Cytogenetic damage related to low levels of methyl mercury contamination in the Brazilian Amazon


Autoria(s): AMORIM, Marúcia Irena Medeiros de; MERGLER, Donna; BAHIA, Marcelo de Oliveira; DUBEAU, Hélène; MIRANDA, Daniela; LEBEL, Jean; RODRÍGUEZ BURBANO, Rommel Mario; LUCOTTE, Marc Michel
Data(s)

30/06/2014

30/06/2014

01/12/2000

Resumo

The mercury rejected in the water system, from mining operations and lixiviation of soils after deforestation, is considered to be the main contributors to the contamination of the ecosystem in the Amazon Basin. The objectives of the present study were to examine cytogenetic functions in peripheral lymphocytes within a population living on the banks of the Tapajós River with respect to methylmercury (MeHg) contamination, using hair mercury as a biological indicator of exposure. Our investigation shows a clear relation between methylmercury contamination and cytogenetic damage in lymphocytes at levels well below 50 micrograms/gram, the level at which initial clinical signs and symptoms of mercury poisoning occur. The first apparent biological effect with increasing MeHg hair level was the impairment of lymphocyte proliferation measured as mitotic index (MI). The relation between mercury concentration in hair and MI suggests that this parameter, an indicator of changes in lymphocytes and their ability to respond to culture conditions, may be an early marker of cytotoxicity and genotoxicity in humans and should be taken into account in the preliminary evaluation of the risks to populations exposed in vivo. This is the first report showing clear cytotoxic effects of long-term exposure to MeHg. Although the results strongly suggest that, under the conditions examined here, MeHg is both a spindle poison and a clastogen, the biological significance of these observations are as yet unknown. A long-term follow-up of these subjects should be undertaken.

Identificador

AMORIM, MARÚCIA I. M. et al. Cytogenetic damage related to low levels of methyl mercury contamination in the Brazilian Amazon. Anais da Academia Brasileira de Ciências, Rio de Janeiro, v. 72, n. 4, p. 497-507, dez. 2000. Disponível em: <http://www.scielo.br/pdf/aabc/v72n4/0048.pdf>. Acesso em: 24 fev. 2014. <http://dx.doi.org/10.1590/S0001-37652000000400004>.

0001-3765

http://repositorio.ufpa.br/jspui/handle/2011/5183

Idioma(s)

eng

Direitos

Open Access

Palavras-Chave #Amazônia Brasileira #Mercúrio #Índice mitótico #Citogenética #Ecossistema aquático
Tipo

article