Human Milk Intake and Pesticide Transfer in Agricultural and Urban Areas of Sonora, Mexico

Abstract

BackgroundBreast milk is considered the best way to feed newborn babies in order to achieve optimal growth, development and health. Despite being essentially sterile and safe, people may be exposed to various pollutants when living in different environments.ObjectiveTo measure human milk production by isotopic techniques, mother's body composition and pesticide transfer to babies through human milk in agricultural and urban areas of Sonora, Mexico.MethodsHuman milk intake was determined by the dose‐to‐the‐mother technique using deuterium oxide dilution. Likewise, mother's body composition was assessed by the intercept method. Organochlorine pesticide residues (p,p'‐DDT, p,p'‐DDE, p,p'‐DDD) and pyrethroids (deltamethrin , cypermethrin and cyhalothrin) in breast milk samples where measured by gas chromatography.Results62 lactating women and their infants participated in the study, 32 where urban residents and 30 lived in the agricultural area. There was a difference of approximately 100 mL on the daily milk intake between the study areas (799 mL in the agricultural area and 707 mL in urban participants (p< 0.05)). The concentrations of DDT metabolites were higher in the urban group (p< 0.002), however none of the samples exceeded the safe limits established by the Environmental Protection Agency and FAO/WHO.ConclusionBreast milk intake was higher in agricultural areas in Sonora compared to the urban region. Consumption of human milk by infants, can still be considered a safe feeding practice in these environments.