Neurological Impacts of Chronic Methylmercury Exposure in Munduruku Indigenous Adults: Somatosensory, Motor, and Cognitive Abnormalities

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 (Sawré Muybu, Poxo Muybu, and Sawré Aboy) from Sawré Muybu Indigenous Land, Southwest of Pará 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 µg/g (average: 8.7; S.D: 4.5; range: 2.0–22.8). In Sawré Aboy village, the median MeHg level was higher (12.5 µg/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 µg/g. Individuals with MeHg exposure level ≥10 µg/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

Characterization of visual symptoms of micronutrient deficiencys of “salada” group tomato plants <br> Caracterização de sintomas visuais de deficiência de micronutrientes em tomateiro do grupo salada

The aim of this research work was to characterize the visual symptoms of micronutrient deficiencies of tomato plants. A greenhouse experiment with nutrient solutions was used with “Salada” group tomato hybrid plants. Treatments were as follows: complete, minus B, minus Zn, minus Mn, minus Mo, minus Fe, and minus Cu. Except the omission of Cu, the other omissions resulted in morphological alteration with peculiar symptoms.  The symptoms firstly and had when either Fe or Zn was deficient. Fe, Zn, Cu, Mn, Mo and B. The Zn deficiency caused fruit cracking and the B omition caused blossom-end rot<p><p>Este experimento foi conduzido em casa-de-vegetação da Universidade Estadual do Sudoeste da Bahia – Vitória da Conquista com o objetivo de caracterizar os sintomas visuais de deficiência de micronutrientes em um híbrido de tomateiro do grupo salada, cultivado em solução nutritiva. Os tratamentos foram: completo, omissão de B, omissão de Zn, omissão de Mn, omissão de Mo, omissão de Fe e omissão de Cu. Com exceção da omissão de Cu, as demais omissões resultaram em alterações morfológicas com sintomas característicos. Os sintomas ocorreram primeiramente, e com maior intensidade nas deficiências de Fe e Zn. A seqüência de surgimento de sintomas foi a seguinte: Fe, Zn, Cu, Mn, Mo, B. A deficiência de Zn promoveu a rachadura no fruto e de B promoveu a podridão apical do fruto de tomate

Chronic Mercury Exposure and GSTP1 Polymorphism in Munduruku Indigenous from Brazilian Amazon

Genetic polymorphisms may be involved with mercury levels and signs and symptoms of intoxication from this exposure. Therefore, the aims were to describe the frequency of the GSTP1 polymorphism and to evaluate its effects on mercury levels and neurological signs in three Munduruku indigenous villages in the Brazilian Amazon. One-hundred-and-seven indigenous (over 12 years old) were included and genotyped (rs1695) using a TaqMan validated assay. Then, associations were evaluated by binary logistic regression, using odds ratios (OR) and 95% confidence intervals (CI). Mean age was 27.4 &plusmn; 13.9 years old, 52.3% were male, mean hair mercury concentration was 8.5 &plusmn; 4.3, exceeding the reference limit (&ge; 6.0 &micro;g/g), and were different among the three villages: 13.5 &plusmn; 4.6 &micro;g/g in Sawr&eacute; Aboy, 7.4 &plusmn; 2.3 &micro;g/g in Poxo Muybu and 6.9&plusmn;3.5 &micro;g/g in Sawr&eacute; Muybu. The minor allele frequency of GSTP1 G was significantly different among the villages: 57% Sawr&eacute; Muybu, 21% Poxo Muybu and 15% Sawr&eacute; Aboy. Finally, after adjustment, GSTP1 GG and GA genotypes were associated with lower levels of Hg (OR = 0.13; CI95% = 0.03&ndash;0.49) and abnormal somatosensory signs (OR = 3.7; 95%IC = 1.5&ndash;9.3), respectively. In conclusion, monitoring this population is imperative to identify individuals at higher risk of developing signs of chronic mercury exposure based on the genetic profile

Chronic mercury exposure and GSTP1 polymorphism in Munduruku Indigenous from Brazilian Amazon

This research was funded by the vice presidency of environment, care and health promotion (VPAAS) of Fundação Oswaldo Cruz through the Decentralized Execution of Resources Document No. 175/2018, Process: 25000.209221/2018-18, signed between the Fundação Oswaldo Cruz and the Special Department for Indigenous Health, both under the Ministry of Health. This study was supported by the Brazilian agency Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro—FAPERJ and by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq).State University of Rio de Janeiro - West Zone. Research Laboratory of Pharmaceutical Sciences. Rio de Janeiro, RJ, Brazil / Oswald Cruz Foundation. National School of Public Health. Program of Post-Graduation in Public Health and Environment. Rio de Janeiro, RJ, Brazil.University of São Paulo. Faculty of Medicine. São Paulo, SP, Brazil.Oswald Cruz Foundation. Polytechnic School of Health Joaquim Venâcio. Laboratory of Professional Education in Health Surveillance. Rio de Janeiro, RJ, Brazil.University of São Paulo. Faculty of Medicine. São Paulo, SP, Brazil.University of São Paulo. Faculty of Medicine. São Paulo, SP, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Ananindeua, PA, Brasil.State University of Rio de Janeiro - West Zone. Research Laboratory of Pharmaceutical Sciences. Rio de Janeiro, RJ, Brazil.Oswald Cruz Foundation. Polytechnic School of Health Joaquim Venâcio. Department of Endemic Diseases Samuel Pessoa. Rio de Janeiro, RJ, Brazil.Oswald Cruz Foundation. Polytechnic School of Health Joaquim Venâcio. Program of Post-Graduation in Public Health and Environment. Rio de Janeiro, RJ, Brazil / Oswald Cruz Foundation. Polytechnic School of Health Joaquim Venâcio. Department of Endemic Diseases Samuel Pessoa. Rio de Janeiro, RJ, Brazil.State University of Rio de Janeiro - West Zone. Research Laboratory of Pharmaceutical Sciences. Rio de Janeiro, RJ, Brazil.Genetic polymorphisms may be involved with mercury levels and signs and symptoms of intoxication from this exposure. Therefore, the aims were to describe the frequency of the GSTP1 polymorphism and to evaluate its effects on mercury levels and neurological signs in three Munduruku indigenous villages in the Brazilian Amazon. One-hundred-and-seven indigenous (over 12 years old) were included and genotyped (rs1695) using a TaqMan validated assay. Then, associations were evaluated by binary logistic regression, using odds ratios (OR) and 95% confidence intervals (CI). Mean age was 27.4 ± 13.9 years old, 52.3% were male, mean hair mercury concentration was 8.5 ± 4.3, exceeding the reference limit (≥6.0 µg/g), and were different among the three villages: 13.5 ± 4.6 µg/g in Sawré Aboy, 7.4 ± 2.3 µg/g in Poxo Muybu and 6.9 ± 3.5 µg/g in Sawré Muybu. The minor allele frequency of GSTP1 G was significantly different among the villages: 57% Sawré Muybu, 21% Poxo Muybu and 15% Sawré Aboy. Finally, after adjustment, GSTP1 GG and GA genotypes were associated with lower levels of Hg (OR = 0.13; CI95% = 0.03–0.49) and abnormal somatosensory signs (OR = 3.7; 95%IC = 1.5–9.3), respectively. In conclusion, monitoring this population is imperative to identify individuals at higher risk of developing signs of chronic mercury exposure based on the genetic profile