The Research On Modeling Of Indoor Particulate Matter Of Outdoor Origin And Control Strategies

The topic of indoor and outdoor particle pollution has triggered quite a lot of concern in recent years. Increasing epidemiological studies have reported that particulate air pollution is associated with increased morbidity and mortality even at the generally low levels of air pollution. However, the biological mechanisms have not been understood. This issue becomes more complicated in a situation when the outdoor air is always contaminated by traffic exhaust, industrial activities, construction activities, etc. Particles entering indoor environment suspend for a long time and are inhaled by humans which aggravates the risk of health. Thus, prediction of indoor particle concentration of outdoor origin is extremely important.In this paper, the impacts of ambient particle on human health are introduced, two methods are involved in current study: epidemiology and toxicology, which are used to cognize the chronic and acute effect based on biology mechanism. In order to advance our understand on the indoor particle level and habit of human during daily life, a large-scale investigation is carried out, results show that people spend 85% of their time indoors, and 50% for residential indoor environment; also, indoor particle pollution is a universal problem, especially when indoor activities exist. Due to the inconvenient and unpractical of measurement for indoor particle concentration in common residence, the establishing of modeling is an optimal method to predict and analyze indoor particle concentration.Developing and validating a model for predicting the indoor concentration of particles of outdoor origin is a key objective of this paper is to, taking particle diameter and climate parameter as input value. This model is based on aerosol dynamics, penetration factor and deposition loss-rate coefficient are two important parameters. For penetration factors, the roughness of crack inner surface is taken into consideration; for deposition loss-rate coefficient, the boundary layer is divided into three sublayers, the deposition velocity can be obtained by integrating particle flux equation in the three sublayers, and then deposition loss-rate coefficient is gained.Taking penetration model, deposition model and filter efficiency theory into particles mass & quantity equation, the evaluation model of indoor particle concentration is gained. As the level of ambient particles is steady or instantaneous, indoor particle concentration is evaluated under different condition in five kinds of typical buildings. Also, the impact of air exchange rate, penetration factor, deposition loss-rate coefficient and resuspension on indoor particle level are discussed.Control strategy of indoor particle pollution is another key objective in this paper, three types of control strategies are presented, which include: decreasing or eliminating indoor particle sources, reducing the transport of outdoor particles into indoor environment and cleaning indoor polluted air with appliances.The evaluation model, which is based on outdoor environmental monitoring data to predict indoor particle size distribution and concentrations of particle pollution, can help to analyze the chemical composition and particle size distribution of indoor particles and reveal the human health pathogens mechanism affected by atmospheric particles at the same time, indoor particulate pollution control strategy which was obtained by the experimental results can guide people's daily lives and reduce indoor persons exposure to particulate pollution.