Exposição humana ao metilmercúrio em comunidades ribeirinhas da Região do Tapajós, Pará, Brasil

Pinheiro, Maria da Conceição Nascimento; Nakanishi, Junko; Oikawa, Teiichi; Guimarães, Geraldo; Quaresma, Manoel; Cardoso, Bernardo da Silva; Amoras, Walter Wanderley; Harada, Masazume; Magno, Carlos; Vieira, José Luís Fernandes; Xavier, Marília Brasil; Bacelar, Denise R.

doi:10.1590/s0037-86822000000300005

Cited by 18 publications

(9 citation statements)

References 5 publications

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“…Most locations present hair mercury levels above 10 μg/g, especially in some populations such as Rainha, Barreiras, Brasília Legal or São Luís do Tapajós [34,70-73], where exposure levels seem to be alarming, even reaching a mean over 30 μg/g in the Apiacás Reservation study [74]. In very few sites the hair mercury levels remained below 5 μg/g [75,76].…”

Section: Resultsmentioning

confidence: 99%

Hair mercury levels in Amazonian populations: spatial distribution and trends

Barbieri

Gardon

2009

International Journal of Health Geographics

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BackgroundMercury is present in the Amazonian aquatic environments from both natural and anthropogenic sources. As a consequence, many riverside populations are exposed to methylmercury, a highly toxic organic form of mercury, because of their intense fish consumption. Many studies have analysed this exposure from different approaches since the early nineties. This review aims to systematize the information in spatial distribution, comparing hair mercury levels by studied population and Amazonian river basin, looking for exposure trends.MethodsThe reviewed papers were selected from scientific databases and online libraries. We included studies with a direct measure of hair mercury concentrations in a sample size larger than 10 people, without considering the objectives, approach of the study or mercury speciation. The results are presented in tables and maps by river basin, displaying hair mercury levels and specifying the studied population and health impact, if any.ResultsThe majority of the studies have been carried out in communities from the central Amazonian regions, particularly on the Tapajós River basin. The results seem quite variable; hair mercury means range from 1.1 to 34.2 μg/g. Most studies did not show any significant difference in hair mercury levels by gender or age. Overall, authors emphasized fish consumption frequency as the main risk factor of exposure. The most studied adverse health effect is by far the neurological performance, especially motricity. However, it is not possible to conclude on the relation between hair mercury levels and health impact in the Amazonian situation because of the relatively small number of studies.ConclusionsHair mercury levels in the Amazonian regions seem to be very heterogenic, depending on several factors. There is no obvious spatial trend and there are many areas that have never been studied. Taking into account the low mercury levels currently handled as acceptable, the majority of the Amazonian populations can be considered exposed to methylmercury contamination. The situation for many of these traditional communities is very complex because of their high dependence on fish nutrients. It remains difficult to conclude on the Public Health implication of mercury exposure in this context.

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Section: Resultsmentioning

confidence: 99%

Hair mercury levels in Amazonian populations: spatial distribution and trends

Barbieri

Gardon

2009

International Journal of Health Geographics

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“…In addition, the elemental mercury released by the burning of amalgam is converted into organic mercury compounds and transferred to the food chain, as indicated by the presence of relatively high concentrations of mercury in fish from regions under the influence of gold mining activity (2,3,(7)(8)(9). The analysis of mercury content in hair samples of inhabitants of riverside communities living in regions under the influence of gold mining activity reveals Hg concentrations higher than WHO (10,11) tolerance limits (2,3,(12)(13)(14)(15)(16).…”

Section: Introductionmentioning

confidence: 96%

Mercury toxicity in the Amazon: contrast sensitivity and color discrimination of subjects exposed to mercury

Rodrigues

Souza

Braga

et al. 2007

Braz J Med Biol Res

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We measured visual performance in achromatic and chromatic spatial tasks of mercury-exposed subjects and compared the results with norms obtained from healthy individuals of similar age. Data were obtained for a group of 28 mercury-exposed subjects, comprising 20 Amazonian gold miners, 2 inhabitants of Amazonian riverside communities, and 6 laboratory technicians, who asked for medical care. Statistical norms were generated by testing healthy control subjects divided into three age groups. The performance of a substantial proportion of the mercury-exposed subjects was below the norms in all of these tasks. Eleven of 20 subjects (55%) performed below the norms in the achromatic contrast sensitivity task. The mercury-exposed subjects also had lower red-green contrast sensitivity deficits at all tested spatial frequencies (9/11 subjects; 81%). Three gold miners and 1 riverine (4/19 subjects, 21%) performed worse than normal subjects making more mistakes in the color arrangement test. Five of 10 subjects tested (50%), comprising 2 gold miners, 2 technicians, and 1 riverine, performed worse than normal in the color discrimination test, having areas of one or more MacAdam ellipse larger than normal subjects and high color discrimination thresholds at least in one color locus. These data indicate that psychophysical assessment can be used to quantify the degree of visual impairment of mercury-exposed subjects. They also suggest that some spatial tests such as the measurement of red-green chromatic contrast are sufficiently sensitive to detect visual dysfunction caused by mercury toxicity. Correspondence

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“…Os valores das STP nas amostras de leite materno no Brasil variaram para DDT de 1-2200 μg/L, para HCH de 2-270 μg/L, para HCB de 1-89 μg/L e para o Dieldrin de 1-10 μg/L [64][65][66][67][68][69][70][71][72][73] . As amostras de cabelo foram avaliadas para metilmercúrio e apresentaram concentrações variando entre 24 a 38000 μg/kg.…”

Section: Seres Humanosunclassified