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In recent years, ambient air has been severely contaminated by particulate matters (PMs) and some gas pollutants (nitrogen dioxide (NO2) and sulfur dioxide (SO2)) in China, and many studies have demonstrated that exposure to these pollutants can induce great adverse impacts on human health. The concentrations of the pollutants were much higher in winter than those in summer, and the average concentrations in this studied area were lower than those in northern China. In the comparison between high-resolution emission inventory and spatial distribution of PM2.5, significant positive linear correlation was found. Though the pollutants had similar trends, NO2 and SO2 delayed with 1 h to PM2.5. Besides, PM2.5 had a lag time of 1 h to temperature and relative humidity. Significant linear correlation was found among pollutants and meteorological conditions, suggesting the impact of meteorological conditions on ambient air pollution other than emission. For the 24-h trend, lowest concentrations of PM2.5, NO2, and SO2 were found around 15:00-18:00. In 2015, the population attributable fractions (PAFs) for ischemic heart disease (IHD), cerebrovascular disease (stroke), chronic obstructive pulmonary disease (COPD), lung cancer (LC), and acute lower respiratory infection (ALRI) due to the exposure to PM2.5 in Zhejiang province were 25.82, 38.94, 17.73, 22.32, and 31.14%, respectively. The population-weighted mortality due to PM2.5 exposure in Zhejiang province was lower than the average level of the whole country—China. [ABSTRACT FROM AUTHOR]

Abstract: Chemical contaminants emitted by dried building material influence the indoor air quality in the long term. Re-circulated ventilation is widely used in the actual ventilation systems and it is one of the important factors affecting the indoor contaminant concentration distribution. The objectives of this paper are to simulate the indoor total volatile organic compounds (TVOCs) distribution emitted from a new floor and the total TVOCs quantity inhaled by an occupant with the different fresh air ratios under a re-circulated ventilation system. Furthermore, contribution ratio of pollution source (CRP) index is utilized to calculate the TVOCs contribution ratio to the inhaled contaminant generated from different locations. Finally, the mean TVOCs emission rate and the residual TVOCs percentage within the building material, average concentration and average ventilation effectiveness at the different locations of the room with respect to time are also investigated. The simulation result and analysis are helpful for designing the indoor healthy occupant environment and improving some features of the re-circulated ventilation system. [Copyright &y& Elsevier]