Experimental evidence for a significant contribution of cellulose to indoor aerosol mass concentration

摘要

An apartment bedroom located in a residential area of Aveiro (Portugal) was selected with the aim of characterizing the cellulose content of indoor aerosol particles. Two sets of samples were taken: (1) PM_(10) collected simultaneously in indoor and outdoor air; (2) PM_(10) and PM_(2.5) collected simultaneously in indoor air. The aerosol particles were concentrated on quartz fibre filters with low-volume samplers equipped with size selective inlets. The filters were weighed and then extracted for cellulose analysis by an enzymatic method. The average indoor cellulose concentration was 1.01 ± 0.24 μg m~(-3), whereas the average outdoor cellulose concentration was 0.078 ± 0.047 μg m~(-3), accounting for 4.0% and 0.4%, respectively, of the PM_(10) mass. The corresponding average ratio between indoor and outdoor cellulose concentrations was 11.1 ± 4.9, indicating that cellulose particles were generated indoors, most likely due to the handling of cotton-made textiles as a result of routine daily activities in the bedroom. Indoor cellulose concentrations averaged 1.22 ± 0.53 μg m~(-3) in the aerosol coarse fraction (determined from the difference between PM_(10) and PM_(2.5) concentrations) and averaged 0.38 ± 0.13 μg m~(-3) in the aerosol fine fraction. The average ratio between the coarse and fine fractions of cellulose concentrations in the indoor air was 3.6 ± 2.1. This ratio is in line with the primary origin of this biopolymer. Results from this study provide the first experimental evidence in support of a significant contribution of cellulose to the mass of suspended particles in indoor air.