Klepeis Neil E, Ott Wayne R, Switzer Paul
Department of Civil and Environmental Engineering, Stanford University, Stanford, CA, USA.
J Air Waste Manag Assoc. 2007 May;57(5):522-34. doi: 10.3155/1047-3289.57.5.522.
The current lack of empirical data on outdoor tobacco smoke (OTS) levels impedes OTS exposure and risk assessments. We sought to measure peak and time-averaged OTS concentrations in common outdoor settings near smokers and to explore the determinants of time-varying OTS levels, including the effects of source proximity and wind. Using five types of real-time airborne particle monitoring devices, we obtained more than 8000 min worth of continuous monitoring data, during which there were measurable OTS levels. Measurement intervals ranged from 2 sec to 1 min for the different instruments. We monitored OTS levels during 15 on-site visits to 10 outdoor public places where active cigar and cigarette smokers were present, including parks, sidewalk cafés, and restaurant and pub patios. For three of the visits and during 4 additional days of monitoring outdoors and indoors at a private residence, we controlled smoking activity at precise distances from monitored positions. The overall average OTS respirable particle concentration for the surveys of public places during smoking was approximately 30 microg m(-3). OTS exhibited sharp spikes in particle mass concentration during smoking that sometimes exceeded 1000 microg m(-3) at distances within 0.5 m of the source. Some average concentrations over the duration of a cigarette and within 0.5 m exceeded 200 microg m(-3), with some average downwind levels exceeding 500 microg m(-3). OTS levels in a constant upwind direction from an active cigarette source were nearly zero. OTS levels also approached zero at distances greater than approximately 2 m from a single cigarette. During periods of active smoking, peak and average OTS levels near smokers rivaled indoor tobacco smoke concentrations. However, OTS levels dropped almost instantly after smoking activity ceased. Based on our results, it is possible for OTS to present a nuisance or hazard under certain conditions of wind and smoker proximity.
目前缺乏关于室外烟草烟雾（OTS）水平的实证数据，这阻碍了对OTS暴露和风险的评估。我们试图测量吸烟者附近常见室外环境中OTS的峰值浓度和时间平均浓度，并探讨OTS水平随时间变化的决定因素，包括与污染源的距离和风速的影响。我们使用五种实时空气颗粒物监测设备，获得了超过8000分钟的连续监测数据，在此期间存在可测量的OTS水平。不同仪器的测量间隔从2秒到1分钟不等。我们在对10个有活跃雪茄和香烟吸烟者的室外公共场所进行的15次实地考察中监测了OTS水平，这些场所包括公园、路边咖啡馆以及餐厅和酒吧的露台。在其中三次考察以及在一户私人住宅进行的额外4天室内外监测期间，我们在距监测位置精确距离处控制吸烟活动。公共场所吸烟调查期间OTS可吸入颗粒物的总体平均浓度约为30微克/立方米。OTS在吸烟期间颗粒物质量浓度出现急剧峰值，在距离污染源0.5米以内时，有时超过1000微克/立方米。在一支香烟燃烧期间以及距离污染源0.5米以内的一些平均浓度超过200微克/立方米，一些下风向的平均浓度超过500微克/立方米。在来自活跃香烟源的恒定上风向，OTS水平几乎为零。在距离单支香烟约2米以上时，OTS水平也接近零。在活跃吸烟期间，吸烟者附近OTS的峰值和平均水平与室内烟草烟雾浓度相当。然而，吸烟活动停止后，OTS水平几乎立即下降。根据我们的结果，在某些风速和吸烟者距离条件下，OTS有可能造成滋扰或危害。
