US. Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory, 109 TW Alexander Dr, Research Triangle Park, NC 27711, USA.
J Air Waste Manag Assoc. 2013 Aug;63(8):934-42. doi: 10.1080/10962247.2013.795919.
A study, conducted in Las Vegas, NV from mid-December 2008 to mid-December 2009 along an interstate highway, collected continuous and integrated samples for a wide variety of air pollutant species including NO2 and NO(x) associated with roadway traffic. This study examined long-term trends of NO2 and NO(x) in a near-road environment compared with previous near-road studies typically lasting only a few days to months. Study results revealed concentration gradients for NO2 and NO(x) with highest absolute and average concentrations at distances closest to the roadway throughout the year. Diurnal ambient temperature changes also influenced concentrations due to atmospheric chemistry activity as well as concentration changes due to seasonal effects. These concentration gradients were observed for all wind conditions; however under downwind conditions (winds from highway), the concentration gradients are more pronounced. Higher pollutant concentrations are generally observed during low wind speed conditions especially when those winds were from the highway. Understanding long-term, seasonal variability and levels of pollutant concentrations in the near-road environment is important to researchers and decision-makers evaluating exposures and risks for near-road populations; identifying locations for future near-road monitoring sites; and determining the viability and effectiveness of mitigation strategies.
Population exposures to traffic emissions near roads have led to heightened public health concerns and awareness of the long-term levels and variability of these air pollutants. Epidemiological studies have lead to improved understanding of the associated risks and health effects of near road air pollutant emissions. While short-term studies provide insights on near-road air quality, longer-term trends need to be understood, especially for reactive pollutants such as NO2.
这项研究于 2008 年 12 月中旬至 2009 年 12 月中旬在内华达州拉斯维加斯的州际公路沿线进行，采集了包括与道路交通相关的二氧化氮和氮氧化物在内的多种空气污染物的连续综合样本。与通常持续数天至数月的以往近路研究相比，本研究检查了近路环境中二氧化氮和氮氧化物的长期趋势。研究结果表明，在接近道路的环境中，二氧化氮和氮氧化物的浓度存在梯度，全年最接近道路的距离处绝对浓度和平均浓度最高。由于大气化学活性以及由于季节性影响导致的浓度变化，昼夜环境温度变化也会影响浓度。在所有风向条件下都观察到了这些浓度梯度；然而，在顺风条件（来自高速公路的风）下，浓度梯度更为明显。在低风速条件下，污染物浓度通常较高，尤其是当这些风来自高速公路时。了解近路环境中污染物浓度的长期季节性变化和水平对于评估近路人群暴露和风险、确定未来近路监测点的位置以及确定缓解策略的可行性和有效性的研究人员和决策者来说非常重要。
道路附近的交通排放物使人们接触到更多的污染物，这引发了公众对健康的担忧，也使人们对这些空气污染物的长期水平和变异性有了更多的认识。流行病学研究使人们对与近路空气污染物排放相关的风险和健康影响有了更好的理解。虽然短期研究提供了近路空气质量的深入了解，但需要了解长期趋势，特别是对于二氧化氮等反应性污染物。
