Sandimirov S. Screening studies of POP levels in fish from selected lakes in the Paz watercourse / In State of the environment in the Norwegian, Finnish and Russian border area. The Finnish Environment. Finland, Jyvaskyla: Kopijyva Oy. 2007, №6.

Screening studies o f POPs in fish from the Paz watercourse higher values in males than females was observed. This can be explained by different biosynthesis speed of cholic acid in males and females liver and differences in excretion via the bile. Bile acid content analysis in pike, caught from the relatively clean region (Rajakoski), revealed significant variance in cholic acid content relative to other species. However, it is important to notice that the measured values in pike were low; much higher Cholate Indexes have been measured in pike from other lakes in earlier studies (Sidorov, Popova, 1978). Therefore, it is possible that some physiological processes may have prevented normal biosynthesis of cholic acid by the liver and normal excretion in the bile in the pikes included in the present study. The screening of biomarkers showed that these effect indicators may be used as an assessment tool for evaluating the impact of contaminants on fish and as early diagnostic tools. However, additional studies are required prior to the use of them in the future environmental monitoring programmes. Akvaplan-niva report APN 514-3365.02 26