Trends of Particulate Matter PM2.5 and PM10 Concentrations in Dar es Salaam City between 2021 and 2022

Abstract

As many African countries enter lower middle-income level, there are increasingly threats to air quality due to rapid development of industrial sectors, rapid urbanizations, rapid increases in populations and rapid motorizations. Preliminary air pollution data from few monitoring networks in African countries show higher levels for daily average concentration of PM_2.5 and PM₁₀ that far exceed the World Health Organization guidelines of 25 µg/m³ and 45 µg/m³ for 24-hour observations. The paper explores the situation of PM_2.5 and PM₁₀ concentration levels in Dar es Salaam city using data recorded by first real time network of low-cost air quality sensors between May 2021 and February 2022. The results for observations of daily mean concentrations of PM_2.5 and PM₁₀ at urban traffic, industrial, residential and landfill based stations, ranged from 11.79 μg/m³ to 130.45 μg/m³, and 14.23 μg/m³ to 184.15 μg/m³, respectively. The site measuring highest daily mean concentration was Pugu Dampo (landfill site), while the site that recorded the lowest value was Kigamboni (rural residential site). The measured maximum 24-hours average concentrations of both PM_2.5 and PM₁₀ were at landfill site (Pugu Dampo) station. In general, landfill site measured the highest PM_2.5 and PM₁₀ level followed by industrial, urban traffic, and residential site. From the results, the population dwelling in the monitored sites may be at health risk based on the relatively poor air quality in these areas. Based on these findings, it is recommended that the responsible regulatory and enforcement agency develop a robust monitoring mechanism, regulations and enforcement. Furthermore, there is need for a national wide drive awareness and campaign on solid waste management plans to ensure a safe environment, as well as reduce particulate matters in the cities.