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 Bromkal 70-5DE (Sjodin et al., 1998). However, the ratio of BDE47 to BDe99 detected in the whitefish and pike samples from Lake Stuorajavri and from Pasvik sites was about 2, while Bromkal 70-5DE shows a ratio of about one for those two congeners. The congener patterns in our samples are similar to the results reported by Zennegg et al. (2003) and Dodder et al. (2002). Other authors report somewhat different congener patterns, showing in contrast to our samples, about equal amounts of BDE99 and BDE100 (Hale et al., 2001). Male whitefish from Lake Stuorajavri contained higher levels of PBDEs than females, probably due to the lower elimination via gonad products. 758 71 2968 ^ Stuorajarvi Kuetsjarvi ---------------------------- > Pike, liver I IPBDE, pg/g ww N 346 I Stuorajavri 69°Lake 22°E 24°E Figure 9. Distribution o fPBDE hepatic levels infish from the study area Exposure and effects: There is evidence that some PBDEs bioaccumulate and exert toxic effects at low levels. The Environmental Protection Agency (EPA) has classified decabromodiphenyl ether as a possible human carcinogen. PBDEs are also endocrine disrupters. Some resemble the thyroid hormone thyroxin and others are estrogenic. It has also been shown that neurotoxic effects are enhanced when newborn mice are exposed to a combination of PBDEs and PCBs (Eriksson et al., 2001). At the Norwegian side there have been two questionnaires (Bull-Berg, 1988), one in 1982 and one in 1988, about the use and importance of the fishing in the Pasvik River. Fishing is mainly carried out in the ice-free period, but some people occasionally fish from the ice. In 1982 the answers revealed that the fishing was mainly taking place in the area from Hestefoss to Vaggatem and the in Vaggatem and Svanevatn (Salmijervi). The answers from the 1988 questionnaire did not reveal any clear geographical preferences for fishing in the river, due to low number of answers (20 out of 100 questionnaires). In Russia, there are no good fishing Akvaplan-niva report APN 514-3365.02 19