People living in South Africa’s biggest city Johannesburg have been subject to pungent smells in the air similar to rotten eggs. It’s not the first time citizens have complained about the smell which is related to polluted air. We asked Rebecca Garland, an expert in air quality and climate change, to shed some light on what’s driving the pollution. How bad is the quality of the air in Johannesburg? In winter in parts of South Africa, there is often a haze in the morning and evening from high levels of air pollution. However, occasionally, it’s possible to smell the pollution as some South Africans did in mid-June 2022 in many areas of Gauteng Province. The province is located in what is known as the Highveld – a high altitude inland area where major cities like Johannesburg are located. The industrial Highveld is South Africa’s industrial heartland.