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Johannesburg and air pollution

From pollution to solution in Africa's cities: The case for investing in air pollution and climate change together

With a current population of over 6 million, Johannesburg will attain official megacity status of 10 million by 2030, according to the UN. South Africa’s largest city and its financial and industrial heartland, Johannesburg is shaped by its chaotic beginnings as a gold mining town in the late 1890s, and later by the politics and spatial logic of apartheid urban planning. Post-apartheid Johannesburg has grown and been developed in parts, attracting new residents from all corners of South Africa and the continent. This sprawling metropolis accounts for 10% of the nation’s population (and 16% of GDP). It is also the richest city in Africa in terms of GDP per capita and often described as the economic powerhouse of the continent.

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The city is a busy gateway to other countries, receiving the highest number of tourists on the continent and huge volumes of freight traffic through O.R. Tambo International airport.

Dirty air could take the shine off this prosperity. The annual average PM2.5 concentration in South Africa in 2019 was almost 6 times greater than WHO 2021 recommended concentration levels. Air pollution produced by industrial and power plants, biomass fuels and road transport, as well as seasonal smog could damage tourism and investment prospects as the city grows. The city is considered to be among the least equal in the world. Just over 2% of the population live in the eastern part of the Johannesburg conurbation and earn about $40,000 per year, while almost 90% earn less than a dollar in a day. Poverty levels are highest among black people, and spatial segregation remains stubbornly intact. As elsewhere, air pollution further exacerbates these inequalities.

Major sources of air pollution

Industrial and power plants

The primary source of air pollution in Johannesburg is industrial and power plants, contributing well over one third of the total PM2.5 concentration (37%). The proximity of the polluting industrial zones to the urban population exacerbates air pollution. 

Johannesburg residents consistently report a heavy sulphur-like smell that fills the air a few times a year. The most recent episode in June 2022, likely caused by hydrogen sulphide fumes from the industrial zone near the city, remains under investigation

The Johannesburg-Pretoria urban area is located relatively close to the most industrialised region, where industrial activities include the energy intensive and high pollutant emitting petrochemical, chemical, brick, tile, and steel industries. The Mpumalanga Highveld and the Vaal Triangle in the area were labelled the first national air pollution hotspots according to the Air Quality Act of 2004 especially due to coal mining and coal-fired power stations. 

Johannesburg’s unique topography, on an escarpment or ‘Highveld’ with high pressure systems, results in calm conditions with minimal wind. As a result, air pollution is often ‘trapped’ over Johannesburg. In 2021, the City of Johannesburg Metropolitan Municipality published ‘Air Pollution Control By-laws’ for the city that include strict enforcements of the prohibitions and regulations for industrial zones, vehicle testing, and open burning inspection, which should improve city air quality and reduce CO2e emissions.

Biomass fuel burning 

Biomass fuels are believed to contribute just under one fifth of the city’s PM 2.5 concentrations (17%). Inadequate distribution of electricity grid expansion has failed to keep pace with rapid urbanisation and the growth of informal settlements.

Consequently, 90% of households in socio-economically deprived areas, including informal or shack settlements, continue to use coal, wood and other polluting fuels for cooking and heating.

Because of regular power outages (known locally as “load shedding”), businesses and residents, especially in wealthier areas of the city, are heavily reliant on off-grid diesel generators. This generates yet more toxic air pollution.


Transport emissions contribute substantially to total air pollution (7%). Public transport provision, while growing and seen as relatively affordable, competes with private car ownership. The number of cars per square kilometre in the city’s Gauteng province is more than any other South African province. Around 12% of roads (1,217km) in Johannesburg are made from gravel, with up to 75% of these roads located in informal settlements, which contributes to particulate emissions in the city.  

Privately owned, and largely unregulated, minibus taxis are widely used in the city, as are municipal bus services, such as Metrobus, PUTCO and Rea Vaya, which are owned, run, and subsidised by the city. The relative affordability, reliability, coverage (in terms of times and routes), comfort and safety of these transport options are key considerations for commuters. 

Steps are being taken to increase the coverage of bus and rail services, among other things. But funding delays hamper progress and pricing compounds inequalities related to air pollution. Completion of the Johannesburg Development Agency’s (JDA) expansion of the Rea Vaya Bus Rapid Transport (BRT) can promote public transport accessibility for the city population, particularly if affordable. Similarly, Johannesburg’s Metro-rail system run by the PRASA is raising additional funding by 2024-25 to restore and modernise the commuter rail network, which links the city centre with the densely populated townships and informal settlements.

Meanwhile, the high-speed Gautrain, built just in time for the South African hosted 2010 Football World Cup, mainly links economic and transport hubs with each other (rather than residential areas) and the ticket prices are out of reach of the average commuter.

Health and financial impact of air pollution in Johannesburg

In 2019, around 5,300 premature deaths were attributed to air pollution in Johannesburg. At the national level, air pollution related deaths (29,830) exceeded premature deaths caused by tuberculosis (19,784) in the same year.

The visualisation above shows the financial cost of air pollution related premature mortality and absenteeism in 2019 and the projected impacts under a business-as-usual scenario.

Impact of clean air policies that reduce air pollution and GHG emissions

The cumulative impact between 2023-2040 from implementing the identified clean air interventions could save Johannesburg ~$640m, which equates to 36% of the South African government’s total budget for HIV and HIV/TB health outcomes in 2019 ($1.76bn). A further 2,800 deaths could be reduced, as well as GHG emissions abated by 28Mt of CO2e, equivalent to ~5% of South Africa’s current GHG emissions.

These findings underline the need for additional domestic and external funding to tackle air pollution. South Africa received merely $35.4m official development funding that directly or indirectly targeted reducing air pollution between 2015-2020. 

Johannesburg’s financial sector contributes 28% (to the total gross value added) in the metropolitan municipality’s economy, and hosts Africa’s largest stock exchange, the Johannesburg Stock Exchange (JSE). 

The services sector also contributes significantly to the city’s economy at 25% (to the gross value added) and makes it the highest job provider in South Africa, especially in IT, finance, engineering, healthcare, and retail. Johannesburg makes up 39% of all IT and tech-related jobs on offer in South Africa. The health impacts of air pollution could increase business relocation. 

The trade and manufacturing sectors contribute 15% and 14% respectively (to the gross value added) of Johannesburg’s economy. As Johannesburg is an international transit hub and a major economic hub, both sectors are high growth industries that are critical to its economic future. Increasing levels of air pollution are likely to decrease the productivity of these sectors due to increasing health risks for workers, growing pressure on industries to provide health insurance coverage, and social protection to employees, driving down the value and sustainability of the industry.

Go to next section: 6. Accra, Ghana

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