Mercury Contamination: A Growing Threat to Riverine and Urban Communities in the Brazilian Amazon

• Published in: International journal of environmental research and public health Vol. 19; no. 5; p. 2816
• Main Authors: Meneses, Heloisa do Nascimento de Moura, Oliveira-da-Costa, Marcelo, Basta, Paulo Cesar, Morais, Cristiano Gonçalves, Pereira, Romulo Jorge Batista, de Souza, Suelen Maria Santos, Hacon, Sandra de Souza
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 28.02.2022; MDPI
• Subjects: Adult; Animals; Anticoagulants; Biomarkers; Blood pressure; Body mass index; Brazil; Community; Contamination; Creatinine; Ecosystem; Fishes; Glucose; Gold; Gold mines & mining; Humans; Information systems; Laboratories; Mercury; Mercury - analysis; Mining; Questionnaires; Rainforests; Urban areas; Urban populations; Brazil; Amazon Basin; blood sampling; Tapajós basin; Santarém; gold mining; biochemical markers
• ISSN: 1660-4601; 1661-7827; 1660-4601
• DOI: 10.3390/ijerph19052816

In recent decades, widespread and uncontrolled use of mercury (Hg) in artisanal small-scale gold mining has released thousands of tons of mercury-contaminated waste in the Amazon biome, endangering the largest tropical rainforest worldwide. In this study, we assessed and compared blood Hg levels in individuals living in urban and riverine areas in the lower Tapajós basin and examined the association between Hg exposure and specific biochemical parameters. In total, 462 adults from eight riverine communities and one urban area were assessed. Overall, 75.6% of the participants exhibited Hg concentrations exceeding the safe limit (10 µg/L). Hg exposure was higher in the riverine population (90%) than in urban areas (57.1%). Mean Hg levels were 21.8 ± 30.9 µg/L and 50.6 µg/L in urban and riverine residents, respectively. The mean Hg level was higher in those aged 41-60 years in both urban and riparian areas, with riparian residents exhibiting a mean double that of urban residents. The highest glucose and hepatic biomarker levels were detected in the urban area, whereas the highest levels of renal biomarker occurred in the riverine population. Our results indicate that Hg contamination remains a persistent challenge for the urban population of Santarém, a major city in the Brazilian Amazon.