厦门西港表层沉积物中多环芳烃(PAHs)的含量、分布及来源

CONCENTRATION, DISTRIBUTION AND SOURCE OF POLYCYCLIC AROMATIC HYDROCARBONS IN SURFACE SEDIMENTS OF XIAMEN WESTERN HARBOR

采用气相色谱与质谱联用 (GC/MS)技术 ,通过 3个航次对厦门西港沉积物中 1 6种优先监控的PAHs的污染状况进行不同季节的连续调查。结果表明 ,厦门西港沉积物中检出的PAHs均以 4— 6环的为主 ,其中荧蒽和芘在不同航次及不同站位均为优势组分。PAHs的总含量变化不明显 ,但高分子量的PAHs(5— 6环 )的含量却有升高的趋势。厦门西港沉积物中的PAHs主要来源于矿物的不完全燃烧 ,与 1 993年的调查结果相比 ,厦门西港沉积物中PAHs的含量有所减少 。

The concentrations of sixteen individual polycyclic aromatic hydrocarbons (PAHs) in sediments collected from six locations in Xiamen Western Harbor (24°29′N, 118°04′E) on spring, summer and autumn cruises in Apr., July and Oct., 2001 were analyzed by GC/MS. The total concentration of 16 PAHs varied from 105 3 to 5118 3ng/g dry weight in April, from 683 6 to 2954 2ng/g dry weight in July and from 564 1 to 2656 0ng/g dry weight in October. The values of the total concentration of 16 PAHs in sediments of Maluan Bay mariculture area were significantly higher than that of non mariculture area, suggesting that more PAHs were accumulated in aquaculture area. The PAHs composition pattern in sediments suggest dominance by high molecular weight PAH components (4—6 rings), fluoranthene and pyrene were the most dominant at different seasons and stations. The variation of total PAHs concentration was insignificant in different seasons, but the level of high molecular weight PAH compounds (5—6 rings) showed an increasing tendency. Ratios of specific PAH compounds such as phenanthrene/anthracene and fluoranthene/pyrene, were calculated to evaluate the possible source of PAH contamination in sediments, the ratios at different stations showed phenanthrene/anthracene<10 and fluoranthene/pyrene>1 indicate that the source of PAH pollution in sediments was mostly petrogenic. Comparing with the results obtained from Xiamen Western Harbor in 1993, the pollution level of PAH in sediments has decreased, but some high molecular weight PAH compounds such as Benzo(b)fluoranthene, Diben(a,h)anthracene and Benzo (ghi) perylene that their toxicity guidelines was not available were detected. This work was of a high interest for Xiamen City since PAHs are ubiquitous persistent environmental contaminants generated by natural combustion processes and human activities and are considered hazardous because of cytotoxic, mutagenic, and carcinogenic effects.