Spatial Variations in Air pollution exposure and Human health outcomes in Ibadan, Nigeria

Abstract

Air pollution is a major environmental challenge in rapidly growing urban centres, particularly in developing countries where increasing population, vehicular traffic, industrial activities, and poor environmental management contribute to declining air quality. This study examined the spatial variationsin air pollution exposures and human health outcomes in Ibadan, Oyo State, Nigeria. A mixed-method approach involving questionnaire administration, field observation, and direct measurement of air pollutants was adopted. Residential neighbourhoods were classified into high-, medium-, and low-density areas. A total of 385 questionnaires were administered, across selected residential neighbourhoods in Ibadan. The distribution was based on residential density classification to ensure proportional representation. while concentrations of Carbon monoxide (CO), Hydrogen sulphide (H₂S), Methane (CH₄), and Carbon dioxide (CO₂) were measured using a Crowcon Gas-Pro multi-gas detector. The collected data were analysed using both descriptive and inferential statistical techniques The findings identified vehicular emissions (26.5%), generator fumes(21.8%), open waste burning(17.7%), construction activities(14.0%), industrial emissions (8.1%), and dust from untarred roads (11.9%) as the major sources of air pollution. Significant spatial variations in pollutant concentrations were observed, with high-density neighbourhoods recording highest pollution levels (4.13) than medium (3.39) and low-density (2.37) areas due to greater population concentration, traffic congestion, and commercial activities. Pollutant concentrations also declined with increasing distance from emission sources, indicating higher exposure among residents living closer to pollution hotspots. The study further revealed that prolonged exposure to polluted air was associated with respiratory problems (32.6%), persistent cough (41.8%), eye and throat irritation (39.5%), headaches (34.2%), and other health-related symptoms. It concludes that residential density, land-use characteristics, and environmental management practices significantly influence air quality in Ibadan. The study recommends stricter vehicle emission control, improved waste management, regular air quality monitoring, enforcement of environmental regulations, and the integration of air quality considerations into urban planning to promote healthier and more sustainable cities.