Spatiotemporal comparison of particulate matter pollution in Port Harcourt and Kano using clarity Node S measurements

This study presents a spatiotemporal comparative analysis of particulate matter (PM) pollution in two cities in Nigeria, Port Harcourt and Kano, using high-resolution data from Clarity Node-S sensors. The research investigates the concentrations of PM₁.₀, PM₂.₅, and PM₁₀ across both cities, focusing on seasonal variations and their consequences for public health and the environment. The results of the analysis show that Port Harcourt exhibits significantly higher mean PM concentrations (PM₂.₅: 64.06 µg/m³; PM₁₀: 65.19 µg/m³) compared to Kano (PM₂.₅: 20.80 µg/m³; PM₁₀: 34.22 µg/m³), with both cities exceeding WHO guidelines. The dry season consistently recorded elevated PM levels, which can be attributed to dust, harmattan winds and biomass burning. Statistical analyses reveal greater variability of this particulate matter concentration in Port Harcourt; this might also be linked to the influence of localised industrial activities and artisanal activities in the city. The risk assessment reveals that Port Harcourt has significantly higher PM2.5 and PM10 pollution than Kano, with AQI levels reaching "Unhealthy". Kano's air quality fluctuates from "Good" to "Unhealthy" but remains less severe than Port Harcourt. Both cities face public health risks from prolonged PM exposure, especially in Port Harcourt, where pollution consistently exceeds WHO guidelines. The study presents an urgent need for targeted air quality interventions, including emission controls and real-time monitoring, to mitigate the adverse health and environmental impacts of PM pollution in these urban centres. These findings help address key gaps in local air quality studies and provide data to guide policies for cleaner air in Nigerian cities.