广州城市土壤砷的含量及其污染评价

采集广州市城市土壤表层(0～10 cm)426个样品,研究土壤As的含量及其分布特征,采用单因子污染指数评价土壤的As污染状况.结果表明,广州城市土壤砷质量比变幅为1.40～144 mg·kg~(-1),平均值为17.4 mg·kg~(-1).各行政区中,土壤砷平均含量和中值均是越秀区和荔湾区最高;各功能区中土壤砷平均含量以城市公园为最高.根据污染指数判断,有37%土壤样品受到不同程度的砷污染,各行政区中越秀区和荔湾区土壤砷污染最严重,各功能区中城市公园土壤砷污染最严重.城市历史和工业活动与城市土壤砷污染密切相关,建议密切关注城市公园土壤砷污染对人类健康和城市环境质量的影响.

Concentration of As in the urban soil in Guangzhou and its contamination assessment

In order to test the concentration of As in the urban soil in Guangzhou and its contamination degree, this paper has collected and analyzed 426 typical soil samples at 0-10 cm depth from different districts in Guangzhou City, which may represent different land-utility patterns including urban parks, residential areas, roadsides, public building zones and industrial zones. In proceeding with our study, we have tested and analyzed the arsenic concentration and distribution in the above said sample soils and measured the pollution degree in accordance with the single pollution index in the given paper. The results of our analysis indicate that the concentrations of arsenic in the city's urban soils range from 1.40-144 mg·kg~(-1), with an average of 17.4 mg·kg~(-1). The highest level of arsenic contamination has been found in the soils of Yuexiu and Liwan Districts, with the highest pollution index seen in the urban parks in accordance with the land-utility patterns. Based on the single pollution index, about 37% of the tested soils are contaminated by the arsenic to some extent. The soils in Yuexiu and Liwan Districts are most severely contaminated by arsenic among those of the urban parks. We have also detected that there exists close connection between the urban history and the industrial activities in a given district. In addition, more attention has been paid to the effect of the soil arsenic pollution in the urban parks on human health and environmental quality, such as its bio-availability to the human existence and the safety of the groundwater for human survival.