Cupitt L T, Glen W G, Lewtas J
Methods Research and Development Division, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711.
Environ Health Perspect. 1994 Oct;102 Suppl 4(Suppl 4):75-84. doi: 10.1289/ehp.94102s475.
A major field study was conducted in Boise, Idaho, during the heating season of 1986 to 1987 as part of the Integrated Air Cancer Project. Filter samples were systematically collected in residences and in the ambient air across the community to characterize the particle-bound pollutants. The extractable organic matter (EOM) from the filter samples was apportioned to its source of origin, either residential wood combustion (RWC) or mobile sources (MS). Two composite samples, with apportioned contributions from RWC and MS, were prepared from the Boise ambient samples and tested for tumor-initiation potency. A comparative potency lung cancer risk estimate has been made based on the two ambient composite samples from this airshed. In addition, a microenvironmental exposure model was developed from the Boise data and from national survey data to estimate the exposure to EOM from RWC and MS. In this paper, the microenvironmental model is extrapolated to provide an estimate of the average annual exposure and dose in Boise to EOM from RWC and MS. The annual model considers actual pollutant levels in Boise, historical changes in RWC usage and meteorological dilution factors and the likely activities in the various microenvironmental zones and their resultant inhalation rates. Combined with the lifetime risk estimates, the average annual dose suggests a risk of about 4 x 10(-4) based upon the composite ambient samples. Despite the fact that RWC accounts for 73% of the EOM on an annual average basis, it accounts for only about 20% of the estimated lifetime risk.
作为综合空气污染与癌症项目的一部分，1986年至1987年供暖季期间，在爱达荷州博伊西市进行了一项大型实地研究。在整个社区的住宅和环境空气中系统地采集过滤器样本，以表征颗粒结合污染物。将过滤器样本中的可提取有机物（EOM）按其来源进行分配，即住宅木材燃烧（RWC）或移动源（MS）。从博伊西市的环境样本中制备了两个综合样本，分别包含RWC和MS的分配贡献，并对其肿瘤引发潜能进行了测试。基于该空气流域的两个环境综合样本，进行了肺癌风险估计的比较效能分析。此外，利用博伊西市的数据和全国调查数据开发了一个微环境暴露模型，以估计来自RWC和MS的EOM暴露情况。在本文中，对微环境模型进行了外推，以估计博伊西市每年平均接触RWC和MS的EOM的暴露量和剂量。年度模型考虑了博伊西市的实际污染物水平、RWC使用的历史变化、气象稀释因子以及各个微环境区域可能的活动及其相应的吸入率。结合终生风险估计，基于综合环境样本，平均年剂量表明风险约为4×10⁻⁴。尽管RWC平均每年占EOM的73%，但它仅占估计终生风险的约20%。
