Urinary Concentrations of Pyrethroid Insecticide Metabolites Among Pregnant Thai Women in the Study of Asian Women and their Offspring’s Development and Environmental Exposures (SAWASDEE) Restricted; Files Only

Bell, Kathleen (Spring 2021)

Permanent URL: https://etd.library.emory.edu/concern/etds/q237ht30d?locale=pt-BR


Pyrethroids (PYR) are a neurotoxic insecticide class with widespread agricultural and household uses and public health applications like preventing malaria and dengue outbreaks. Exposure to these neurotoxicants during pregnancy is particularly concerning as research suggests PYR can cross the placenta and adversely impact fetal development. The present study aimed to evaluate the distribution and determinants of urinary PYR metabolite concentrations among 333 pregnant women enrolled in the Study of Asian Women and their Offspring’s Development and Environmental Exposures (SAWASDEE) from 2017 to 2019. SAWASDEE is a prospective, longitudinal birth cohort of mother-child pairs from the Chom Thong and Fang districts in northern Thailand’s Chiang Mai Province exploring the impacts of prenatal pesticide exposures on infant and early childhood development. Up to six urine samples were collected from participants during pregnancy and composited to generate specimens representing early, middle, and late pregnancy. Composite samples were analyzed for three PYR metabolites: 3-phenoxybenzoic acid (3PBA) and cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (cDCCA and tDCCA). Occupational PYR exposure predictor data were collected via questionnaires administered each trimester. Descriptive statistics of urinary PYR metabolite concentrations were obtained. Multiple linear regression was used to identify associations between occupational predictors and 3PBA concentrations in early, middle, and late pregnancy and the mean concentration across these periods. 3PBA was detected in the majority of urine samples, ranging from 49.54% to 84.08% for each time period. Detection frequencies of cDCCA and tDCCA were generally much lower than 50%, so these metabolites were excluded from further analysis. Packing fruits, vegetables, or flowers for storage or sale, performing other tasks (i.e., packing fruit, vegetables, or flowers for storage or sale, waxing fruit, or working in a nursery or greenhouse), handling pesticides, and using a long-sleeved shirt in two and three pregnancy periods were found to be significantly associated with 3PBA concentrations in different pregnancy periods. No consistent associations across pregnancy periods were observed. These findings suggest agricultural-related occupational factors are not likely major sources of PYR exposure among pregnant female farmworkers in northern Thailand. 

Table of Contents



Study Population.... 4

Pyrethroid Exposure Assessment.... 4

Demographics and Other Covariates.... 6

Statistical Analyses.... 7


Study Population Characteristics.... 9

Distributions of Urinary PYR Metabolite Concentrations.... 11

Predictors of 3PBA Metabolite Concentrations.... 12


Comparisons to Other Studies.... 14

Exposure Predictors.... 17

Limitations.... 20



TABLES.... 30

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