‘Rotten egg’ smell across Johannesburg likely from Highveld industries, says city

Levy Masiteng

The sulphur-like smell that unsettled residents across large parts of Johannesburg last week was not caused by a local source, but was most likely blown into the city from industrial areas in Mpumalanga, the City of Johannesburg has said.

The explanation followed numerous social media complaints received by the city, with residents in areas like Sandton, Randburg, Roodepoort, Fourways and Parktown reporting a strong, pungent smell reminiscent of “rotten eggs”.

“The odour described by residents as a ‘rotten egg’ smell is more commonly associated with hydrogen sulphide (H₂S),” said the city’s Environment & Infrastructure Services Department (EISD) late on Monday.

According to the department, investigations suggested that the odour was the result of “transboundary” air pollution linked to industrial activity in the Highveld Priority Area, which hosts power generation and petrochemical operations.

“Given the geographical spread of the complaints and prevailing meteorological conditions, it is likely that the