The University of York, Wolfson Atmospheric Chemistry Laboratories, Department of Chemistry, Heslington, York YO10 5DD, UK.
National Centre for Atmospheric Science, The University of York, Department of Chemistry, Heslington, York YO10 5DD, UK.
Environ Int. 2014 Oct;71:139-47. doi: 10.1016/j.envint.2014.06.012. Epub 2014 Jul 16.
In addition to passive inhalation, non-smokers, and especially children, are exposed to residual tobacco smoke gases and particles that are deposited to surfaces and dust, known as thirdhand smoke (THS). However, until now the potential cancer risks of this pathway of exposure have been highly uncertain and not considered in public health policy. In this study, we estimate for the first time the potential cancer risk by age group through non-dietary ingestion and dermal exposure to carcinogen N-nitrosamines and tobacco-specific nitrosamines (TSNAs) measured in house dust samples. Using a highly sensitive and selective analytical approach we have determined the presence of nicotine, eight N-nitrosamines and five tobacco-specific nitrosamines in forty-six settled dust samples from homes occupied by both smokers and non-smokers. Using observations of house dust composition, we have estimated the cancer risk by applying the most recent official toxicological information. Calculated cancer risks through exposure to the observed levels of TSNAs at an early life stage (1 to 6years old) exceeded the upper-bound risk recommended by the USEPA in 77% of smokers' and 64% of non-smokers' homes. The maximum risk from exposure to all nitrosamines measured in a smoker occupied home was one excess cancer case per one thousand population exposed. The results presented here highlight the potentially severe long-term consequences of THS exposure, particularly to children, and give strong evidence of its potential health risk and, therefore, they should be considered when developing future environmental and health policies.
除了被动吸入，不吸烟者，尤其是儿童，会接触到残留在表面和灰尘中的二手烟残留气体和颗粒，即三手烟（THS）。然而，到目前为止，这种暴露途径的潜在癌症风险还高度不确定，也没有被纳入公共卫生政策。在这项研究中，我们首次通过非饮食摄入和皮肤接触，对房屋灰尘样本中测量到的致癌物 N-亚硝胺和烟草特异性亚硝胺（TSNAs），按年龄组估计了潜在的癌症风险。我们采用了一种高度敏感和选择性的分析方法，在 46 个居住着吸烟者和不吸烟者的家庭的沉降灰尘样本中，检测到了尼古丁、八种 N-亚硝胺和五种烟草特异性亚硝胺。利用房屋灰尘成分的观测结果，我们应用最新的官方毒理学信息，估计了癌症风险。在生命早期阶段（1 至 6 岁），通过接触观测到的 TSNAs 水平，计算出的癌症风险在 77%的吸烟者家庭和 64%的不吸烟者家庭中超过了美国环保署推荐的上限风险。在吸烟者居住的家庭中，通过接触所有测量到的亚硝胺，导致每千名暴露人群中出现一例额外癌症病例的风险最大。这里呈现的结果强调了三手烟暴露的潜在严重的长期后果，特别是对儿童而言，这为其潜在健康风险提供了有力证据，因此，在制定未来的环境和健康政策时，应该考虑到这一点。
