Urban pollution: Clearing the air

OECD Observer

©Peter Treanor/Alamy Stock Photo

Air pollution in African cities is a major health and environmental challenge that must become a focus of urban policies. 

It’s hard to breathe in Onitsha, a major river port in Nigeria. The air is dark with car fumes. Old freighters on the River Niger expell smoke. Burning rubbish dumps outside the city’s many sprawling markets thicken the air even further. Add to that diesel generators, and open coal, oil and wood fires, and this southeastern port town in Nigeria becomes handily the world’s biggest producer of small particulate matter (PM10). When these miniscule pollutants are inhaled deep down into the lungs, they do lethal damage: lung cancer, stroke, heart disease, and chronic and acute asthma.

According to the World Health Organisation (WHO) Global Urban Ambient Air Pollution Database released in May 2016, Onitsha is the city with the highest PM10 count in the world. It has 30 times more than the WHO recommended levels of PM10. It is just one of four Nigerian cities in the WHO’s top 20 air-polluters, a list that includes Kaduna, Aba and Umuahia.

Nigeria may be a particularly tough case, though the African continent as a whole needs to grapple with the startling increase in premature deaths from air pollution. According to the Global Burden of Disease Study 2013, (Institute for Health Metrics and Evaluation IHME, 2015) nearly 250,000 people died in Africa in 2013 of diseases attributable to ambient PM pollution; that is, air pollution from industry, power generation and road transport. Household air pollution, mainly from inefficient fuel stoves for indoor cooking, were contributing factors to diseases that resulted in the premature deaths of over 450,000 people that year.

Indoor and outdoor air pollution is not the only environmental risk factor in premature deaths. Childhood undernutrition, poor sanitation and unsafe water are other killers. And, though these last three factors have fallen since last measured by the IHME in 1990, they have by no means been vanquished: in 2013, 400,000 people died due to unsafe sanitation, 550,000 from unsafe water and 275,000 from childhood undernutrition.

Not only must Africa fight a multi-front war on these risk factors to health, its time frame for doing so is short. According to Climate Change News, Africa comprises 16% of the world’s total population and only 3% of all motor vehicles, though road transport still accounts for 50% of pre-mature deaths due to ambient pollution. The rate of industrialisation has been, with some exceptions, slow and has even reversed in some countries. Despite this, deaths from outdoor pollution rose by 36% between 1990 and 2013 to 250,000 and those from indoor pollution by 18% to over 450,000. Half of the world’s population growth in the next 30 years is expected to take place in Africa. If measures aren’t taken to control air pollution now, these numbers will skyrocket.

Though the WHO designated Onitsha as the city with the most befouled air, there was one problem with its data: Onitsha has only one monitoring station. This compromises the statistical reliability of the information. To get serious about tackling air pollution, African cities need ground-monitoring stations that collect information on different emissions over longer periods of time, and various sources.

With a more detailed inventory of emissions, policy-makers can begin to explore ways to solve air pollution problems. Some ideas can come from what advanced economies have successfully implemented. To improve decision-making, the cost of air pollution and different ways to solve it need to be quantified. Currently, the cost of deaths due to air pollution in Africa is roughly US$450 billion.

Cost-benefit analysis can be applied to different proposals based on how much one is willing to pay to reduce the risk of premature deaths, called Value of Statistical Life (VSL). The OECD determined in 2012 from multiple surveys that individuals were willing to pay $30 to reduce the annual risk of dying from air pollution from 3 in 100,000 people to 2 in 100,000. This establishes $3 million for every 100,000 people as a base amount for calculating the VSL for each country. This provides an important tool for calculating which air pollution policies yield the best value for money ratio for each country.

Of the panoply of air pollution measures in play, reforming fuel subsidies must be seriously considered in Africa. A working study by the International Monetary Fund (IMF) and OECD in 2015 claims that removing energy subsidies in sub-Saharan African countries would cut deaths from air pollution by over 50%. In North Africa, removing petroleum subsidies would reduce deaths from air pollution by roughly 80%.

Singling out car emissions, particular in North Africa with its growing vehicle congestion, would have an immediate health benefits, as well as help fight against climate change. Nigeria and South Africa have imposed emissions standards roughly equivalent to those introduced in Europe in 1996. But for emissions standards to work, three things are needed: cleaner fuel, more fuel-efficient cars and better enforcement capabilities. Significant investments need to be made to upgrade refineries so that they can remove sulfur from fuel. Cheap old cars brought in from developed countries need to be phased out–governments could slap tariffs on secondhand car imports or ban them outright. And governments need to have the wherewithal to enforce emissions standards, whether on individual cars or industrial installations and power plants.

Household biomass fuel is another target area, particularly in sub-Saharan Africa. Here, candles and kerosene lamps are frequently the sole sources of lighting because there is no access to electricity or supply is unreliable. Coal, candle and kerosene burning emits PM 2.5 particular matter. There are initiatives to replace candle and kerosene with clean solar lamps, but this needs to be more widespread. Upgrading kitchens with more efficient cooking and heating fuels would lower particulate matter even further, as projects in Niger reported in this magazine have shown. Senegal, Cameroon and Ghana have supported the switch from biomass to liquefied petroleum gas. Kenya has passed a law whereby new buildings must be equipped with solar water heating systems.

Africa is urbanising, so now is a good time to build effective ways of tackling air pollution into well-designed city planning. From organising rubbish collection to reduce refuse burning and investing in public transport systems to piping natural gas to homes and replacing leaky stoves, to upgrading electricity grids and doing away with dirty diesel generators: it is possible to clear the air in African cities. It requires good planning and budgeting, strong co-operation among stakeholders and investors, and political will to succeed.



