Sandimirov S. Screening studies of POP levels in bottom sediments 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 of PO P levels in bottom sediments from selected lakes in the P az watercourse These recommendations include: • knowledge of lake bathymetry is necessary in order to select deep sedimentary basin within the lake; • using 7.5-10 cm diameter cores in small lakes; • slices at 0.5 or 1.0 cm intervals in top 5 to 10 cm depending on sedimentation rate; • outer 0.5 cm o f core should be removed to reduce effect o f smearing from the walls of core; • the sliced samples should be stored in precleaned glass jars at 4 °C until analyses. The surface (0-1 cm) sediment samples were collected from the deepest part o f each lake with modified Kajak-Brinkhurst gravity corer (Mudroch and Azcue, 1995). Two deeper slices (15­ 18 cm and 22-23 cm) were also collected in Inrijarvi and Stuorajavri lakes respectively. 5 Results and discussion 5.1. Analyses The following contaminants were analyses in the sediment samples: Trace elements (Cd, Cu, Ni, Hg) Polycyclic aromatic hydrocarbons (PAHs) - 21 compounds Basic POPs PCBs (50 ortho-substituted congeners; including all congeners recommended by AMAP), DDT-family (6 isomers), chlorobenzenes, (tetra-, penta- and hexachlorobenzene), hexachlorocyclohexane (HCH; a - , P- and y-isomers), chlordane compounds (heptachlorepoxide, oxychlordane, cis- and trans-chlordane, trans- nonachlor, heptachlor) New compounds Coplanar PCBs, brominated flame retardants (PBDEs), chlorinated phenols, polychlorinated naphthalenes (PCNs) and dioxins/furans (PCDD/PCDF). Analyses were carried out at Typhoon Analytical Centre (Obninsk, Russia). The laboratory has national accreditation within the framework o f Russian Analytical Laboratories Accreditation System (ALAS) for POPs and mercury in abiotic and biotic environmental media (fresh- and seawater, air, soil, bottom sediments, biological material, including human tissues). The laboratory has also successfully participated in the QUASIMEME International interlaboratory study on POPs and heavy metals in biological samples (2000-2002). Moreover, in 2001-2002 the laboratory took part in the intercalibration analyses started by Department o f Energy DOE (MAPEP-2001-2002), USA; NIST/NOAA-NS&T/EPA-EMAP QA Program; AMAP Ring Test (Round 1-2 at 2002 and Round 1 at 2002; 6-th and 7-th Round International Intercalibration Study by MTM Research Center Orebro University, Sweden (for DIOXIN 2001 and 2002); Second Italian Free Intercalibration Round. Detailed method description are given in Appendix 1. Additional quality assurance was provided by Akvaplan-niva and University of Michigan on a subset of samples. Rapport APN- 514.3665.01 8