Spatiotemporal Distribution of PM_2.5 and Its Correlation with Other Air Pollutants in Winter During 2016~2018 in Xi’an, China

Abstract

High concentration of PM 2.5 has seriously affected people's daily lives in recent years. It is necessary to analyze PM 2.5 and the correlations with other pollutants in winter. Data presented in this paper were obtained from monitoring stations from 2016 to 2018. Attention was fixed on PM 2.5 and its monthly and daily variations in winter. Furthermore, the correlations between PM 2.5 and CO, SO 2 , NO 2 , O 3 and PM 10 were studied. The results showed concentrating PM 2.5 was roughly consistent with the monthly and daily trends. It was January>December>February>November>March. The mass concentration ranges of PM 2.5 before and after the adjustment of heating energy structures were 64.5-184.1 μg/m 3 , and 86.4-140.1 μg/m 3 , respectively. The average concentrations of PM 2.5 were 135.5 μg/m 3 , and 109.1 μg/m 3 , decreased by 26.4 μg/m 3. PM 2.5 /PM 10 was changed from 64.6% to 62.6%, reduced by 2%. The linear correlation analysis revealed a strong correlation between PM 2.5 and CO, SO 2 , NO 2 , and PM 10 , but a negative correlation between PM 2.5 and O 3. Two multiple linear regression models on the pollutants were established, respectively. This study helps understand the concentrating distribution of PM 2.5 and other pollutants in winter. It will provide some useful references to control air pollution for some cities, which have a similar type of heating energy structure.

Concentration Characteristics and Correlations with Other Pollutants of Atmospheric Particulate Matter as Affected by Relevant Policies

“…Xi'an, with located longitude 107.40 • ~109.49 • E and latitude 33.42 • ~34.45 • N, was selected as the research area [23]. It is a long-established, old-civilization city with more than 5000 years of civilization history [23], and it has a large population.…”

“…Xi'an, with located longitude 107.40 • ~109.49 • E and latitude 33.42 • ~34.45 • N, was selected as the research area [23]. It is a long-established, old-civilization city with more than 5000 years of civilization history [23], and it has a large population. However, the atmospheric environmental conditions in Xi'an have become increasingly serious in recent years, and this has deeply affected people's lives.…”

“…The main reason was the demand for heating in winter, which leads to an increase in the concentrations of particulate matter. Another reason was the influence of vertical movement in the atmosphere, which is not conducive to the spread of particles [22,23]. As a result, the concentrations of particulate matter reached the maximum at around 11 o'clock at night.…”

Comparison of the Application of Three Methods for the Determination of Outdoor PM2.5 Design Concentrations for Fresh Air Filtration Systems in China

“…With the increasing concentrations of particulate matter in the atmosphere, how to build a good indoor environment is a current focus of attention. Haze weather frequently appears in most cities in China [ 1 , 2 , 3 ], especially in winter [ 3 ]. In addition, PM 2.5 in the atmosphere might cause some diseases related to human lung disease, cardiovascular disease, etc.…”

High-Resolution Population Exposure to PM_2.5 in Nanchang Urban Region Using Multi-Source Data

“…According to the World Health Organization (WHO), air pollution was responsible for more than 7.6% of global deaths in 2015 [7]. From 2008 to 2015, 92% of the worldwide populations were exposed to PM 2.5 concentrations that exceeded the WHO Air Quality Guidelines (AQG) levels (10 μg/m 3 ), and 56% of the populations lived in areas with PM 2.5 concentrations higher than the Interim Target 1 (IT-1) (35 μg /m 3 ) [8]. In many Asian cities, the PM 2.5 concentrations are much higher than in U.S. or Europe, such as India and China, 86% of the populations experienced remarkably serious PM 2.5 concentrations over 75 μg/m 3 [9].…”