Iranian Journal of

Background and Objectives: Due to the importance of Sanandaj Gheshlagh Reservoir (SGR) in the region and proven mercury pollution in SGR water, a research project was carried out to determine the amount of mercury concentration and bioaccumulation and its behavior through a food route in SGR food chain (i.e., water, sediments, fish, and human).This was done, because it has been reported that mercury concentration and its toxicity could increase during mercury exchange between trophic levels. Materials and methods: During April to December 2012, 24 water, sediment, and fish samples (Capoetta trutta) (4 samples per month) from SGR and 24 human hair samples from Sarab Ghamish village settlers (the major Capoetta trutta consumers in the region) were collected. Results: Total mercury mean concentration in water, sediment, Capoeta trutta, and human hair were 0.0028±0.000128, 0.110±0.0057, 0.296±0.0119, 2.059±0.1704 ppm respectively. Calculated bioconcentration factors were 4 × 10 and 1 × 10² in SGR sediment and fish, and related biomagnifications factors were 40 and 5 respectively. Conclusion: Due to the high bioaccumulation, biomagnifications factors and mercury concentration recorded in edible parts of SGR fish, local consumers should not eat more than 1182 gram of this fish weekly without accounting for other potential sources of total mercury in their food basket.

Background and Objective: Mercury (Hg) is considered as a global pollutant that is widely dispersed in the environment. Monitoring of total mercury (THg) concentration in the sediments without determination of organic mercury (OHg) and selenium (Se) is an unreliable approach to evaluate the precise toxicological effects of Hg. In the present study, concentrations of THg, OHg and Se in the surface sediments of the eastern and western parts of Anzali wetland were investigated. In addition, the correlation of THg and OHg with Se and total organic carbon were analyzed.

Materials and Methods: Forty surface sediment samples were collected from the eastern and western parts of the wetland. Analysis of total and organic mercury in the sediment samples were done with Advanced Mercury Analyzer and the concentration of selenium was measured using inductively coupled plasma atomic emission spectroscopy (ICP-OES).

Results: The average concentrations of THg in the East and West wetlands were 109.53 and 68.39 ng/g dw, respectively. The average concentration of THg in the sediments of the eastern part of Anzali Wetland was significantly higher than that of the western part (P<0.001). The mean concentrations of OHg in East and West wetland were about 34.91 and 28.84 ng/g dw, respectively. There was  no significant relationship. The ratio of OHg to THg showed significant differences in the two studied areas. The average concentrations of Se in East and West wetlands were 156.25 and 163.75 ng/g dw, respectively. There was a significant negative correlation between the concentration of selenium and organic mercury in sediments of  the western part of  wetland (P<0.05).

Conclusion: The THg concentration in the sediments of Anzali wetland was lower in comparison to other studied regions of the world. However, the percentage of OHg in the Eastern and Western part of wetland was high. Therefore, bioavailability and toxicity of Hg would be high in the sediments and aquatic environment. In this study, in spite of high molar ratio of Se to THg, there was relatively high content of OHg. We recommend to measure the various Se-species that are effectively bound to inorganic Hg and to determine the amount of Se and Hg in aquatic organisms.