Atmospheric trace metal pollution is a striking environmental problem globally. Because of the limitations in monitoring data, our knowledge of the historical processes and sources of atmospheric trace metal pollution in China and its influence on remote terrestrial environmental quality is limited. The historical variations in atmospheric trace metal (Cd, Cr, Cu, Hg, Ni, Pb, and Zn) pollution during the past 400 years in the Fanjing Mountain area, northern Guizhou Province were studied by analyzing the metal concentrations and Pb isotopes in lake sediments. The results showed that concentrations of all metals in the sediments were relatively constant before 1800(A.D.). After 1800, concentrations of Cr, Cu, Ni, and Zn increased at first and then decreased, while concentrations of Hg, Cd, and Pb generally increased gradually over the most recent century and subsequent decades. The enrichment factor and 207Pb/206Pb analysis results indicated that Cd, Pb, and Hg were typical pollutants. Pollution of Hg began at around 1880(A.D.), and pollution of Cd and Pb has occurred since the 1950s; all pollutants exhibited aggravated trends in recent times. Pollution levels of Hg in recent years in the Fanjing Mountain area were comparable to those in other remote areas of East China, but levels were lower than those in Europe, America, and the Tibetan Plateau. In contrast, pollution levels of Cd and Pb in these areas showed large variability. By comparing the historical processes of trace metal pollution in different regions and exploring the potential pollution sources of metals in the study region, it can be deduced that atmospheric Hg pollution in the Fanjing Mountain area was the result of both global and regional emissions, while Cd and Pb pollution largely came from regional sources such as non-ferrous metals smelting and coal combustion emissions.
Keywords: Fanjing Mountain area; atmospheric pollution; historical trends; lake sediments; sources; trace metals.