Mercury Concentrations and Sourcing Mercury Exposures in Pregnant Women from the Republic of Suriname, South America

PDS 62: Chemicals and metals: exposure and biomarkers, Johan Friso Foyer, Floor 1, August 28, 2019, 10:30 AM - 12:00 PM Background/Aim: Freshwater fish species in the interior regions of Suriname have elevated concentrations of mercury thought to be a result of the use of elemental mercury in artisanal and small-scale gold mining operations. Interior communities rely on freshwater fish for dietary protein. Our aims were to determine mercury levels in pregnant women and evaluate methylmercury and total mercury relationships among hair, blood, and urine. Methods: Pregnant women enrolled in the Caribbean Consortium for Research in Environmental and Occupational Health (CCREOH) program participated in this project. Concentrations of total mercury (THg) in hair were determined for 354 women from Paramaribo (coastal capitol), 83 from Nickerie (coastal city), and 44 from interior communities. THg and methylmercury (MeHg) concentrations were determined in hair, blood, and urine from an additional 20 women from Paramaribo, 20 from Nickerie, and 35 from interior communities. Cold-vapor atomic absorption spectrometry and cold-vapor fluorescence spectrophotometry were used to identify and quantify mercury concentrations. Results: Women from interior communities have significantly higher concentrations of THg in hair compared to women from coastal communities. Median levels are 2.2 ug/g (7.0 ug/g [95%-ile]) in the interior, 0.6 ug/g (2.0 ug/g) in Paramaribo, and 0.8 ug/g (2.1 ug/g) in Nickerie. Concentrations of MeHg are highly correlated with THg in both hair (r=0.97) and blood (r=0.99) and make up approximately 97% of the THg in hair and 86% of the THg in blood. THg concentrations are highly correlated in blood and hair (r=0.83) and modestly correlated with those in urine (hair and urine, r=0.64; blood and urine, r=0.70). Conclusions: THg mercury levels in hair are significantly higher in interior women and often exceed safety thresholds established by health organizations. Neuropsychiatric testing of children is warranted and ongoing. Mercury speciation indicates that fish consumption is the most likely source thus informing possible future interventions.