Johannesburg’s air pollution problem does not stop at the front door

New vehicle emissions research and renewed scrutiny of Highveld pollution are putting the air Johannesburg residents breathe back in focus, including what happens once they go indoors.

A University of Johannesburg and TRUE Initiative study based on more than 250,000 vehicle exhaust measurements found that particulate pollution from vehicles was highest in central and southern Johannesburg. The research estimates that transport-related emissions contributed to around 500 premature deaths and 200 new cases of childhood asthma in the city during 2024.

Johannesburg’s pollution picture is also being impacted by what happens beyond the city itself. In March, residents across Gauteng reported a strong sulphurous smell, and the Department of Forestry, Fisheries and the Environment recorded elevated hydrogen sulphide levels at monitoring stations. The department said weather conditions at the time had carried pollution from Mpumalanga into Gauteng.

A 7 September report by the Centre for Research on Energy and Clean Air estimated that particulate matter and nitrogen dioxide emissions from Sasol’s Secunda operations contribute to around 1,000 premature deaths a year and impose an annual health-related economic cost of roughly R19 billion. Sasol has said it is reviewing the methodology and cannot endorse the specific estimates, cautioning that air quality across the Highveld is influenced by multiple industrial, domestic, transport, and regional sources.

It’s more than the air that you breathe

Trevor Brewer, Director at consumer technology specialist Solenco, says the conversation should not stop with the air people breathe outdoors.

“People tend to draw a line between outdoor and indoor air, but homes are part of the environment around them. Where you live, how your home is ventilated and what is happening nearby can all influence the conditions indoors,” says Brewer.

Local monitoring gives a sense of how different the air inside South African homes can be. A 2025 study in Soweto and Agincourt recorded clear differences between the two communities and between seasons. In Soweto, average indoor PM2.5 concentrations rose from 50 micrograms per cubic metre during summer monitoring to 82 in winter. Across the households in the study, average concentrations in winter were twice those in summer.

Another South African study found that indoor and outdoor PM2.5 peaks often occurred at similar times, although indoor activity could considerably increase exposure. In other words, closing the door does not necessarily separate a household from the surrounding pollution.

That nuance is important, Brewer says, because a household near a busy transport corridor may face a different combination of conditions than a home where indoor activities, such as cooking, using fireplaces, or cleaning with products containing Volatile Organic Compounds (VOCs) are a major source of particles.

“Before choosing any air-treatment technology, you need some idea of the problem you are trying to address. A purifier cannot fix Johannesburg’s vehicle emissions, and households cannot solve an industrial pollution problem from their living rooms. What they can do is pay closer attention to the quality of the environment inside their own homes.”

Protect your health

The health implications are also receiving more attention from government. At the National Priority Area Air Quality Summit in June, the Department of Forestry, Fisheries and the Environment acknowledged that many communities continue to experience unacceptable pollution levels.

Brewer says consumers should make the same distinction between understanding a problem and buying a product to protect their health. An appropriately selected air purifier can help reduce airborne particles indoors. Where persistent excess moisture and subsequent toxic mould is the issue, humidity control with a dehumidifier is a different intervention. Neither replaces the need to address pollution at its source, but they give residents a sense of control over their immediate environment at home.

“The recent Johannesburg research shows how uneven exposure can be even within one city. That is why I would rather see people understand what is happening in their own homes than assume everybody needs the same response. The bigger air-quality challenge belongs to all of us, but what you breathe indoors is still worth paying attention to,” he says.

About Solenco

Solenco is a South African leader in air treatment and lifestyle technology, offering unique solutions for both homes and businesses. With over 20 years of experience and exclusive rights to top global brands like Meaco, Mill, and Hobot, Solenco delivers healthier, more efficient, and more refined living.

For the consumer market, Solenco helps South Africans breathe easier, live better, and entertain in style – available through trusted retailers like Yuppiechef, @Home, and Hirsch’s.

Its commercial division partners with industries such as agriculture, pharmaceuticals, and hospitality to provide reliable, tailored air treatment solutions built for South African conditions.

With nationwide distribution, expert support, and a commitment to sustainability, Solenco empowers smarter living and working every day.

Through its partnership with Eden Projects and the Community Rhino Conservation Initiative (CRCI), every Solenco website order plants three trees, while Kusasa and Thuza air purifier sales support conservation and community development in Hwange National Park, Zimbabwe.

Learn more: www.solenco.co.za | Hwange Initiative

The article was supplied by Solenco.