Gauteng’s air quality monitoring choking with most stations offline in SA’s most polluted province

Gauteng, the most polluted province in South Africa, now has just 39% of its municipal air quality monitoring stations operating as they should be.

Gauteng’s new MEC for Environment, Ewan Botha, confirmed to Daily Maverick that of the province’s 31 municipal-owned stations, only 12 are fully operational. A further three are partially operational, while 16 are completely non-operational.

The operational stations measure a range of pollutants: six monitor ozone, seven nitrogen dioxide, four carbon monoxide, 10 coarse particulate matter (PM₁₀), five fine particulate matter (PM₂.₅) and 12 sulphur dioxide.

Democratic Alliance environment spokesperson Leanne de Jager first flagged the crisis in March with then-MEC Sheila Peters. Peters admitted in a written reply that 13 stations were fully operational at the time, though nearly half of those could only upload raw data due to budget shortfalls. Ten stations were completely offline.

“Without functioning monitoring networks, authorities cannot issue timely health warnings, assess compliance with air quality standards, or take urgent action when pollution reaches dangerous levels,” said De Jager.

Since then, the network has deteriorated further, with only 12 stations currently able to produce credible, usable data.

“Residents across Gauteng are effectively playing Russian roulette with their health every time they step outside,” said De Jager.

Gauteng: SA’s pollution hotspot

Gauteng in particular needs its air quality monitoring stations online — not just because it’s the most populated province, but because it is the most polluted province in the country.

In 2024, the average Gauteng resident was breathing air with a fine particle (PM₂.₅) concentration of 52 micrograms per cubic metre (μg/m³), according to the Centre for Research on Energy and Clean Air (Crea). 

“This makes Gauteng the most polluted province in South Africa,” said Dr Jamie Kelly, who leads the Centre for Research on Energy and Clean Air’s Health Impact Assessment team.

“To put this in context, the level is over twice the national legal standard (20 μg/m³) and a staggering 10 times higher than the World Health Organization’s guideline.”

PM₂.₅ are airborne particles smaller than 2.5 micrometres. They are mainly produced by burning coal, industry, mining and vehicles, and are dangerous because they’re small enough to pass from the lungs into the bloodstream, where they can damage vital organs. 

Read more: Air pollution in Gauteng at dangerously high levels this winter

In Gauteng, the Centre for Research on Energy and Clean Air estimates that PM2.5 contributes to about 16,000 deaths every year. This means that if we were to meet South Africa’s own national standard for PM2.5, we’d save 7,000 lives every single year.

 “These are preventable deaths, which makes the lack of adequate monitoring and policy response even more urgent,” said Kelly.

Read more: Polluted SA air killed 42,000 in 2023, study finds — yet loopholes persist

The health burden is particularly severe for children: PM₂.₅ causes 1,300 premature deaths in children under five each year in Gauteng. 

It may come as a surprise that Gauteng is South Africa’s most polluted province, given that Mpumalanga is the country’s coal heartland, home to 12 Eskom power stations and Sasol’s Secunda plant.

But as air quality expert Dr Kelly explained, “Where emissions peak and where pollutant concentrations peak are not always the same — this is especially true for PM₂.₅.”

Both PM₂.₅ particles and the gases that form them, such as nitrogen oxides and sulphur dioxide, can linger in the atmosphere for days or weeks. Pollution therefore doesn’t stay near its source — it spreads widely, creating a blanket of exposure across communities.

While sulphur dioxide is dominated by coal power plants, PM₂.₅ comes from multiple sources: mining, industry, transport and urban emissions. Gauteng’s dense population, heavy industry and traffic intensify the problem, while prevailing winds carry pollutants from Mpumalanga into the province.

“This means that PM₂.₅ is regionally distributed,” Kelly said. “Because of this, concentrations are highest in Gauteng.”

Funding gap

“The main reason for non-operational stations is lack of funding,” said new MEC Botha.

“Ambient air quality monitoring is a costly exercise, which is why the government is now combining reference stations with low-cost sensor networks to expand spatial coverage and provide community-level data, while the reference stations ensure accuracy and compliance with air quality standards.” 

