Sources Of Manganese Exposure In Pregnant Women Living Near Banana Plantations In Costa Rica: Results From The Infant's Environmental Health Study (ISA) In Costa Rica

Abstract

Introduction: Elevated manganese (Mn) in drinking water has been reported worldwide due to natural and anthropogenic contamination. Mancozeb is an ethylene-bis-dithiocarbamate (EBDC) fungicide containing 21% Mn. In Costa Rica, it is applied weekly by light aircraft on banana plantations. Within the context of the ISA study, we examined factors that explained Mn drinking water concentrations in communities located near banana plantations. Methods: We collected 126 drinking water samples from ISA participant's homes. In addition, we obtained repeated samples from 30 homes. We determined Mn concentrations in acidified samples using ICP-MS. Results: Median Mn concentration was 5.4 µg/L (interquartile range: 0.34 to 87 µg/L; range 0.4-1600 µg/L). For the repeated samples, the intraclass correlation coefficient was 0.95. Multiple regression analysis on log10-transformed Mn showed distance (in km) from a banana plantation was inversely associated with Mn water concentrations (β per 10-fold increase in exposure=-0.26, 95% CI: -0.41; -0.11). Distribution system predicted Mn concentrations, with significantly higher concentrations for banana farm and private wells (β=0.84, 95% CI: 0.36; 1.32) and lower concentrations for the National water supplier (β=-0.67, 95% CI: -1.06; -0.28) compared to miscellaneous systems. Immigrant communities, situated closest to the banana plantations, had higher concentrations of Mn in their drinking water compared to Costa Rican born participants. Conclusions: Mn concentrations were relatively high; several studies have shown negative associations between Mn in drinking water and children's cognition and behavior at concentrations similar to those observed in this study. Our findings suggest that both natural and anthropogenic sources contribute to elevated Mn in drinking water in these communities, possibly due to mancozeb spraying. Future studies should examine its possible contribution to elevated Mn in drinking water.