An assessment of air-soil exchange of polychlorinated biphenyls and organochlorine pesticides across Central and Southern Europe
An assessment of air-soil exchange of polychlorinated biphenyls and organochlorine pesticides across Central and Southern Europe
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DOI：
10.1021/es071406f
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发表时间：
2008-01-01
影响因子：
11.4
通讯作者：
Holoubek, Ivan
中科院分区：
文献类型：
--
作者：
Ruzickova, Petra;Klanova, Jana;Holoubek, Ivan
估算多氯联苯和有机氯农药的净通量方向对于了解土壤作为这些化学品进入大气的汇或源的作用非常重要。在这项研究中，土壤-空气平衡状态进行了调查，在中欧和南欧的各种土壤类别，使用一个广泛的数据库耦合土壤和时间积分的空气样品。在5个月的时间内从47个站点收集样品，以评估特定站点以及逸度分数的季节性变化，计算作为土壤-空气交换的潜在措施。抽样地点经过精心挑选，以代表各种背景，农村，城市和工业区。特别注意了前南斯拉夫境内的一些地点，这是一个受最近冲突影响的国家，那里的土壤被发现受到多氯联苯的高度污染。捷克共和国的工业土壤由于以前的农药生产而受到严重污染，也被列入调查范围。土壤被发现是一个汇高氯化多氯联苯和二氯二苯三氯乙烷（DDT）;二氯二苯二氯乙烯（DDE）的状态更接近平衡，在冬季和夏季净挥发的净沉积的趋势。对于低分子量多氯联苯同系物以及氯化萘而言，土壤往往是空气污染的来源，特别是在夏季，但不限于此。逸度分数被发现减少在寒冷的季节，特别是对于更挥发性的化合物，虽然在战争破坏的地区和严重污染的工业场地，季节性变化非常低，逸度分数接近1，表明强有力的净土壤到空气的转移为所有季节。最初的假设是，由于最近的战争，西巴尔干地区的居民仍然接触到较高水平的多氯联苯，这一假设得到了证实。一般而言，多氯联苯和有机氯农药的土壤-空气转移是因地点而异的，并取决于有关污染物的物理化学性质、土壤性质、历史污染记录和地点与污染源的邻近程度以及当地的气象条件。
Estimating the net flux direction of polychlorinated biphenyls and organochlorine pesticides is important for understanding the role of soil as a sink or source of these chemicals to the atmosphere. In this study, the soil-air equilibrium status was investigated for various soil categories in Central and Southern Europe using an extensive database of coupled soil and time-integrated air samples. Samples were collected from 47 sites over a period of 5 months to assess both site-specific as well as seasonal variations in fugacity fractions, calculated as a potential measure of soil-air exchange. Sampling sites were carefully selected to represent a variety of background, rural, urban, and industrial areas. Special attention was given to sites in the former Yugoslavia, a country affected by recent conflicts, where soils were found to be highly contaminated with polychlorinated biphenyls (PCBs). Industrial soils from the Czech Republic, heavily polluted as a result of previous pesticide production, were also included in the survey. Soil was found to be a sink for highly chlorinated PCBs and for dichlorodiphenyltrichloroethane (DDT); for dichlorodiphenyldichloroethylene (DDE), the status was closer to equilibrium, with a tendency for net deposition during winter and net volatilization during summer. For lower-molecular-weight PCB congeners, as well as for CAN, soil tends to be a source of pollution to the air, especially, but not exclusively, during summer. Fugacity fractions were found to decrease during the colder seasons, especially for the more volatile compounds, although in both the war-damaged areas and the heavily contaminated industrial sites, seasonal variability was very low, with fugacity fractions close to 1, indicating strong net soil-to-air transfer for all seasons. The original assumption that residents of the Western Balkans are still exposed to higher levels of PCBs due to the recent wars was confirmed. In general, the soil-air transfer of PCBs and organochlorine pesticides was found to be site-specific and dependent on the physicochemical properties of the contaminant in question, the soil properties, the historical contamination record and a site's vicinity to sources, and the local meteorological conditions.