BC-koncentrationer i sjösediment: en jämförelse mellan Kina, Schweiz och Finland.

Sammanfattning

Black carbon (BC) are particles that are formed during incomplete combustion of biomass and fossil fuels. BC remains in nature for centuries to millennia, has an extensive spread and a negative impact on both climate and health. In the following literature study, concentrations from lake sediments stretching back approximately 150 years in Finland, Switzerland and China have been compiled. The concentrations were compared between the regions, they were also compared with the regions' estimated emissions, and it has been investigated whether lake area, depth and altitude control concentrations in lake sediments. The results showed lower than expected concentrations in lake sediments from China, apart from one lake with very high concentrations, likely due to nearby anthropogenic sources. The low concentrations, despite China's large emissions may be due to the remoteness of the lakes, which means that the majority of the black carbon is transported in the atmosphere. Concentrations in lake sediments from the European lakes also show (on average) higher values than those in China, again with the exception of one lake in China. This may be because the lakes in China are more remote than those in Europe, and thus further away from urban environments. In addition, a negative correlation is observed between BC concentration and the lake's size, maximum depth and altitude.