Environmental hazards and their health impacts

Environmental Hazards

Open dumps

An open dump is a land disposal site where solid waste is deposited indiscriminately and with no or limited measures taken of controlling the operation or protection the environment surrounding this area. Open dump from engineering perspective is; widely spread and not covered, waste are on fire periodically, waste is not controlled and compacted, the gas in the dump is not managed and there is no cover soil applied on the waste. The open dump is poorly planned in that there is no security and a lot of unorganized scavenging takes place at the site. In addition to these, the open dump has no planning like local sensitivity or even engineering measures like linear system put in place before the waste is placed.

The open dumps have several impacts which depend on site specific factors such as location, geological and climatic conditions. Among these impacts are environmental such as the contamination of ground and surface water. This occurs through leachate from the dump through flow paths get to the surface or underground water. The other impact is air pollution as there are organic wastes within the open dump that can contribute to green house effects through emission of methane. The uncontrolled burning of the waste in the open dumps release gases and smoke that contaminate the air too.

Early landfills

Early landfills are sites where there is disposal of waste that is environmentally accepted on the ground. These early landfills replaced the open dumps which were hazardous. However, these early landfills still have some problems associated with them. The problems are as a result of the poor design of the landfills and are such as incomplete decomposition, production of methane and leachate contamination.

A leachate is a liquid that is formed when water goes into the landfill and filters through the waste. This resultant liquid is toxic and easily pollutes ground water, land and waterways. Another problem with the early landfills is production of methane gas. The organic materials placed in the landfills like green waste and food are compacted and then covered, the compacting results in removal of oxygen leading to anaerobic breakdown of the waste. This releases methane gas, a greenhouse gas which is quite potent. The methane gas leads to global warming hence the climatic change. Methane is also flammable and could be dangerous if left to build up (Skye, 2011).

Modern landfills

To reduce the effects of the early landfills, there is creation of modern landfills that are sophisticated and regulated. They are different from early landfills in that they have protective liners which are engineered, a leachate collection system, equipment for collecting gasses, groundwater monitoring and requirements for environmental reporting. Linear systems are constructed with layers of natural materials with low permeability. Leachate collection system is designed to remove liquid that is found in the liners. Waste is placed above the collection leachate system in layers.

Modern landfills are now built in locations which protect environment and human health as well as having structural integrity. There is restriction of the construction of modern landfills in floodplains, wetland or fault areas (Repa, 2010). Once the modern landfills reach the height which is permitted it is closed down an engineered in such a way that it prevents the infiltration of water through the installation of a cap low in permeability which is same as the linear system. On top of the low-permeability barrier there is a granular drainage layer that diverts water from the top of the landfill. There is a protection cover at the filter blanket's top as well as top soil which is placed for growth of vegetation. The system of engineering in the modern landfills is in such a way that it ensures protection of environment and human health through the containing of leachate which could otherwise contaminate ground water. At the same time there is collection of gases which could be used as energy sources or even destroyed.