Assessment of mercury intake associated with fish consumption in Serbia

Abstract

Nutritional benefits of fish can be attributed primarily to the content of high-quality proteins, vitamins, elements and omega-3 polyunsaturated fatty acids. On the other hand, fish and fishery products are susceptible to contamination by chemicals that have been recognized as ubiquitous environmental pollutants such as toxic elements and polychlorinated organic compounds. Fish consumption could be therefore considered as one of the major sources of human exposure to all above-mentioned environmental contaminants. This paper is focused on mercury (Hg) that enters the environment by both, natural means (such as volcanic activity, erosions and weathering, factors which contribute to the presence of Hg in water, soil and the atmosphere) and human activities - mining, fossil fuels combustion, industrial emissions, direct application of fertilizers and fungicides as well as disposal of solid waste. Total concentrations of Hg were measured in fish muscle and canned fish products available on Serbian market. Total of 651 samples were analyzed: 350 samples of marine fish (hake, mackerel, sprat, scorpanea, gilthead, salmon), 34 samples of freshwater fish (trout and carp) and 267 samples of canned fish products (tuna and sardines). Data were collected during 2011. For the purpose of intake assessment, we used the data obtained from the GEMS/Food Consumption Cluster Diets database. According to this source, estimated average weekly consumption of marine fish is 106.4 g/week, while freshwater fish and canned fish contribute to the consumption with 29.4 g and 18.2 g/week respectively. Mercury concentrations in marine fish were in the range of 0.005-0.208 μgg-1 (mean 0.040 μgg-1); in freshwater fish 0.005- 0.099 μgg-1 (mean 0.020 μgg-1) and in canned products they were in the range of 0.005-0.642 μgg-1 (mean 0.064 μgg-1). All analyzed samples contained mercury below the maximum level laid down by the European Union and Serbian regulation. The estimated weekly intake for total mercury, based on mean mercury value in fish and average body mass of 70 kg, was 0.095 μg/kg b.w./week. Based on FAO/WHO recommended safe limit and on obtained results, we can conclude that the intake of mercury in the case of consuming fish and canned fish products is lower than the safe limit.

Nutritivna korist od konzumacije ribe ogleda se, pre svega u sadržaju visoko vrednih proteina, vitamina, makro i mikroelemenata i omega-3 polinezasićenih masnih kiselina. Sa druge strane, riba i proizvodi od ribe su u značajnoj meri podložni hemijskoj kontaminaciji ubikvitarnim zagađivačima kao što su teški metal i polihlorovana organska jedinjenja. Zbog svega ovoga, konzumacija ribe se smatra jednim od najznačajnijih izvora izloženosti navedenim kontaminentima. U radu je ispitivana kontaminacija živom koja se u spoljašnjoj sredini može naći kao posledica prirodnih procesa (vulkanska aktivnost, erozija tla i klimatska dešavanja koja doprinose prisustvu žive u vodi, zemljištu i atmosferi), kao i aktivnosti čoveka - eksploatacija ruda, sagorevanje fosilnih goriva, emisija industrijskih gasova, direktna primena veštačkih đubriva i fungicida, kao i neadekvatno odlaganje čvrstog otpada. Sadržaj ukupne žive je određivan u svežoj i konzervisanoj ribi sa srpskog tržišta. Ispitan je 651 uzorak: 350 uzoraka morske ribe (oslić, skuša, sardela, škarpina, orada i losos), 34 uzorka slatkovodne ribe (šaran i pastrmka) i 267 uzoraka konzervisane ribe (tuna i sardela). Svi uzorci su analizirani tokom 2011. godine. Za procenu unosa korišćeni su podaci iz 'GEMS/Food Consumption Cluster Diets database'. Prema ovom izvoru, procenjena prosečna nedeljna konzumacija morske ribe iznosi 106,4 g, slatkovodne 29,4 g dok je ova vrednost za konzervisane proizvode od ribe 18,2 g. Sardžaj žive u morskoj ribi se kretao u opsegu od 0,005 do 0,208 μgg-1 (srednja vrednost 0,040 μgg-1); u slatkovodnoj ribi 0,005-0,099 μgg-1 (srednja vrednost 0,020 μgg-1), dok se u konzervisanim ribljim proizvodima sadržaj žive kretao od 0,005 do 0,642 μgg-1 (srednja vrednost 0,064 μgg-1). Nivo žive u svim ispitanim uzorcima je bio ispod maksimalno dozvoljenih vrednosti propisanih relevantnom legislativom EU kao i domaćim propisima. Procenjeni nedeljni unos žive baziran na srednjoj vrednosti žive u konzumiranoj ribi i prosečnoj telesnoj težini od 70 kg, bio je 0,095 μg/kg telesne mase nedeljno. Na osnovu preporuka FAO/WHO i dobijenih rezultata, može se zaključiti da je unos žive pri konzumaciji morske i slatkovodne ribe i konzervisanih ribljih proizvoda, niži od preporučenih graničnih vrednosti.