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Comparison of Hourly PM2.5 Observations Between Urban and Suburban Areas in Beijing, China.

Yao L, Lu N, Yue X, Du J, Yang C - Int J Environ Res Public Health (2015)

Bottom Line: The data demonstrates a unique monthly variation form, as compared with other major cities.Additionally, the nighttime peak in weekdays (21:00 p.m.) is one hour later than weekends (20:00 p.m.) which also shows the evidence of human activity.These observed facts indicate that the variations of PM2.5 concentration between urban and suburban areas in Beijing are influenced by complex meteorological factors and human activities.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, No.11A, Datun Road, Chaoyang, Beijing 100101, China. yaoling@lreis.ac.cn.

ABSTRACT
Hourly PM2.5 observations collected at 12 stations over a 1-year period are used to identify variations between urban and suburban areas in Beijing. The data demonstrates a unique monthly variation form, as compared with other major cities. Urban areas suffer higher PM2.5 concentration (about 92 μg/m³) than suburban areas (about 77 μg/m³), and the average PM2.5 concentration in cold season (about 105 μg/m³) is higher than warm season (about 78 μg/m³). Hourly PM2.5 observations exhibit distinct seasonal, diurnal and day-of-week variations. The diurnal variation of PM2.5 is observed with higher concentration at night and lower value at daytime, and the cumulative growth of nighttime (22:00 p.m. in winter) PM2.5 concentration maybe due to the atmospheric stability. Moreover, annual average PM2.5 concentrations are about 18 μg/m³ higher on weekends than weekdays, consistent with driving restrictions on weekdays. Additionally, the nighttime peak in weekdays (21:00 p.m.) is one hour later than weekends (20:00 p.m.) which also shows the evidence of human activity. These observed facts indicate that the variations of PM2.5 concentration between urban and suburban areas in Beijing are influenced by complex meteorological factors and human activities.

No MeSH data available.


Day-of-week pattern in urban and suburban areas. Though urban concentration is higher than suburban in both weekdays and weekends, the day-of-week patterns are similar. Interestingly, the evening peak is an hour later in weekdays than weekends, reflecting human activities.
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ijerph-12-12264-f004: Day-of-week pattern in urban and suburban areas. Though urban concentration is higher than suburban in both weekdays and weekends, the day-of-week patterns are similar. Interestingly, the evening peak is an hour later in weekdays than weekends, reflecting human activities.

Mentions: In general, yearly average PM2.5 concentration is about 18 μg/m3 (about 21% of the annual mean concentration) higher on weekends (Saturdays and Sundays) than on weekdays (Figure 4). This phenomenon is probably due to the driving restriction in Beijing, that is, about 20% of cars have to stay off the road on each weekday. Since the vehicle possession level amounts to close to 5.35 million units, this means there will be 1.07 million more cars on the road on weekends than weekdays. Supposing the other emissions are constant, the sudden increase of cars on the road might be the main cause of the higher PM2.5 concentration at weekends.


Comparison of Hourly PM2.5 Observations Between Urban and Suburban Areas in Beijing, China.

Yao L, Lu N, Yue X, Du J, Yang C - Int J Environ Res Public Health (2015)

Day-of-week pattern in urban and suburban areas. Though urban concentration is higher than suburban in both weekdays and weekends, the day-of-week patterns are similar. Interestingly, the evening peak is an hour later in weekdays than weekends, reflecting human activities.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4626967&req=5

ijerph-12-12264-f004: Day-of-week pattern in urban and suburban areas. Though urban concentration is higher than suburban in both weekdays and weekends, the day-of-week patterns are similar. Interestingly, the evening peak is an hour later in weekdays than weekends, reflecting human activities.
Mentions: In general, yearly average PM2.5 concentration is about 18 μg/m3 (about 21% of the annual mean concentration) higher on weekends (Saturdays and Sundays) than on weekdays (Figure 4). This phenomenon is probably due to the driving restriction in Beijing, that is, about 20% of cars have to stay off the road on each weekday. Since the vehicle possession level amounts to close to 5.35 million units, this means there will be 1.07 million more cars on the road on weekends than weekdays. Supposing the other emissions are constant, the sudden increase of cars on the road might be the main cause of the higher PM2.5 concentration at weekends.

Bottom Line: The data demonstrates a unique monthly variation form, as compared with other major cities.Additionally, the nighttime peak in weekdays (21:00 p.m.) is one hour later than weekends (20:00 p.m.) which also shows the evidence of human activity.These observed facts indicate that the variations of PM2.5 concentration between urban and suburban areas in Beijing are influenced by complex meteorological factors and human activities.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, No.11A, Datun Road, Chaoyang, Beijing 100101, China. yaoling@lreis.ac.cn.

ABSTRACT
Hourly PM2.5 observations collected at 12 stations over a 1-year period are used to identify variations between urban and suburban areas in Beijing. The data demonstrates a unique monthly variation form, as compared with other major cities. Urban areas suffer higher PM2.5 concentration (about 92 μg/m³) than suburban areas (about 77 μg/m³), and the average PM2.5 concentration in cold season (about 105 μg/m³) is higher than warm season (about 78 μg/m³). Hourly PM2.5 observations exhibit distinct seasonal, diurnal and day-of-week variations. The diurnal variation of PM2.5 is observed with higher concentration at night and lower value at daytime, and the cumulative growth of nighttime (22:00 p.m. in winter) PM2.5 concentration maybe due to the atmospheric stability. Moreover, annual average PM2.5 concentrations are about 18 μg/m³ higher on weekends than weekdays, consistent with driving restrictions on weekdays. Additionally, the nighttime peak in weekdays (21:00 p.m.) is one hour later than weekends (20:00 p.m.) which also shows the evidence of human activity. These observed facts indicate that the variations of PM2.5 concentration between urban and suburban areas in Beijing are influenced by complex meteorological factors and human activities.

No MeSH data available.