广东典型湿地环境沉积物及鱼体中多环芳烃的污染特征及风险评估

为了解广东典型湿地环境表层沉积物及鱼体中多环芳烃(PAHs)的污染特征,分别于2014年10月和2015年4月采集沉积物及鱼类样品,分析其中16种US EPA优控多环芳烃的主要来源和风险。结果表明,广东典型湿地环境表层沉积物中多环芳烃的含量范围为139.4～1 134.3 ng·g~(-1)干重,鱼类肌肉中多环芳烃含量范围为11.1～33.9 ng·g~(-1)湿重。表层沉积物中有机碳与不同环数的多环芳烃含量均呈现显著的正相关关系。来源分析的结果表明,研究区域表层沉积物中多环芳烃的主要来源为石油排放及燃烧来源的混合。风险评估的结果表明,该区域表层沉积物中多环芳烃存在一定的生态风险,需引起重视;通过食用鱼类造成的致癌风险为2.25×10~(-6)～4.23×10~(-6),略高于美国环保局(US EPA)推荐的可接受风险(10~(-6)),存在一定的潜在致癌风险。对于成年人来说,研究区域鱼类肌肉中多环芳烃产生致癌风险允许的最大日食用量(CR_(lim))范围为124.5～234.6 g·d~(-1),尽管食用这几种鱼的致癌风险不大,居民摄入时仍应加以控制。

Pollution Characteristics and Risk Assessment of PAHs in Sediments and Fishes from Typical Wetlands of Guangdong Province

In order to investigate the pollution characteristics of polycyclic aromatic hydrocarbons, (PAHs) in sediments and fishes of typical wetland environment in Guangdong, surface sediment and fish samples from wetlands were collected in October, 2014 and April, 2015, respectively. Main source and risk assessment of 16 US EPA priority PAHs in the study area were examined. The results showed that the concentration of PAHs ranged from 139.4 to 1 134.3 ng g^-1 dry weight in the sediment samples and ranged from 11.1 to 33.9 ng g^-1 wet weight in the fish muscle samples. The concentrations of total organic carbon (TOC) were highly significantly correlated with those of 2-rings, 3-rings, 4-rings and 5, 6-rings of PAHs respectively. PAH isomer pair ratios analysis indicated that main source were derived from petroleum emission and combustion in the sediments, while from mixed combustion in the fish muscles. The ecological risk of PAHs in surface sediments was relatively low but more attention were needed to be paid. The carcinogenic risks through fish ingestion were in the range of 2.25×10^-6~4.23×10^-6 and slightly higher than the baseline value of acceptable risk (10^-6). Based on the maximum acceptable level of PAHs cancer control, the maximum acceptable daily intakes of fishes should be 124.5~234.6 g d^-1 (by wet mass) in the study regions. Although little carcinogenic risks were found in these fish species, it should be controlled when ingested by residents.