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Post-Doctoral Fellowships
In Utero and Early Childhood Pesticide Exposure and Respiratory Symptoms
and Lung Function in Children
The causes of chronic respiratory disease are not fully understood. Exposure to environmental
pollutants such as air pollution has been linked to chronic pediatric respiratory disease. Although
pesticide use is widespread and known to have potential adverse health effects, the contribution of
organophosphate pesticides (OPs) to the development of these disorders is not well described. OPs
can affect respiratory function by inhibition of acetylcholinesterase. Additionally, recent reports
from animal studies show that at doses below those that can cause acetylcholinesterase inhibition,
OPs can induce airway hyper-reactivity. This is potentially important for the occurrence and
severity of respiratory chronic disease.
The project’s main objective was studying the association between prenatal and early childhood
exposure to OPs and respiratory symptoms and spirometry measures in the CHAMACOS (The
Center for the Health Assessment of Mothers and Children of Salinas) prospective birth cohort. The
CHAMACOS center is aimed at studying the association between exposure to pesticides and other
environmental agents and the health of pregnant women and their children. The study followed
526 pregnant women to delivery of a live-born, surviving singleton. Mothers were interviewed
twice during pregnancy, after delivery, and six times during childhood. Dialkyl phosphate (DAP)
metabolites of OPs were measured in urine samples from mothers, twice during pregnancy, and in
urine samples from their children, five times during childhood.
The results show that higher prenatal DAP metabolite concentrations in urine were associated
with increased odds of respiratory symptoms consistent with possible asthma in the children five
to seven years later. Additionally, childhood exposure assessed by DAPs was also associated with
respiratory symptoms at ages five and seven and with pulmonary lung function measurements in
7-year-old children.
This is the first report on adverse associations between early-life OP exposure and respiratory
symptoms and spirometry measurements in children. The strengths of the study include a
prospective design, use of biomarkers for exposure assessment instead of relying on questionnaire
data, and use of the objective measurement of spirometry tests in addition to symptoms reports.
Research publications
(1)
Raanan, R., Harley, K.G., Balmes, J.R., Bradman, A., Lipsett, M., & Eskenazi, B. (2014). Early-life exposure to
organophosphate pesticides and pediatric respiratory symptoms in the CHAMACOS cohort.
Environmental Health
Perspectives
. Advance online publication. doi: 10.1289/ehp.1408235
Fellow
Rachel Raanan
(Arnon)
University of California,
Berkeley, USA
Supervisor
Brenda Eskenazi
2012-2014