The land use-air pollution nexus is an evident yet convoluted aspect of the urban air quality problem. With particulate matter (PM) garnering attention due to its invasive and insidious nature, this study analyses the land use configuration of urban particulate pollution in Ibadan. A total of 772 buildings from 39 selected neighbourhoods across 8 schematized land use areas (LUAs) within the 5 local government areas of Ibadan Metropolis served as data collection points for a 3-month survey between October and December, 2022. Concentrations of respirable (PM2.5) and inhalable (PM10) particles were measured with Aerocet-531 S Particle Counter, data on municipal practices obtained with questionnaire administration and land use/built environment details recorded with observation sheets. Socio-environmental attributes (SEVA) were collapsed with Factor Analysis, their influence on ambient PM explained with regression analysis and Student’s t-test was used to compare ambient PM across LUAs with WHO IT-1 daily guidelines. Findings reveal higher indoor PM2.5 and PM10 levels, respectively, in medium-density residential (94.00 µg/m³±72.06) and commercial-residential (535.60 µg/m³±276.00) areas; higher outdoor levels in medium-density residential (103.24 µg/m³±54.60) and commercial-transportation (675.76 µg/m³±253.00) areas, but lowest levels of both PM fractions in low-density residential area, indoors (69.66 µg/m³±24 and 239.51 µg/m³±78) and outdoors (239.51 µg/m³±78 and 252.65 µg/m³±118.96). Relative Particulate Contribution Index (RaPCI) showed exposure to PM as negligible (< 1.0) in mechanic shops (PM2.5=102.7 µg/m³; PM10=487.4 µg/m³), but hazardous (> 3.0) in sawmills (PM2.5=221.4 µg/m³; PM10=1799.0 µg/m³) and in factories (PM2.5=163.9 µg/m³; PM10=3257.6 µg/m³). Air quality in Ibadan was relatively poor; it was deplorable, tolerable and within permissible limits, respectively, in the commercial-transportation, commercial-industrial and low-density residential LUAs. Ambient PM also exhibited SEVA underpinnings. It reduced with increasing urban greenery/development mix (b=-0.529; p = 0.000) and decreasing traffic/other combustion sources (r = 0.322; p = 0.015). The study recommends initiation of traffic rerouting schemes, installation of monitoring stations and urban greenery specifications, respectively, for the land use areas, alongside other pragmatic measures in a LUA-guided framework, toward mitigating particulate pollution and furthering healthier living environments.

An urban planner’s perspective of land use dynamics of particulate pollution in Ibadan Metropolis, Nigeria

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发表日期：

2026年3月27日

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Abimbola T. Alabi,
Musibau O. Jelili,
Olajoke Abolade

摘要

The land use-air pollution nexus is an evident yet convoluted aspect of the urban air quality problem. With particulate matter (PM) garnering attention due to its invasive and insidious nature, this study analyses the land use configuration of urban particulate pollution in Ibadan. A total of 772 buildings from 39 selected neighbourhoods across 8 schematized land use areas (LUAs) within the 5 local government areas of Ibadan Metropolis served as data collection points for a 3-month survey between October and December, 2022. Concentrations of respirable (PM_2.5) and inhalable (PM₁₀) particles were measured with Aerocet-531 S Particle Counter, data on municipal practices obtained with questionnaire administration and land use/built environment details recorded with observation sheets. Socio-environmental attributes (SEVA) were collapsed with Factor Analysis, their influence on ambient PM explained with regression analysis and Student’s t-test was used to compare ambient PM across LUAs with WHO IT-1 daily guidelines. Findings reveal higher indoor PM_2.5 and PM₁₀ levels, respectively, in medium-density residential (94.00 µg/m³±72.06) and commercial-residential (535.60 µg/m³±276.00) areas; higher outdoor levels in medium-density residential (103.24 µg/m³±54.60) and commercial-transportation (675.76 µg/m³±253.00) areas, but lowest levels of both PM fractions in low-density residential area, indoors (69.66 µg/m³±24 and 239.51 µg/m³±78) and outdoors (239.51 µg/m³±78 and 252.65 µg/m³±118.96). Relative Particulate Contribution Index (R_aPCI) showed exposure to PM as negligible (< 1.0) in mechanic shops (PM_2.5=102.7 µg/m³; PM₁₀=487.4 µg/m³), but hazardous (> 3.0) in sawmills (PM_2.5=221.4 µg/m³; PM₁₀=1799.0 µg/m³) and in factories (PM_2.5=163.9 µg/m³; PM₁₀=3257.6 µg/m³). Air quality in Ibadan was relatively poor; it was deplorable, tolerable and within permissible limits, respectively, in the commercial-transportation, commercial-industrial and low-density residential LUAs. Ambient PM also exhibited SEVA underpinnings. It reduced with increasing urban greenery/development mix (b=-0.529; p = 0.000) and decreasing traffic/other combustion sources (r = 0.322; p = 0.015). The study recommends initiation of traffic rerouting schemes, installation of monitoring stations and urban greenery specifications, respectively, for the land use areas, alongside other pragmatic measures in a LUA-guided framework, toward mitigating particulate pollution and furthering healthier living environments.