How Is Toxic Waste Disposed Of?

Any substance that is harmful to humans and the environment is classified as toxic. The most hazardous pollutants are treated chemically or biologically and disposed of in remote locations. Most toxic waste is from manufacturing and chemical processing industries, but some domestic waste may be toxic, too.

Domestic toxic waste includes pesticides, fluorescent tubes, asbestos, electrical equipment, such as TVs and computer monitors, used vehicle oils, some paints, some household and car batteries, refrigerators and freezers. Chemicals inside of these items can leach into the Earth and contaminant the water table when buried in a dump.

Failure to dispose of toxic waste in the appropriate manner poses considerable hazards to you health and the environment.

Identification

• Adding chemicals may reduce toxicity in harmful substances

  There is a risk from being exposed to small quantities of toxic waste at home and at work, such as taking old medicines or working with pesticides.

  Household products containing toxic and hazardous substances must be labeled in secure containers. Toxic material may be explosive, corrosive, poisonous, mutagenic (harmful to chromosomes), radioactive, flammable, bioaccumulative (causes build-up in plants and animals in food chains).

  Flushing anti-depressants and birth control pills down the toilet can contaminate wastewater and harm fish, amphibians and other aquatic life. Contaminants may be carcinogenic (causes cancer) and teratogenic (causes birth defects).

  Toxic, or poisonous waste is created as a by-product of chemical, industrial and biological processes. The most toxic types include radioactive waste from nuclear power stations.

  Herbicides become serious contaminants through combustion, chlorine bleaching and manufacturing processes. Heavy metals, such as cadmium, mercury and lead, may be found in discarded motor vehicles, batteries and computer components.

Treatment

• Some toxic waste containers may leak

  Toxic waste should be disposed of immediately rather than stored or deposited in a landfill site. Some toxic urban refuse may be suitable for incineration (burning). Industrial waste that is incinerated such as tar, paint, pesticides and solvents must be incinerated at higher temperatures than domestic waste.

  Hazardous materials that not suitable for incineration, such as asbestos, may be permanently sealed in containers lined with concrete, clay or plastic and buried in a landfill site. Incineration is not considered suitable for any waste that may give rise to noxious or offensive gases and dioxins, which are considered highly dangerous.

  A better treatment method involves adding chemical or biological agents before disposal that make the waste less toxic. A biological treatment would encourage bacteria to "eat" the waste so that it becomes a less toxic residue. Some wastewater treatment plants introduce water-borne microorganisms to freely consume biodegradable organic contaminants and emit harmless waste.

International Significance

• Waste disposal is becoming big business

  Highly toxic waste is very expensive to dispose of. A specialized international toxic waste industry has been created due to the high cost and limited storage for large quantities of toxic waste.

  Bamenda and Yaounde, two cities in the African country Cameroon, specialize in dealing with excess waste. Other Third World countries eager for foreign investment employ similar programs.

Regulations

• Toxis waste dangers may not be obvious

  Local and national governments take ultimate responsibility for waste disposal policies. Governments are increasingly working with environmentalists and activists from non-governmental organizations to devise better integrated strategies to handle toxic waste.

  As a result, waste disposal rules and regulations are becoming stricter. For example, medical waste is now more commonly incinerated instead of dumping into a landfill. Conservationists are lobbying governments to eliminate regulatory loopholes as well as encouraging citizens to better preserve our environment.

  The U.S. Environmental Protection Agency re-addressed two hazardous waste rules in 2009---the Definition of Solid Waste and the Emission Comparable Fuels---to encourage better recycling of certain materials and to help conserve resources.

Future Considerations

• Alternatives for manufactured goods that are less polluting are becoming popular. Chlorine, which is commonly used to bleach wood, but forms harmful dioxins, is being replaced with oxygen. But Chlorine has yet to be replaced in many of its other uses.

  More efficient manufacturing processes are helping to reduce waste. Computers are used to control welding and car companies are using recycled components in new vehicles.

  Better maintenance of machinery cuts toxic waste production. Recycling is becoming economically viable so that expensive and toxic heavy metals will be reused more often.