There are three big pieces to using air quality data for social impact: (1) air quality data from government, industry and civil society monitoring stations, (2) atmospheric emissions licenses granted to specific organisations allowing them to pollute the air up to a certain level, and (3) legislation, regulations and case law. There are open data resources related to all of these below.
The South African Air Quality Information System (SAAQIS) captures and visualises data from a large number of monitoring stations across the country.
You can view emissions license information for individual industry on the South African Atmospheric Emission Licensing and Inventory Portal (SAAELIP). In this way you can see what individual industry sites are allowed to emit.
Finally, you can view online versions of relevant national air quality legislation xxxx and regulations xxxx on SAFLII [note: links are broken, looking for update. See PDF of NEMA here] and at a local level for some cities on OpenByLaws.