Comparative Assessment of Ground-level Ozone in Rivers and Kano States: Impact of Meteorological Conditions

Ground-level ozone is a secondary air pollutant formed through photochemical reactions involving nitrogen oxides and volatile organic compounds in the presence of sunlight. Its concentration is influenced by meteorological factors such as temperature, solar radiation, humidity, wind speed, and precipitation. While climatic conditions play a key role, anthropogenic activities often exert a stronger influence, particularly in urban and industrial settings. An assessment of ozone concentrations in Rivers and Kano States for the years 2019 and 2024 reveals distinct spatial and temporal patterns. Despite Kano’s arid climate, characterized by high temperatures and intense sunlight, ozone levels in Rivers consistently exceeded those in Kano. This disparity is attributed to the intensity of industrial activities in Rivers, including oil refining, gas flaring, and high vehicular density, which contribute significantly to the release of ozone precursors. Between 2019 and 2024, ozone concentrations increased by 1.7% in Rivers State (from 0.1206 to 0.1227 mol/m²) and by 2.7% in Kano State (from 0.1181 to 0.1213 mol/m²). Both states recorded values above the World Health Organization’s recommended limit of 0.100 ppm, indicating potential health risks, especially for vulnerable populations. Spatial analysis identified higher concentrations in urban and industrial zones such as Bonny, Port Harcourt, Takai, and Sumaila. Ozone variability was more pronounced in Kano, likely influenced by seasonal transitions and regional wind systems like the Harmattan. These findings underscore the dominance of anthropogenic emissions over climatic influences in shaping ground-level ozone patterns. Effective mitigation requires targeted regulatory actions focused on emission control, particularly in high-risk areas. Integrating satellite-based monitoring into national air quality frameworks can support data-driven policy decisions aimed at reducing health and environmental impacts.