Concentrations of Cd, Pb, Zn and Cu in pristine wetlands of the Russian Arctic

Background concentrations of Cd, Pb, Zn and Cu were studied for wetlands from pristine regions of the Russian Arctic: Severnaya Zemlya Archipelago, Vrangel Island, Arctic deserts and tundra of the North Taimyr Peninsula, Byrranga Mountainous Area, tundra zone of Mid-Siberia, North-East Siberia, Far North-East, and Amguemo-Anadyr Mountainous Area. These wetland regions were known to be relatively remote and isolated, with little human population and no local industry. Samples were collected during the period 1976–1993 and included: (a) snow and thaw water, (b) particulate matter, (c) bottom sediments, (d) hydric organo-mineral deposits and hydric soils, (e) polygonal bog peat and sedge-moss peat. Observed ranges for the background concentrations of Cd, Pb, Zn, and Cu in water were 0.001–0.15, 0.02–0.36, 0.05–2.9 and 0.23–6.2 μg l−1 respectively. For (b)–(e) the corresponding values were [0.04–0.46; 1.3–41; 8.6–190; 0.7–63]; [0.05 0.99; 1.5–49; 2.5–153; 2.4–55]; [0.05–0.96; 1.7–44; 2.2–154; 2.0–82] and [0.03–0.83; 1.3–31; 2.1–124; 1.7–68] mg kg−1, dry wt, respectively. Although full assessment of the pristine nature of the wetlands was not possible due to the limited data available, the observed metal concentrations reflect natural geochemical background levels and influence from localized minor ore-deposits present for some regions. In general, there was no evidence of impact from remote industrial regions of the Russian Arctic.