Impact of COVID-19 Restriction Measures on Ambient PM₁₀ Concentrations during Universiti Putra Malaysia Convocation

Abstract

The outbreak of COVID-19 resulted in many significant restricted social and economic activities. The pandemic provided unprecedented natural experiment in which the study was specifically conducted to investigate the impact on particulate matters with aerodynamic diameter less than 10 µm (PM10) resulting from the restriction measures taken by the university management to manage COVID-19 during convocation. PM10 and meteorological parameters (ambient temperature, relative humidity and wind speed) were monitored using TSI Dusttrak aerosol monitor and Kestrel 4500, respectively. Traffic volume was also considered as the significant source of air pollutants due to higher number of vehicles during the event. Two sets of data were collected during peak hours (7.30-9.30 a.m., 12.30-14.30 p.m. and 16.30-18.30 p.m.) on normal working days (before the outbreak in 2018) and during the convocation (after the outbreak in 2022) at two monitoring points along the major road of Persiaran Universiti 1. The results showed that ambient PM10 concentrations were remarkably reduced by ~65-84%, especially during afternoon peak hours. Parking space allocated far from the main hall area contributed to lower PM10 concentrations. From the parking space, graduands were required to either walk with guidance or take the provided university buses to go to the main hall. Pearson correlation analysis showed that PM10 concentrations have significant relationship with the meteorological parameters (p<0.05). However, in terms of traffic emission, it does not necessarily influence solely by the vehicles. From the observation, walking activities by the graduands, students, visitors, etc. around the monitoring areas also contributed to the dust uplifting, hence influencing the level of PM10. The study elucidated the influence of COVID-19 restriction measures on PM10 concentrations which can be a steppingstone towards a better management in reducing the pollutant in the future convocation events.