Analysis of Contamination Characteristics and Exposure of Microbial Aerosol in Commuter Motor Vehicles During Autumn
To understand the contamination characteristics and exposure risks of microbial aerosols in commuter carriages during peak commuting hours,especially the morning and evening rush hours,this paper selected a bus and a small passenger car in Beijing as the research objects.The airborne bacteria and fungi were sampled on site from their compartments during the morning and evening peak hours,and subsequently cultured in the laboratory.Microbial aerosol concentration levels and particle size distribution characteristics were analyzed in the passenger and driver seats of commuter carriages during peak hours.The effects of particulate matter concentration and passenger flow on microbial aerosols were discussed,and microbial exposure risk was assessed.The results showed that:1)During peak hours,the small passenger car exhibited fungal and bacterial aerosol contamination levels that met the cleaner class standards.However,in the bus,the concentration of bacterial aerosol basically did not exceed the standard value,but fungal contamination was evident,and the pollution was concentrated in the passenger seats;2)Microbial aerosol concentration in the small passenger car during peak hours is influenced by outdoor sources.Bacterial aerosol concentrations in passenger compartments of buses are influenced by indoor sources,and microbial aerosol concentration in buses under air-conditioned ventilation is mainly influenced by the air-conditioning and occupants;3)The particle size distribution of bacterial aerosols in commuter carriages mainly falls in the range of 2.1 to 7.0 μm,while the fungal distribution falls mainly in the range of 1.1 to 4.7 µm;4)Microbial aerosol concentrations in the compartments were positively correlated with the flow of people,and total bacterial and fungal concentrations were positively correlated with PM1.0,PM2.5,and PM10;5)The coefficient of influence of microbial exposure on human health is less than 1,with a slightly higher value for males compared with females,and higher for drivers compared with passengers.
commuter motor vehiclespeak hoursmicrobial aerosolscontamination characteristicsexposure risk
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万方数据
