SPATIAL ASSESSMENT OF AIR QUALITY PARAMETERS, CARBON MONOXIDE AND NITROGEN DIOXIDE IN EDO STATE OVER A PERIOD OF FIVE YEARS (2019-2023) USING SENTINEL 5P

ABSTRACT

This study focuses on the spatial assessment of air quality parameters, specifically carbon monoxide (CO) and nitrogen dioxide (NO2), in Edo State over a five-year period from 2019 to 2023 using Sentinel 5P satellite data. The results indicate that areas with low concentrations of carbon monoxide (CO) increased during the Covid-19 lockdown in 2020 due to restrictions on outdoor and industrial activities, as well as vehicular movements. The global lockdown led to reduced emissions from transportation sectors, resulting in lower carbon monoxide (CO) levels. However, by 2023, the areas with low concentrations of carbon monoxide (CO) decreased. Areas with moderate concentrations of carbon monoxide (CO) increased over the years, while places initially characterized by high concentrations experienced a decline and fell within regions of moderate concentrations. Benin City consistently experienced high carbon monoxide (CO) concentrations due to factors such as traffic congestion, industrial activities, cooking, and waste incineration. The assessment of NO2 concentrations revealed a significant increase in areas with low concentrations during the Covid-19 lockdown, indicating a reduction in emissions levels. Areas with moderate concentrations of NO2 increased over the years, while areas with high concentrations decreased, particularly during and after the lockdown period. Similar trends were observed in studies conducted in the United States, where the Covid-19 pandemic resulted in stabilization and subsequent declines in carbon monoxide (CO) and NO2 concentrations. Winter seasons exhibited deviations from typical patterns, with lower carbon monoxide (CO) levels recorded in 2021. The response of carbon monoxide (CO) concentrations to emission reductions had a time lag, attributable to policy implementation and atmospheric assimilation. The findings suggest that the Covid-19 lockdown and associated restrictions on industrial activities and vehicular movements contributed to the reduction in air pollutant concentrations in Edo State. This study highlights the impact of anthropogenic activities on air quality and the potential benefits of implementing measures to reduce emissions and improve air quality in urban areas. Air quality monitoring agencies, such as NIMET (Nigerian Meteorological Agency) and the federal and state ministries of Environment, which serve as the enforcement and regulatory bodies, are reassessing existing regulations pertaining to air quality monitoring. They are also working towards the development of more effective and comprehensive monitoring mechanisms.