EFFECTS OF COVID-19 POLICY ON AIR QUALITY IN LAGOS STATE, NIGERIA

Decrease in air quality has been a major concern in the world for decades and it has continued to worsen with dangerously toxic pollutant gases accumulating at a rapid rate every second. The atmosphere has majorly been polluted as a result of human day to day activities and these activities reduced a great deal during the covid-19 pandemic when a lockdown policy was established. The study area which is Lagos state, Nigeria is the state with the highest population count making it most prone to the spread of the covid virus and as such had the strictest policy regulation. This study was carried out to assess the effect of the covid-19 lockdown policy on air quality in Lagos state. The study adopted geographic information systems (GIS) using the Sentinel-5P data to obtain information on the concentration of Nitrogen dioxide (NO2), Particulate matter (PM2.5), Carbon monoxide (CO) and Sulphur dioxide (SO2) as parameters for air pollution for the year before the lockdown (2019), the year of the lockdown (2020) and the year after the lockdown (2021) which were compared and the results were analysed statistically to determine a significant difference in the concentrations per year. The data showed the year2020 had less concentrations of PM2.5 and NO2 which increased in 2021 when human and vehicular activities were back to normal, while SO2 and CO concentrations were higher in 2020
than in 2021 as a result of the increase in the use of indoor air pollution sources.