Spatial PCA and Pollutant Sources of Topsoil PAHs in Tianjin Area
天津表土PAHs的空间主成分与污染源分析

Polycyclic aromatic hydrocarbons (PAHs) are some of persistent organic pollutants (POPs), which are widely existed in our environment. PAHs can result in some latent danger to our human being, such as cancer. More and more studies about PAHs are performed to discuss the chemical and physical characteristics, the spatial and temporal characteristics, the source and final of PAHs. Principal component analysis (PCA) is one method which can efficiently extract the main information from various data. In the environmental research, PCA is often used to extract character, concentrate information and reduce dimension. With one or some integrated index of PCA, the environmental samples can be classified and identified, and the source of pollution can be estimated. The method of PCA is also used in the research of PAHs pollution. The Spatial principal component analysis (SPCA), which is based on the theory of coregionaliza-tion, can enhance the understanding of the spatial characteristics of PAHs. In this study, 188 sampling sites in Taijin area were selected, and on each site, the top 10cm soil was collected for analysis. In the laboratory, the contents of 16 prior PAHs, as well as the soil properties, were determined for all the samples. Based on the multi-spatial structure analysis, the spatial PCA characteristics among 16 prior PAHs in topsoil in Tianjin area were studied. The pollution sources were also discussed. It is discovered in the result that the main polluting processes of PAHs in Tianjin area are petroleum source and combustion of fossil fuel. By the view of spatial scale, the influence range of petroleum source is less than 5km and the range of combustion source is from 5 to 10km. On the large scale, the principal origin of PAHs may be the regional deposit from atmosphere.