Daily mercury intake in fish-eating populations in the Brazilian Amazon

Abstract

Although high levels of fish consumption and bioindicators of mercury exposure have been reported for traditional populations in the Amazon, little is known about their actual daily intake of Hg. Using an ecosystem approach, calculate daily mercury intake in adult fish-eaters, examine the relations between mercury intake and bioindicators of exposure and the factors that influence these relations. A cross-sectional dietary survey on fish and fruit consumption frequency was carried out with 256 persons from six villages of the Tapajo´s River. Fish portion per meal was determined. Mercury concentration was determined for 1123 local fish specimens. Daily mercury intake (mg/kg/day) was determined for men and women from each village using the average fish-mercury concentration for the fish caught in their fishing zone, the average quantity of fish per meal, fish-species frequency consumption and participants' body weight. Fish-mercury averaged 0.33 mg/g70.33. Daily mercury intake varied between 0 and 11.8 mg/kg/day (mean 0.92 mg/kg/day70.89) and varied by gender and village. Mean blood-and hair-mercury were 58.7736.1 mg/l and 17.9711.5 mg/g, respectively. There was a strong and positive relation between blood-mercury and daily mercury intake, with an inverse relation for fruit intake and schooling; significant variations were observed with immigrant status, and among villages. Hair-mercury was directly associated with daily mercury intake and inversely related to schooling and fruit consumption. Fruit consumption modified the relation between daily mercury intake and blood-mercury levels: for the same daily mercury intake, persons eating more fruit had lower blood-mercury concentrations (ANCOVA Interaction term: F ¼ 10.9, Po0.0001). The median difference of the ratio of blood-mercury to daily mercury intake between low and high fruit consumers was 26, representing a 26.3% reduction. These findings reveal high levels of daily mercury intake. Rigorous studies for developing risk-based reference doses in the Amazon should be undertaken to orient viable risk-management strategies to reduce exposure, while maintaining fish diet.

Evaluation of GlutathioneS-transferaseGSTM1andGSTT1Polymorphisms and Methylmercury Metabolism in an Exposed Amazon Population

“…The results of the present study are in agreement with earlier findings that show high levels of Hg exposure in the Amazon region (Dórea et al 2005, Pinheiro et al 2006Passos et al 2008). It is notable that high variations in Hg levels were found among participants in the present study; for example, in total blood, Hg levels ranged from 4.7 to 122 μg/L, while in hair the variation was from 1 to GST POLYMORPHISMS AND METHYLMERCURY METABOLISM 965 FIGURE 3.…”

“…In an earlier study, Passos et al (2008) demonstrated that fish consumption was related to Hg concentrations in the same population. In the present study, fish intake ranged between one and four portions per day, and this can also be related to variations in metal concentrations in the blood stream and hair.…”

Mercúrio total em músculo de cação Prionace glauca (Linnaeus, 1758) e de espadarte Xiphias gladius Linnaeus, 1758, na costa sul-sudeste do Brasil e suas implicações para a saúde pública

“…Segundo Fréry et al 34 , em períodos de abundância o consumo diário de peixe pode alcançar 600g. Em crianças de até 5 anos na região do rio Madeira, Boischio & Henschel 31 estimaram uma ingestão diária de Hg de 6.4ugkg -1 , e no Tapajós, Passos et al 35 observaram uma ingestão diária em adultos variando de 0 a 11.8µgkg -1 , com média de 0.92µgkg -1 .…”

Protective Effect of Bacopa monniera on Methyl Mercury-Induced Oxidative Stress in Cerebellum of Rats

“…This type of exposure is much more common in humans. Recently, Passos et al (2008) described the typical daily intake of MeHg in traditional riparian populations of the Tapajos River in Brazil as being about 70 lg/day. This level is much lower than that usually evaluated adverse effects of MeHg in animal models .…”