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Ural

(Encyclopedia)Ural yo͝orˈəl, Rus. o͞orälˈ [key], river, c.1,580 mi (2,540 km) long, rising in the S Urals, flowing through Russia and Kazakhstan. Part of the traditional boundary between Europe and Asia, the ...

solid waste

(Encyclopedia)solid waste, discarded materials other than fluids. In the United States in 1996, nearly 210 million tons—about 4.3 lb. (2 kg) per person daily (up from 2.7 lb./1.2 kg in 1960)—were collected and ...

hygiene

(Encyclopedia)hygiene, science of preserving and promoting the health of both the individual and the community. It has many aspects: personal hygiene (proper living habits, cleanliness of body and clothing, healthf...

Earth Day

(Encyclopedia)Earth Day, Apr. 22, a day to celebrate the environment. The first Earth Day was organized in 1970 to promote the ideas of ecology, encourage respect for life on earth, and highlight growing concern ov...

Environmental Protection Agency

(Encyclopedia)Environmental Protection Agency (EPA), independent agency of the U.S. government, with headquarters in Washington, D.C. It was established in 1970 to reduce and control air and water pollution, noise ...

toxic waste

(Encyclopedia)toxic waste is waste material, often in chemical form, that can cause death or injury to living creatures. It usually is the product of industry or commerce, but comes also from residential use, agric...

biosphere

(Encyclopedia)biosphere, irregularly shaped envelope of the earth's air, water, and land encompassing the heights and depths at which living things exist. The biosphere is a closed and self-regulating system (see e...

hydrology

(Encyclopedia)hydrology, study of water and its properties, including its distribution and movement in and through the land areas of the earth. The hydrologic cycle consists of the passage of water from the oceans ...

aquaculture

(Encyclopedia)aquaculture, the raising and harvesting of fresh- and saltwater plants and animals. The most economically important form of aquaculture is fish farming, an industry that accounts for an ever increasin...

Carson Sink

(Encyclopedia)Carson Sink, swampy area, c.100 sq mi (260 sq km), W Nev.; a remnant of ancient Lake Lahontan. Fallon National Wildlife Refuge is located there. The Carson River (c.125 mi/200 km long), fed by melted ...