Assessment of mercury contamination in the Bílina River (Czech Republic) using indicator fish

Abstract

The aim of the study was to determine mercury content in the muscle of indicator fish and to assess mercury pollution along the Bílina River, which is one of the most important tributaries of the Elbe River. A total of eight sites were chosen on the Bílina River for sampling. Indicator fish chub (Leuciscus cephalus L), roach (Rutilus rutilus L.) and brown trout (Salmo trutta m. fario L.) in the total numbers of 24, 26 and 27, respectively, were sampled at four locations, since at the remaining sites fish were absent. Mercury concentrations in the muscle of sampled indicator fish were measured using cold vapour atomic absorption spectrometry on an AMA 254 analyser. The highest mercury content (0.12 ± 0.027 mg·kg-1) was found in the muscle of roach at the Ústí nad Labem site and the lowest mercury content (0.04 ± 0.008 mg·kg-1) in the muscle of brown trout from the Březenec (the first upstream site) site. A significant difference (P < 0.05) between the analyzed fish species was found only between chub (0.08 mg·kg-1) and brown trout (0.04 mg·kg-1) at the Březenec site. The priority of this study was to assess the mercury contamination of the Bílina River because this river flows through a heavy industrial activity in the region (especially production of petrochemicals, agrochemicals, sorbents, plasticizers and textile auxiliaries). Despite the fact that the Bílina is an extensively polluted river, the obtained mercury results were very low and did not exceed the limit of 0.5 mg·kg-1 set by Commission Regulation No. 1881/2006.