Characteristics of indoor/outdoor PM 2.5 and elemental components in generic urban, roadside and industrial plant areas of Guangzhou City, China

Abstract

Quantitative information on mass concentrations and other characteristics, such as spatial distribution, seasonal variation, indoor/outdoor (I/O) ratio, correlations and sources, of indoor and outdoor PM 2.5 and elemental components in Guangzhou City were provided. Mass concentration of PM 2.5 and elemental components were determined by standard weight method and proton-induced X-ray emission (PIXE) method. 18 elements were detected, the results showed positive results. Average indoor and outdoor PM 2.5 concentrations in nine sites were in the range of 67.7–74.5 μg/m 3 for summer period, and 109.9–123.7 μg/m 3 for winter period, respectively. The sum of 18 elements average concentrations were 5362.6–5533.4 μg/m 3 for summer period, and 8416.8–8900.6 μg/m 3 for winter period, respectively. Average concentrations of PM 2.5 and element components showed obvious spatial characteristic, that the concentrations in roadside area and in industrial plant area were higher than those in generic urban area. An obvious seasonal variation characteristic was found for PM 2.5 and elemental components, that the concentrations in winter were higher than that in summer. The I/O ratio of PM 2.5 and some elemental components presented larger than 1 sometimes. According to indoor/outdoor correlation of PM 2.5 and element concentrations, it was found that there were often good relationships between indoor and outdoor concentrations. Enrichment factors were calculated to evaluate anthropogenic versus natural elements sources.