(주)에이피엠엔지니어링

Sensitivity analysis of volatioe organic compounds to PM2.5 concentrations in a representative industrial city of Korea

Abstract

This study aims to analyze the sensitivity of volatile organic compounds (VOCs) to ambient concentrations of fine particles

(PM2.5) in the representative industrial city of Ulsan, Korea. For the calculation of sensitivity coefficients between VOCs and

PM2.5 (SVOCs-PM2.5), PM2.5 data were obtained from an air quality monitoring station, and their corresponding 6-h average

concentrations of VOCs (alkanes, alkenes, aromatics, and total VOCs) were measured at the Yeongnam intensive air monitoring

station. The air monitoring period was divided into the warm-hot season (May–October 2020) and the cold season (November

2020–January 2021). The sensitivity coefficients in the low pollution period of PM2.5 (5 < PM2.5 ≤ 15 μg/m3) were higher and

much higher than those in the medium pollution period (15 < PM2.5 ≤ 35 μg/m3) and high pollution period (35 < PM2.5 ≤

50 μg/m3), respectively. This result indicates that the change ratios of PM2.5 concentrations to the background (PM2.5 ≤ 5 μg/m3)

per unit concentration change of VOCs (particularly alkenes) in the high PM2.5 pollution period were much higher than those

in the low pollution period. This also indicates that PM2.5 concentrations above 35 μg/m3 were more easily affected by the unit

concentration change of VOCs (particularly alkenes) than those below 15 μg/m3. The average sensitivity coefficients during

the cold season increased in a range of 23–125% as compared to those during the warm-hot season, except the alkenes-PM2.5

sensitivity with a decrease of 7%. It means that the impact of VOCs (except alkenes) on PM2.5 concentrations was relatively

low in the cold season. However, in the cold season, the alkenes might contribute more to PM2.5 formation, particularly over

the high pollution period, having PM2.5 > 35 μg/m3, than other VOC groups. The result of this study can be a basis for

establishing PM2.5 management plans in industrial cities with large VOC emissions.

Key words 

VOCs, PM2.5, Sensitivity, Secondary formation, Ulsan