CARBON MONOXIDE POLLUTION AND URBAN BIOCLIMATIC CONDITIONS IN RAPIDLY URBANIZING CITIES: A SPATIO-TEMPORAL ASSESSMENT OF SOURCES, HEALTH RISKS, MONITORING APPROACHES, AND RESEARCH PRIORITIES 0 0
DOI:
https://doi.org/10.83374/jesber.vol1no2.102Keywords:
Carbon monoxide, Urban air pollution, Urban climate, Bioclimatic conditions, Thermal comfort, Thermohygrometric index, Urban heat islandAbstract
Rapid urbanization, population growth, motorization, energy insecurity, and climate change are transforming the atmospheric and thermal environments of cities, particularly across sub-Saharan Africa. Carbon monoxide (CO), produced mainly through incomplete combustion of carbon-based fuels, remains an important but comparatively under-monitored urban air pollutant. Concurrently, urban expansion alters air temperature, humidity, wind circulation, surface energy balance, and thermal comfort, creating complex interactions between air pollution and urban bioclimatic conditions. This critical integrative review synthesizes evidence on CO sources, spatio-temporal variability, health effects, urban thermal environments, monitoring technologies, and the emerging air-pollution-bioclimate nexus, with particular attention to Nigeria and Kaduna Metropolis. Evidence indicates that traffic, ageing vehicle fleets, petrol and diesel generators, industrial combustion, household energy use, and biomass burning are major CO sources. Concentrations vary spatially and temporally and are influenced by traffic intensity, urban morphology, atmospheric stability, wind, and boundary-layer dynamics. Satellite products, particularly Sentinel-5P/TROPOMI, can complement sparse ground-monitoring networks and support city-scale assessments, although satellite column measurements cannot directly substitute for near-surface exposure observations. Urban climate studies similarly show that land-cover transformation, reduced vegetation, building density, and anthropogenic heat modify thermal conditions and may intensify heat exposure. However, few studies integrate CO, meteorology, urban morphology, and human thermal exposure within a unified analytical framework. The review proposes an integrated framework combining high-frequency ground sensors, satellite remote sensing, GIS, Local Climate Zones, meteorological observations, traffic and energy-use data, machine learning, and population exposure assessment. Future research should prioritize multi-season monitoring, source apportionment, exposure modelling, health surveillance, and climate-sensitive urban planning.Downloads
References
Adefeso, I. B., Sonibare, J. A., & Isa, Y. M. (2020). Further evidence on environmental impacts of carbon monoxide from portable power generator on indoor air quality. Cogent Engineering, 7(1), 1809771. https://doi.org/10.1080/23311916.2020.1809771
Agbozu, I. E., & Oghama, O. E. (2022). Spatial and diurnal distribution of carbon monoxide (CO) and its health and environmental implications in selected locations in the Niger Delta area of Nigeria. African Journal of Science, Technology, Innovation and Development, 14(5). https://doi.org/10.1080/20421338.2021.1954493
Amaechi, C. F., Okoye, D. O., & Okoduwa, A. K. (2025). Tropospheric assessment of carbon monoxide, nitrogen dioxide, and aerosols in Onitsha, Anambra State, southeastern Nigeria: A case study of 2019–2024. NIPES Journal of Science and Technology Research, 7(3). https://doi.org/10.37933/nipes/7.3.2025.1589
Ariko, J. D. Sawa, B.A. &Ibrahim, A.A. (2014). Variability in carbon monoxide concentration in Kaduna Metropolis, Nigeria. Research Journal of Environmental and Earth Sciences, 6(4), 189–194.
Ariko, J. D., Sawa, B.A., Abdulhamed, I.A.,Aruya, E.I. & Abdulsalam, J.A (2018). An assessment of variability of bioclimatic conditions within Kaduna Metropolis, Kaduna State, Nigeria. Zaria Geographer, 25(1), 28–38.
