Airborne contamination by heavy metals and aluminum in the freshwater ecosystems of the Kola subarctic region (Russia) / Moiseenko T. I., Kudryavtseva L. P., Rodyushkin I. V. [et al.] // The Science of the Total Environment. - 1995. - Т. 160/161. - С. 715-727.

722 T.f. Moiseenko et al. /S c i. Total Environ, 160 /161 (1995) 715-727 ing flooding is considerably higher than that of the general concentrations and colloid-associated speciations. By dynamic intensity, the elements are arranged in the following succession common for all four streams: Sr < Ni < Zn < Al < Cu < Mn (Table 2). Similar increases in Mn concen­ tration in ionic form during snowmelt have been observed in other regions (Ctoronovski et al., 1988). Based on the coefficient values of Y, we can conclude that in all streams, the concentration of dissoluted Sr speciations changes very little when the water acidity increases. Whereas Mn, Al, Zn, Cu, and Ni concentration in ionic speciation in­ creases in streams in a polluted zone of 30 km around the smelters, it remains constant (exclud­ ing Mn and Al) in a more remote stream, despite a relatively high acidity and input from thawed waters. The concentration levels and dynamics of Ni, Mn, and Cu species are presented in Fig. 3. It should be noted that Ni, Cu (stream 3), and Al (stream 4) in ionic speciation do not cause an increase in the general concentration of those metals, which indicates a redistribution of the element speciations towards an increase in the more toxic ones. The redistribution process of aluminum speciations (Fig. 4) in the flood period is subject to greater regularity (Driscoll et al., 1984). 3.4. Heavy metal andAl accumulation in fish organs and the toxic effects: critical levels In lakes polluted by heavy metals, changes to­ wards simplification have occurred in the struc­ ture-functional organization of the aquatic ecosystems, often including the formation of a monoculture of pollution-resistant organisms. In salmon and whitefish, pathologies and dysfunc­ tions of organ systems appear and develop (e.g. nephrocalcitosis, scoliosis, anaemia, liver cirrho­ sis). The fish population level is decreasing. Sal­ mon and whitefish are the most sensitive indica­ tors of water pollution by heavy metals (Moiseenko and Yakovlev, 1990; Langeland, 1993). Heavy metals (Ni, Cu, Co, Zn, Sr, Mn) in micro-quantities are a part of living organisms and are necessary for their normal vital activity. However, when the concentration level increases, pathologies and dysfunctions in the organisms arise (Moore and Ramamoorthy, 1987). Studies of fish as the final product of water ecosystems give the most complete information about the ability of elements to bioaccumulate and the resulting toxic effects. Here we briefly discuss bioaccumu­ lation by elements that are airborne pollutants in the Kola North and outline related toxic effects. Nickel, like other elements, concentrates mostly in the organs, where intensive metabolic processes take place (Sidorenko and Itskova, 1980). Our data show extremely high Ni accumulation in the kidneys of fish, followed by the gills and liver (Table 3). The increase in element concentration in the organs of fish can be traced in the lakes, where the waters and sediments are not appar­ ently vulnerable to pollution. The most prevalent fish disease in water bodies of the Kola North is nephrocalcitosis, the kidney- stone disease (Moiseenko and Yakovlev, 1990). This disease results from emissions from the cop­ per and nickel smelters to air and water. A reli­ able relationship in the system has been de­ termined: Ni in the water -* Ni in a kidney -> % pathology of fish (pf, %} with nephrocalcitosis. C Ni in kidney = 1.4 + 48.9 X C Ni in water, F = 92.8, P = 0.0000. Ypf, % - 6.7 - 9.96 XC Ni in a kidney, F = 57, 0.0000. These equations have been developed based on the discovery of a relationship between parame­ ters investigated for 22 local sites. For every site, weighted average values of Ni content were de­ fined for water and fish kidney and for % morbid­ ity, indicating a strong correlation. The F-ratio coefficient (F = 92.8) and probability (P = 0.0000) indicate that these relationships are very dependable. Based on these equations, we have estimated the critical level of water pollution by Ni, which is 20 p.g/1 in water bodies characterized by high ANC (> 200 pequiv./l). In acidic lakes (ANC < 0 jiiequiv./l), the value would be much lower. Cases of nephrocalcitosis disease have been found in an acidified lake in Norway, in the border