Bioaccumulation and bioaccessibility of arsenic and mercury in the common carp (Cyripnus carpio) of the Hex river catchment in rustenburg, south africa

Abstract

Mining is one of the anthropogenic activities that increase heavy metal contamination in the aquatic environment. Arsenic (As) and Mercury (Hg) are well-known cancer causing agents and they are a major concern all over the world. Their effects may be on the freshwater rivers, fish or marine biota and consumers' health. Since this is in a liquid ecological condition, As and Hg might be converted into organic species that are able to bioaccumulate through the trophic food chain to get to the highest level of heavy metal bioaccumulation in fish that will end up causing health risk to the consumers. This study investigated bioaccumulation and accessibility of As and Hg concentrations on the Common carp (Cypinus caprio) in the Hex River of Rustenburg, North West, South Africa and associated health risks to consumers. Bioaccumulation levels of As and Hg Common carp were determined on raw and cooked (Frying and Boiling) fish muscle using microwave acid digestion. While the assessment of consumer health risk due to As and Hg was investigated using the static in-vitro digestion model, by quantifying the bioaccessibility levels of the elements, As and Hg, to consumers this could be able to estimate their health risk. Both methods were analysed using inductive coupled plasma mass spectrometry (ICPMS). According to the results, Bioaccumulation levels of As and Hg on the fish were very low on raw and cooked fish, except for mercury levels in the fried fish muscles were above the acceptable limits recommended by South African Department of Health (SA-DOH). These suggest that Hg levels in the fried fish can cause bad effect to consumers. While Bioaccessibility estimates suggest that cooking processes can elevate the concentrations of As and Hg bioaccessibility by solubulisation and volutilisation effects