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 within the framework of Russian Analytical Laboratories Accreditation System (ALAS) for POPs and mercury in abiotic and biotic environmental media (fresh- and seawater, air, soil, bottom sediments, biological tissues). The laboratory has recently and successfully participated in the QUASIMEME International interlaboratory study on POPs and heavy metals in biological samples (exercise number: 20, 22, 24 and 28). 4.3. Biochemical biomarker analyses Pike and whitefish collected in Rajakoski and Kuetsjarvi were selected for biochemical biomarker analyses. Bile acids were quantified using the method described by Ripatti et al. (1969). Aniline hydroxylase activity was measured using the method described by Mazel (1972). Detailed method descriptions are given in the Appendix 2. 5 Results and discussion 5.1 Legacy POP levels 5.1.1. Organochlorines Of all legacy organochlorine compounds that were analyzed the most frequently observed compounds were chlordane and related compounds, HCB and the DDT series of structural analogs (DDT, DDE, DDD). Analytical data are presented in Table 3.1. (Pasvik area) and Table 3.2. (Stuorajavri) in Appendix 3. DDT DDT was, from 1946, widely used as a pesticide and insecticide, but DDT has since the early 1970’s been banned in North America, Europe and the former USSR. In Norway, DDT use was restricted in 1969 and banned in 1988. However, it continues to be used in Asia, Africa, Central and South America (Voldner and Li, 1995), resulting in a continued global source. Total DDT is the sum of the DDT structural analogs and breakdown products: p ,p ’ - and o ,p ’ - DDT, p ,p - ’ and o ,p ’ -DDD, and p ,p ’- and o ,p ’ -DDE. DDT found in the environment gradually degrades to DDE. The highest concentrations of p , p ’-DDE was measured in liver from whitefish (75.3 ng/g ww) and pike (55.4 ng/g ww) from Kuetsjarvi. Concentrations of p ,p ’- DDE comprised approximately 80% and 50% of the total DDT concentrations in liver of whitefish and pike from Kuetsjarvi, respectively. In whitefish liver from Ruskebukta, Skrukkebukta and Tj^rebukta, contribution of p , p ’-DDE to the total DDT was 65%, 75% and 85%, respectively. In liver of male whitefish the contribution of p , p ’-DDE to the total DDT was higher compared to those in female whitefish of the same size group - 88% vs 72% (Table 3.2, Appendix 3). p,p’-DDT was not detected in whitefish from Finnmark and Stuorajavri. However, it was detected in whitefish from Kuetsjarvi at low level in muscle (0.95 ng/g) and liver (1.73 ng/g). Geographical distribution of total DDT in fish liver is shown in Figure 2. In a study carried out in selected Finnmark lakes in the 1990s (Skotvold et al., 1997), all DDT concentrations in whitefish (muscle) were below 1 ng/g ww, with average concentrations between 0.17 and 0.6 ng/g ww. Of the DDT components and their metabolites, the largest proportion (about 80%) was made up ofp ,p ’-DDE. Akvaplan-niva report APN 514-3365.02 9