Nine out of ten people breathe polluted air every day. In Nigeria, 94% of the population is exposed to harmful levels of polluted air (WHO, 2021).
Our cities are developing – industrialization and economic activities are on the rise with high rates of urbanization and infrastructural developments but at a heavy price. Increasing pollutant emissions in the atmosphere of devastating proportions have come up in several reports particularly in megacities of developing countries. World Health Organization identified four pollutants for which there is strong evidence of health effects on humans: particulate matter (PM2.5 & PM10), ozone (O3), sulfur dioxide (SO2), and nitrogen dioxide (NO2). Fine particulate matter (PM2.5) are tiny particles (30 times smaller than the diameter of our hair) that can travel through lung barriers into the bloodstream. The major sources of these four pollutants are road transportation, industrial emissions, and power generation. In Lagos for example, there is an average of 277 vehicles per kilometer per day plying the roads. Some of these vehicles are older than 15 years and use fuels with high sulfur content – one of the sources of sulfur oxides in the air – making road transportation one of the major sources of air pollution. Industrialization in major cities in Nigeria, often without the right technology, also accounts for many oxides of sulfur and nitrogen in the air. According to some reviewed articles, poor waste management, construction of infrastructure, use of polluting fuel, and stoves for household cooking are also contributing factors to air pollution. Besides the exhaust from vehicles, pollution from power generators also contribute to the concentration of pollutants in the air. Without an adequate power supply, most Nigerians are heavily dependent on diesel and gasoline generators. Onitsha, for instance, is a hub of commercial and industrial activities with lots of combustion, dust storms, cooking fires, and rubbish burning.
Cooking fires and burning rubbish in Onitsha Source: Hadassah Egbedi for the Guardian
In 2020, studies by Croitoru et al. showed that fine particulate matter (about seven times above the WHO limit) resulted in 11,200 premature deaths in Lagos alone – the highest number in West Africa. Children below five years account for 60% of these deaths. According to the report, particulate matter can enter the bloodstream and move all around the body making them destructive to organs. Short-term exposure to nitrogen oxide has been linked to aggravated respiratory diseases, particularly asthma, leading to respiratory symptoms (such as coughing, wheezing, or difficulty breathing), hospital admissions (US EPA, 2021). Besides its effects on respiratory systems, sulfur oxides can react with particulate matter, penetrating lungs. Air pollution has been linked to high risks of heart attacks, strokes, colon/bladder cancer, premature birth, obesity, and cognitive problems in kids (Nat Geo, 2021).
The health cost of air pollution for Lagos in 2018 was estimated at US$2.1b (N631b) (World Bank, 2019), this corresponds to 2.1% of the state’s GDP (World Bank Calculations, 2020). This estimate exceeded the proposed Federal allocation for education the same year, highlighting the magnitude of the impact of air pollution on the nation’s economy (Budget Office of the Federation, accessed 2021).
Open Burning At Lagos Island (Croitoru et al., 2020)
In places like the Niger Delta, high levels of sulfur and nitrogen oxides in the air produces acid rain during precipitation. These have resulted in low pH values from water obtained from shallow hand-dug wells in Ughelli, Warri, and Okurekpo areas of Delta state (Akpaborie et al., 2000). Acid rain also increases the corrosion rate of roofing sheets, monuments, and other economic structures.
The magnitude of the hazard posed by pollutants in the air has been underestimated due to the lack of air monitoring stations and few studies on air pollution effects. An instance is the case of Kaduna whose PM2.5 concentration of 90µg/m3 is much higher than that of Lagos (68µg/m3), yet little is known of the impacts on residents (WHO 2016). In addition, recent reports have focused on particulate matter in the air, however, the economic, health and environmental impacts (local and regional) of other pollutants such as ozone, oxides of Nitrogen, and Sulfur are scanty to non-existent. Yet, new studies suggest that the health effects of Nitrogen dioxide on mortality may be as great as those of PM2.5 and largely independent of them.
Odor pollution can become a nuisance and bother people causing temporary symptoms such as headache and nausea. Odors can be toxic and cause harmful health effects. Young children, the elderly, and pregnant women may be more sensitive to odors.
In addressing the challenge of air pollution, the focus needs to be on the major sources – transportation, power generation, and industrialization. For road transportation, a shift to a cleaner fuel, more fuel-efficient engines, use of more public transportation like trains, and incentives programs that encourage the use of cleaner transportation options. An efficient and sustainable power generation, transmission, and distribution are imperative for a significant reduction in air pollution from fossil fuels. Current developments in smart grid systems and alternative energy sources such as wind, solar, tidal, and bioenergy can be adopted and implemented within our local sphere. However, adopted measures should be with economic, technical, and institutional feasibility in view. Economic growth is tied to industrialization, powered by energy. A gradual shift from a fossil-based economy to a renewable-based economy should be part of the National Air Pollution Control Plan.
In addition, the need to build systems to monitor air pollution and conduct more studies of its effect on public health has never been urgent than now. Often, awareness of the impacts of air pollution has been crippled by a lack of scientifically backed, insufficient data or inconsistent and standardized monitoring of air quality. A comprehensive national and local air pollution monitoring program needs to be set up.
Adopting a biodegradable and eco-friendly solution that eliminates the formation of odorous compounds like ammonia, hydrogen sulfide, mercaptans, etc. instead of chemical agents and mechanical devices would make a huge difference in the carbon footprint. Raising more awareness on the impacts of open burning/cooking at grass root levels is necessary to inculcate a sense of responsibility towards pollution-free air. Together we can make the air we breathe cleaner.