Air Pollutant Dispersion Pattern around Yoff, Dakar

Particulate matter (PM) with an aerodynamic diameter of 2.5 μm or less (PM2.5) poses a significant threat to human health. This study employs the Gaussian model to simulate the dispersion of PM2.5 in Yoff from 2018 to 2019. A total of 69 PM2.5 samples were collected using the Gent stacked filter unit sampler, with an average concentration of 292.4 ± 43.2 µg·m−3. The simulation was conducted under neutral atmospheric conditions (stability class D), following Pasquill’s stability classification. The findings indicate that PM2.5 disperses up to approximately 2,800 meters from the source. Higher concentrations were observed to the north (N) and North-Northwest (NNW), primarily due to the influence of sea salts and secondary sulphur, affecting locations such as Yoff Bay and the Yoff Tangor market. Additionally, traffic emissions from the West (W) and West-Southwest (WSW) contribute to increased pollution, impacting sensitive areas such as Philippe Maguilen Senghor Hospital, the Océan Hotel, and the military base. Further away, Grand Yoff and Parcelles Assainies are also affected by PM2.5 dispersion. This study identifies road traffic and sea salt/secondary sulphur as the primary sources of PM2.5 pollution in Dakar. These findings play a crucial role in air quality management in Yoff, enabling local authorities to forecast pollutant dispersion and implement measures to protect both the environment and public health.