Size Distribution and Lung Deposition Surface Area(LDSA)of Carbon Aerosols in Nanchang Based on ELPI+
Size distribution of aerosols and carbon fractions can help identify sources and explore formation mechanisms,and lung deposition surface area(LDSA)is an important indicator for health risk assessment of aerosol particles deposited in the alveolar region of the human respiratory tract.From December 2017 to November 2018,the size distribution and LDSA of indoor and outdoor aerosols in Nanchang was investigated by using the electrical low-pressure impactor(ELPI+),and the results showed that the major airborne particles in the regional mixing receptor sites,roadside,printing room,and students'dormitories during the sampling period were the Nucleation and Accumulation modes,the Aitken and Nucleation modes,the Nucleation mode,the Accumulation mode.The size distributions of organic carbon(OC)in outdoor and indoor air parti-cles were similar,with a single peak,and the peak appeared in the 7 th particle size class(0.256～0.382 μm).The size distribu-tions of elemental carbon(EC)in particles showed a single peak indoors,and multiple peaks outdoors.The size distribution of OC/EC ratios of different microenvironmental particles mostly showed a"L"shape,but there is no significant difference in the OC/EC ratio of particles with different particle sizes in the printing room,which is approximately in a"—"shape.The dominant carbon components of outdoor air particulate matter were OC2,OC3,OC4 and EC1,which mainly originated from coal combustion emissions and motor vehicle exhaust,while the dominant carbon components of indoor air particulate matter were OC1,OC2 and OC3,which mainly originated from cigarette combustion and outdoor air infiltration.The LDSA of differ-ent microenvironmental particles varied,and the daily mean values of LDSA were 49.0,10.9,29.9,and 31.0 μm2/m3 for the outdoor mixed-source receptor sites,the roadside,and the indoor printing room and the students'dormitory,respectively,and the LDSA of the particles was very high in the indoor environments with obvious contributing sources(e.g.,printing work or cigarette combustion)for a short period of time,especially under the influence of the cigarette combustion,exceeding the max-imum value of ambient air particulate LDSA.High percentage of LDSA was for particles smaller than 100 nm in roadside air,and high percentage of LDSA for particles in the 100～600 nm size range in indoor environments where there is a cigarette combustion source.
万方数据
维普
