Van Ryswyk Keith, Wheeler Amanda J, Grgicak-Mannion Alice, Xu Xiaohong, Curran Jason, Caravaggio Gianni, Hall Ajae, MacDonald Penny, Brook Jeffrey R
Water and Air Quality Bureau, Health Canada, Ottawa, ON K1A 0K9, Canada.
Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC 3000, Australia.
Toxics. 2022 May 26;10(6):284. doi: 10.3390/toxics10060284.
There have been several methods employed to quantify individual-level exposure to ambient traffic-related air pollutants (TRAP). These include an individual's residential proximity to roads, measurement of individual pollutants as surrogates or markers, as well as dispersion and land use regression (LUR) models. Hopanes are organic compounds still commonly found on ambient particulate matter and are specific markers of combustion engine primary emissions, but they have not been previously used in personal exposure studies. In this paper, children's personal exposures to TRAP were evaluated using hopanes determined from weekly integrated filters collected as part of a personal exposure study in Windsor, Canada. These hopane measurements were used to evaluate how well other commonly used proxies of exposure to TRAP performed. Several of the LUR exposure estimates for a range of air pollutants were associated with the children's summer personal hopane exposures (r = 0.41-0.74). However, all personal hopane exposures in summer were more strongly associated with the length of major roadways within 500 m of their homes. In contrast, metrics of major roadways and LUR estimates were poorly correlated with any winter personal hopanes. Our findings suggest that available TRAP exposure indicators have the potential for exposure misclassification in winter vs. summer and more so for LUR than for metrics of major road density. As such, limitations are evident when using traditional proxy methods for assigning traffic exposures and these may be especially important when attempting to assign exposures for children's key growth and developmental windows. If long-term chronic exposures are being estimated, our data suggest that measures of major road lengths in proximity to homes are a more-specific approach for assigning personal TRAP exposures.
已经采用了几种方法来量化个体层面暴露于环境交通相关空气污染物（TRAP）的情况。这些方法包括个体住所与道路的距离、将个体污染物测量作为替代物或标志物，以及扩散和土地利用回归（LUR）模型。藿烷是仍普遍存在于环境颗粒物上的有机化合物，是内燃机一次排放的特定标志物，但此前尚未用于个人暴露研究。在本文中，利用从加拿大温莎市一项个人暴露研究中每周收集的综合过滤器中测定的藿烷，评估了儿童对TRAP的个人暴露情况。这些藿烷测量值用于评估其他常用的TRAP暴露替代指标的表现。一系列空气污染物的几种LUR暴露估计值与儿童夏季个人藿烷暴露相关（r = 0.41 - 0.74）。然而，夏季所有个人藿烷暴露与他们家500米范围内主要道路的长度关联更强。相比之下，主要道路指标和LUR估计值与任何冬季个人藿烷的相关性都很差。我们的研究结果表明，现有的TRAP暴露指标在冬季和夏季存在暴露误分类的可能性，而且LUR比主要道路密度指标更明显。因此，使用传统替代方法来确定交通暴露存在明显局限性，而在试图确定儿童关键生长和发育阶段的暴露时，这些局限性可能尤为重要。如果要估计长期慢性暴露，我们的数据表明，测量家附近主要道路的长度是确定个人TRAP暴露的更具体方法。
