7.1 Systems of waste management  (Page 5/43)

LLW nuclear wastes are produced in hospitals by pharmaceutical laboratories and in performing nuclear medicine procedures (e.g. medical imaging to detect cancers and heart disease); however, the danger posed by these wastes is relatively low. A variety of hazardous substances have also been identified in medical wastes, including metals such as lead, cadmium, chromium, and mercury; and toxic organics such as dioxins and furans. All medical wastes represent a small fraction of total waste stream, estimated to constitute a maximum of approximately two percent. Medical wastes are commonly disposed of through incineration: as with most wastes, the resulting volume is greatly reduced, and it assures the destruction and sterilization of infectious pathogens. Disadvantages include the potential of air pollution risks from dioxins and furans as well as the necessary disposal of potentially hazardous ash wastes. New options for disposal of medical wastes (including infectious wastes) are still being explored. Some other technologies include irradiation, microwaving, autoclaving, mechanical alternatives, and chemical disinfection, among others.

Environmental concerns with wastes

Managing growing waste generation

An enormous quantity of wastes are generated and disposed of annually. Alarmingly, this quantity continues to increase on an annual basis. Industries generate and dispose over 7.6 billion tons of industrial solid wastes each year, and it is estimated that over 40 million tons of this waste is hazardous. Nuclear wastes as well as medical wastes are also increasing in quantity every year.

Generally speaking, developed nations generate more waste than developing nations due to higher rates of consumption. Not surprisingly, the United States generates more waste per capita than any other country. High waste per capita rates are also very common throughout Europe and developed nations in Asia and Oceania. In the United States, about 243 million tons (243 trillion kg) of MSW is generated per year, which is equal to about 4.3 pounds (1.95 kg) of waste per person per day. Nearly 34 percent of MSW is recovered and recycled or composted, approximately 12 percent is burned a combustion facilities, and the remaining 54 percent is disposed of in landfills. Waste stream percentages also vary widely by region. As an example, San Francisco, California captures and recycles nearly 75 percent of its waste material, whereas Houston, Texas recycles less than three percent.

With respect to waste mitigation options, landfilling is quickly evolving into a less desirable or feasible option. Landfill capacity in the United States has been declining primarily due to (a) older existing landfills that are increasingly reaching their authorized capacity, (b) the promulgation of stricter environmental regulations has made the permitting and siting of new landfills increasingly difficult, (c) public opposition (e.g. "Not In My Backyard" or NIMBYism ) delays or, in many cases, prevents the approval of new landfills or expansion of existing facilities. Ironically, much of this public opposition arises from misconceptions about landfilling and waste disposal practices that are derived from environmentally detrimental historic activities and practices that are no longer in existence. Regardless of the degree or extent of justification, NIMBYism is a potent opposition phenomenon, whether it is associated with landfills or other land use activities, such as airports, prisons, and wastewater treatment facilities.