Department of Occupational and Environmental Health, Center for Primary Care and Public Health (Unisanté), University of Lausanne, CH-1066 Epalinges, Switzerland.
Department of Occupational and Environmental Health, Center for Primary Care and Public Health (Unisanté), University of Lausanne, CH-1066 Epalinges, Switzerland.
Environ Pollut. 2023 Jan 1;316(Pt 1):120441. doi: 10.1016/j.envpol.2022.120441. Epub 2022 Oct 29.
In December 2020, high soil concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) were discovered across large parts of Lausanne, Switzerland. Concentrations reached up to 640 ng TEQ/kg dry weight. The most likely source was a former municipal waste incinerator. A three-step, multidisciplinary approach to human health risk assessment was conducted to determine the potential population exposure to PCDD/Fs and identify appropriate preventive measures. First, exposure scenarios were developed based on contaminated land uses. Second, the toxicological risks of different scenarios were evaluated using a toxicokinetic model estimating increases in blood serum PCDD/F concentrations over background concentrations from the general population's food consumption. Third, a detailed geostatistical mapping of PCDD/F soil contamination was performed. Stochastic simulations with an external drift and an anisotropic model of the variogram were generated to incorporate the effects of distance from emission source, topography, and main wind directions on the spatial distribution of PCDD/Fs in topsoil. Three main scenarios were assessed: i) direct ingestion of soil by children in playgrounds; ii) consumption of vegetables from private gardens by children and adults; and iii) consumption of food from livestock and poultry raised on contaminated soil. The worst exposure scenario involved the consumption of eggs from private hen houses, resulting in PCDD/F concentrations in serum an order of magnitude higher than might normally be expected. No relevant increases in serum concentrations were calculated for direct soil ingestion and vegetable consumption, except for cucurbitaceous vegetables. Combining mapping and exposure scenario assessment resulted in targeted protective measures for land users, especially concerning food consumption. The results also raised concerns about the potential unsafe consumption of products derived from animals raised on land with PCDD/F concentrations only moderately over environmental background levels.
2020 年 12 月，瑞士洛桑市大片地区的土壤中发现多氯二苯并对二恶英（PCDDs）和二苯并呋喃（PCDFs）浓度很高，达到 640ng TEQ/kg 干重。最有可能的来源是一个前城市垃圾焚烧炉。采用了三步、多学科方法进行人类健康风险评估，以确定潜在的人群接触 PCDD/F 情况，并确定适当的预防措施。首先，根据受污染的土地用途制定了暴露情景。其次，使用毒代动力学模型评估了不同情景的毒理学风险，该模型估计了人群从食物中摄入 PCDD/F 后血清浓度相对于背景浓度的增加。第三，对 PCDD/F 土壤污染进行了详细的地统计制图。采用具有外部漂移和变差函数各向异性模型的随机模拟，以纳入距排放源的距离、地形和主要风向对表层土壤中 PCDD/F 空间分布的影响。评估了三个主要情景：i）儿童在游乐场直接摄入土壤；ii）儿童和成人食用私人花园中的蔬菜；iii）食用受污染土壤上饲养的牲畜和家禽的食物。最严重的暴露情景涉及从私人鸡舍食用鸡蛋，导致血清中 PCDD/F 浓度比正常情况下高出一个数量级。除了葫芦科蔬菜外，直接摄入土壤和食用蔬菜不会导致血清浓度出现相关增加。结合制图和暴露情景评估，针对土地使用者制定了有针对性的保护措施，特别是关于食物消费。结果还引起了人们对食用受 PCDD/F 污染的土地上饲养的动物所产生的产品的潜在不安全问题的关注，尽管这些产品的浓度仅略高于环境背景水平。
