Please use this identifier to cite or link to this item: https://observatorio.fm.usp.br/handle/OPI/44109
Title: Neurological Impacts of Chronic Methylmercury Exposure in Munduruku Indigenous Adults: Somatosensory, Motor, and Cognitive Abnormalities
Authors: OLIVEIRA, Rogerio Adas Ayres dePINTO, Bruna DuarteREBOUCAS, Bruno HojoANDRADE, Daniel Ciampi deVASCONCELLOS, Ana Claudia Santiago deBASTA, Paulo Cesar
Citation: INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH, v.18, n.19, article ID 10270, 20p, 2021
Abstract: There has been increasing evidence about mercury (Hg) contamination in traditional populations from the Amazon Basin due to illegal gold mining. The most concerning health impact is neurotoxicity caused by Hg in its organic form: methylmercury (MeHg). However, the severity and extent of the neurotoxic effects resulting from chronic environmental exposure to MeHg are still unclear. We conducted a clinical-epidemiological study to evaluate the neurological impacts of chronic MeHg exposure in Munduruku indigenous people, focusing on somatosensory, motor, and cognitive abnormalities. All participants were subjected to a systemized neurological exam protocol, including Brief Cognitive Screening Battery (BCSB), verbal fluency test, and Stick Design Test. After the examination, hair samples were collected to determine MeHg levels. Data collection took place between 29 October and 9 November 2019, in three villages (Sawre Muybu, Poxo Muybu, and Sawre Aboy) from Sawre Muybu Indigenous Land, Southwest of Para state. One hundred and ten individuals > 12 years old were included, 58 of which were men (52.7%), with an average age of 27.6 years (range from 12 to 72). Participants' median MeHg level was 7.4 mu g/g (average: 8.7; S.D: 4.5; range: 2.0-22.8). In Sawre Aboy village, the median MeHg level was higher (12.5 mu g/g) than in the others, showing a significant statistical exposure gradient (Kruskal-Wallis test with p-value < 0.001). Cerebellar ataxia was observed in two participants with MeHg levels of 11.68 and 15.68 mu g/g. Individuals with MeHg exposure level & GE;10 mu g/g presented around two-fold higher chances of cognitive deficits (RP: 2.2; CI 95%: 1.13-4.26) in BCSB, and in the verbal fluency test (RP: 2.0; CI 95%: 1.18-3.35). Furthermore, adolescents of 12 to 19 years presented three-fold higher chances of verbal development deficits, according to the fluency test (RP: 3.2; CI 95%: 1.06-9.42), than individuals of 20 to 24 years. The worsened motor and cognitive functions are suggestive of neurotoxicity due to chronic MeHg exposure. In conclusion, we believe monitoring and follow-up measures are necessary for chronic mercury exposed vulnerable people, and a basic care protocol should be established for contaminated people in the Brazilian Unified Health System.</p>
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Artigos e Materiais de Revistas Científicas - HC/ICESP
Instituto do Câncer do Estado de São Paulo - HC/ICESP

Artigos e Materiais de Revistas Científicas - HC/ICHC
Instituto Central - HC/ICHC

Artigos e Materiais de Revistas Científicas - LIM/62
LIM/62 - Laboratório de Fisiopatologia Cirúrgica

Artigos e Materiais de Revistas Científicas - ODS/03
ODS/03 - Saúde e bem-estar


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