Johannesburg residents can track and predict air pollution spikes in real time, as Wits University Scientists launch AI_r app to make the city’s invisible dangers visible.
Johannesburg is tackling one of the city’s most pressing health challenges - air pollution. A team of particle physicists and scientists at the University of the Witwatersrand have developed AI_r – South Africa’s first low-cost, AI-powered air quality monitoring and prediction system.
Coal emissions, dump fires and heavy traffic all contribute to fluctuating pollution levels. Globally, 7.9 million premature deaths are linked to poor air quality every year, according to The State of Global Air 2025 report. Until now, real-time monitoring has been very expensive. AI_r changes that, with the public dashboard already live, and the app set to launch in the coming weeks.
The project is led by Professor Bruce Mellado, the Director of the Wits Institute of Collider Particle Physics. The team also includes Dominique Adams, Project Coordinator at the South African Consortium of Air Quality Monitoring (SACAGM) and Dr Edward Nkadime, Lecturer in the School of Physics at Wits. They have found that Johannesburg has very high and unstable levels of air pollution. The quality will appear to be steady but then suddenly have a massive spike. “If pollution is coming across the city from an industrial or mining site, the system will pick it up and we can see where it is coming from,” explains Adams.
Residents of Johannesburg often complain of a rotten-egg smell drifting through the streets. Environment Minister Willie Aucamp recently attributed this to hydrogen sulphide emissions from mining operations hundreds of kilometres away. Johannesburg is located on the ‘Highveld’, where the air is often still, which means pollution sometimes hangsfor longer. Air quality is not felt equally across neighbourhoods, as a Clean Air Fund report highlights, “poverty levels are highest among black people, and spatial segregation remains stubbornly intact. As elsewhere, air pollution further exacerbates these inequalities”. “Some are close to sources of air pollution,” says Ngelekanyo Tshishonga, a recent Wits Environmental Science graduate, who researches air quality awareness and analyses. Other areas “are affected geographically through mountains, more or less tress and wind direction.”
AI_r started 3 years ago and deployed the first sensors in 2024. Today, devices are spread across Johannesburg, including at Wits University. The system focuses on PM2.5, tiny particles of dust and smoke that can enter the bloodstream and cause cardiovascular infections, diseases, reduced mental capacity, and other illnesses. “Our bodies cannot function without oxygen,” Tshishonga reminds us. By tracking these particles, AI_r helps reveal the everyday risks people face.
The system uses small sensor boxes that sample air. Artificial Intelligence then analyses the data, identifies pollution hotspots, and predicts areas where conditions might get worse on specific days. Residents can check real-time data online, and soon the app will alert via SMS and email when they are in highly polluted areas. “They can then enforce wearing a mask and taking preventative measures,” says Nkadime.
By making the dangers in the air we breathe visible, AI_r is more than just innovation; it is empowering people with the tools to protect themselves and demand cleaner air.