Other researchers such as Coolidge, Porter and Zhang (1998), Kendie (1998) and UNEP (2005) have also looked at solid waste problem and its relationship to increasing population growth. Taiwo (2011) attributes the issue of poor management of solid waste in developing countries to poverty, rapid population growth and urbanization. This is due to fast growing rate and increasing human populations, medium and small towns which has led to the generation of more waste.
Another report of UNEP(2009) as cited in the work of Belay(2015) indicated that rapid urbanization has been taking place during the 20th century virtually transformed the world in to communities of cities and towns facing similar challenges on environmental issues in which most of them have to be addressed at international level (Smith 2010). Among those environmental issues solid waste management (SWM) is a critical one because as long as humans have been living in settled communities, no awareness to managing waste, solid waste generation has been an unavoidable and critical issue both in developed and developing nations. As a result, SWM became a worldwide agenda at united nation conference on Environment and Development in Rio de Janeiro in 1992 with a great emphasis on reducing wastes and maximizing environmentally sound waste reuse and recycling at first step in waste management.
According to Hoornweg & Tata, (2012) population in urban areas is increasing at alarming rate, parallel to this most cities’ waste quantity is increasing rapidly; an enormous volume of waste is generated every day. Recent studies show that 1.3 billion tons of solid waste per year has been generated from global cities with an annual cost of $205.4 billion the materials or substances in waste are even increasing in complexity and variety. This large amount of solid waste generation has become one of the serious challenges for environment and public health; particularly it is more serious in developing continents/ countries, like Africa.