Botha said the provincial department was only allocated R560,000 this financial year to support monitoring networks, which was enough to assist just one municipality — the West Rand. 

But keeping a single station running requires about R500,000 annually for maintenance alone, excluding analyser replacement and major repairs.

Kelly from the Centre for Research on Energy and Clean Air acknowledged that while air quality monitors were not cheap, and maintaining them  required sustained funding, the cost of not maintaining them was far greater. 

“Our study revealed that the health impacts of PM2.5 air pollution in South Africa amount to around R960-billion every year,” he said. “That’s nearly a trillion rand lost to hospitalisations, sick days, reduced productivity, and premature deaths.

“In that context, the budget required to keep Gauteng’s monitoring stations fully operational is negligible. Monitors are a high-return investment. They allow us to measure, manage and ultimately reduce air pollution, saving both lives and money.”

De Jager agreed: “If the department does not urgently address lethal levels of air pollution, residents will be hospitalised or forced off work, reducing their ability to contribute to the economy.”

A network in disrepair

Many stations have collapsed in recent years. Tshwane lost five between late 2024 and early 2025 due to cable theft, equipment failure, and budget shortages. Bedfordview went offline in April 2023; Krugersdorp in December 2023. Delta Park in Johannesburg has been shut since 2015 for “security reasons” and is awaiting relocation.

‘Flying blind’ without monitors

Air quality monitors are central to evidence-based environmental policy. They track whether emissions are rising or falling, reveal which interventions are working, and show which communities are most affected.

“Without functioning monitors, we are effectively flying blind, leaving residents unprotected and policymakers unable to track progress,” said Kelly.

Municipalities and government agencies rely on air quality data to enforce pollution laws, develop air quality management plans, issue timely health warnings, guide urban planning, engage with communities, and report to national authorities. 

Independent research organisations like the Centre for Research on Energy and Clean Air that collect and analyse data globally, also rely on data from local stations to build a comprehensive picture of pollution exposure and its health impacts.

But with fewer than 40%  of Gauteng’s air quality monitoring stations currently operational, critical data gaps remain. 

“These gaps limit our ability to capture the true scale of exposure in one of the country’s most polluted and densely populated regions,” said Kelly. “The lack of reliable, continuous monitoring undermines both scientific assessment and the development of evidence-based policies.”

In a province like Gauteng — South Africa’s industrial and transport hub, home to major fossil fuel power plants, heavy industry, and dense traffic — fully functioning monitors are crucial. 

“In such a high-risk environment, fully functioning monitoring stations are essential,” said Kelly. “They are the only way to measure whether current activities and policies are reducing the pollution burden, or allowing it to worsen. 

“Without them, communities near major emitters are left without the data needed to demand accountability and protection.”

Calls for accountability and government response

The DA has called for urgent funding to repair and replace stations, “emergency health protocols” for affected communities, and accountability for officials if monitors remain offline.

“The failure to maintain these stations is not a bureaucratic inconvenience — it is a public health crisis,” said De Jager. “The right to breathe clean air is not negotiable. It is a constitutional right.”

MEC Botha said the Gauteng Department of Agriculture, Rural Development and the Environment was prioritising its limited budget to 12 strategically important stations across Gauteng that provided critical data to the national air quality monitoring system. 

To assist municipalities with limited resources, the department had procured spare parts pools that could be loaned to stations needing repairs, though financial constraints prevented all stations from being supported simultaneously.

To expand coverage, the province was partnering with national and local bodies, including the Department of Forestry, Fisheries and the Environment, the South African Local Government Association, and the Clean Air Fund, to deploy 124 low-cost sensors. In Emfuleni, 200 sensors would provide real-time data and health alerts in areas where traditional monitors were offline.

Botha said the department would engage municipal managers and chief financial officers to ensure air quality monitoring received adequate budgets and staffing. A new transversal contract system would also streamline procurement, allowing municipalities to access parts and services more quickly. DM