Environmental Risk Indices for Municipal Solid Waste in the City of Dar es Salaam, Tanzania: Assessing Pressure-Response Relationship

Abstract

This paper based on the previous study which used DPSIR model and analytical hierarchy process (AHP) to assess environmental risk from Municipal Solid Waste in the city of Dar es Salaam, Tanzania, by Kazuva, et al., (2018) The DPSIR Model for Environmental Risk Assessment of Municipal Solid Waste in Dar es Salaam City, Tanzania. Int. J. Environ. Res. Public Health 15(8). In that study the Comprehensive Environmental Risk Index-(CERI) was categorised into five major indices of drivers-pressure-state-impact-response, as simulated from the model. Despite that each index contributed significantly to the CERI, pressure and response indices have been found with peculiar features. While pressure index showed the greatest influence to the alarming state of environmental pollution, response index found with dictating power to the trend of other indices. Therefore, this study intends to present the relationship between pressure and response indices from the established environmental risk indicator system, by using the experts’ questionnaires method and the AHP. Analysis was done by computing trend of the two indices in the period of 12 years (2006-2017). Literally, pressure and response indices have been found with opposing tendencies for the entire period of assessment. The response index with all its subordinates have continued found with a controlling power over pressure index. It slows down the risk value for pressure index, thus withholding the ERI from reaching the critical point (>0.8). However, this power has not been effective and sufficient to suppress the entire pressure which was constantly increasing in upward trend, somewhat threatening ecological environment and human health in urban setting.