| With the rapid development of economy, society and technology, numerous studies were carried out to study outdoor concentrations and compositions of atmospheric fine particles (PM2.5) in China. However, less effort is devoted to indoor air quality research. To understand the indoor air quality in the city of Jinan, the capital of Shandong Province, samples of atmospheric fine particles (PM2.5) in three types of public indoor places (the supermarket, the commercial office and the university dining hall) were collected in four different seasons. Outdoor PM2.5samples were collected simultaneously. Water-soluble inorganic ions (F-、C1-、NO2-、 NO3-、 SO42-、Na+、NH4+、K+、Mg2+、Ca2+) in the samples were analyzed by ion chromatography. The meteorological factors (wind direction, wind speed, temperature and relative humidity) of the outdoor environment were recorded throughout the sampling period. The main conclusions of this thesis are listed as follows:1. PM2.5mass concentrations of public indoor places were significantly higher than concentrations of similar indoor places in other cities of the world. Mass concentrations of PM2.5in the supermarket, commercial office A, university dining hall and commercial office B (summer/autumn) were102.3,143.8,123.7,83.4and70.2ug·m-3, respectively, which were5-12times of the World health Organization (WHO) recommended value of PM2.5daily standard (25ug·m-3). Indoor air quality in the city of Jinan is poor. Indoor air is seriously polluted by fine particles.2. Generally speaking, mass concentrations of indoor PM2.5were significantly contributed by outdoor sources, while contributions of indoor sources were small. Average I/O ratios of PM2.5in the four public indoor places were in the range of0.34-0.78, which was less than unity, suggesting that outdoor air was more seriously polluted than indoor air, being inside a building will reduce the exposure risk.3. Diurnal variation trends of PM2.5mass concentrations in the supermarket, university dining hall and commercial office B (autumn) seemed to track the outdoor trends, which also indicates that outdoor PM2.5was the main sources of indoor fine particles. Measuring results of the commercial office A suggests that smoking would elevate mass concentrations of indoor PM2.5significantly, which led to the phenomenon of I/O ratio larger than1.4. The percent of total water-soluble ions in the supermarket, commercial office A and commercial office B were lower than that in the outdoor environment. The percent of total water-soluble ions in the university dining hall were higher than that in the outdoor environment, which was probably due to the higher relative humidity of the university dining hall.5. Indoor and outdoor ionic concentrations were generally in the same order, suggesting that indoor water-soluble ions were mainly from the outdoor environment. In winter, due to the coal combustion, SO42-, NH4+, NO3-and C1-were major water-soluble ions of both indoor and outdoor PM2.s. In spring, summer and autumn, SO42-, NH4+and NO3-were major water-soluble ions of both indoor and outdoor PM2.5. Due to the instability of nitrate, it will decrease remarkably when it permeated into the indoor environment.6. Generally speaking, affected by the factor of ventilation, the I/O ratios of all water-soluble ions were higher at daytime than at nighttime. Cleaning would elevate the concentration of indoor Cl-; smoking would release K+, dust resuspension caused by human movement would elevate concentrations of Na+and Ca2+... |
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