scholarly journals Effects of Haze Experiments by Artificial Intervention on Atmospheric Mixing Layer Height (MLH) and Air Pollution in Pearl River Delta Region

2021 ◽  
Author(s):  
Duan Peng ◽  
Chang Liu ◽  
Meiling Chen ◽  
Chunlin Xu ◽  
Minyan Liang
Keyword(s):  
Air Pollution ◽  
Pearl River Delta ◽  
Mixing Layer ◽  
Air Pollutant ◽  
Pollutant Concentration ◽  
Pearl River ◽  
Pearl River Delta Region ◽  
Daily Average ◽  
Pollutant Concentrations ◽  
Pm2.5 And Pm10

In this paper, the effects of 16 times of aircraft artificial intervention operations on atmospheric MLH and air pollution in Pearl River Delta Region were investigated. By analyzing the surface observation meteorological data collected hourly each day from 2015 to 2019 using the Nozaki Method and Statistical Analysis Method, the differences of MLH’s daily variations on haze and non-haze days were studied. Then the variations of MLH, pollutant concentrations and visibility before and after artificial intervention were studied. And the variations in the concentration of fine particles were obtained by analyzing the depolarization ratio’s vertical distribution detected by Guangzhou Polarized Micropulse Lidar System. Finally, the analysis of daily average air pollutant concentrations and thickness of atmospheric mixing layer, together with the analysis of MLH, surface ventilation and the corresponding pollutant concentration sequence 18 hours post-experiment can lead to effects of MLH on air pollution. The results showed that (1) MLH varies daily significantly; (2) The atmospheric MLH, air pollutant concentration and visibility vary significantly after aircraft artificial precipitation intervention: (a) the MLH and surface ventilation increase during the first three hours of rainfall; (b) the visibility increases significantly; (c) the concentrations of PM2.5 and PM10 decrease while the concentrations of coarse and modal particles show a significant trend of decrease; (d) the subsequent dilution effect on PM2.5 and PM10 also show out in a clear way, especially on PM10. The daily average concentrations of PM2.5 and PM10 are positively correlated with the daily average MLH in the region and the correlation coefficients are -0.71 and -0.63 respectively. After haze experiments by artificial intervention, PM2.5, PM10, SO2, NO2, CO and AQI indexes were negatively correlated with MLH and surface ventilation while positively correlated with O3. The research results show its value in the aspects of the atmospheric environmental quality assessment and pollutant diffusion capacity improvement in the region. It also helps in future data demonstration tests for the effects of haze experiments by artificial intervention on atmospheric turbulence and air pollution elimination. And it provides scientific decision-making basis for future relevant measures for the quality of urban atmospheric environment improvement.

scholarly journals Prolonged Exposure to Air Pollution Increases Periodontal Disease Risk: A Nationwide, Population-Based, Cohort Study

Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1668
Author(s):  
Han-Jie Lin ◽  
Stella Chin-Shaw Tsai ◽  
Frank Cheau-Feng Lin ◽  
Yi-Chao Hsu ◽  
Shih-Wei Chen ◽  
...  
Keyword(s):  
Air Pollution ◽  
Cohort Study ◽  
Prolonged Exposure ◽  
Disease Risk ◽  
Cox Proportional Hazards ◽  
Air Pollutant ◽  
Daily Average ◽  
Pollutant Concentrations ◽  
Air Pollutant Concentrations

(1) Background: No association between air pollution and periodontitis has yet been shown. Thus, we merged two nationwide databases to evaluate the risk of periodontitis in Taiwanese residents with long-term exposure to air pollution. (2) Methods: We conducted a nationwide retrospective cohort study using the Longitudinal Generation Tracking Database and the Taiwan Air Quality-Monitoring Database. The daily average air pollutant concentrations were categorized into quartiles (Q1, Q2, Q3, and Q4). We carried out Cox proportional hazards models to compute the hazard ratios of periodontitis, with 95% confidence intervals, in Q2–Q4 of the daily average air pollutant concentrations, compared with Q1. (3) Results: the adjusted HR (95 CI%) for periodontitis in Q2–Q4 increased with increased exposure to SO2, CO, NO, NO2, NOX, PM2.5, and PM10 from 1.72 (1.70, 1.76) to 4.86 (4.78–4.94); from 1.89 (1.85–1.93) to 2.64 (2.59–2.70); from 1.04 (1.02–1.06) to 1.52 (1.49–1.55); from 1.61 (1.58–1.64) to 2.51 (2.47–2.56); from 1.48 (1.45–1.51) to 2.11 (2.07–2.15); from 2.02 (1.98–2.06) to 22.9 (22.4–23.4, and from 2.71 (2.66–2.77) to 17.2 (16.8–17.6), respectively, compared to Q1. (4) Conclusions: Residents in Taiwan with long-term exposure to higher levels of air pollutants had a greater risk of periodontitis.

