Brown Kathleen Ward, Sarnat Jeremy A, Suh Helen H, Coull Brent A, Koutrakis Petros
Exposure, Epidemiology and Risk Program, Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA.
Sci Total Environ. 2009 Jun 1;407(12):3754-65. doi: 10.1016/j.scitotenv.2009.02.016. Epub 2009 Mar 13.
Previous exposure studies have shown considerable inter-subject variability in personal-ambient associations. This paper investigates exposure factors that may be responsible for inter-subject variability in these personal-ambient associations. The personal and ambient data used in this paper were collected as part of a personal exposure study conducted in Boston, MA, during 1999-2000. This study was one of a group of personal exposure panel studies funded by the U.S. Environmental Protection Agency's National Exposure Research Laboratory to address areas of exposure assessment warranting further study, particularly associations between personal exposures and ambient concentrations of particulate matter and gaseous co-pollutants. Twenty-four-hour integrated personal, home indoor, home outdoor and ambient sulfate, elemental carbon (EC), PM(2.5), ozone (O(3)), nitrogen dioxide (NO(2)) and sulfur dioxide were measured simultaneously each day. Fifteen homes in the Boston area were measured for 7 days during winter and summer. A previous paper explored the associations between personal-indoor, personal-outdoor, personal-ambient, indoor-outdoor, indoor-ambient and outdoor-ambient PM(2.5), sulfate and EC concentrations. For the current paper, factors that may affect personal exposures were investigated, while controlling for ambient concentrations. The data were analyzed using mixed effects regression models. Overall personal-ambient associations were strong for sulfate during winter (p<0.0001) and summer (p<0.0001) and PM(2.5) during summer (p<0.0001). The personal-ambient mixed model slope for PM(2.5) during winter but was not significant at p=0.10. Personal exposures to most pollutants, with the exception of NO(2), increased with ventilation and time spent outdoors. An opposite pattern was found for NO(2) likely due to gas stoves. Personal exposures to PM(2.5) and to traffic-related pollutants, EC and NO(2), were higher for those individuals living close to a major road. Both personal and indoor sulfate and PM(2.5) concentrations were higher for homes using humidifiers. The impact of outdoor sources on personal and indoor concentrations increased with ventilation, whereas an opposite effect was observed for the impact of indoor sources.
以往的暴露研究表明，个体与环境之间的关联存在相当大的个体间差异。本文调查了可能导致这些个体与环境关联中个体间差异的暴露因素。本文所使用的个人和环境数据是作为1999 - 2000年在马萨诸塞州波士顿进行的一项个人暴露研究的一部分收集的。该研究是由美国环境保护局国家暴露研究实验室资助的一组个人暴露面板研究之一，旨在解决暴露评估中需要进一步研究的领域，特别是个人暴露与颗粒物和气态共污染物的环境浓度之间的关联。每天同时测量24小时综合个人、家庭室内、家庭室外和环境中的硫酸盐、元素碳（EC）、细颗粒物（PM(2.5)）、臭氧（O(3)）、二氧化氮（NO(2)）和二氧化硫。在冬季和夏季对波士顿地区的15个家庭进行了7天的测量。之前的一篇论文探讨了个人 - 室内、个人 - 室外、个人 - 环境、室内 - 室外、室内 - 环境和室外 - 环境中PM(2.5)、硫酸盐和EC浓度之间的关联。对于本文，在控制环境浓度的同时，研究了可能影响个人暴露的因素。使用混合效应回归模型对数据进行分析。冬季（p<0.0001）和夏季（p<0.0001）硫酸盐以及夏季（p<0.0001）PM(2.5)的总体个人与环境关联很强。冬季PM(2.5)的个人与环境混合模型斜率在p = 0.10时不显著。除NO(2)外，大多数污染物的个人暴露随着通风和在户外花费的时间增加而增加。对于NO(2)，由于燃气炉灶可能发现了相反的模式。居住在主要道路附近的个体，其个人对PM(即2.5)以及与交通相关的污染物EC和NO(2)的暴露更高。使用加湿器的家庭，其个人和室内硫酸盐及PM(2.5)浓度更高。室外源对个人和室内浓度的影响随着通风增加，而对于室内源的影响则观察到相反的效果。
