title: No evidence of selenosis from a selenium-rich diet in the Brazilian Amazon.
abstract: Selenium (Se) is an essential element and a well-known anti-oxidant. In the Lower Tapajós River region of the Brazilian Amazon, biomarkers of Se range from normal to very high. The local traditional diet includes important Se sources such as Brazil nuts, chicken, game meat and certain fish species. Some studies have reported alterations in keratin structure, gastrointestinal problems and paresthesia in populations with high Se intake. The objective of the present study was to evaluate cutaneous and garlic odor of the breath signs and sentinel symptoms of Se toxicity (selenosis) in relation to Se status in communities along the Tapajós River. Participants (N=448), aged 15-87 years, were recruited from 12 communities. Se concentrations were measured in blood (B-Se) and plasma (P-Se) by ICP-MS. A nurse performed an examination of the hair, nails, skin and breath for signs of Se toxicity. Interview-administered questionnaires were used to collect information on socio-demographics, medical history and possible symptoms of Se toxicity. In this population, the median levels of B-Se and P-Se were 228.4 μg/L (range 103.3-1500.2 μg/L) and 134.8 μg/L (range 53.6-913.2 μg/L) respectively. Although B-Se and P-Se surpassed concentrations considered toxic (B-Se: 1000 μg/L (U.S. EPA, 2002)), no dermal or breath signs or symptoms of Se toxicity were associated with the biomarkers of Se status. In the present study population, where Se intake is mostly from traditional diet, there is no evidence of selenosis. These findings support the need to re-assess Se toxicity considering factors such as the chemical form of Se exposure, route of exposure (inhaled versus ingested), co-exposures to toxic elements such as mercury. Considering the current food transition towards a western diet in the Amazon, further studies should address the possible association between high Se status and cardiometabolic health in this study population.
authors.affiliation: Axe santé des populations et environnementale, Centre de recherche du CHUQ, Université Laval, Québec, Canada; Centre de recherche interdisciplinaire sur la biologie, la santé, la société et l'environnement (CINBIOSE), Université du Québec à Montréal, Montréal, Canada. Electronic address: melanie.lemire@crchuq.ulaval.ca.
authors.forename: Mélanie
authors.initials: M
authors.lastname: Lemire
authors.affiliation: Centre de recherche interdisciplinaire sur la biologie, la santé, la société et l'environnement (CINBIOSE), Université du Québec à Montréal, Montréal, Canada. Electronic address: philibert.aline@gmail.com.
authors.forename: Aline
authors.initials: A
authors.lastname: Philibert
authors.affiliation: Centre de recherche interdisciplinaire sur la biologie, la santé, la société et l'environnement (CINBIOSE), Université du Québec à Montréal, Montréal, Canada. Electronic address: fillion.myriam@courrier.uqam.ca.
authors.forename: Myriam
authors.initials: M
authors.lastname: Fillion
authors.affiliation: Faculdade UnB-Planaltina, Universidade de Brasília, Brasília, Brazil. Electronic address: cjpassos@unb.br.
authors.forename: Carlos José Sousa
authors.initials: CJS
authors.lastname: Passos
authors.affiliation: Laboratório de Traçadores, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil. Electronic address: jeanrdg@biof.ufrj.br.
authors.forename: Jean Rémy Davée
authors.initials: JRD
authors.lastname: Guimarães
authors.affiliation: Laboratório de Toxicologia e Essencialidade de Metais, Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil. Electronic address: fbarbosa@fcfrp.usp.br.
authors.forename: Fernando
authors.initials: F
authors.lastname: Barbosa
authors.affiliation: Centre de recherche interdisciplinaire sur la biologie, la santé, la société et l'environnement (CINBIOSE), Université du Québec à Montréal, Montréal, Canada. Electronic address: mergler.donna@uqam.ca.
authors.forename: Donna
authors.initials: D
authors.lastname: Mergler
mesh_terms: D000328:Adult; D031383:Bertholletia; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D001938:Brazil; D001944:Breath Tests; D003430:Cross-Sectional Studies; D004032:Diet / Q000706:statistics & numerical data*; D005260:Female; D006197:Hair / Q000737:chemistry; D006801:Humans; D008297:Male; D018977:Micronutrients / Q000378:metabolism / Q000506:poisoning*; D008875:Middle Aged; D009262:Nails / Q000737:chemistry; D012643:Selenium / Q000032:analysis / Q000378:metabolism / Q000506:poisoning*; D012867:Skin / Q000378:metabolism
chemical_list: D015415:Biomarkers; D018977:Micronutrients; D012643:Selenium