Characteristics of indoor and outdoor black carbon aerosol during winter and summer in rural area of Guanzhong Plain

【摘要】：Black Carbon(BC) were measured continuously in rural area of Guanzhong Plain during winter and summer.The concentrations of BC varied acutely over a range of 3.9-25.6 μg m-3 for outdoor and 4.8-24.7 μg m-3 for indoor in daily mean concentration,with the overall average values of 14.6 μg m-3 and 14.4 μg m-3 for outdoor and indoor in winter,respectively.Daily mean BC concentrations varied over a range of 2.9-9.9μg m-3 for outdoor and 4.7-10.2μg m-3 for indoor,with the overall average value of 6.0 μg m-3 and 7.2 μg m-3 for outdoor and indoor,respectively in summer.The results shows the concentrations of black carbon is high in the rural area,especially in winter,which is probably due to the local biomass burning for warming and cooking.In rural area of Guanzhong Plain,Obviously diurnal variation of BC was observed,with the hourly average concentrations ascending to its peaks twice a day in the morning and at the evening.The frequency distributions of BC concentrations in both indoor and outdoor environments showed a similar pattern.In indoor environment,it was found that the BC concentrations were distributed over the high spectrum of concentrations than that for outdoor environment.The relationships between indoor and outdoor concentrations(separately for LT,WN and HX sites) of BC were discussed,which showed a good correlation between indoor and outdoor air of the three sites.The results suggest that indoor black carbon was derived at least in part from outdoor air.