| Popis: |
Reindeer herding is a vitally important agricultural sector in the Russian Far North. It is believed, that Nothern ecosystems are prone to accumulation of persistent pollutants for the reasons of trophical chains, features and climate. Reindeers graze on vast areas, having seasonal migrations on distances up to hundreds kilometers in one side in North-South direction, that increases likehood to cross a locally polluted area. Here we present results of a large-scale countrywide study of reindeer liver, kidneys and meat pollution by dioxins, cadmium and mercury. Samples were taken in 2015-2020 years from 41 locations in 8 reindeer-herding regions of Russia. Dioxins were determined in 383 samples of liver and 13 of meat, cadmium and mercury – in 505 samples of liver, 315 of kidneys and 22 of meat. Dioxin pollution has shown a clear geographical trend: liver concentrations gradually decrease from the Western to the Eastern parts on the country, with the highest concentration of 76.5 pg/g of fat WHO-TEQ. The following factors are likely to explain the discovered trend: localization of chemical enterprises and density of reindeer population. The highest concentrations of metals were found in kidneys (7.3 mg/kg of cadmium and 1.1 mg/kg of mercury). The contribution of local sources to cadmium and mercury pollution was found to be less, than expected. We also speculate, that reindeer liver may serve as a good additional indicator of environmental pollution by the investigated contaminants. |
