At this stage, the Department of Environment, Forestry and Fisheries (DEFF) and Gert Sibanda Municipality cannot say definitively what the major source/s of the air pollution was. It has therefore been recommended that other sources that could have contributed to the odour experienced in the Gauteng also be investigated. These include power plants and waste water works that also emit hydrogen sulphide. The findings of the probe will be made available once completed.