Pesticide Residues in Fruits and Vegetables: Assessment and Their Associations With Reproductive Health Outcomes

Abstract

According to the Dietary Guideline, consumption of fruits and vegetables (FVs) are recommended throughout the lifespan, including during pregnancy. FVs, on the other hand, can serve as a vehicle of exposure to pesticide residues. In the US, Environmental Protection Agency (EPA) is responsible for regulating pesticides under the Federal Insecticide, Fungicide, and Rodenticide Act and the Food Quality Protection Act. While majority of the produce sampled through the US Department of Agriculture had residues below the EPA limits, there is a growing concern whether chronic exposure to these pesticide residues may have adverse health effects, especially among susceptible populations such as pregnant women. Yet, such research is scarce. This dissertation focuses on the assessment of pesticide residues in FVs and evaluates their associations with pregnancy outcomes. We previously have developed the Pesticide Residue Burden Score (PRBS) based on self-reported diet and national surveillance data on food pesticide residues to characterize dietary exposure over the past year. In Chapter 1, we evaluated the association of the PRBS with urinary pesticide metabolites in the Environment and Reproductive Health (EARTH) Study. We found intake of high pesticide residues FVs was positively associated with urinary concentrations of pesticide biomarkers, suggesting that PRBS can characterize dietary exposure to select pesticides. In Chapter 2, we assessed the relation between preconception intake of high and low FVs and assisted reproductive technology outcomes in EARTH study. We found that intake of high pesticide residues FVs was associated with lower probability of clinical pregnancy and live birth, while intake of low pesticide residue FVs had the opposite relations among women undergoing infertility treatment. This is the first report of such relation in humans. In Chapter 3, we examine the association between maternal intake of high and low pesticide residue FVs with birth outcomes in a pre-birth cohort. We found that maternal intake of high pesticide residue FVs during the first trimester was associated with higher risks of small-for-gestational-age among white women, while these exposures was associated with large-for-gestational-age among non-white women. In conclusion, this work demonstrated the usefulness of PRBS in assessing pesticide residue intake through FVs. Using this method, these studies suggest exposure to pesticide residues may adversely affect pregnancy and birth outcomes.