Lead, cadmium, arsenic and mercury in canned tuna fish marketed in Tehran, Iran

Fifty-four canned tuna fish samples corresponding to 10 widely used different brands were purchased from local markets in Tehran, Iran during 2012-2013 and analysed on heavy metals. Mercury was determined by a direct mercury analyser without any sample preparation. For analysis of other elements samples were digested using a microwave apparatus. Lead and cadmium were determined by graphite furnace atomic absorption spectrometry and arsenic via hydride vapour generation. All samples had arsenic and mercury contamination. Arsenic levels showed a range of 0.25-1.42mgkg(-1), which might be due to lack of national and international limits for arsenic in canned tuna fish. Lead and cadmium were measured in a small number of samples with a mean of 0.053 +/- 0.058mgkg(-1) and 0.013 +/- 0.015mgkg(-1), respectively. Results obtained for these heavy metals in all samples were lower than the corresponding limits, whereas arsenic and mercury contents might raise some attention.