Assessment of PM2.5 in Blantyre City, Malawi

Measuring and evaluating environmental levels of air pollution is very crucial for determining detrimental effects of air pollution to people working in sources of air pollution as well as the general public. In this study, PM2.5 levels were measured in Malawi (Blantyre City). 36 short-term ground measurements were performed using an active mobile multi-gas portable monitor known as Dylos DC1100 PRO Laser Particle Counter, in 18 different locations for a period of 60 days in 2020. 3 monitoring points were selected from school campuses, hospitals, industrial areas, markets, residential areas and Central Business District (CBD) of Blantyre for this air quality investigation. PM2.5 monitoring was conducted between 10:00–12:00 and 17:00–19:00. The result show that the values of PM2.5 ranged from 2.51 to 27.69 μg/m3, 1.67 to 24.81 μg/m3, 5.74 to 26.69 μg/m3, 2.72 to 42.57 μg/m3, 1.31 μg/m3 to 15.57 μg/m3 and 3.54 μg/m3 to 20.93 μg/m3 for school campuses, hospitals, industrial areas, markets, residential areas and CBD respectively. The findings were compared with the public exposure limits of both local air quality Malawi Standards and on World Health Organisation standards particulate pollution of   25 μg/m3 and  15 μg/m3 for 24 h respectively. Significant higher exposures of PM2.5 due to direct exposure to emissions from dirty solid fuel combustion and dusty storms were observed, indicating poor air quality. Long term and continuous monitoring of PM2.5 is required over the city to establish concentration trends for decision making.