Institute of Ecosystem Study - CNR - National Research Council of Italy, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Florence, Italy.
Department of Economics, Management and Statistics, University of Milano Bicocca, Building U7, Piazza dell'Ateneo Nuovo 1, 20126 Milan, Italy.
Sci Total Environ. 2015 Dec 15;538:712-23. doi: 10.1016/j.scitotenv.2015.08.077. Epub 2015 Aug 30.
A regional survey of eight volatile organic compounds (VOCs), namely BTEX (benzene, toluene, ethylbenzene and p-xylene) and four chlorinated aliphatic hydrocarbons (CAHs: chloroform, 1,2-dichloroethane, trichloroethene and tetrachloroethene), was carried out at 174 sites, in 17 alluvial aquifers of Abruzzo, a Mediterranean region of southern Italy, from 2004 to 2009. Frequency of detection, concentration range, spatial distribution pattern, and temporal trend of contaminant concentration in each aquifer were analyzed as well as the relationships between VOC concentrations and the total amount of precipitation during the 90days preceding each sampling date. A review of published ecotoxicological data, providing an indication of the biological risk associated with the observed levels of VOC contamination, was presented and discussed. BTEX concentrations were under detection limits in all the investigated aquifers, indicating absence of contamination. In contrast, CAH contamination occurred in 14 out of 17 aquifers. The two most frequently detected compounds were chloroform and tetrachloroethene. No significant temporal trend was observed for chloroform and tetrachloroethene concentrations during the six years of observation, indicating the persistence of stable contaminations, except for some slightly decreasing trends observed in three out of 17 aquifers. In four aquifers chloroform and tetrachloroethene concentrations increased with precipitations in the preceding months. Spatial patterns of contamination differed among aquifers, indicating highly complex contaminant distributions at aquifer scale not related to single-plume geometries. Patterns of contamination by chloroform and tetrachloroethene in the most urbanized aquifers were likely associated with multiple sources of VOCs not clearly detectable at the scale used in this study. In five out of 17 aquifers, chloroform and tetrachloroethene co-occurred at concentrations that are lethal to groundwater-dwelling organisms under a short exposure period (four days). Future studies should therefore consider the possibility that in the other aquifers groundwater-dwelling organisms might be physiologically damaged by sublethal VOC concentrations.
2004 年至 2009 年期间，在意大利南部地中海地区阿布鲁佐的 17 个冲积含水层的 174 个地点，对八种挥发性有机化合物（VOCs），即苯、甲苯、乙苯和二甲苯（BTEX），以及四种氯化脂肪烃（CAHs：氯仿、1,2-二氯乙烷、三氯乙烯和四氯乙烯进行了区域调查。分析了每个含水层中污染物的检出频率、浓度范围、空间分布模式和时间趋势，以及 VOC 浓度与每个采样日期前 90 天内总降水量之间的关系。本文还对已发表的生态毒理学数据进行了回顾，这些数据表明了与观察到的 VOC 污染水平相关的生物风险。BTEX 浓度在所有调查的含水层中均低于检测限，表明不存在污染。相比之下，CAH 污染发生在 17 个含水层中的 14 个中。最常检测到的两种化合物是氯仿和四氯乙烯。在六年的观测期间，氯仿和四氯乙烯的浓度没有明显的时间趋势，表明稳定的污染持续存在，除了在 17 个含水层中的 3 个中观察到的一些略有下降趋势。在四个含水层中，氯仿和四氯乙烯的浓度随着前几个月的降水而增加。含水层之间的污染空间模式不同，表明在含水层尺度上存在复杂的污染物分布，与单个羽流几何形状无关。在最城市化的含水层中，氯仿和四氯乙烯的污染模式可能与在本研究中使用的尺度上无法清楚检测到的 VOC 多种来源有关。在 17 个含水层中的 5 个中，氯仿和四氯乙烯同时存在于浓度下，在短时间暴露下对地下水生物具有致命性（四天）。因此，未来的研究应考虑到在其他含水层中，地下水生物可能会因亚致死浓度的 VOC 而受到生理损害的可能性。
