Monitoring of Benzene in an Ambient Air on the Roadside at Udon Thani of Thailand

Abstract

Vehicles of Transportation in the urban area was the major source of benzene emission that caused to effect on human health and air quality. A monitoring air quality in an ambient air was designed and sampling of benzene level on the roadside in Udon Thani province from May 2018 to October 2018. The samples of the air were collected at different five sites from the roadside of a traffic jam, namely hospital, university, shopping mall, park, and market. Benzene was sampling by activated charcoal tubes and analyzed by GC-FID. Total Benzene concentration at roadside sites ranged in our study from 0.004±0.0017 to 2.120±2.519 mg/m3. The higher traffic volume and traffic congestion on the roadside of the university leads to remarkably higher benzene concentration (1.260±2.418 mg/m3) than that of other sites indicating the stronger contributions from benzene emissions. The results of source apportionment were highly consistent with the vehicles compositions, strongly evidenced that the precise characterization of the vehicles emission sources. The market and park roadside were clean with daily benzene concentrations below 0.001mg/m3. The daily benzene concentrations in the shopping mall and hospital roadsides were 0.939±0.298 mg/m³ and 0.739±1.808 mg/m3, respectively. The average benzene was 0.588±0.862 mg/m3 that was higher than the range reported in other cities. This indicates that the benzene on roadsides was equivalent and acceptable for daily outdoor benzene monitoring. The information of this study complements the air pollution database regarding the vehicle emission sources in Udon Thani of Thailand.