Although the research station is far from major sources of human pollution, atmospheric circulation brings air from Europe and North America into the Arctic region.
虽然这个研究站远离人类主要的污染源，但是大气环流会把欧洲和北美的空气带到北极地区。
2
According to the heavy metal contents in the fruits, soil absorption and atmospheric dust become the main sources of heavy metal pollution in crops.
通过对不同处理方式处理后的水果中重金属的分析表明，土壤吸收和大气尘降是农作物中重金属的主要来源。
3
The mineral composition and morphology of atmospheric dust fall serve as important criteria in identifying pollutionsources.