Study On The Pollution Characteristics And Dynamic Changes Of Particulate Matter In An Office Environment

People generally spend most of their time indoors, so the indoor air quality has a direct impact on human health. Particulate matter is one of the important factors that affect the indoor air quality. The particle with size of less than 2.5μm is especially harmful to human health. Therefore, the study of indoor particulate pollution characteristics and dynamic changes can make us better understand the impact of pollution sources on indoor air quality. It provides scientific basis to improve indoor environment quality and to develop indoor air quality standards.This paper takes an office as the research object. It carries on smoking experiment,cleaning experiment, printing experiment, walking experiment, air humidification experiment and outdoor pollution source experiment. The changes of mass concentration and particle number concentration of particulate matter in various conditions are measured. The results show that smoking, tap-water-humidification and cold boiled-water-humidification have significant impacts on indoor particulate matter and result in the rapid increase of the fine particulate matter. They are the main pollution sources in the office. Sweeping floor has a significant effect on the particles with size of greater than 1μm, and it makes the mass concentration of particles with size of greater than 2.5μm increase sharply. Wiping table has no significant effect on indoor particulate matter.This paper analyses the purification effect of purifier with different units and different wind speeds on indoor particulate matter. Then it obtains the relationship between purifier air volume and effectiveness. The results show that increasing purifier air volume leads to the lager increment of effectiveness for the particle with size of less than 2.5μm, but it has no significant effect on the particle with size of lager than 2.5μm.This paper studies the effects of smoking on indoor particle characteristics in opened-window and closed-window environment. It obtains the pollution characteristics and the variety law of the indoor particulate matter in the two different environments.The results show that the opened-window can greatly reduce the growth rate of indoor particulate matter and make the concentration of indoor particulate matter rapidly down to the level of outdoor particulate matter concentration. Therefore, it is a fast and effective method to reduce higher particle concentration.The results can provide reference and basis for the evaluation of indoor air quality.It is conducive to put forward the targeted measures to improve the indoor air quality.