Dependence of urban air pollutants on morning/evening peak hours and seasons

Arch Environ Contam Toxicol. 2019 May;76(4):572-590. doi: 10.1007/s00244-019-00616-x. Epub 2019 Mar 16.

Abstract

Traffic emission is a major source of air pollution in urban cities of developing world. This paper shows dependence of traffic-related air pollutants in urban cities on morning/evening peak hours and winter/summer seasons. This research also shows the meteorological impact, such as temperature (T), relative humidity (RH), and wind speed (WS), on traffic-related air pollutants in urban cites. Based on the research output, the elevated level of PM concentration was observed between 1.8 and 6.7 times at all nearby roadway locations compared with background (IIT [ISM] campus). We have found 2.3, 2.4, 2.6 (morning) and 2.0, 2.1, and 2.1 (evening) times higher average PM10, PM2.5, and PM1 concentrations, respectively, in the winter than summer monitoring periods across all locations, due to the stable boundary layer, lower mixing height, and lower friction velocity. It is indicated that urban meteorology plays a crucial role in increasing or decreasing exposed pollutant concentrations in various microenvironments. The analysis of PM2.5/PM10 ratios was lower during whole campaign due to higher contribution of coarser particles generated by vehicles. During winter and summer seasons, 0.57 and 0.33 was observed, respectively. It is indicated that 57% and 33% of PM10 makes up PM2.5 particle, respectively. PM concentrations have showed a negative linear relationship with T and WS and positive relationship with RH in winter/summer seasons. Therefore, traffic and meteorology play a big role to increase or decrease in traffic-related air pollutants in urban air quality.

MeSH terms

  • Air Pollutants / analysis*
  • Cities
  • Environmental Monitoring / methods*
  • India
  • Particle Size
  • Particulate Matter / analysis*
  • Seasons*
  • Temperature
  • Vehicle Emissions / analysis*
  • Wind

Substances

  • Air Pollutants
  • Particulate Matter
  • Vehicle Emissions