Department of Chemistry, Umeå University, SE-901 87, Umeå, Sweden.
Environ Sci Pollut Res Int. 2010 Jan;17(1):26-39. doi: 10.1007/s11356-009-0223-4. Epub 2009 Jul 30.
BACKGROUND, AIM, AND SCOPE: The main pathway for human exposure to the highly toxic polychlorinated-p-dioxins and polychlorinated furans [polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs)] is via dietary intake. Other exposure pathways may, however, be important in close proximity to point sources, such as wood preservation sites, where PCDD/F contaminated chlorophenols (CP) were previously used. In this study, a heavily PCDD/F contaminated CP saw mill site in Sweden was investigated. Human exposure through a broad spectrum of exposure pathways was assessed. Such studies are in demand since the question whether contaminated sites represent a current or future risk can only be answered by detailed site-specific risk assessments.
Sampling of exposure media (soil, air, groundwater, raspberries, carrots, potatoes, grass, milk, eggs, and chicken fodder) was made. Exposure media concentrations and congener distribution patterns were used to investigate the mobilization of PCDD/Fs from soil to the environment and to calculate exposure levels for adults. Blood serum levels from site-exposed and control individuals were also analyzed.
Congener distribution patterns at the site were generally dominated by a specific marker congener (1234678-HpCDF), which is highly abundant in the polluted soil. The dioxin toxic equivalents (TEQ) concentrations were notably elevated as compared to national reference samples for most exposure media, and the marker congener was a major contributor to increased TEQ levels. There were also indications of soil-to-air volatilization of tetra- and penta-CDD/Fs. People who participated in the restoration of a contaminated building showed higher levels of 1234678-HpCDF compared to controls, and calculated exposure levels suggest that several site-specific exposure routes may be of importance for the daily intake of PCDD/F. CONCLUSIONS, RECOMMENDATIONS, AND PERSPECTIVES: Despite low mobility of higher chlorinated PCDD/Fs, these contaminants were transferred from the polluted soil to the surroundings and into human tissue. The extent of increased exposure from contaminated sites depends on the PCDD/F source strength of the soil, composition of the pollution, human activities, and dietary patterns of the residents. Impact from the contaminated soil on other exposure media was seen also for areas with low to moderate soil contamination. In the future, not only the levels of PCDD/F soil pollution but also the composition must be considered in risk assessments of contaminated sites.
背景、目的和范围：人类接触剧毒多氯二苯并对二恶英和多氯二苯并呋喃（多氯二苯并对二恶英和呋喃（PCDD/Fs））的主要途径是通过饮食摄入。然而，在靠近点源的地方，其他暴露途径可能很重要，例如木材保存场所，以前曾在这些场所使用过被多氯二苯并对二恶英污染的氯酚（CP）。在这项研究中，对瑞典一个受到严重多氯二苯并对二恶英污染的 CP 锯木厂场址进行了调查。评估了广泛的暴露途径的人体暴露情况。由于只有通过详细的特定地点风险评估才能回答污染场地是否代表当前或未来风险的问题，因此此类研究非常有必要。
对暴露介质（土壤、空气、地下水、覆盆子、胡萝卜、土豆、草、牛奶、鸡蛋和鸡饲料）进行了采样。利用暴露介质浓度和同系物分布模式，研究了 PCDD/F 从土壤向环境中的迁移情况，并计算了成人的暴露水平。还分析了暴露于该场址的个体和对照个体的血清水平。
该场址的同系物分布模式通常以一种特定的标记同系物（1234678-HpCDF）为主，这种同系物在污染土壤中含量非常丰富。与大多数暴露介质的国家参考样本相比，二恶英毒性当量（TEQ）浓度明显升高，标记同系物是 TEQ 水平升高的主要原因。还存在四氯和五氯二苯并二恶英从土壤到空气挥发的迹象。参与污染建筑物修复的人员的 1234678-HpCDF 水平高于对照组，计算出的暴露水平表明，一些特定于现场的暴露途径可能对 PCDD/F 的日常摄入很重要。结论、建议和展望：尽管高氯代 PCDD/F 的迁移性较低，但这些污染物仍从污染土壤转移到周围环境和人体组织中。受污染土壤引起的暴露增加程度取决于土壤中 PCDD/F 源的强度、污染的组成、人类活动以及居民的饮食模式。在土壤污染程度较低或中等的地区，也可以看到受污染土壤对其他暴露介质的影响。在未来，污染场地的风险评估不仅要考虑 PCDD/F 土壤污染水平，还要考虑其组成。
