The effects of intrauterine exposure to pesticides on cognition in early childhood in a cohort of mothers and daughters in Bristol, UK Open Access

Allen, Kristen Emily (2015)

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Background: Prenatal exposure to pesticides may be associated with a negligible increase in development and communicative assessment scores in early childhood.

Objective: We explored associations of prenatal serum concentrations of hexachlorobenzene (HCH), beta-Hexachlorocyclohexane (HCCH), 2,2-Bis(4-chlorophenyl)-1,1-dichloroethene (DDE) and 2,2-Bis(4-chlorophenyl-1,1,1-trichloroethan (DDT) with maternal-reported measures of cognition and communication in 15 month-old girls, using the MacArthur Bates Communicative Inventory (MCDI).

Methods: We studied a sample of 309 singleton girls and their mothers participating in the Avon Longitudinal Study of Parents and Children (ALSPAC). Maternal serum samples were obtained at 15 weeks gestation and assessed for pesticide levels. Maternal demographic and health-related characteristics were recorded through questionnaires. Child characteristics and MCDI scores at 15 months were obtained through questionnaires mailed to the mothers at various time points after the child's birth. We explored associations between prenatal pesticide exposures and MCDI scores as well as total pesticide exposure and MCDI scores at 15 months of age in multivariate linear regression models after adjusting for maternal education, HOME score at 6 months of age, alcohol and tobacco use during the first trimester of pregnancy, maternal age at delivery and duration of breastfeeding (weeks).

Results: The geometric mean values of HCH and HCCH were similar, at 11.61 pg/g (95% CI 7.98, 16.89) and 11.27 pg/g (95% CI 6.94, 18.29), respectively. The geometric mean value of DDE, 25.77 pg/g (95 % CI 14.12, 46.99), was nearly four times that of DDT, 6.25 ph/g (95% CI 3.89, 10.06). Generally, crude associations between prenatal pesticides and MCDI components were null. In contrast, the adjusted multivariate linear regression models revealed several significant associations. For each twenty percent increase in HCB there was a 3.82 point (11.94%) increase in the social development score. A twenty percent increase in DDT was associated with a 24 point (8.96%) increase and a 29 point (8.79%) increase in the vocabulary and total communication components, respectively.

Conclusions: There is a slight positive association between serum pesticide levels and MCDI scores. These results, although unexpected, account for only small changes in MCDI scores.

Table of Contents

  1. Abstract
  2. Acknowledgements
  3. Introduction
  4. Methods
    1. Population
    2. Cognitive Measures
    3. Exposure Measures
    4. Covariates
    5. Statistical Analysis
  5. Results
  6. Discussion
  7. Conclusion
  8. Tables
  9. References

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