scholarly journals Relationship between Air Pollution in Hong Kong and in the Pearl River Delta Region of South China in 2003 and 2004: An Analysis

2006 ◽  
Vol 45 (2) ◽  
pp. 269-282 ◽  
Author(s):  
Y. C. Lee ◽  
A. Savtchenko
Keyword(s):  
Air Pollution ◽  
Hong Kong ◽  
South China ◽  
Pearl River Delta ◽  
The Philippines ◽  
River Delta ◽  
Pearl River ◽  
Pearl River Delta Region ◽  
The Pearl River Delta ◽  
The Pearl River

Abstract Air pollution in the Pearl River Delta (PRD) region of south China, which is one of the four regions in China most heavily affected by haze, is found to correlate with that of Hong Kong, indicating the regional nature of the Hong Kong problem. Of the 10 territory-wide episode days occurring in Hong Kong in 2003 and 2004, 3 of them coincide with the most polluted days of the month in the PRD. On two other episode days, the most polluted days in the PRD occurred within 2 days of the Hong Kong episodes. The air pollution trends of the PRD cities and Hong Kong are found to resemble each other more under certain meteorological conditions than others, notably when a tropical storm is positioned at the Luzon Strait between Taiwan and Luzon in the Philippines, and the entire PRD, including Hong Kong, is equally affected by it, resulting in photochemical events. During this time, Hong Kong is downwind of nearly all pollution sources in the region. At other positions of the storm, the eastern part of the PRD is often affected more significantly. In winter episodic conditions, which occur when weak anticyclones prevail over south China, local meteorological factors, namely, inversions and sea-breeze convergences, are believed to contribute to the temporal difference of the pollution peaks in Hong Kong and the rest of the PRD.

scholarly journals Spatial-Temporal Analysis of Air Pollutant Concentrations in Relation to Land Use and School Environment

2021 ◽  
Vol 36 (1) ◽  
pp. 568-582
Author(s):  
Healice Julit ◽  
Nafisah Khalid ◽  
Abdul Rauf Abdul Rasam ◽  
Mohamad Hezri Razali ◽  
Maisarah Abdul Halim
Keyword(s):  
Land Use ◽  
Air Pollution ◽  
School Environment ◽  
Strong Relationship ◽  
Temporal Analysis ◽  
Air Pollutant ◽  
Pollutant Concentration ◽  
Motor Vehicles ◽  
Pollutant Concentrations ◽  
Air Pollutant Concentrations

Excessive exposure schoolchildren to air pollution can lead to long-lasting health problems, allergies and respiratory disease. It is well known that the major factors contributing to increase of air pollution are motor vehicles and industries. Thus, it is important to analyze the spatial temporal air pollutant concentrations and its relation with school location as the location of schools and its surrounding can increase their exposure. In this study, six schools in Johor were selected and the land use surrounding the schools were updated using ArcGIS. The Inverse Distance Weighting (IDW) interpolation technique was used to identify which schools’ area in Johor has a higher range of air pollutant concentration. There are four air pollution parameters obtained from the Department of Environment (DOE) which are PM2.5, CO, O3 and SO2. Hourly air pollutant concentration reading was obtained from the DOE in order to analyze air pollutant concentration during school period. The results obtained from the IDW technique showed that Sekolah Menengah Pasir Gudang (2) located in Pasir Gudang, Malaysia has reached a very unhealthy and hazardous level as compared to other schools in Johor. On the other hand, Sekolah Menengah Kebangsaan Tanjung Pengelih, Pengerang, Malaysia showed good to unhealthy range as compared to other schools in Johor. The spatial autocorrelation tool was used to analyze the relationship between the air pollution concentration and the school’s location in Johor. The results showed that the Moran’s Indices is positive showing a strong relationship that is clustering. It can be stated that there is a relationship between air pollutant concentrations with the school locations.

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