成都市地铁站及车厢内挥发性有机化合物种类探究及影响因素分析

Investigation of volatile organic compounds types in Chengdu metro stations and carriages and their influencing factor analysis

为探究成都地铁站及车厢内部挥发性有机化合物(VOCs)种类、来源及影响因素,使用恒流气体采样器和TENAX-TA采样管,对不同路线不同人流量期间地铁车厢内、车厢通风口和站台内部(站厅层和站台层)空气进行采样,利用气相色谱质谱联用仪(GC-MS)对车厢内VOCs进行分析。结果表明:地铁站及车厢内部VOCs主要以烷烯烃类和苯系物为主,分别占污染物种类的42.59%和27.78%;高峰期时段车厢内VOCs整体质量浓度(46.47±3.2)μg·m^(−3)略高于非高峰期时段(41.35±3.82)μg·m^(−3);地铁机械通风系统可以有效稀释车厢内VOCs质量浓度;站厅层VOCs质量浓度(44.99±13.84)μg·m^(−3)高于站台层的质量浓度(35.05±11.28)μg·m^(−3)。由此可以看出,成都地铁内VOCs污染种类受人员密集、大气环境和通风设施等综合因素影响。本研究成果可为西南地区地铁系统VOCs污染的监管和防治提供数据支撑,亦可为相关部门提高地铁内部空气质量、降低乘客健康风险决策的制定提供参考。

Aiming to investigate the types,sources,and influencing factors of volatile organic compounds(VOCs)inside Chengdu metro stations and carriages,a constant flow gas sampler and a TENAX-TA sampling tube were used to sample the air inside the metro carriages,at the carriage vents,and inside the platforms(station hall layer and platform layer)during different pedestrian flows on different routes.The sampled VOCs were analyzed by using a gas chromatography-mass spectrometry(GC-MS).The results showed that the VOCs inside the stations and carriages were mainly alkyl olefins and benzenes,accounting for 42.59%and 27.78%of the air pollutants,respectively.The total VOCs mass concentration in the carriages was(46.47±3.2)μg·m^(−3) during peak hours,which was slightly higher than(41.35±3.82)μg·m^(−3) during off-peak hours.The mechanical ventilation system of the metro could effectively dilute the VOCs mass concentration in the carriages.The VOCs mass concentration at the station hall layer was(44.99±13.84)μg·m^(−3),which was higher than(35.05±11.28)μg·m^(−3) at the platform layer.VOCs pollution in the Chengdu metro was comprehensively influenced by diverse factors such as people flow,atmospheric environment,and ventilation facilities.This study can provide a support for the regulation and prevention of VOCs pollution in the metro system in Southwest China,also provide a reference for making decisions to improve the air quality inside the metro and reduce health risks to passengers.