| Polycyclic aromatic hydrocarbons (PAHs) are a class of typical persistent organic pollutants, widely exist in various environmental media, and have great hazards on the environments and human health. So making known of the pollutants level and distribution characters, indicating the pollutant sources are of particular significance to prevent and control PAHs pollution.Mosses is a natural passive sampling material, because of its special physiological structure, mosses could indicate the pollutants level and distribution characters of PAHs in atmospheric environment within a period of time. This study collected Hypnum plumaeforme and Haplocladium microphyllum as samples, analyzed the 16 PAHs contamination levels, distribution characters in mosses from different regional environments, and further more the contaminants sources were preliminary analyzed. The primary results as follows:1. The concentrations of 16 PAHs in mosses in Lu Mountain area were comparable with that reported in background areas, and Phe has the highest concentration, The ring sequence of PAHs in the moss samples showed a decreasing trend as 3 ring>4 ring>2 ring>5 ring>6 ring. The high molecular weight PAHs(HMW PAHs) content in northern slop was significantly higher than southern slop, which was the main reason for theΣPAHs spatial difference between northern and southern slop. In contrast, the contents of low molecular weight PAHs (LMW PAHs) which mainly from atmospheric long-rang transport were similar in both sides. Correlation analysis showed that the HMW PAHs were significantly correlated, on the contrary, the correlation among the LMW PAHs were weak.2. The altitudinal gradient has little impact on the content of PAHs in mosses. Especially in the northern slope, the PAHs contents were weak correlated to altitude. The combined influences of tourism economic development and terrain features which brought local pollution probably lead to this result.3. The 16 PAHs concentrations were slightly lower in industrial area compared to related reports in foreign countries. Phe, Chr, Pry, NaP, BbF and FLu were the principal pollutants, and the ring sequence of PAHs in the moss samples showed a decreasing trend as 3 ring>4 ring>5 ring>2 ring>6 ring. The pollution levels were significantly different in the distance gradient, most PAHs showed a good negative correlation with distance.The concentration changes more obvious as the rings of PAHs increase, at the distance of>4000m from the boundary, the contents level were close to the bachground area.4. The 16 PAHs concentrations in traffic area were lower than related reports in foreign countries. Phe, NaP, Pry, Chr, and FLu were the principal pollutants, and the ring sequence of PAHs was similar to the Lu Mountain area. Emission factor method were used to estimate the composition of PAHs in atmospheric environment of traffic area, the result had some differences to the composition of PAHs in mosses.It reflected the differences of the PAHs composition between the instant pollutants level and the average level after a period.5. In different reginal environment, the concentration of PAHs in mosses were industrial area> northern slop> traffic area> southern slope,the compositions were all dominated by 2-3 ring PAHs.The relative content of HMW PAHs were higher than ther regions. The total toxic equivalent concentration of 16PAHs in different regions showed industrial area> northern slop> traffic area> southern slope, although there were not significant point source pollution in northern slop, the potential carcinogencity were still high which need great attention.6. We used the factor analysis and the diagnostic ratios method to comprehensive analysis of the predominant sources of PAHs in mosses of Lu Mountain area. The result showed that the predominant sources were the traffic sources, and also including a small amount of coal source and burning source. |
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