Residents of Johannesburg reported a foul sulphur smell lingering over the city late last week, prompting an investigation by municipal authorities. The city has determined the odour originated from a neighbouring province, most likely due to the long-range movement of air pollutants from large industrial operations in Mpumalanga.
Monitoring and Potential Health Impacts
This isn’t an isolated incident. The city reports regular occurrences of a similar “rotten egg” smell between January and March over the past five years. Johannesburg maintains six ambient air quality monitoring stations, measuring particle matter, sulphur dioxide, nitrogen oxides, and ozone. Additionally, two stations specifically monitor hydrogen sulphide (H₂S) levels, located in Buccleuch and Alexandra.
H₂S is the source of the unpleasant odour, and authorities advise limiting prolonged outdoor recreation when the smell is present. The city warns that vulnerable populations – the elderly and children – should be closely monitored for symptoms including eye and throat irritation, headaches, dizziness, and fatigue. Prolonged exposure could lead to respiratory complications and neurological impacts.
Industry Response and Scrutiny
The municipality stated that Johannesburg itself does not host “major heavy industrial activities,” and that existing industrial operations within the city limits are licensed and monitored. Following the recent complaints, the environment, infrastructure and services department found the pollution was “widespread and not confined to a single location,” pointing to power generation and petrochemical operations east of Gauteng as the likely source.
Sasol, which operates a plant in Secunda, stated on Friday that its operations were functioning normally and emissions levels were “well within the limits” authorized by its atmospheric emissions licenses. However, some environmentalists question the adequacy of current air quality standards.
Robyn Hugo, Climate Change Engagement Director at Just Share, stated that “Sasol is the biggest private emitter of toxic air pollutants in Africa,” and operating within license limits doesn’t guarantee acceptable emission levels. Lauri Myllyvirta, Co-founder of the Centre for Research on Energy and Clean Air, added that air pollution dispersion modelling predicted the arrival of an air mass from Secunda in Johannesburg coinciding with reports of the odour. Myllyvirta also noted that H₂S contributes to the formation of PM2.5, a significant environmental health threat.
Frequently Asked Questions
What caused the smell in Johannesburg?
The Johannesburg municipality believes the sulphur smell originated from a neighbouring province, likely due to air pollutants from large industrial operations in Mpumalanga.
What are the potential health effects of the smell?
Exposure to the odour, caused by hydrogen sulphide (H₂S), may cause eye and throat irritation, headaches, dizziness, and fatigue. Prolonged exposure could lead to respiratory complications and neurological impacts.
What is Sasol’s response to the situation?
Sasol stated that its Secunda plant was operating within normal parameters and that emissions levels were within authorized limits.
As investigations continue, it remains to be seen whether further action will be taken to address the source of the pollution and protect public health. Will this incident spur a reevaluation of current air quality standards and monitoring practices?
