Measurement of Fines Particle Concentrations and estimation of Air Quality Index (AQI) over Northeast Douala, Cameroon

Abstract

Abstract The paucity of data regarding air quality monitoring and pollutant emissions from various sources in the city of Douala, allowed us to initiate a measuring campaign at the main road entrance of the university campus. Using the OC 300 Laser Dust Particle, fines particles concentrations are monitored during one week from Monday to Sunday. The instrument used detects four (04) different sizes of particles: PM10, PM5, PM2.5, and PM1. The daily average concentrations measured ranged from 9.47 ± 0.26 to 50.14 ± 2.42 µg.m− 3 for PM1.0 ; 13.13 ± 0.38 to 86.65 ± 3.96 µg.m− 3 for PM2.5 ; 13.60 ± 0.40 to 100.56 ± 4.20 µg.m− 3 for PM5 and 14.52 ± 0.42 to 114.59 ± 4.60 µg.m− 3 for PM10. Exceptions made from PM5 and PM1.0 which were not in relation to the WHO (World Health Organization) guideline values, the level of PM10 and PM2.5 are higher than the WHO standards. The air quality index (AQI) is between very poor and poor during this measurement campaign, indicating that residents of the study region are highly exposed. Through the use of correlation studies, it has been demonstrated that the predominant source of fine particles in the studied region is vehicular activity. As a result, traffic density is the most significant factor causing the different air pollution levels seen in the tested areas.