Pre-ECQ versus ECQ: a comparison of PM1 measurements

Abstract

One of the pollutants that contribute to air pollution is particulate matter. The 2020 Philippine Enhanced Community Quarantine (ECQ) provided an opportunity to study changes in Particulate Matter levels as compared to the pre-ECQ period. In this study, we analyzed PM₁, wind speed, and wind direction time series measurements from an air quality monitoring station located at the Lung Center of the Philippines. Before ECQ, we determined that PM₁ concentrations are high during early mornings (12AM − 8AM) and wind speeds < 2.75 ms⁻¹ coming from the direction of adjacent public roads are likely to bring high concentrations (75^th − 100^th percentile). During ECQ, PM₁ peaks evident in pre-ECQ during early mornings became absent, hourly spread of concentration values were much closer, concentration values were lower, and wind speeds between 2 − 3 ms⁻¹ are much more likely to bring high concentrations. Moreover, the probability of wind speed values with respect to wind direction and time are similar for pre-ECQ and ECQ.