Ariko, J. D. Ikpe, E., Yerima, N.D., Abdulkadir H. &Abdullahi, A.A. (2024). Analysis of thermal comfort trend of Kaduna Metropolis, Kaduna State, Nigeria. Kaduna Journal of Geography, 6(1), 1–13.
Ariko, J. D. (2026). Variability of temperature, relative humidity and thermal comfort of Zaria Metropolis, Kaduna State, Nigeria. Journal of Exploration, 2(3), 52–73.
Bechtel, B., Alexander, P. J., Böhner, J., Ching, J., Conrad, O., Feddema, J., Mills, G., See, L., & Stewart, I. (2015). Mapping local climate zones for a worldwide database of the form and function of cities. ISPRS International Journal of Geo-Information, 4(1), 199–219. https://doi.org/10.3390/ijgi4010199
Calhoun, Z. D., Willard, F., Ge, C., Rodriguez, C., Bergin, M., & Carlson, D. (2024). Estimating the effects of vegetation and increased albedo on the urban heat island effect with spatial causal inference. Scientific Reports, 14, 540. https://doi.org/10.1038/s41598-023-50981-w
Chen, D., et al. (2024). Mapping local climate zones for cities: A large review. Remote Sensing of Environment.
Chen, Z., Liu, N., Tang, H., et al. (2022). Health effects of exposure to sulfur dioxide, nitrogen dioxide, ozone, and carbon monoxide between 1980 and 2019: A systematic review and meta-analysis. Indoor Air, 32, e13170. https://doi.org/10.1111/ina.13170
Eshetie, S. M. (2024). Exploring urban land surface temperature using spatial modelling techniques: A case study of Addis Ababa City, Ethiopia. Scientific Reports, 14, 6323. https://doi.org/10.1038/s41598-024-55121-6
Garuma, G. F. (2023). Tropical surface urban heat islands in East Africa. Scientific Reports, 13, 4509. https://doi.org/10.1038/s41598-023-31678-6
Goma, D., & Kuku, Y. I. (2024). Assessment of urban heat island in Abuja Municipal Area Council, FCT-Abuja. Jalingo Journal of Social and Management Sciences, 6(1).
Gyimah, R. (2023). The hot zones are cities: Methodological outcomes and synthesis of surface urban heat island effect in Africa. Cogent Social Sciences, 9, 2165651. https://doi.org/10.1080/23311886.2023.2165651
Höppe, P. (1999). The physiological equivalent temperature—A universal index for the biometeorological assessment of the thermal environment. International Journal of Biometeorology, 43, 71–75.
Ikpe, E., & Ejeh, L. U. (2018). Perception of the risk of climate change and its impact on human health and environment in Samaru, Zaria, Nigeria. Journal of Disaster Risk Reduction, 1(1), 20–29.
Jacob, D. J. (1999). Introduction to atmospheric chemistry. Princeton University Press.
Jendritzky, G., de Dear, R., & Havenith, G. (2012). UTCI—Why another thermal index? International Journal of Biometeorology, 56, 421–428.
Lee, K. K., Spath, N., Miller, M. R., Mills, N. L., & Shah, A. S. V. (2020). Short-term exposure to carbon monoxide and myocardial infarction: A systematic review and meta-analysis. Environment International, 143, 105901. https://doi.org/10.1016/j.envint.2020.105901
Leguijt, G., Maasakkers, J. D., Denier van der Gon, H. A. C., Segers, A. J., Borsdorff, T., & Aben, I. (2023). Quantification of carbon monoxide emissions from African cities using TROPOMI. Atmospheric Chemistry and Physics, 23, 8899–8916. https://doi.org/10.5194/acp-23-8899-2023
Li, X., Stringer, L. C., & Dallimer, M. (2022). The impacts of urbanisation and climate change on the urban thermal environment in Africa. Climate, 10(11), 164. https://doi.org/10.3390/cli10110164
Nigerian Meteorological Agency. (2025). Air quality bulletin: October–December 2025.
