm(3), 95% CI: -259.1, 1514.0), white matter volumes (e.g. total cerebral white matter: β: 21230.0mm(3), 95% CI: -4512.6, 46971.7) or gray matter volumes (e.g. total cerebral gray matter: β: 11976.0mm(3), 95% CI: -13657.2, 37609.3). The results of this study suggest that exposure to PCE during gestation and early childhood, at the levels observed in this population, is not associated with alterations in the brain structures studied.

Adult neuropsychological performance following prenatal and early postnatal exposure to tetrachloroethylene (PCE)-contaminated drinking water

This population-based retrospective cohort study examined adult performance on a battery of neuropsychological tests in relation to prenatal and early postnatal exposure to tetrachloroethylene (PCE)-contaminated drinking water on Cape Cod, Massachusetts. Subjects were identified through birth records from 1969 through 1983. Exposure was modeled using pipe network information from town water departments, a PCE leaching and transport algorithm, EPANet water flow modeling software, and a Geographic Information System (GIS). Results of crude and multivariate analyses among 35 exposed and 28 unexposed subjects showed no association between prenatal and early postnatal exposure and decrements on tests that assess abilities in the domains of omnibus intelligence, academic achievement or language. The results were suggestive of an association between prenatal and early postnatal PCE exposure and diminished performance on tests that assessed abilities in the domains of visuospatial functioning, learning and memory, motor, attention and mood. Because the sample size was small, most findings were not statistically significant. Future studies with larger sample sizes should be conducted to further define the neuropsychological consequences of early developmental PCE exposure.