Exposição pré-natal ao mercúrio e os desfechos ao nascer em população ribeirinha da região do Xingu, Amazônia

Abstract

Exposure to methylmercury (MeHg) during pregnancy poses a potential risk to fetal development, especially among Amazonian populations who frequently consume fish. This study aimed to assess the relationship between fish consumption by pregnant women, total mercury (THg) levels in umbilical cord tissue, and possible adverse gestational and neonatal outcomes in the municipality of Porto de Moz, Pará. The study was observational with a quantitative approach, conducted with 108 pregnant women receiving care at a primary health unit between 2024 and 2025. A subsample of participants with biomarker data was analyzed, and THg levels in the umbilical cord were measured using atomic absorption spectrometry. Information was collected on dietary intake, sociodemographic profile, and perinatal data of the newborns. The mean THg level in the cord was 0.25 ± 0.18 μg/mg, with all values below the risk threshold (6 μg/L). A trend was observed indicating increased THg levels proportional to the frequency of fish consumption, especially of carnivorous species such as peacock bass (Cichla spp.) and wolf fish (Hoplias spp.). No congenital malformations or prematurity were identified, but there was a trend toward reduced birth weight with increasing THg levels, although not statistically significant (p = 0.174; R² = 11.9%). Although the detected mercury levels were below risk thresholds, the findings suggest relevant chronic exposure associated with regional dietary patterns. The predominant consumption of non-carnivorous species may have acted as a protective factor. The results underscore the need for continuous monitoring of MeHg exposure in Amazonian pregnant women, along with food education and environmental surveillance actions tailored to local sociocultural specificities.