Mercury contaminations to the ambient air, soil and water compartments in the zinc smelting area in Weining County, Guizhou, China

Abstract

Guiyang (26~176 106~176 the capital city of Guizhou Province, is located in southwestern China, which is classified as one of the most seriously polluted cities in China. One investigation was carried out to determine total mercury (THg) in surficial soil and some plants in different function districts in center urban areas and at one contrast site in a rural area of Guiyang in 2005. Dried soil and plant samples were digested with aqua regia and HNO3, and THg was measured by CVAFS with Model Tekran| 2500 analyzer. In addition, total atmospheric mercury (TAM) concentrations were measured at different sampling sites from April 2005 to January 2006. THg concentrations in soil of a business district, a residential district, an ordinary industrial district, a tourism district and a rural district were 4.540, 0.358, 0.270, 0.041 and 0.269 mg.kg l , respectively, which are much elevated compared to national background Hg concentration in soil that is 0.038 mg ~ kg -t. THg in moss in four function districts in urban areas ranged from 0.196 to 0.307 mg ~ -1 with an average of 0.258 mg okg -1, which was about 1.5 times that at the contrast site. The highly positive correlation between THg in moss and TAM was produced. THg concentrations in leaves of urban woody plants ranged from 0.068 to 0.181 mg ~ kg -I. Mercury uptake by leaves was in the order of: deciduous plants > evergreen plants. The difference of THg concentrations in leaves of Frimiana simplex from an ordinary industrial district, a traffic district and a residential district was not obvious. However, THg concentrations in leaves of Frimiana simplex at the three sampling sites were about 2 times higher than those in a tourism district. The spatial distribution of the THg concentrations in leaves of Frimiana simplex and the annual average TAM concentrations display no difference.