Ozone Episodes and Related Vehicle Pollutant Emission Ratios in the Greater Johannesburg Area

Abstract

Ozone (O₃) episodes occur downwind of Johannesburg’s Central Business District and can be attributed to the high levels of Non-Methane Hydrocarbons (NMHC), found in the urban atmosphere of Johannesburg. The high levels of NMHC are attributed to poor combustion in the automobile engine at altitude.

As O₃ is detrimental to both human health and the environment, it must be concluded that the present levels of NMHC in the urban atmosphere of Johannesburg must be reduced. NMHC emissions from automobiles have been reduced in the United States and Japan, by the introduction of catalytic converters into exhaust systems and by automobile modifications. Australia and the EEC, led by West Germany, with the notable exception of France and the United Kingdom, have recently announced similar approaches to control automobile pollution. From the results of this report, it can be concluded that South Africa has reached the stage where serious consideration needs to be given to automobile pollution.