Assessment of arsenic's bioaccumulation and associated risks from fish consumption in Brazil

Abstract

Seafood market in Brazil have been expanded significantly in recent years, reaching an average consumption of 11.4 kg per capita in 2011 and with forecasting even further growth. Increasing search for for this food source in the country leads to a concern associated with fish quality, especially when dealing with toxic metals present in the waters and sediments of rivers. Fish, and other aquatic organisms, has the capacity to bioaccumulate metals in his organism, either by direct contact or feeding on other beings already contaminated. Arsenic is one of these contaminants and is present naturally in water and sediments, and also arising out human activities such as burning fossil fuels and pesticides. Most of the arsenic present in fish is in organic form (eg. Arsenobetaína) less toxic to humans, but there is a portion in its inorganic form (As (III) and (V)) and this must be given further attention due to their toxicity and carcinogenicity. This project has as main objectives the determination of the total arsenic content as well as the study of bioaccumulation of these contaminant, and assessment of risks to human health by calculating the estimated amount ingested by fish consumption in Brazil. Determinations will be made by an inductively coupled plasma mass spectrometry (ICP-MS) and samples digestion performed by microwave radiation in closed vessels. ICP-MS to be employed which allows working in the standard configuration and universal cell technology (UCT) enabling the instrument to operate in kinetic energy discrimination (KED), removing a large portion of the polyatomic interference. The estimate of arsenic intake allows assessing health risks by means of benchmarks set by international agencies such as Joint Food and Agriculture Organization of the United Nations / World Health Organization (FAO / WHO) Expert Committee on Food Additives (JECFA) which in 2011 recommended a intake value ranging from 2 to 7 µg kg-1 body weight per day, corresponding to the dose limit for a 0.5% increase in the incidence of lung cancer (BMDL05). The results of this project will be of paramount importance in the characterization of security levels in fish consumption in the region, and will be applied to them validation parameters of the methodology employing certified reference materials. (AU)