Solid Waste Click on the image to see the chart
Solid wastes are unwanted solid materials such as garbage, paper, plastics and other synthetic materials, metals, and wood. Billions of tons of solid waste are thrown out annually. The United States alone produces about 200 million metric tons of municipal solid waste each year (see Solid Waste Disposal). A typical American generates an average of four pounds of solid waste each day. Cities in economically developed countries produce far more solid waste per capita than those in developing countries. For instance, Washington D.C. produces five times the solid waste, per person, of Quito, Ecuador. Moreover, waste from developed countries typically contains a high percentage of synthetic materials that take longer to decompose than the primarily biodegradable waste materials of developing countries.
Areas where wastes are buried, called landfills, are the cheapest and most
common disposal method for solid wastes worldwide. But landfills quickly become
overfilled and may contaminate air, soil, and water. Incineration, or
burning, of waste reduces the volume of solid waste, but produces dense ashen
wastes (some of which become airborne) that often contain dangerous
concentrations of hazardous materials such as heavy metals and toxic compounds. Composting,
using natural biological processes to speed the decomposition of organic wastes,
is an effective strategy for dealing with organic garbage and produces a
material that can be used as a natural fertilizer. Recycling, extracting
and reusing certain waste materials, has become an important part of municipal
solid waste strategies in developed countries. According to the EPA, over
one-fifth of the municipal solid waste produced in the United States is now
recycled or composted. Recycling also plays a significant, informal role in
solid waste management for many Asian countries, such as India, where organized
waste-pickers comb streets and dumps for items such as plastics, which they use
or resell.
Expanding recycling programs worldwide can help reduce solid waste pollution, but the key to solving severe solid waste problems lies in reducing the amount of waste generated. Waste prevention, or source reduction, such as altering the way products are designed or manufactured to make them easier to reuse, reduces the high costs associated with environmental pollution.