The reuse of products, materials, and parts can have significant environmental and economic benefits. Waste is not just created when consumers throw items away.

Right to Know

An industrial democracy requires well-informed citizens. The use of public information as a means of reducing harm from pollution evolved throughout the twentieth century.


Risk is the potential for harm. Although the concept of risk—and some of the same analytic tools—are also used in finance and actuarial science, as well as to describe threats from natural events, this discussion focuses on risks to human health and the environment from toxic pollution.

Rivers and Harbors Appropriations Act

The modern form of the Rivers and Harbors Act was enacted in 1890, and amended by the Rivers and Harbors Appropriation Act of 1899, also known as the Refuse Act. It was amended again several times during the twentieth century.


Scientists collect samples of air, water, soil, plants, and tissue to detect and monitor pollution. Pollutants are most often extracted from samples, then isolated by a technique called chromatography and analyzed by appropriate detection methods.


Scrubbers are air-pollution-control devices that remove harmful gases and particulates from the smokestacks of incinerators, chemical manufacturing facilities, and electric power plants before they enter the atmosphere. There are different types of scrubbers, including wet and dry, regenerative and nonregenerative.


Sediments in the aquatic ecosystem are analogous to soil in the terrestrial ecosystem as they are the source of substrate nutrients, and micro- and macroflora and -fauna that are the basis of support to living aquatic resources. Sediments are the key catalysts of environmental food cycles and the dynamics of water quality.

Settlement House Movement

As more women gained access to a college education in the late nineteenth century, many hoped to use their skills and talents for more than homemaking and child rearing. Jane Addams, born in 1860 to a Quaker miller in Illinois, was one of these women who hoped to improve the life of others and society at large.

Smart Growth

The "smart growth" movement arose in the 1990s to combat the perceived negative aspects of the dominant growth patterns of the time: rapidly spreading development that tended to draw people and resources away from existing neighborhoods and created new, look-alike communities where vehicle use was mandatory and walking was discouraged. Proponents of smart growth—a group that includes city planners, environmentalists, urban designers, neighborhood activists, and others—do not try to stop development, but instead work to make development improve life in existing cities and towns, rather than degrade it.


Mined ores are processed to concentrate the minerals of interest. In the case of metal ores, these mineral concentrates usually need to be further processed to separate the metal from other elements in the ore minerals.


Originally, the term smog was coined to describe the mixture of smoke and fog that lowered visibility and led to respiratory problems in industrial cities. More recently, the term has come to mean any decrease in air quality whether associated with reduced visibility or a noticeable impact on human health.

Snow, John British Anesthesiologist (1813–1858)

In 1854, John Snow was a well-regarded London anesthesiologist, tending to Queen Victoria, among others. He was born in 1813 of humble stock, but through education and intellectual perseverance—he obtained his M.D.

Soil Pollution

Soil pollution comprises the pollution of soils with materials, mostly chemicals, that are out of place or are present at concentrations higher than normal which may have adverse effects on humans or other organisms. It is difficult to define soil pollution exactly because different opinions exist on how to characterize a pollutant; while some consider the use of pesticides acceptable if their effect does not exceed the intended result, others do not consider any use of pesticides or even chemical fertilizers acceptable.

Solid Waste

The garbage that is managed by local governments is known as municipal solid waste (MSW). Specifically, MSW is waste generated by commercial and household sources that is collected and either recycled, incinerated, or disposed of in MSW landfills.

Space Pollution

In the most general sense, the term space pollution includes both the natural micrometeoroid and man-made orbital debris components of the space environment; however, as "pollution" is generally considered to indicate a despoiling of the natural environment, space pollution here refers to only man-made orbital debris. Orbital debris poses a threat to both manned and unmanned spacecraft as well as the earth's inhabitants.


A term used in debates about urban growth, sprawl does not have a precise, academic definition. As a noun, it most often refers to spread-out development that requires people to use a car for every activity, because it strictly separates housing, shopping, schools, offices, and other land uses from each other.

Strong, Maurice Canadian Environmental Advocate; First Executive Director of the United Nations Environment Programme (1929–)

No single international civil servant has contributed more to global attention to environmental problems, including those relating to air and water pollution, than has Maurice F. Strong.

Sulfur Dioxide

Sulfur dioxide (SO2) is an air pollutant known primarily for its role in acid rain. SO2 is emitted naturally from volcanoes.


Superfund is a term used for the monies available to the U.S. Environmental Protection Agency (EPA) to clean up abandoned or inactive hazardous waste sites.

Sustainable Development

The term sustainable development gained international recognition after the World Commission on Environment and Development (the Brundtland Commission) released its report Our Common Future in 1983.

Swallow, Ellen

Ellen Swallow Richards (1842–1911) was the first female chemist in the United States and the mother of the science of ecology. As she walked to the Massachusetts Institute of Technology (MIT) each day, this sanitary chemist noticed horse wagons carrying uncovered food over Boston's dirty, unpaved Ellen Swallow.

Systems Science

Most traditional science works within a very restricted disciplinary domain requiring a careful and often technically rigorous and demanding approach that includes, at least in theory, the use of the Baconian scientific method of test and control in a restricted laboratory environment. This is how most science operates, and it is often a very successful approach.