全氟辛烷磺酸和全氟辛烷羧酸在天津大黄堡湿地地区鱼体和蔬菜中的分布研究

Distribution of Perfluorooctane Sulfonate and Perfluorooctanoic Acid in Different Tissues of Fishes and Vegetables from Dahuangpu Wetland Nature Reserve,Tianjin City,China

对天津市大黄堡湿地自然保护区的池塘水体、两种常见鱼体（鲤鱼和鲶鱼）和两种蔬菜（大白菜和萝卜）的不同组织以及两种蔬菜根际土中的全氟辛烷羧酸（PFOA）和全氟辛烷磺酸（PFOS）的污染水平进行了调查,并计算了生物富集（迁移）系数,分析比较了陆生植物与水生生物的富集规律。研究表明,在池塘水体中,PFOA的浓度为22.0±1.3ng·L-1（n=3）,PFOS为8.4±0.6ng·L-1（n=3）。在鱼体中,PFOA的检出浓度均低于PFOS,说明PFOA具有较低的生物富集能力;PFOS在鲤鱼和鲶鱼中的最高浓度均出现在肝脏中,分别为17.8、21.7ng·kg-1（湿重,WT）,组织分布的变化趋势均表现为肝脏〉肾脏〉肉（腮）。在两种蔬菜中,PFOA和PFOS最高浓度均出现在大白菜的地下部分（菜根）,浓度分别为0.84、0.42μg·kg-1（WT）。鱼体对目标化合物的富集系数为1.7~2588,远高于蔬菜的富集（迁移）系数,0.01~0.59;水溶性较大的PFOA在蔬菜中转移系数大于PFOS,在鱼体中的富集系数却小于PFOS。对该地区的两种蔬菜和两种鱼的风险暴露进行了初步评价,鲤鱼对人体每日可贡献2.6ngPFOA和104ngPFOS;而鲶鱼的贡献量分别为1.7ng和39ng。大白菜和萝卜对人体中PFOA的贡献量要高于上述两种鱼类,分别为18.4ng和4.1ng,对于PFOS的贡献量分别为13.4ng和11.5ng。通过与欧盟食品安全局对PFOA和PFOS暴露风险评价的日可最高摄入量对比,发现本研究中该地区的两种蔬菜和两种常见鱼类的暴露风险均较低。

The concentrations of perfluorooctane sulfonate（PFOS） and perfluorooctanoic acid（PFOA） were measured in water of a pond,or-gans of freshwater fish（i.e.,carp and catfish）,tissues of vegetables（i.e.,Chinese cabbage and carrot） and their corresponding rhizospheric soil,collected in Dahuangpu Wetland Nature Reserve.Biotransfer factors（BTFs） and bioaccumulation factors（BAFs） of PFOA and PFOS in target vegetables and fishes were calculated,and the trend of distribution for PFOS and PFOA between terrestrial plants and aquatic organ-isms were also compared by this study.The mean concentrations of PFOA and PFOS in water samples（n=3） collected in pond were 22.0±1.3 ng·L-1 and 8.4±0.6 ng·L-1,respectively.In general,PFOA levels in fish were lower than PFOS,which indicated PFOA had lower bioaccumu-lation tendency.The highest concentrations of PFOS were detected in fish liver[carp：17.8 ng·kg-1（WT） ;catfish：21.7 ng·kg-1（WT） ],fol-lowed by kidney,meat and cheek.Among all tissues of Chinese cabbage,root had the highest concentration of PFOA and PFOS with a value of 0.84 μg·kg-1 and 0.42 μg·kg-1（WT）,respectively.The BAFs of PFOS and PFOA in fish ranged from 1.7 to 2583,these values were much higher than the BTFs in vegetables（0.01 to 0.59）.Furthermore,the BTFs of PFOA in vegetables was greater than PFOS,while the BAFs of PFOA in fish was lower than PFOS.Human exposure through the consumption of target freshwater fishes and vegetables was estimated by this study.The daily intake by general adults via carp and catfish were 104 and 39 ng·day-1 for PFOS,and 2.6 ng·kg-1 and 1.7 ng·d-1 for PFOA,respectively.The contribution for PFOA from the Chinese cabbage and carrot was greater than the two kinds common fish,the values were 18.4 ng·day-1 and 4.1 ng·day-1,respectively.Comparing with the Tolerance Daily Intake（TDI） for PFOA and PFOS from European Food Safety Agency,our results showed that human exposure risk via consumption of carp,catfish,Chinese cabbage and carrot were low.