Effects of short-duration vehicular traffic control on volatile organic compounds in roadside atmosphere

Özet

Traffic air pollution control is an important aspect of air quality management in urban areas. In this study, weinvestigated whether short-duration vehicular traffic control could be applied as a temporary tool to improve theroadside air quality based on concentrations of roadside volatile organic compounds (VOCs). Experiments wereconducted targeting a 30-min “no-vehicle” event observed on 30th May 2019 (13:30–14:00) in Central Taiwan.Although the event was not imposed for air quality management, it provided an excellent opportunity toevaluate it as a potential tool of air quality management. Roadside air samples were collected before, during andafter the no-vehicle event from two locations in Central Taiwan. Samples were analyzed for a total of 87 targetVOCs. Results showed that alkanes, aromatics and oxygenated organics were the major contributors of roadsideVOCs. Mean concentrations of the sum of detected VOCs (∑VOCs) were about 8%–24% lower during the no-vehicle event compared to those before or after the event. Correlation analysis showed that a total of 20 VOCswere related to traffic emissions. During-event concentrations of the sum of those traffic related VOCs were lessthan pre- or post-event concentrations by 40.77%–83.20%. Diagnostic ratios among VOCs revealed a notableimpact of no-vehicle event on the composition and concentrations of the roadside VOCs. Although the short-duration vehicular traffic control had only a limited impact on ∑VOCs due to the presence of multiple emissionsources, it had significant impact on the traffic related VOCs.