THESIS
2001
xi, 133 leaves : ill. ; 30 cm
Abstract
The elemental compositions and size distributions of indoor aerosol and outdoor aerosol are key factors to investigate the impact of outdoor aerosol on indoor environment and the impact of indoor aerosol on human health. In this study, PM
2.5 and PM
10 samples in 34 residential apartments were collected in Hong Kong during the Fall and Winter period. Outdoor samplings were conducted in nearby environments for comparison. Elemental species analyses of the aerosol samples were conducted by Proton Induced X-Ray Emission (PIXE) method. Information of 17 elements was revealed. The average indoor PM
10 and PM
2.5 concentrations were 75.9 and 53.1 μg/m
3 respectively while the average outdoor PM
10 and PM
2.5 concentrations were 87.7 and 54.1 μg/m
3 respectively. Total inorganic species concentrations...[
Read more ]
The elemental compositions and size distributions of indoor aerosol and outdoor aerosol are key factors to investigate the impact of outdoor aerosol on indoor environment and the impact of indoor aerosol on human health. In this study, PM
2.5 and PM
10 samples in 34 residential apartments were collected in Hong Kong during the Fall and Winter period. Outdoor samplings were conducted in nearby environments for comparison. Elemental species analyses of the aerosol samples were conducted by Proton Induced X-Ray Emission (PIXE) method. Information of 17 elements was revealed. The average indoor PM
10 and PM
2.5 concentrations were 75.9 and 53.1 μg/m
3 respectively while the average outdoor PM
10 and PM
2.5 concentrations were 87.7 and 54.1 μg/m
3 respectively. Total inorganic species concentrations in the indoor samples were found to be 6.4 μg/m
3 and 10.2 μg/m
3 respectively for PM
2.5 and PM
10 while for the outdoor samples, they were 7.9 μg/m
3 and 14.1 μg/m
3 respectively. Sulfur and Potassium contributed the most in terms of mass concentration among all species, while there were trace amounts of Titanium, Vanadium and Nickel. Besides, enrichment factor analysis was employed to investigate the impact of outdoor air on indoor environment. Low enrichment factors of Calcium, Iron, Magnesium, Silicon, Sodium and Titanium were observed. This indicated that these species were mostly derived from soil. The high enrichment factors of Sulfur, Chlorine, Titanium, manganese, Nickel, Copper, and Zinc were reported. This indicated that industrial operations were a major contributor to the existence of these species.
In addition, indoor and outdoor particulate size distributions in 60 residential apartments were measured during winter and summer in Hong Kong. The indoor and outdoor particulate size distributions were obtained from a pair of cascade impactors. The seasonal effects on indoor particulate concentrations were investigated in this study. High indoor and outdoor particulate concentrations were reported in winter. The reasons of this issue were that local source emission and long distance transportation of pollutants led to high outdoor particulate concentrations. Highly polluted outdoor air and various indoor activities led to the high indoor particulate concentration in winter. Besides, PM
0.0 - 0.4 was identified as the highest peak size of indoor and outdoor particulate matters and the indoor particulate matters was mainly contributed by fine particles. I/O ratio was employed to investigate the relationship between indoor particulate matters and outdoor particulate matters. The results showed that the I/O ratio of each size range in summer was higher than in winter.
Pearson paired t-tests were employed to correlate indoor particulate concentrations and outdoor particulate concentrations in the inorganic species study and the particulate size distribution study. The results indicated that poor correlation was found between indoor particulate concentrations and outdoor particulate concentrations in winter. The R
2 was less than 0.1. However, the results indicated that moderate correlation was found between indoor particulate concentrations and outdoor particulate concentrations in summer. The R
2 was found to range from 0.3 to 0.4.
Post a Comment