Mercury Levels and Their Determinants in Women of Reproductive Age in the Brazilian Amazon: A Cross-Sectional Study

Mercury exposure remains a public health concern in Amazonian populations. This study assessed hair total mercury levels and associated determinants in 205 women of reproductive age from riverine communities in the Lower Tocantins and Xingu regions, Pará,Brazil. Hair Hg concentrations were measured using cold vapor atomic absorption spectrometry. Multivariable linear regression was used to identify predictors of log-transformed mercury total levels. Median concentration was 0.332 µg/g, with 85.4% below 1 µg/g. Women from the Lower Tocantins had significantly higher levels than those from the Xingu (p < 0.001). Region (β = -0.516; p < 0.001) and high fish consumption (> 4 times/week; β = 0.207; p = 0.024) were significant predictors. Mercury levels were low, but regional differences and high fish consumption frequency were associated with exposure, highlighting the need for targeted biomonitoring strategies.