A Survey of Environmental Pollution by Mercury Derived from a Chemical Factory Drain in Guizhou, China

摘要

Guizhou Chemical Factory, a government-enterprise, has been producing acetal-dehyde from carbide, using mercury as a catalyst, from 1970 to 2001 at Qingzhen City in Guizhou Province, Peoples Republic of China. The factoiy drained wastewater containing mercury into a stream, which is utilized for irrigation of 180 ha of farmland. After the irrigation the water merges with Maotiao River and flows into Baihua Lake. The water in that lake is widely used for drinking and industry around Guiyang City, the capital of Guizhou Province. Fortunately, in our investigation, mercury concentration in the water and fish in the Lake or river, as well as in hair of the residents in the irrigated area was not significant. However, hair mercury in residents along the stream increased in concentration in the direction of the factoiy. Also, the total mercury concentration is higher than that of methyl mercury, which indicates that the soil of the irrigated farmland suffers pollution by mercury. We systematically investigated the distribution of soil mercury in the farmland under 100-m mesh. The highest concentration of total mercury in soil was 271.6 ppm, while that of methyl mercury was 199.9 ppb. The two-dimensional distribution of methyl mercury within 3.5 km from the factoiy was somewhat different form that of total mercury, though both contain 80 pencent of the whole amount throughout the stations.