Estimate of mercury and methyl mercury intake associated with fish consumption from Sagua la Grande River, Cuba

Abstract

This paper provides an estimate of the weekly intake of total mercury (THg) and methyl mercury (MeHg) from consumption of fish from the Sagua la Grande River, Villa Clara, Cuba, by determining the THg levels in different fish species. The levels varied between 0.143 and 0.484 μg g⁻¹ on a fresh weight basis. None of the analysed fish was found to have levels above the national and international regulatory levels, although THg levels over 0.2 μg g⁻¹, the threshold concentration established by the World Health Organization (WHO) for the consumption by vulnerable population groups, were found in 75% of samples. The MeHg level was found to be 84% of the THg content. A Food Frequency Survey was given to 127 townspeople to estimate river fish consumption. The weekly intake of MeHg was found to be greater than the value established by the provisional tolerable weekly intake (PTWI) in 50% of children, in 80% of pregnant women, and in 75% of women in childbearing age. These weekly intakes can represent an important risk to the population's health, especially for vulnerable groups.

Keywords:

• total mercury
• methyl mercury
• weekly intake
• fish consumption
• freshwater fish
• Clarias gariepinus

Acknowledgements

The authors would like to thank the CyTED 105PI0272 Program for carrying out this study, and especially Drs Rosa Montoro and Dinoraz Vélez from the Instituto de Agroquímica y Tecnología de los Alimentos in Valencia, Spain, for the methodological help in total mercury analysis. They also thank the fishermen of the city of Sagua la Grande: Yimi Rodríguez, Wildo Rodríguez and Aramis La Rosa, who enthusiastically collaborated with the authors.