The Study of Atmospheric Transport and Deposition of Cadmium Emitted from Primitive Zinc Production Area

Laoyingshan town lead zinc mine is one of the important zinc production centers in Guizhou province, China. The cadmium (Cd) is one of the mineral resources associated of lead zinc mine. The exploitation and uses of lead zinc mine would lead to Cd pollution to the environment. Soil Cd concentrations in this area are elevated by 30–50 times compared to the national background value in soil which is 0.279 mg kg^?1. In situ air Cd concentrations air/soil Cd fluxes were measured at 26 sampling sites in Laoyingshan town by moss bag from Jan. to Sep. 2005. The results showed that the average Cd concentration of total suspended particulates (TSP) and soil were 5.3 and 4.6 times higher than those measured at downwind direction 10 km due to a large amount of Cd emission from traditional melting. The results showed a clear decreasing trend along with the distance increasing from the pollution source for all the study parameters, namely cadmium contents in soil and TSP and deposition rate determined using moss-bag method. The results are consistent with the studied results previously. The correlations between Cd fluxes and soil show the relationship between the content in atmospheric TSP and spatial distribution of deposited heavy metal. The authors found that air spread is the major route of Cd pollution.