The industrial sector is the prime contributor to air pollution. Coal combustion can lead to particulate matter in the air, as well as contribute to acid rain. While major cities in South Africa do not possess pollution levels comparable to many major cities in China, India or Mexico, pollutant levels are not insignificant. Nitrogen dioxide levels in Capetown, South Africa, for instance, were significantly higher than those measured in Calcutta, and surpassed the World Health Organization's annual mean guideline for air quality standard of 50 micrograms per cubic meter. Vehicular emissions, while not nearly as significant as in cities such as New York, Tokyo or Los Angeles, have a negative impact on the environment.
Regulations apply to diesel-powered vehicles and are geared towards ensuring proper maintenance.
Enforcement, however, is weak and sporadic. South Africa also must concern itself with marine pollution. South Africa is especially vulnerable to oil spills due to the high volume of oil transported around the country's coasts by ship from the Middle East to Europe and the Americas. The South African Department of Transport and the Department of Environmental Affairs and Tourism cooperate to ensure both prevention of oil spills and clean-up in the event of accidents. Measures supported by the Department of Transport include the maintenance of at least a 12 mile distance from the South African coast, prosecution of ship owners if any oil is discharged from their ships, control of aircraft patrols over shipping lanes, and contingency plans for any oil spills that occur.