(a global urban initiative of the World Health Organization)
In 2017, local and international media were reporting particulate air pollution levels in Nairobi that were 70% over the “safe limit” recommended by the World Health Organisation (WHO). These were powerful warnings. An inadvertent consequence of Covid had reduced traffic air pollution, but that was temporary, and other air pollution continued unabated.
It is well-known that smoke contains particulate pollution and poisonous gases. The smoke particles lodge in our lungs, and gradually reduce our lung capacity. Smoke pollution is responsible for both respiratory and cardio-vascular ailments, and exposure levels do not need to be either of high concentration or long-term to cause health problems. Plus, we are affected indoors as well, especially our children, and especially by indoor wood burners, which are now banned in some cities abroad.
Whilst traffic air pollution is a recognised challenge, it is also notable that “biomass burning” is one of the main particulate air pollution sources in the city today. We encounter “biomass burning” every day, and with plot sub-division, the number of these pollution sources is increasing. The following “burning” examples will be familiar to most of us:
- Shamba bonfires (the palls of garden smoke are seen daily throughout the city)
- Rubbish burning (often evident along the city’s road verges)
- Inefficient wood burning fireplaces (evident throughout high class residential areas)
- Biomass burning water heaters (likewise)
Visible smoke and smell are indicative of incomplete combustion, and hence air pollution. A clean hot burn produces only water vapour and carbon dioxide (no smoke nor smell). We all have a responsibility to reduce global emissions. It is best not to burn at all.
Note that whenever we smell smoke, we are inhaling particulate pollution along with gases and components harmful to health.
“Air pollution” is of course prohibited under Kenyan law, and the “polluter pays” principle is applicable. An “air pollutant” is defined by law as “any fume, particulate matter, vapour, gas, odorous substance or any combination thereof…” Following complaints about smoke nuisance, cigarette smoking in public places was banned many years ago, and a Nairobi city byelaw dated 1959 prohibited the “indiscriminate making of fires” in residential areas. Over 50 years on, that byelaw is being ignored, and pollution from biomass burning is infinitely worse, and is compounding the pollution from fossil fuel burning emissions.
We can all easily reduce our own residential air pollution footprint, and we can eliminate the nuisance it causes. The following alternatives are worth considering:
- Stop all illegal smoky shamba bonfires and instead insist on total composting. Branches can be cut by panga into small pieces and spread as mulch, or stacked and left to rot naturally, a process entirely environmentally beneficial. In stark contrast, burning kills everything, and in so doing degrades the macro-environments in our gardens, diminishes soil biota, and diminishes bird and other life.
- Use solar energy for water heating (clean energy).
- Never burn any rubbish (nasty fumes are produced, especially from plastics). Dispose non-compostable rubbish though recycling outlets or licensed garbage collectors.
- Eliminate inefficient wood burning fireplaces. Instead adopt clean energy cooking and heating indoors (government policy). Better still, to keep warm, wrap up and save energy and the environment.