Odunsi, O. M., & Rienow, A. (2024). Estimating surface urban heat island effects of Abeokuta within the context of its economic development cluster in Ogun State, Nigeria: A baseline study utilising remote sensing and cloud-based computing technologies. Climate, 12(12), 198. https://doi.org/10.3390/cli12120198
Oke, T. R. (2004). Initial guidance to obtain representative meteorological observations at urban sites. World Meteorological Organization.
Oke, T. R., Mills, G., Christen, A., & Voogt, J. A. (2017). Urban climates. Cambridge University Press. https://doi.org/10.1017/9781139016476
Okoduwa, A. K., & Amaechi, C. F. (2023). Monitoring and mapping of atmospheric concentration of carbon monoxide, sulphur dioxide, and nitrogen dioxide from 2019–2022 in Benin City, southern Nigeria. Journal of Applied Sciences and Environmental Management, 27(12), 2715–2722. https://doi.org/10.4314/jasem.v27i12.7
Olufemi, A. P., Fawole, O. G., Owoade, O. K., Popoola, O. A. M., Jones, R. L., Toyeje, A. B., Abiodun, P. O., Omokungbe, O. R., Abiye, O. E., & Sunmonu, L. A. (2023). Spatiotemporal distribution of pollutants and impact of local meteorology on source influence on pollutants' level in a traffic air-shed in Lagos megacity, Nigeria. Environmental Monitoring and Assessment, 195, 1126. https://doi.org/10.1007/s10661-023-11757-x
Park, K., & Baik, J.-J. (2024). Nonlinear changes in urban heat island intensity, urban breeze intensity, and urban air pollutant concentration with roof albedo. Scientific Reports, 14, 24911. https://doi.org/10.1038/s41598-024-76935-4
Popoola, O. A. M., Carruthers, D. J., Lad, C. S., Hall, J. Q., & others. (2018). In-vehicle and pedestrian exposure to carbon monoxide and volatile organic compounds in a mega city. Transportation Research Part D: Transport and Environment.
Romanello, M., Di Napoli, C., Green, C., et al. (2023). The 2023 report of the Lancet Countdown on health and climate change: The imperative for a health-centred response in a world facing irreversible harms. The Lancet, 402, 2346–2394.
Salthammer, T. (2024). Carbon monoxide as an indicator of indoor air quality. Environmental Science: Atmospheres, 4, 291–305. https://doi.org/10.1039/D4EA00006D
Stewart, I. D., & Oke, T. R. (2012). Local climate zones for urban temperature studies. Bulletin of the American Meteorological Society, 93, 1879–1900. https://doi.org/10.1175/BAMS-D-11-00019.1
Stewart, I. D., Oke, T. R., & Krayenhoff, E. S. (2014). Evaluation of the 'local climate zone' scheme using temperature observations and model simulations. International Journal of Climatology, 34, 1062–1080. https://doi.org/10.1002/joc.3746
Udeh, E. L., & Ikpe, E. (2022). Public perception of the risk of climate change issues in Zaria City and its environs in Kaduna State, Nigeria. International Journal of Geography and Regional Planning, 15(1), 1–9.
United Nations. (2018). World urbanization prospects: The 2018 revision. United Nations, Department of Economic and Social Affairs.
Wahab, A. B. (2020). Evaluation of carbon monoxide emissions of electric power generators used in buildings in Ibadan Metropolis, Nigeria. Economic and Environmental Studies, 19(4), 545–560. https://doi.org/10.25167/ees.2019.52.3
World Health Organization. (2021). WHO global air quality guidelines: Particulate matter (PM2.5 and PM10), ozone, nitrogen dioxide, sulfur dioxide and carbon monoxide.
Yashiro, H., Sugawara, S., Sudo, K., Aoki, S., & Nakazawa, T. (2010). Variations of tropospheric carbon monoxide. Atmospheric Chemistry and Physics.
Zhang, J., et al. (2023). Factors affecting in-vehicle exposure to traffic-related air pollutants: A review. Atmospheric Environment, 295, 119560.
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