When solid waste, from food remnants to chemical by-products from manufacturing, isn't discarded properly it can have far-reaching consequences for the environment and its natural vegetation and inhabitants, as well as for public health. Usually proper solid waste management practices are in place, but particularly in low-income areas or developing countries, those standards aren't always practiced or, in some cases, are non-existent.
The solid waste that can create such a problem falls into nine categories. There is garbage, which is your rotten banana peel or other food-related waste that can decompose. Then there's the stuff that doesn't decay, like glass and metals. Ashes from manufacturing operations and large debris like trees, as well as chemicals from industrial, mining and agricultural ventures, are thrown into the mix. As unpleasant as it is, dead animals and sewage are among the types of waste that those in the disposal business concern themselves with. Looking at the types of waste, it's easy to see the negative side effects associated with not discarding it in a responsible manner.
Ninety percent of solid waste goes straight to the landfill. Incineration is the next most popular method of disposal, followed by composting to a much lesser extent. The dangers from landfills come into play when the site is in a place where it shouldn't be--such as near wetlands. The other danger is a lack of monitoring the site. Usually, standards dictate that a plastic liner or clay soil be utilized to keep waste from seeping into the groundwater. In the case of incineration, problems usually arise when toxic materials, like batteries, aren't set aside and recycled and are instead burned--releasing pollutants into the air.
If waste isn't discarded properly on land, when it rains the waste is soaked and is then carried through the landfill, eventually making its way into the water you may drink. Especially dangerous chemicals are volatile organic compounds, or VOCs, which usually come from household cleaners and industrial solvents used in operations like dry cleaning. These compounds have been linked to everything from cancers to birth defects.
Another danger, especially with open pits, comes from the spread of diseases--usually carried by rodents and bugs. An example of this is malaria, which festers in open areas with standing water and particularly hot and muggy temperatures. In addition, there may be a propensity for people to scavenge wastes in landfills and open pits, which again can create unsanitary conditions and aid the spread of disease.
Disposal locations may encroach upon existing habitat for native flora and fauna, especially when sited in areas near wetlands. In some cases, people have taken steps to reclaim the land by capping the landfill and later attempting to grow vegetation on it.
As waste begins to break down, methane is produced. Methane is considered a greenhouse gases that is responsible for some of the spike in the earth's temperatures.
When wastes are burned, especially toxic chemicals like dioxin, they're released into the surrounding environment and can then cause serious public health risks.