Passive sampling of SO2 and NO2 ambient air concentrations in Zambia April 1999.
Abstract
As part of a second screening study to develop a plan for ambient air pollution monitoring in Zambia (Guerreiro, 1999), 34 SO2 and 17 NO2 passive samplers were placed inside the cities of Lusaka and Ndola, in Maamba and Mazabuka and around industries in the Copperbelt area. The passive samplers were installed in field to measure ground level concentrations as a result of emissions from traffic and industrial activities. SO2 is particularly a problem in the Copperbelt area, due to the high industrial activity that characterises this area. The World Health Organisation’s (WHO) air quality guideline for SO2 is exceeded in Mufulira and Nkana, downwind of the smelters. While in Mufulira these concentrations can have a very serious impact on both vegetation and population living downwind of the smelter, in Nkana the population is less often exposed to extremely high SO2 concentrations, since the townships are not located on the prevalent downwind direction from the industry. The SO2 ambient air concentrations measured in Maamba, Ndola and Chingola were below the WHO air quality guideline. Nevertheless under episodes with high local emissions of SO2 and / or poor meteorological dispersion conditions in these areas, high concentrations of SO2 are likely to occur in neighbouring areas, exceeding the WHO air quality guideline. The measured NO2 concentrations are well below the WHO air quality guideline and do not represent presently a motive of concern.