Department of Public Health, Erasmus MC, Rotterdam, CA, The Netherlands.
J Expo Sci Environ Epidemiol. 2010 Jul;20(5):478-85. doi: 10.1038/jes.2009.56. Epub 2009 Oct 28.
In a rural area widespread pollution of friable and non-friable waste products was present, used to harden dirt tracks, yards, and driveways during 1935-1974. Exposure to environmental asbestos was assessed by a site approach, based on number of polluted sites within postal code areas, and by a household approach, based on number of households in the close vicinity to polluted sites within postal code areas. Based on asbestos soil investigations, 293 sites were identified with asbestos waste material at the surface, of which 77% contained crocidolite fibres as well as chrysotile fibres. The 293 sites-at-risk varied from 5 m(2) to 2722 m(2) and were surrounded by 347 households within 100 m of these sites. Distance to the plant was associated with the number of sites (r=0.36), and with the number of households (r=0.52). However, categorization of postal code areas into low, intermediate or high likelihood of exposure to asbestos showed a modest agreement between the site and household approach. In the site approach a total of 2.3 million person-years at risk were estimated with an average exposure of 1674 fibres/m(3) and an expected 1.8 cases of malignant mesothelioma each year. The household approach resulted in estimates of 1.2 million person-years at risk, and 0.9 cases of malignant mesothelioma per year, respectively. This study illustrates that asbestos waste on the surface of roads and yards in an area with over 130,000 inhabitants may result in long-term exposure to asbestos that will cause several cases of malignant mesothelioma each year. Although distance to plant, number of polluted sites and number of exposed household were associated, the modest agreement among these measures of exposure indicate that the exposure assessment strategy chosen in a particular study may result in considerable misclassification. Without detailed information on individual behaviour within the polluted area, it is difficult to show that a more individually oriented approach will perform better than an ecological approach.
在一个农村地区，广泛存在着易碎和非易碎废物的污染，这些废物曾被用于在 1935 年至 1974 年期间硬化土路、庭院和车道。通过基于邮政编码区域内污染地点数量的地点法和基于邮政编码区域内污染地点附近家庭数量的家庭法，评估了环境石棉暴露情况。基于石棉土壤调查，确定了 293 个表面存在石棉废物的地点，其中 77%含有青石棉纤维和温石棉纤维。这些有风险的 293 个地点的面积从 5 平方米到 2722 平方米不等，周围有 347 户家庭，距离这些地点 100 米以内。距离工厂的距离与地点数量(r=0.36)和家庭数量(r=0.52)有关。然而，将邮政编码区域分为低、中或高暴露于石棉的可能性类别，表明地点法和家庭法之间的一致性不高。在地点法中，估计有 230 万人年面临风险，平均暴露于 1674 根/立方米的纤维，每年预计有 1.8 例恶性间皮瘤。家庭法的结果是，估计有 120 万人年面临风险，每年有 0.9 例恶性间皮瘤。本研究表明，在一个拥有超过 13 万居民的地区，道路和庭院表面的石棉废物可能导致长期接触石棉，每年将导致几例恶性间皮瘤。尽管工厂距离、污染地点数量和暴露家庭数量有关，但这些暴露评估措施之间的一致性不高，表明在特定研究中选择的暴露评估策略可能会导致相当大的分类错误。在没有有关污染区域内个人行为的详细信息的情况下，很难证明更侧重于个人的方法会比生态方法表现更好。
