Air

A regional monitoring programme was found to be viable and is proposed as a public private partnership covering air emissions, air quality and energy efficiency on the Mpumalanga Highveld. The assessment concluded that the worst health impacts fall on residential areas, driven by inefficient coal burning for heating and by housing sited close to large industry.

Aircraft and ground based measurements at Kleinkopje Colliery showed spontaneous combustion to be a significant source of fine particles, with PM2.5 concentrations 91 per cent higher inside a combustion plume than outside it. Sulphur dioxide, nitrogen dioxide and carbon dioxide were also raised in plume, and benzene and toluene were detected. Average particle size was below one micron.

Emission factors derived from measured South African seam gas data give simple models for methane released by underground mining, surface mining and coal after mining. Applied across the industry they put total methane emissions at 52 000 to 93 000 tons a year. The models follow the IPCC Tier 2 approach using country specific factors.

Gas sampling on coal mine dumps found rehabilitation very effective at cutting emissions. Even incomplete rehabilitation held carbon dioxide below about 1 kg per square metre a year, against over 100 on unrehabilitated ground and as much as 7 000 where combustion was active, though burning areas were small. Sulphur oxides, nitrogen oxides, ammonia and methane were low.