Exposure to organochlorine pesticides via breastmilk and infant length-for-age in a cross-sectional study in the Lake Atitlán watershed, Guatemala

Organochlorine pesticides (OCPs) are persistent and bioaccumulative, disrupt development, and are still used in some parts of the world despite local and global bans and restrictions. Guatemala has the highest prevalence of stunting (length-for-age that is two standard deviations below the median of childhood growth standards) in the Americas, affecting ~ 50% of children under five, and it has the sixth highest prevalence worldwide. This manuscript examines concentrations of OCPs and their degradation products (18 chemicals) in the breastmilk of Mayan women from the Lake Atitlán watershed in Guatemala to assess current exposures and to explore potential relationships among demographic parameters and stunting prevalence in infants. We conducted a cross-sectional study ( n = 80 mother/infant dyads, infants were 90–182 days in age) with 20 mothers/infants from each of four communities: San Juan La Laguna, San Pedro La Laguna, Panajachel, and Santiago Atitlán during June - July, 2022. We administered a survey based on the language preference of the mother with the help of a community translator to collect demographic information and assess exposure to pesticides. We measured the length of each infant to assess stunting (based on age) and plotted data on the World Health Organization (WHO) growth charts. We detected all 18 OCPs in at least one breastmilk sample and 11 were detected in at least five samples (2,4’-DDD, 4,4’-DDD, 4,4’-DDE, 4,4’-DDT, cis-heptachlor epoxide, HCB, heptachlor, pentachlorobenzene, trans-chlordane, trans-heptachlor epoxide, trans-nonachlor). Concentrations were the highest for 4,4’-DDE (mean ± SE = 60.6 ± 5 ng/g lipid weight, maximum = 313.1 ng/g lipid weight). No statistically significant associations were observed between OCP concentrations and stunting measures; however, exploratory analyses suggested an inverse trend between 4,4’-DDT concentration and stunting ( p = 0.08) that warrants future study. The detection of legacy pesticides demonstrates ongoing environmental exposure and supports further investigation of routes of exposure for the mother and potential health implications for the child. Our results also have policy implications for Guatemalan regulations and enforcement.