Currently of great concern, air pollution is one of the main causes of mortality in the world. According to the WHO, more than 7 million people die every year from air pollution. Indeed, its consequences on human health are numerous and extremely harmful (asthma, cardiovascular and pulmonary diseases, cancers, immune system impairments, cataracts, etc.).
Air pollution constitutes a higher risk for human health in low- and middle-income countries, particularly in urban areas. For most people, what come first to mind when they think about air pollution are Asian megacities, like Beijing or Delhi, and for good reasons since developing Asia contributes “two-thirds of air pollution disease burden” (Krewski, 2008).
Yet, the high levels of pollution in African cities are comparable to those in Asian cities (Val, 2013). Such pollution represents a crucial challenge in sub-Saharan Africa where urbanisation rates are among the highest with largely unregulated traffic emissions. Moreover, in Western African cities, including Dakar, anthropogenic pollution is exacerbated by “desert dust” (Bauer, 2019) and “savanna burning” (Cachier, 1995).
Despite its coastal location influenced by oceanic air masses that promote “the dispersion of pollutants” (Val, 2013), Dakar is one of the most polluted city in the world where November marks the beginning of the dry season and “the start of the peak in air pollution levels” (WHO, 2018). Thus, from December to March, the particulate matter levels are up to four times the recommended threshold (Doumbia, 2012).
In fact, Dakar is characterised by uncontrolled urban expansion, increased traffic density, aged vehicles with “70% public transport vehicles over 10 years old” (Doumbia, 2012) circulating with poor fuel quality, high per-vehicle emissions, industrial activities and waste dumps that generate significant emissions of pollutants, while cityscape with “street canyons” promotes their accumulation (Ndong, 2019).
Moreover, a large proportion of old vehicles still use leaded-gasoline causing lead poisoning described as a silent epidemic to which children are the most vulnerable since they absorb lead more readily (Diouf, 2006). This exposes them to severe and irreversible damages to their central nervous system that can lead to death.
Although “road traffic accounts for 90% of pollution” in developing cities (Ndong, 2019), energy consumption (gas, wood, charcoal) for heating and cooking also contributes to increased pollution. Inevitably, the first choice among poor Dakarois people is solid fuels for their cheap price and easy use, despite the fact that they have “the highest indoor pollution potentials” (Omole, 2014).
This unsustainable way to use energy and transportation in order to keep up with the pace of development activities is done at the expense of public and environmental health. Furthermore, financial cost of air pollution is heavy because of health-driven expenses and lost of labour (World Bank, 2016). Besides, constant demographic growth in Dakar will only lead to increased demand and consumption whereas economic poverty levels remain high.
Surely human development is dependent on resources consumption but, as we can see, human survival is much more reliant on the practice of sustainable and responsible use of these resources. Knowing the problem amplitude is the first step in addressing it and, fortunately, Dakar is one of the few cities in sub-Saharan Africa that tracks air quality. But the next step is to actually develop cleaner activities with long-term perspectives.
Dakar should definitely promote renewable sources of energy (solar, wind, geothermal, hydropower, biogas), public transports and green spaces. But, first and foremost, the government must enforce traffic regulations by banning the most polluting fuels and vehicles and establishing vehicle age limits.