Godson Rowland, Ana (2011), “Air Pollution in the Niger Delta Area: Scope, Challenges and Remedies”, an Open Access chapter on www.intechopen.com, DOI: 10.5772/16817

 “Cooking lesson” in OECD Observer No 284, Q1 2011, see http://oe.cd/1xd

Global Burden of Disease Study 2013 (GBD 2013), Institute for Health Metrics and Evaluation: University of Washington, http://vizhub.healthdata.org/gbd-compare/

IEA (2016), World Energy Outlook Special Report

OECD et al (2016), African Economic Outlook 2016

Roy, Rana (2016) “The Cost of Air Pollution in Africa”, OECD Development Centre Working Paper for African Economic Outlook 2016

Smart-Abbey, Nii Akrofi, “Nigeria's Onitsha, the city with worst air quality globally”, Africanews, May 18, 2016

Vidal, John and Dehghan, Saeed Kamali, “Which are the world's two most polluted cities – and why?”, The Guardian, May 12, 2016

World Health Organization (2016), Global Urban Ambient Air Pollution Database

Yeo, Sophie (2014), “Africa adopts sustainable transport plan”, at www.ClimateChangeNews.com, 30 October

©OECD Observer September 2016

Economic data


Stay up-to-date with the latest news from the OECD by signing up for our e-newsletter :

Twitter feed

Suscribe now

<b>Subscribe now!</b>

To receive your exclusive print editions delivered to you directly

Online edition
Previous editions

Don't miss

  • Africa's cities at the forefront of progress: Africa is urbanising at a historically rapid pace coupled with an unprecedented demographic boom. By 2050, about 56% of Africans are expected to live in cities. This poses major policy challenges, but make no mistake: Africa’s cities and towns are engines of progress that, if harnessed correctly, can fuel the entire continent’s sustainable development.
  • “Nizip” refugee camp visit
    July 2016: OECD Secretary-General Angel Gurría visits the “Nizip” refugee camp, situated between Gaziantep and the Turkish-Syrian border, accompanied by Turkey’s Deputy Prime Minister Mehmet Şimşek. The camp accommodates a small number of the 2.75 million Syrians currently registered in Turkey, mostly outside the camps. In his tour of the camp, Mr Gurría visits a school, speaks with refugees and gives a short interview.
  • OECD Observer i-Sheet Series: OECD Observer i-Sheets are smart contents pages on major issues and events. Use them to find current or recent articles, video, books and working papers. To browse on paper and read on line, or simply download.
  • Queen Maxima of the Netherlands gives a speech next to Mexico's President Enrique Pena Nieto (not pictured) during the International Forum of Financial Inclusion at the National Palace in Mexico City, Mexico June 21, 2016.
  • How sustainable is the ocean as a source of economic development? The Ocean Economy in 2030 examines the risks and uncertainties surrounding the future development of ocean industries, the innovations required in science and technology to support their progress, their potential contribution to green growth and some of the implications for ocean management.
  • OECD Environment Director Simon Upton presented a talk at Imperial College London on 21 April 2016. With the world awash in surplus oil and prices languishing around US$40 per barrel, how can governments step up efforts to transform the world’s energy systems in line with the Paris Agreement?
  • Happy 10th birthday to Twitter. This 2008 OECD Observer interview with Henry Copeland said you’d do well.
  • The OECD Gender Initiative examines existing barriers to gender equality in education, employment, and entrepreneurship. The gender portal monitors the progress made by governments to promote gender equality in both OECD and non-OECD countries and provides good practices based on analytical tools and reliable data.
  • Once migrants reach Europe, countries face integration challenge: OECD's Thomas Liebig speaks to NPR's Audie Cornish.

  • Message from the International Space Station to COP21

  • The carbon clock is ticking: OECD’s Gurría on CNBC

  • If we want to reach zero net emissions by the end of the century, we must align our policies for a low-carbon economy, put a price on carbon everywhere, spend less subsidising fossil fuels and invest more in clean energy. OECD at #COP21 – OECD statement for #COP21
  • They are green and local --It’s a new generation of entrepreneurs in Kenya with big dreams of sustainable energy and the drive to see their innovative technologies throughout Africa. blogs.worldbank.org
  • Pole to Paris Project
  • In order to face global warming, Asia needs at least $40 billion per year, derived from both the public and private sector. Read how to bridge the climate financing gap on the Asian Bank of Development's website.
  • How can cities fight climate change?
    Discover projects in Denmark, Canada, Australia, Japan and Mexico.
  • Climate: What's changed, what hasn't, what we can do about it.
    Lecture by OECD Secretary-General Angel Gurría, hosted by the London School of Economics and Aviva Investors in association with ClimateWise, London, UK, 3 July 2015.
  • Is technological progress slowing down? Is it speeding up? At the OECD, we believe the research from our Future of ‪Productivity‬ project helps to resolve this paradox.
  • Is inequality bad for growth? That redistribution boosts economies is not established by the evidence says FT economics editor Chris Giles. Read more on www.ft.com.
  • Interested in a career in Paris at the OECD? The OECD is a major international organisation, with a mission to build better policies for better lives. With our hub based in one of the world's global cities and offices across continents, find out more at www.oecd.org/careers .

Most Popular Articles


What issue are you most concerned about in 2016?

Euro crisis
International conflict
Global warming

OECD Insights Blog

NOTE: All signed articles in the OECD Observer express the opinions of the authors
and do not necessarily represent the official views of OECD member countries.

All rights reserved. OECD 2016