Sandimirov S. Pollution of the Sediments of the Paz River basin / In State of the environment in the Norwegian, Finnish and Russian border area. The Finnish Environment. Finland, Jyvaskyla: Kopijyva Oy. 2007, №6, 98p.

1.4. Recommendations to the monitoring program 1.4.1. Obligatory monitoring - minimum quantity of researches carried out on sea­ sons annually 1.4.1.1. Concrete lakes Bjornevatn, Skrukkebukta, Vaggatem (Paz River), Kuetsjarvi, Kochejaur, Virtuovoshjaur, Alla- Akkajarvi, Kirikovanjarvi (Russian Lakes), Isalombola, Sametivatn, Gardsjoen (Norwegian Lakes), Inari Vasikanselka, Lampi 222, Kantojarvi (Finnish Lakes) - 14 lakes at all. 1.4.1.2. Controllable param eters, the suggested approach and method a) Controllable parameters - water content, loss on ignition, elements - Ni, Cu, Co, Zn, Cd, Pb, Sr, Mn, Fe, Ca, Mg, Na, K, Al, As, Hg and P. b) The suggested approach and method - sediment samples are collected by the Skogheim’s sediment corer from the first 5 cm in layers through 1 cm and from the deepest part (usually 20 - 25 cm) o f the sediment core. 1.4.1.3. Frequency and periodicity of sampling - once a year, in September. 1.4.2. The comprehensive monitoring, spent ones in 3 - 4 years 1.4.2.1. Concrete lakes - all lakes investigated during this monitoring program . 1.4.2.2. Controllable param eters, the suggested approach and method a) Controllable parameters - water content, loss on ignition, elements - Ni, Cu, Co, Zn, Cd, Pb, Sr, Mn, Fe, Ca, Mg, Na, K, Al, As, Hg and P. b) The suggested approach and method - in accordance to earlier carried out investigations on the methods above described in this report. The sediment samples are collected by the Skog- heim’s sediment corer. The sediment cores are divided into 1-cm thick horizontal layers on the whole core. 1.4.2.3. Frequency and periodicity of sampling - once in 3 - 4 years, in September 2. Heavy Metals in the Sediments of the Paz System The sediment cores from the different parts o f the Paz River System (Bjornevatn, Vaggatem, Ruskebukta, Skrukkenbukta, Hestefoss) have been taken during the field work in September 2002 to study chemical composition o f sediments and assess the pollution o f water ecosystems. 2.1. Background Concentrations of Heavy Metals The maximum background concentrations o f heavy metals that were recorded in Vaggatem (Zn, Co, As), Ruskebukta (Ni, Cu, Hg), Skrukkenbukta (Pb), Bjornevatn (Cd), result from the geo­ chemical and morphometric features o f the lake and its drainage basin (Table 1). The back­ ground concentrations o f Ni, Cu, Co, Zn, Cd, Pb and As in the abovementioned lakes were es­ tablished to be higher than those in other lakes under study by a factor o f 1.2-2. The highest variation o f the background concentrations was noticed for Hg (more than 10 times). The aver- 10