Kim Janice J, Huen Karen, Adams Sara, Smorodinsky Svetlana, Hoats Abby, Malig Brian, Lipsett Michael, Ostro Bart
Office of Environmental Health Hazard Assessment, Air Pollution Epidemiology Section, Oakland, California, USA.
Environ Health Perspect. 2008 Sep;116(9):1274-9. doi: 10.1289/ehp.10735.
Living near traffic has been associated with asthma and other respiratory symptoms. Most studies, however, have been conducted in areas with high background levels of ambient air pollution, making it challenging to isolate an independent effect of traffic. Additionally, most investigations have used surrogates of exposure, and few have measured traffic pollutants directly as part of the study.
We conducted a cross-sectional study of current asthma and other respiratory symptoms in children (n = 1,080) living at varying distances from high-traffic roads in the San Francisco Bay Area, California, a highly urbanized region characterized by good regional air quality due to coastal breezes.
We obtained health information and home environmental factors by parental questionnaire. We assessed exposure with several measures of residential proximity to traffic calculated using geographic information systems, including traffic within a given radius and distance to major roads. We also measured traffic-related pollutants (nitrogen oxides and nitrogen dioxide) for a subset of households to determine how well traffic metrics correlated with measured traffic pollutants.
Using multivariate logistic regression analyses, we found associations between current asthma and residential proximity to traffic. For several traffic metrics, children whose residences were in the highest quintile of exposure had approximately twice the adjusted odds of current asthma (i.e., asthma episode in the preceeding 12 months) compared with children whose residences were within the lowest quintile. The highest risks were among those living within 75 m of a freeway/highway. Most traffic metrics correlated moderately well with actual pollutant measurements.
Our findings provide evidence that even in an area with good regional air quality, proximity to traffic is associated with adverse respiratory health effects in children.
居住在交通繁忙区域与哮喘及其他呼吸道症状有关。然而，大多数研究是在环境空气污染背景水平较高的地区进行的，这使得分离交通的独立影响具有挑战性。此外，大多数调查使用的是暴露替代指标，很少有研究将直接测量交通污染物作为研究的一部分。
我们对加利福尼亚州旧金山湾区不同距离交通繁忙道路居住的儿童（n = 1080）进行了一项关于当前哮喘及其他呼吸道症状的横断面研究。该地区高度城市化，由于沿海微风，区域空气质量良好。
我们通过家长问卷获取健康信息和家庭环境因素。我们使用地理信息系统计算的几种居住与交通接近程度的指标来评估暴露情况，包括给定半径内的交通流量和到主要道路的距离。我们还对一部分家庭测量了与交通相关的污染物（氮氧化物和二氧化氮），以确定交通指标与测量的交通污染物之间的相关性。
使用多变量逻辑回归分析，我们发现当前哮喘与居住接近交通之间存在关联。对于几个交通指标，居住暴露处于最高五分位数的儿童与居住暴露处于最低五分位数的儿童相比，当前哮喘（即前12个月内有哮喘发作）的调整后比值约为两倍。风险最高的是那些居住在高速公路75米范围内的儿童。大多数交通指标与实际污染物测量结果中度相关。
我们的研究结果提供了证据，表明即使在区域空气质量良好的地区，居住接近交通也与儿童不良的呼吸道健康影响有关。
