Air Quality Index: Case of One-Day Monitoring of 253 Urban and Suburban Towns in Nigeria

Government departments use the air quality index (AQI) to inform the public about how unhealthy the air is now or may become in the future. As the AQI increases, so do health threats. In addition to reporting daily air quality, it is also a measure of how air pollution impacts one’s health over a limited period of time. The AQI was created to assist people in understanding how local air quality affects their health. Therefore, the aim of this study was to assess the air quality of one day of 253 towns in Nigeria, thereby determining the health threat in these towns. The data were collected from the Tutiempo Network’s regular dataset by the Environmental Protection Agency (EPA). Data on all of the major pollutants (O3, PM2.5, PM10, CO, NO, SO2) were collected and statistical analysis was performed. Kura (Kano State), a town in northern Nigeria, recorded the highest level of 184, while Idiroko, a border town (Nigeria–Benin Republic) in Ogun State, had the lowest value of 41. Kura was portrayed as unhealthy, while Idiroko was portrayed as healthy, implying that Idiroko air poses little to no danger, while Kura air showed that certain people of the general public, as well as members of sensitive groups, could encounter more severe health effects.

Air Pollution Impacts During 2020 COVID-19 Pandemic: Emphasis on Urban, Suburban and Rural Zones

Air quality improvements pollution changes due to COVID-19 restrictions have been reported for many urban developments and large metropolitan areas, but the respective impacts at rural and remote zones are less frequently analysed. This study evaluated air pollution changes across all Portugal (68 stations) considering all urban, suburban and rural zones. PM10, PM2.5, NO2, SO2, ozone was analysed in pre-, during, and post-lockdown period (January-May 2020) and for a comparison also in 2019. NO2 was the most reduced pollutant in 2020, which coincided with decreased traffic. Significant drop (15– 240%) of traffic related NO2 was observed specifically during lockdown period, being 55% for the largest and most populated region in country. PM was affected to a lesser degree (with substantial differences found for largely populated areas (Lisbon region 30–40%; North region: up to 95%); during lockdown traffic-related PM dropped 10–70%. PM10 daily limit was exceeded 50% less in 2020, with 80% of exceedances before lockdown period. SO2 decreased by 35%, due to suspended industrial productions, whereas ozone concentrations slightly (though not significantly) increased (83 vs. 80 µg m− 3).