Research Article
K. S. Madhava Rao, T. S. Verma
Abstract
The present experimental study was conducted to monitor the aerosol particle concentration and carbon dioxide gas concentration in Gaborone, Botswana. The measurements of concentration of aerosol particles larger than 0.3 μm and carbon dioxide gas concentration in Gaborone, between September 2006 and August 2008 were made at 12 noon everyday. Particle measurements were made using a battery -powered hand held particle counter-model HHPC- 6 - Met One. Carbon dioxide gas concentration measurement was made using Horiba VIA-510 gas analyzer. The collected data was analyzed using graphical and traditional statistical techniques. A new classification criterion is introduced to identify severity states of airborne particles. Two new measures to assess the symmetry of counts of severity states and spread of severity states around the normal states are proposed. This study shows that the mean monthly particle concentration increases and becomes its maximum during winter [June-August]. Similar trend is also observed with the mean monthly carbon dioxide gas concentration. The new measures proposed reveal a strong correlation between the airborne particles, precipitation and biomass burning. The particles and carbon dioxide originate from vehicular emissions and biomass burning. In Botswana, during winter the biomass is by and large used in cooking and heating purposes. It is worthwhile to note that 47% of the world biomass is burnt in African continent.