PURPOSE: Chlor-alkali plants are one of the most important point sources of mercury to aquatic environment. The problem of Hg contamination has been studied in a region, Rm Valcea (Romania), impacted by the wastewater discharge of a chlor-alkali plant. The purpose of the present study is to evaluate the current status of mercury pollution in the Babeni reservoir (Olt River) and the exposure of local population via fish consumption to mercury originating from the chlor-alkali plant. METHODS: Sediments were collected from Valcea, Govora and Babeni reservoirs. Grain size distribution, organic content and total mercury (THg) concentrations were analysed in sediments. Fish were purchased from local anglers, and the scalp hair was collected from volunteers. THg in sediment, fish and hair samples was determined using an atomic absorption spectrophotometer for Hg determination. Monomethylmercury (MMHg) was analysed in the muscle and liver tissues by species-specific isotope dilution and capillary gas chromatography hyphenated to inductively coupled plasma mass spectrometer. RESULTS: High mercury concentrations were found in the sediments and in fish from Babeni reservoir, with a median of 2.1 mg/kg (IQR = 3.2) in sediments and a mean value of 1.8 ± 0.8 mg/kg_ww in fish muscle. MMHg concentrations in fish were well above the WHO guidelines for fish consumption. Local population consuming fish from the Babeni reservoir had THg concentrations in hair significantly higher than those consuming fish from upstream reservoirs and/or from the shops and reached a median value of 2.5 mg/kg (IQR = 3.6). CONCLUSIONS: The remnant pollution in the fish of this reservoir, and probably many other lakes and reservoirs receiving Hg polluted wastewater, represents a considerable health risk for the local fish consumers.

This paper presents the results of assessment of dredging activities at the Romanian side of the channel on the quality of water and sediment in the Begej channel (in Serbia). Sediment monitoring results have pointed to the increasing content of metals in surface sediments, as well as increased concentrations of some metals (Cd, Ni and Cr) compared to the period from 2008. Results of the water quality after the dredging at the Romanian side shows low metal concentrations, which is probably caused by coprecipitation of metal in the iron in forms of amorphous and hydrated oxide. Monitoring of water and sediment should be conducted continously through the year in order to follow the trend of sediment and water quality and targeted when we know the exact time of some of the activities in the channel.