Ecosystem and human health assessment to define environmental management strategies: the case of long-term human impacts on an Arctic lake / Moiseenko T. I., Gashkina N. A., Voinov A. A. [et al.] // The Science of the Total Environment. - 2006. - Т. 369, № 1-3. - С. 1-20.

12 T.I. Moiseenko et al. /Science o f the Total Environment 369 (2006) 1-20 cells and connective tissue expansions. The histological sections of gills show evidence of hyperemia and necrosis of epithelial cells. Nephrocalcitos and fibroe­ lastosis of kidney may be related to specific diseases whose etiology is associated with water pollution by heavy metals (see Fig. 3) . The hemogenesis system of fish is sensitive to any environmental changes and changes in the physiological state of the fish organism. The changes revealed in hemathologic parameters of the examined fishes confirm the development of toxicoses in fishes inhabit­ ing Lake Imandra. For whitefish, the concentration of hemoglobin under environmentally optimal conditions varies from 80 to 130 g/l, average — 110 g/l (Moiseenko and Yakovlev, 1990) . A decrease in hemoglobin concentration more then 80% is a signal of disease, which can be caused by toxic agents. Thus, the following biological parameters were used as criteria of fish and ecosystem health: (a) the percentage of fishes in which the second or third stages of diseases were diagnosed; (b) the Z -index defined above; (c) the percentage of fish with hemoglobin concentration not reaching 80 g/l. An integrated impact dose . In nature, aquatic organisms are exposed to the influence of the combined dose of all metals. It is important an estimate a uniform numerical parameter adequately describing the total metal impact on biota. An integrated impact dose of metals is determined by the number of metals, their concentration and toxic properties for each of them. The values of Guideline Concentrations (GC) or Maximum Permeation Concentrations (MPC) largely differ by country, in spite of the fact that experimental research techniques to establish the MPCs are universal (Can. Water Qual. Guidelines, 1994; Env. Quality Obj., 2001; Bioassay meth. aquatic org., 1985; Methodolog­ ical recommendations, 1998) . For example, in Russia, the MPC values for Cu, V, Mn and some other elements are unreasonably underestimated, whereas the MPCs for Cd, As, Pb, and Al are overestimated (Moiseenko, 2005) . Although accepted in Russia, as well as in other countries, water quality standards for metals in water do not take into account the integrated impact dose. Using data about toxicological properties of each metal based on guidelines concentrations (GC), we can define the integrated impact dose by summing the excess of real concentration for each of metals to their GC or known threshold of impact as follows: Itox-1 = ^ (C i/G Q -a q J.). Where Itox-1 is the integrated toxicity index, O < Itox-1 < 1; Ci are concentrations registered in water; GCi-aq.l. Guideline Concentration for metals accepted in Russia for aquatic life. Note that for ecosystem health measures we used the GC for aquatic life, which are more stringent than those for drinking water. Despite of critical GC analysis and taking into account that Imandra is situated on the territory of Russia, for the assessment of metals toxicity in surface water for fisheries and aquatic life the following concentrations, legislatively accepted in Russia, are used (p.g/l): Cd=5, Ni=10, Cu=1, Pb=10, Zn=10, 0 20 40 60 0 10 20 30 40 50 0 10 20 30 40 50 Fig. 6. Measuring ecosystem health: dependence between an integrated parameter of toxic loading (Itox= S(Ci/GCi) and indicators offish diseases (% of fish with deviances, % of fish with anemia (decrease of hemoglobin in blood lower than critical 80% level).