Residents across Johannesburg — from Sandton and Randburg to Roodepoort, Fourways and even areas beyond the city boundary — have reported a strong sulphur-like odour in the air, first noticed on 16 January and again on 9 March.
In response, the City of Johannesburg said its environment and infrastructure services department (EISD) immediately initiated an investigation, activating its air quality monitoring network to track and analyse the source of the odour.
“Protecting the health and well-being of residents remains our priority,” said city manager Floyd Brink.
“Our technical teams are actively monitoring air quality data and working with other spheres of government to determine the source of the odour and ensure residents are kept informed.”
On Tuesday, Bedfordview resident Wendy Zipp wrote to Forestry, Fisheries and Environment Minister Willie Aucamp to express her concerns. In her email, she explained that residents in Bedfordview and neighbouring areas experienced toxic air pollution on 9 and 10 March.
“This has happened before but this recent incident is worse than ever,” Zipp wrote.
“I am suffering from headaches, burning eyes and a tight chest.
“I have been informed by two ward councillors that the fumes are due to wind direction and most likely caused by Sasol (Secunda) and people with health issues should stay indoors or go outside wearing an N95 mask.
“This is a poor and unacceptable explanation. I am neither ill nor elderly but this pollution is affecting my health.”
Zipp asked the minister whether the government was aware of the issue, actively investigating it and monitoring Sasol’s emissions to ensure residents were not being exposed to dangerous pollutants.
Residents also shared posts on social media, highlighting the extent of public concern.
A closed Bedfordview Facebook group, which has more than 22 000 members, featured multiple reports of odours, health symptoms and unusual environmental effects.
Zipp provided screenshots from the group to the Mail & Guardian, showing complaints about “terrible odours”, “sour smells” and observations of dead insects coinciding with the nausea-inducing odour episodes.
Sasol said: “Sasol is aware of reports regarding a suspected sulphurous odour noted by some residents in the Johannesburg region.
“We confirm that Secunda Operations is stable, with no operational incidents or abnormal process conditions that could have resulted in increased emissions or off‑site impacts.
“Available operational information indicates that all key plant systems have been functioning within normal parameters and emissions monitoring shows levels well within the limits authorised in our atmospheric emissions licences.
“As part of our commitment to responsible environmental management, we continuously track operational and ambient air quality data across the Secunda region.
“Recent assessments, including data from Sasol-managed and independent monitoring stations, do not indicate exceedances of applicable ambient air quality standards.
“While Sasol cannot comment on the source of odours reported in Johannesburg, we continue to monitor our operations and the regional ambient network closely.
“We remain committed to transparency and to engaging constructively with communities and stakeholders.”
The city noted that Johannesburg had experienced typical late-summer weather this week, characterised by warm temperatures, humid air and occasional rainfall.
“Such atmospheric conditions can intensify odour episodes like those observed in January and March.”
Monitoring data from the city’s stations at Buccleuch and Alexandra confirmed elevated levels of hydrogen sulphide (H2S) during the episodes. On 9 March, fluctuating concentrations were observed, with more pronounced spikes on 10 March.
“At the Alexandra station, H2S concentrations peaked at approximately 36–37 parts per billion (ppb), while sulphur dioxide (SO2) peaked at around 52ppb,” said Dr Tebogo Modiba, the executive director of the EISD.
While the short-term spikes were sufficient to produce a noticeable odour, overall pollutant concentrations remained generally low and close to background levels.
The city said the levels recorded were below concentrations typically associated with serious health risks, adding that the “rotten egg” smell reported by residents was commonly linked to hydrogen sulphide.
Johannesburg periodically experiences transboundary pollution. “This episode has been escalated to the national department of forestry, fisheries and the environment and the Gauteng department of environment.
“These agencies are responsible for addressing cross-boundary emissions, which in this case are consistent with activities within the Highveld industrial complex,” Modiba said.
Modiba added that the city’s air quality management unit continued to analyse air quality data and track dispersion patterns to better understand the odour plume’s origin
and movement.
Johannesburg does not host major heavy industrial operations and all industrial facilities are licensed and regularly monitored to ensure compliance with environmental legislation.
As a precaution, residents are advised to remain indoors during strong odours and avoid strenuous outdoor activity. Vulnerable groups, including children, the elderly and individuals with respiratory conditions, should monitor for symptoms such as eye or throat irritation, headaches, dizziness or fatigue.
The city said its unit was working closely with national and provincial departments to identify the odour source. Complaints from residents would be monitored continuously as weather improved and pollutants dispersed.
“Our technical monitoring and investigation processes are designed to respond to these incidents quickly. Residents’ health and well-being remain our priority,” Brink added.
Air quality data was publicly available through the South African Air Quality Information System, allowing residents to track fluctuations in pollutant concentrations.
The city said it would continue to provide updates as investigations progressed, “ensuring transparency and timely information for all affected communities”.
Ntombi Maphosa, an attorney at the Centre for Environmental Rights, told the M&G: “The way I understand it is that it is transboundary [pollution] from the Highveld because of the weather patterns. It’s not the first time that it’s happening.
“It started in 2022 — that was the first time it happened — and it’s usually in the beginning of the year but I’m not sure why; it could be because of the wind direction.”
With outdoor air, she said, it was hard to determine the source, she said, referring to Sasol’s statement, and “pin it on one specific polluter because there’s also [Eskom] power stations there [on the Highveld] and other industries and all of them are contributing”.
Zipp expressed concern over the reported SO2 concentration of about 52ppb.
“The World Health Organisation recommends maximum 24-hour exposure of 15ppb to 20ppb,” she said. I got a reply from Minister Aucamp’s office (his PA) saying that they would get back to me.
“Nothing further … I am just a concerned citizen with a headache, burning eyes, throat and chest, not an expert. I really want to know what is being done to address this, though.”
The department of forestry, fisheries and the environment did not respond to the M&G’s enquiries.
People have been reporting strong sulphur odours causing headaches and eye irritation. The city is monitoring air quality while authorities investigate potential Highveld emissions
