Particulate matter pollution over artisanal crude oil refining areas of Niger-Delta Nigeria: Spatiotemporal analysis, transport modelling and risk assessment

The increasing rate of particulate matter pollution in Niger-Delta region of Nigeria due to artisanal crude oil refining and other unregulated emission activities is of great concern. This research work therefore quantify particulate matter (PM2.5) level over the Niger-Delta region of Nigeria. Also, backward trajectory and dispersion pattern of PM2.5 over six selected municipal areas within the region were simulated and health risks of PM2.5 exposure were assessed. IQAir satellite-based sensor was used to quantify PM2.5 (hourly) for 61 days (1st November 2022 to 31st December 2022) over the selected areas during the dreadful environmental and health challenged harmattan period. HYSPLIT model i.e Hybrid single-particle Lagrangian integrated trajectory model was used to simulate the trajectory, dispersion pattern and the dispered particulate matter position over the region. Air quality index (AQI) via the updated World Health Organization (WHO) standard was used to evaluate risks associted with PM2.5 exposure in the region. The result showed that the levels of PM2.5 quantified on daily average basis for the region were above the WHO standard. The trajectory models revealed the movement of the similar sourced PM2.5 pollutant and the dispersion model showed that it takes more than 24 hr for any released particulate matter to be fully dispersed. Also, majority of the dispersed particles were located between 0 m and 500 m. Finally, the AQI levels for the period considered ranged from unhealthy for sensitive groups (145.50 μg/m3) to hazardous (425.23 μg/m3) air quality. It can therefore be deduced that the inhabitants of the Niger-Delta region of Nigeria are liable to hazardous health effects over a prolong exposure to the high level PM2.5 in the region. Hence, more robust measures should be put in place to ensure an improved air quality and also to achieve a sustainable future for the Niger-Delta region, where economic growth can coexist with a healthy and pollution-free environment.