Scientists at the University of Witwatersrand in Johannesburg have developed South Africa’s first real-time air pollution monitoring and alert application — a response to a growing public health crisis in Africa’s wealthiest city, where a wave of coal-related emissions has left residents battling breathing problems, sinus inflammation, and severe asthma flare-ups in recent weeks.
The application, called SACAQM (South African Consortium for Air Quality Monitoring), uses data streamed from hundreds of ground-level air monitoring sensors deployed across the Johannesburg metropolitan area and its surroundings. It sends push notifications to residents when pollution levels spike, advising protective measures such as staying indoors and wearing protective masks during high-emission periods.
The Rotten Egg Smell Hanging Over Africa’s Richest City
For weeks, residents of Johannesburg have been reporting the persistent smell of sulphur in the air — an acrid, chemical odour that has disrupted daily life, caused headaches and nausea, and compounded existing respiratory conditions among vulnerable populations.
Environment Minister Willie Aucamp attributed the smell to hydrogen sulphide emissions from mining and industrial operations as far as 400 kilometres east of the city, in the coal-rich Mpumalanga province. South Africa hosts some of the world’s largest coal mines and coal-to-chemical conversion facilities, operated by companies including state electricity provider Eskom and the petrochemical giant Sasol.
“We don’t know which specific mines yet. Investigations are still ongoing,” Aucamp told Reuters in Johannesburg, conceding that the regulatory response had been slow and that the responsible parties had not yet been formally identified.
A City’s Health Emergency
For Johannesburg resident Philasande Shange, who has asthma, the recent pollution surge had serious consequences. “I couldn’t breathe or sleep properly, and I lost 15 kilograms in just a few weeks,” Shange told Reuters in an interview in the Braamfontein district. A healthcare practitioner attributed his deteriorating condition directly to poor air quality, he said.
Shange is not an isolated case. Reuters interviewed five Johannesburg residents who reported flu-like symptoms, dizziness, sinus inflammation, and worsening asthma coinciding with the recent surge in sulphur odours. The city’s high-density suburbs, many of which lie in close proximity to industrial zones and coal processing facilities, have been worst affected.
Bruce Mellado, the Wits researcher who pioneered the SACAQM system, said the monitoring network had recorded a worrying increase in the frequency and intensity of pollution spikes over the past 18 months. “What we are seeing is not random — it reflects systematic changes in industrial emissions behaviour, combined with regulatory gaps that allow major polluters to operate with minimal oversight,” he said.
The Industrial Lobby vs. Public Health
South Africa’s coal sector employs hundreds of thousands of people and generates the overwhelming majority of the country’s electricity. Sasol, which converts coal into liquid fuels and chemical feedstocks, is one of the country’s largest industrial companies and a significant contributor to national GDP. Eskom, the state electricity utility, operates a fleet of coal-fired power stations that remain the backbone of South Africa’s energy system.
In 2025, both Sasol and Eskom were granted extensions to emissions exemption permits that environmental advocates say effectively allow them to operate well above internationally accepted pollution thresholds. The extensions were justified on grounds of economic necessity — the need to protect energy supply and industrial employment — but critics argue the human and economic cost of pollution-related disease is systematically underestimated.
“We need more community monitoring to truly understand how much air pollution is costing us — not just in terms of health outcomes, but in lost productivity and economic potential,” said Rico Euripidou, a campaign coordinator at GroundWork, an environmental justice organisation.
A Technological Response to a Policy Failure
The SACAQM app, launching to the public later this year, represents a rare instance of scientific innovation filling a gap left by regulatory inaction. It draws on real-time sensor data to provide neighbourhood-level air quality readings — a significant improvement on the current system, under which pollution data is collected and published with significant time delays that render it useless for residents trying to make daily decisions about outdoor activity.
Mellado says the app will eventually include predictive modelling — using weather data, industrial activity schedules, and historical pollution patterns to warn residents of likely spikes before they occur. The goal, he says, is to give people tools to protect themselves while broader regulatory reforms catch up with the scale of the problem.
For residents like Shange, any tool that offers advance warning of dangerous air quality is a welcome development. “I shouldn’t have to wait until I can’t breathe to know the air is bad,” he said.
Sources: Reuters (April 20, 2026), BBC Africa, Impakter