NATURAL BACKGROUND LEVELS OF HEAVY METALS AND ASSOCIATED ELEMENTS IN TROUGH SEDIMENTS, KARA SEA, ARCTIC OCEAN

More than 470 samples in 52 cores from the Novaya Zemlya, Voronin and St. Anna Troughs, Kara Sea, taken during 1965 were evaluated for heavy metals/metalloids contents. Samples lower in section than would be affected by bioturbation of anthopogenic-contaminated sediment were used to establish the natural background values that follow:

Heavy Metals/Metalloids - As=22 ppm; Cd=<0.5 ppm*; Co=23 ppm; Cr=112 ppm; Cu=30 ppm; Fe=4.7 %; Hg=310 ppb; Mn=0.1 % Mo=3 ppm**; Ni=51 ppm; Pb=17 ppm; Sb=1.8 ppm; Sc=16 ppm; Th=8.3 ppm; Ti=0.42 ppm; U=2.4 ppm; V=187 ppm; Zn=96 ppm; Associated Elements - Al=7.6 %; Ba=514 ppm; Ca=0.8 %; Hf=5 ppm; K=2.2 %; Mg=1.3 %; Na=2.0 %; P=0.083%; Rb=100 ppm; Sr=144 ppm.

These values are likely background contents for provenance areas (e.g., Western Siberian Shield and Eastern Urals). The data serve as a starting point to assess metal pollution risk to Kara Sea ecosystems and juxtaposed arctic terrestrial ecosystems post-1965. They are essential 1) to determine if pollution exists; 2) to measure pollution intensity; 3)to reveal changes with time in pollution intrusion of an ecosystem; and 4) to recognize a decrease in pollution risk (from legislated environmental controls at source(s). *373 of >470 samples were below the 0.5 ppm detection limit. **139 of >470 samples were below the 2 ppm detection limit. Se, Sn, Ag and Bi were below detection limits (3 ppm, 0.01%; 0.4 ppm and 5 ppm, respectively) in all samples.