Residential Proximity to Methyl Bromide Use and Birth Outcomes in an Agricultural Population in California

Abstract

Background: Methyl bromide, a fungicide often used in strawberry cultivation, is of concern for residents who live near agricultural applications because of its toxicity and potential for drift. Little is known about the effects of methyl bromide exposure during pregnancy.Objective: We investigated the relationship between residential proximity to methyl bromide use and birth outcomes.Methods: Participants were from the CHAMACOS (Center for the Health Assessment of Mothers and Children of Salinas) study (n = 442), a longitudinal cohort study examining the health effects of environmental exposures on pregnant women and their children in an agricultural community in northern California. Using data from the California Pesticide Use Reporting system, we employed a geographic information system to estimate the amount of methyl bromide applied within 5 km of a woman’s residence during pregnancy. Multiple linear regression models were used to estimate associations between trimester-specific proximity to use and birth weight, length, head circumference, and gestational age.Results: High methyl bromide use (vs. no use) within 5 km of the home during the second trimester was negatively associated with birth weight (β = –113.1 g; CI: –218.1, –8.1), birth length (β = –0.85 cm; CI: –1.44, –0.27), and head circumference (β = –0.33 cm; CI: –0.67, 0.01). These outcomes were also associated with moderate methyl bromide use during the second trimester. Negative associations with fetal growth parameters were stronger when larger (5 km and 8 km) versus smaller (1 km and 3 km) buffer zones were used to estimate exposure.Conclusions: Residential proximity to methyl bromide use during the second trimester was associated with markers of restricted fetal growth in our study.

Occupational Exposure to Endocrine-Disrupting Chemicals and Birth Weight and Length of Gestation: A European Meta-Analysis

“…Agricultural workers were classified as exposed to this chemical group, among several other EDC groups, whereas pesticides was the only EDC group to which veterinarians and life science technicians were classified as exposed. In the past, exposure to pesticides among pregnant women has been widely investigated (Chevrier et al 2011; Gemmill et al 2013; Rauch et al 2012; Wickerham et al 2012), and our findings fall in line with other studies that have reported associations between reduced birth weight and maternal exposure to pesticides, both ambient and occupational (Burdorf et al 2011; Chevrier et al 2011; Wickerham et al 2012; Wohlfahrt-Veje et al 2011). However, these studies evaluated continuous birth weight, not term LBW.…”

Residential proximity to organophosphate and carbamate pesticide use during pregnancy, poverty during childhood, and cognitive functioning in 10-year-old children

“…Using data from the California Pesticide Use Reporting (PUR) system, we estimated the total kilograms of OP and carbamate pesticides used in agriculture near the residence where each woman lived the longest during her pregnancy, applying methods that have been described in detail elsewhere (Gemmill et al 2013; Gunier et al 2011; Nuckols et al 2007). The California PUR system reports the pounds of active pesticide applied, the date of application, and the location, which is reported by one-square mile sections (approximately 1.6 km × 1.6 km) as defined by the Public Land Survey System (PLSS) (U.S.…”

Residential proximity to agricultural fumigant use and IQ, attention and hyperactivity in 7-year old children

“…We previously found that living within 5 km of methyl bromide use in the second trimester of pregnancy was associated with decreased birth weight, length, and head circumference (Gemmill et al, 2013). Methyl bromide was banned by the Montreal Protocol due to harmful effects on the ozone layer and is currently being phased out of use, resulting in increased usage of chloropicrin, metam sodium and 1,3-DCP in recent years (CDPR, 2016).…”