Zapata-Marin Sara, Schmidt Alexandra M, Crouse Dan, Ho Vikki, Labrèche France, Lavigne Eric, Parent Marie-Élise, Goldberg Mark S
Quantitative Life Sciences, McGill University, Montreal, Quebec, Canada.
Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, Quebec, Canada.
Environ Epidemiol. 2022 Sep 14;6(5):e226. doi: 10.1097/EE9.0000000000000226. eCollection 2022 Oct.
Volatile organic compounds (VOCs) are components of the complex mixture of air pollutants within cities and can cause various adverse health effects. Therefore, it is necessary to understand their spatial distribution for exposure assessment in epidemiological studies.
The objective was to model measured concentrations of five VOCs within the city of Montreal, Canada, developing spatial prediction models that can be used in health studies.
We measured concentrations using 3M 3500 Organic Vapor Monitors, over 2-week periods, for three monitoring campaigns between 2005 and 2006 in over 130 locations in the city. Using GC/MSD (Gas Chromatography/Mass Selective Detector), we measured concentrations of benzene, n-decane, ethylbenzene, hexane, and trimethylbenzene. We fitted four different models that combine land-use regression and geostatistical methods to account for the potential spatial structure that remains after accounting for the land-use variables. The fitted models also accounted for possible variations in the concentration of air pollutants across campaigns.
The highest concentrations for all VOCs were found in December with hexane being the most abundant followed by ethylbenzene. We obtained predicted surfaces for the VOCs for the three campaigns and mean surfaces across campaigns. We found higher concentrations of some VOCs along highways and in the Eastern part of Montreal, which is a highly industrialized area.
Each of the fitted models captured the spatial and across-campaigns variability for each VOC, and we found that different VOCs required different model structures.
挥发性有机化合物（VOCs）是城市空气污染物复杂混合物的组成部分，可导致各种不良健康影响。因此，有必要了解其空间分布，以便在流行病学研究中进行暴露评估。
目的是对加拿大蒙特利尔市五种挥发性有机化合物的测量浓度进行建模，开发可用于健康研究的空间预测模型。
我们在2005年至2006年期间进行了三次监测活动，每次为期两周，使用3M 3500有机蒸汽监测仪在该市130多个地点测量浓度。我们使用气相色谱/质谱选择性检测器（GC/MSD）测量苯、正癸烷、乙苯、己烷和三甲苯的浓度。我们拟合了四种不同的模型，这些模型结合了土地利用回归和地统计方法，以考虑在考虑土地利用变量后仍然存在的潜在空间结构。拟合模型还考虑了不同监测活动期间空气污染物浓度的可能变化。
所有挥发性有机化合物的最高浓度出现在12月，其中己烷含量最高，其次是乙苯。我们获得了三次监测活动中挥发性有机化合物的预测表面以及各次活动的平均表面。我们发现，在高速公路沿线和蒙特利尔东部（一个高度工业化的地区），某些挥发性有机化合物的浓度较高。
每个拟合模型都捕捉到了每种挥发性有机化合物的空间和跨活动变异性，并且我们发现不同的挥发性有机化合物需要不同的模型结构。
