A challenge of rapidly urbanizing cities is outdoor air pollution which reduces the quality of air people breathe. Urbanization in rapidly growing cities is characterized by population growth; thereby increasing the demand for energy for cooking, lighting, transport and industrial activities. Energy use is a major source of air pollution across rapidly expanding cities; sources of pollution in urbanizing cities are multiple ranging from household fuel use, bush burning, industrial activities and transport emission. Nigeria ranks low in its air quality index (indoor and outdoor) which has negative implication on health (Environmental Performance Index, 2018).
The interest in air quality is owing to its negative impact on respiratory health; different anthropogenic activities are likely to be associated with emission of different pollutants with varying effect on health. However, PM 2.5 poses the highest risk to human health. World Health Organization (WHO, 2014) air quality guideline for PM 2.5 is 25 ug/m3 but most urbanizing cities have values higher than 25 ug/m3 as evidence shows that one in ten people breathe clean air in 2014. While research is ongoing to understand the nexus between air quality and COVID 19, the outbreak of the disease led to the imposition of lockdown measures to curtail the spread of the disease.
Comparatively, the atmosphere in most cities was characterized by presence of smog and blurry sky before lockdown measures were imposed; the decline in commuting and industrial activities in European cities led to a 45% reduction in air pollution, this is also noticed in Wuhan (44%), Seoul (54%) and in New Delhi (60%) with lockdown imposition. While there is no complementary data on Nigerian cities yet, simple observation has revealed clearer skies and decline in soot from which one can infer improved outdoor environmental conditions. This has been happening since the various lockdown measures were announced across the country since March 2020.
In Ibadan, dusk to dawn curfew was imposed on 29th of March, 2020 to help curtail the spread of the coronavirus. Also, inter-state commuting was suspended, while free movement of people and intra-state transport activities were permitted within stipulated times. With the decline in the level of economic activities, transport activities has also declined significantly in the usually busy roads in the city. Studies by Olamijulo, (2013) in Ibadan revealed that vehicular movement and traffic flow influence air quality. Therefore, one can link the marginal improvement in outdoor air quality to reduced vehicular traffic consequent to the lockdown. Paradoxically, there was a decline in electricity generation capacity from the national grid to 1,601 megawatts, hence household dependence on alternative power (usually petrol fueled generating set) to supply electricity for about six million residents rose. The stay at home order increased the use of petrol generating sets which also have implications for outdoor air quality.
While there are expected gains from staying indoors through improved outdoor air quality and reducing the spread of COVID 19 through reduced contact, indoor air quality is compromised through living in overcrowded and poorly ventilated environment, dependence on generator and increased cooking with highly emitting fuel.
With the stay at home order, cooking and other fuel use increases. The indoor air quality is negatively impacted as most households cook with firewood and kerosene. In fact, only five percent of households in Nigeria use environmentally friendly fuels for cooking. As such, there is likelihood of exposure to high polluting fuel thereby, increasing the risk of respiratory diseases. Furthermore, households living in overcrowded environment which are poorly ventilated are exposed to the risk of contracting and spreading COVID 19. About 70-80% of Ibadan residents live in slum-like conditions.
The defect of conventional energy use is evident in the short term benefit of improved air quality outdoor during COVID 19 lockdown and curfew imposition. This is a remarkable change which can be considered post COVID. Since there is desired full restoration of economic activities soon, there is need to adopt energy efficiency measures and gradually shift to cleaner energy (renewable energy) in the nearest future across different sectors in Ibadan and Nigeria at large.
Energy Performance Index (2018) ‘Air quality snapshot’ https://epi.envirocenter.yale.edu/epi-indicator-report/AIR
Olamijulo, J. (2013) characterization of traffic related air pollutants and assessment of respiratory conditions of traffic wardens across two selected local government areas of Ibadan, Nigeria. B.Sc. thesis. Available at ir.library.ui.edu.ng.
World Health Organisation 2014. WHO guidelines for indoor air quality: household fuel combustion. Retrieved July, 5th, 2017 from http://www.who.int/indoorair/guidelines/hhfc/HHFC_guidelines.pdf
The views expressed in this article are those of the author(s) and not necessarily those of the Centre for Housing and Sustainable Development or the University of Lagos, Nigeria