Record of heavy metals in Huguangyan Maar Lake sediments: Response to anthropogenic atmospheric pollution in Southern China

The historical atmospheric heavy metal pollution of southern China over the past 200 years was explored by analyzing radiometric dating, heavy metals, and Pb isotopes from a sediment core in Huguangyan Maar Lake. Zn, Cd, Sb, Tl, and Pb in the lake are closely related to anthropogenic activities, while Cr and Ni are mainly derived from the weathering of basalt surrounding the lake. Atmospheric Zn, Cd, Sb, and Tl increased rapidly after 1980, consistent with the local industrial development. The increase of atmospheric Pb in southern China occurred earlier than in other regions of China, with the increase after 1850. War and the use of leaded gasoline were the main causes for the rapid increase in atmospheric Pb during 1910-1950. From 1950 to 2000, the input of Pb from anthropogenic activities decreased gradually due to the stable social environment. After 2000, atmospheric Pb continued to rise due to continued industrial development. The three-end-member model of Pb isotopes indicates that coal combustion is the main source of current atmospheric Pb. The proportion of Pb derived from vehicle exhaust emissions reached a peak in the 1960s, then gradually decreased and further reduced with the ban on leaded gasoline after 2000. These results are important in identifying the sources of atmospheric heavy metal pollution and in formulating pollution control strategies.

Automated summary

The historical atmospheric heavy metal pollution in southern China over the past 200 years was studied using analysis of a sediment core from Huguangyan Maar Lake. The study found that Zn, Cd, Sb, Tl, and Pb in the lake were closely related to human activities, while Cr and Ni were mainly from the weathering of surrounding basalt. The increase of atmospheric Pb in southern China occurred earlier than in other regions of China, mainly due to war and the use of leaded gasoline. After 2000, atmospheric Pb continued to rise due to continued industrial development.