Abatement is a general term used for methods or technologies that reduce the amount of pollutant generated in a chemical or other manufacturing facility. In contrast, the terms cleanup and remediation refer to removal or appropriate disposal of the pollutants after they have been generated; these methods are also often referred to as end-of-the-pipe treatment.

Acid Rain

Acid rain is any form of atmospherically deposited acidic substance containing strong mineral acids of anthropogenic origin. It was reportedly first described in England by Robert Angus Smith in 1872.


"In wildness is the preservation of the world," wrote Henry David Thoreau, a nineteenth-century New England writer who became a founding figure of today's environmental movement. His life and work ushered in a uniquely American perspective on nature, a philosophy that made an unprecedented defense of the value of wilderness.

Adaptive Management

Adaptive management is a systematic process for continually improving management policies and practices by learning from the outcomes of operational programs. Traditionally, management plans for addressing the impacts of pollution, and addressing the risks of exposure of toxics to humans and ecosystems were strictly followed as written.

Addams, Jane

Jane Addams (1860–1935) is remembered primarily as the feisty American founder of the Settlement House Movement, which sought to challenge the industrial and urban order of the period to achieve social and environmental reforms. Inspired by a visit to London's East End and Toynbee Hall, a "settlement house" addressing the needs of the urban poor, Addams and her friend Ellen Starr cofounded Hull House in the slums of Chicago in 1889.

Agencies, Regulatory

There are large numbers of federal and state agencies in the United States that have been authorized by Congress or state legislatures to implement and enforce environmental laws. As a general matter, environmental regulatory agencies are responsible for establishing maximum allowable levels of pollutants in air, water, and soil to protect human health and the environment, and for developing programs to achieve such levels of protection.

Agenda 21

Agenda 21, agreed to at the United Nations Conference on Environment and Development (more commonly known as the Earth Summit) in Rio de Janeiro in 1992, was the nonbinding plan of action that identified and prioritized environmental, financial, legal, and institutional issues to serve as a guide for countries to direct their resources and energies. Among Agenda 21's most notable elements were calls for the creation of the Commission on Sustainable Development (CSD), whose functions include monitoring the agenda's implementation and conducting negotiations toward a treaty on desertification, a high-priority concern of many developing countries.


Agriculture, the deliberate raising of plants and animals to enhance and secure food production, evolved in the Near East about 10,000 years ago. It was this transition from hunting-gathering to settled agriculture that created civilization as we know it and led to a rapid increase in the human population from about five to six million at that time to six billion in 2000.

Air Pollution

Air pollution is a phenomenon by which particles (solid or liquid) and gases contaminate the environment. Such contamination can result in health effects on the population, which might be either chronic (arising from long-term exposure), or acute (due to accidents).

Air Pollution Control Act

The Air Pollution Control Act (APCA) of 1955 was the first legislation on air pollution enacted by the U.S. federal government.

Antinuclear Movement

"I am become death, the shatterer of worlds." Robert Oppenheimer, the "father" of the atomic bomb, muttered these Hindu words after the initial successful test of the new weapon during the summer of 1945. Although Oppenheimer's scientific expertise produced the bomb, he grew increasingly uneasy over its application and destructive power.


Arbitration is a process in which disputing parties abandon their right to litigate or appeal to the judicial court and instead put their case before an impartial third party who renders an opinion or recommendation. If the arbitration is nonbinding, the parties may choose to accept it or not.

Arctic National Wildlife Refuge

The Arctic National Wildlife Range was established in 1960 to conserve 8.9 million acres of Alaska's remote northeast corner. This roadless area, north of the Arctic Circle, consists of arctic and alpine tundra, coastal lagoons and barrier islands, and boreal forest.


Arsenic (As) is a naturally occurring element that has been used in a variety of applications—in pesticides, as wood preservatives, and as a treatment for syphilis. Throughout history, arsenic was the most often used poison.


Asbestos is a mineral rock with a chemical composition of mostly silicon, water, and magnesium. Most asbestos fibers are long, thin, strong, flexible, fireproof, and resistant to chemical attack.


Asthma is a chronic disease of the lungs that affects millions around the world, particularly in industrialized countries. The symptoms of asthma Number of Persons with Asthma in the United States, National Health Interview Survey, 1980-1996 include shortness of breath, chest tightness, wheezing, and coughing; nighttime symptoms that interfere with sleep can be particularly troublesome.

Beneficial Use

Beneficial use is the productive use of water or solid material that is normally discarded or disposed of in a landfill or burned.


Bioaccumulation is the accumulation of contaminants by species in concentrations that are orders of magnitude higher than in the surrounding environment.


Biodegradation is the decay or breakdown of materials that occurs when microorganisms use an organic substance as a source of carbon and energy. For example, sewage flows to the wastewater treatment plant where many of the organic compounds are broken down; some compounds are simply biotransformed (changed), others are completely mineralized.


Bioremediation means to use a biological remedy to abate or clean up contamination. This makes it different from remedies where contaminated soil or water is removed for chemical treatment or decontamination, incineration, or burial in a landfill.


Biosolids are nutrient-rich organic materials that result from the treatment of wastewater. They are commonly recycled as a fertilizer for crops and as a soil amendment to improve depleted soils.

Bottle Deposit Laws

Bottle deposit laws, policy that requires the containers for carbonated beverages such as soft drinks and beer to carry a refundable deposit, have been a subject of controversy for more than thirty years. Designed to reduce waste by motivating more people to recycle bottles and cans, the strategy imposes a mandatory fee of usually five or ten cents per container that consumers pay at the cash register; when customers return the containers to stores selling the product or redemption centers, they get their deposit back.