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Word List

abiotic

a system characterized by the absence of life or living organisms.

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acid

a sour substance, typically soluble in water, which neutralizes bases to form salts. A compound containing hydrogen atoms (H) which are capable of being replaced by a positive element or radical. A substance which gives up H to another substance.

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acute toxicity

any poisonous effect produced within a short time after exposure to the toxic compound, usually within 24 to 96 hours

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alkalinity

the total measurable bases (OH, HCO3, CO3) in a volume of water; a measure of a material's capacity to neutralize acids.

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alloy

a substance composed of two or more metals.

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amalgam

an alloy that consists chiefly of silver mixed with mercury and variable amounts of other metals and is used as dental filling.

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anthropogenic

man-made

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anthropogenic mercury emissions

the atmospheric emission of geologically bound mercury by human activity (e.g. emission of mercury in fossil fuels such as coal)

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antifouling

a coating process or the like that prevents the accumulation of aquatic animals and plants.

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atmosphere

the gaseous layer that surrounds the earth (air)

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base

a substance which neutralizes an acid. A substance which furnishes hydroxyl (OH) ions and a positive ion, usually a metal. An ion which will combine with hydrogen ions. An alkali.

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benthic

of or pertaining to the benthos

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benthos

the bottom of the sea or of any body of water.

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bioaccumulation

the uptake and retention of substances by an organism from its food and its surrounding environment. Chemicals that bioaccumulate become more concentrated at each successively higher level of the food chain.

Bioaccumulative chemicals can be toxic to organisms at the upper end of a food chain, such as predatory fish, loons, eagles, otters, or humans that eat fish

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biocide

any chemical that destroys life by poisoning.

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bioconcentration

a specific bioaccumulation process by which the concentration of a chemical in an organism becomes higher than its concentration in the air or water around the organism. Although the process is the same for both natural and manmade chemicals, the term bioconcentration usually refers to chemicals foreign to the organism.

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bioconversion

the conversion of biomass to usable energy, as by burning solid fuel for heat, by fermenting plant matter to produce fuel, as ethanol, or by bacterial decomposition of organic waste to produce methanol.

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biogeochemical cycle

a cycle dealing with the relationship between the chemical changes of the earth's crust of a given region and its flora and fauna, including the circulation of such elements as carbon, and nitrogen between the environment of the cells of living organisms.

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biohazard

the health risk posed by the possible release of a pathogen into the environment.

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biomagnification

it describes a process that results in the accumulation of a chemical in an organism at higher levels than are found in its food. It occurs when a chemical becomes more and more concentrated as it moves up through a food chain. At the top of the food chain an animal, through its regular diet, may accumulate a much greater concentration of chemical than was present in organism lower in the food chain.

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biomass

the amount of living matter in a given habitat.

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biosphere

all living organisms (plant and animal life)

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biota

living organisms.

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calorie

the amount of heat required to raise the temperature of one gram of water by one degree centigrade

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carcinogenic

event, condition or effect that produces cancer.

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catalyst

a substance or agent which alters the velocity of a chemical reaction but is not itself changed in the process. An enzyme is an example of a catalyst.

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chlorophyll

one of a number of green pigments present in plant cells which are essential in the utilization of light energy in photosynthesis.

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chronic toxicity

any poisonous effect having long duration, usually months or years.

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combustion

the act or process of burning.

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condensation

the process in which water vapor is cooled to the liquid phase. The water film produced is reffered to as condensate.

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conductivity

the property of conducting heat, electricity, or sound.

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crematory

a place where a dead body is reduced to ashes by fire.

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DDT (dichlordiphenyltrichloroethane)

a white, water-insoluble solid used as an insecticide, and whose agriculture use was prohibited in the U.S. in 1973.

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degassing

to free from gases.

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degradation

to wear down, reduce to lower quality, by erosion or reduce the complexity of a chemical compound

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degreaser

solutions that remove grease

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discharge

(1) the flow of surface water in a stream or canal or the outflow of groundwater from a well, ditch, or spring

(2) the release of wastewater through a pipe outlet or similar apparatus to a discharge point such as a ditch or storage lagoon

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ductility

malleable. Able of undergoing change of form without breaking.

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ecosystem

an ecological system, a natural unit of living and nonliving components which interact to form a stable system in which a cyclic interchange of materials takes place between living and nonliving units, as in a balanced aquarium or in a large lake or forest.

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effluent

the discharge of a pollutant in a liquid form from a containing space.

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emission

the act of sending forth, to emanate.

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environmental release

the introduction of a pollutant into the environment through waste-water discharge, air emission, or volatilization or leaching from soil, landfill, or other contaminated site

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erosion

the wearing away of the land surface by running water, wind, ice, or other geological agents, including such processes as gravitational creep. Geological erosion is natural occurring erosion over long periods of time. Accelerated erosion is more rapid than normal erosion and results primarily from man's activities. Erosion is further classified by the amount and pattern of soil removal and transport as gully, interrill, rill, sheet, and splash or raindrop erosion.

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evaporation

the process in which liquid water is transferred into the atmosphere.

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excretion

the elimination or discharge of waste products or substances present in excess from the body.

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fauna

the animal life of a locality or a region

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felting process

process where nonwoven fabrics of wool, fur, or hair are matted together by heat, moisture, and great pressure.

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fermentation

a change which converts grape sugar into ethyl alcohol.

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fertilizer

any substance, like manure, used to enrich the soil.

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flora

the plant life of an area or locality.

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fluorescence

the property of absorbing light of a particular wave length and then emitting light of a different color and wave length.

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food chain

a group of organisms involved in the transfer of energy from its primary source, plants, as algae, insects, small fishes, larger fishes, fish-eating birds or mammals.

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fossil

any remains, impression, cast, or trace of an animal or plant of a past geological period. The term is generally restricted to parts which have been petrified or converted to stone.

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fossil fuel

any combustible organic material as oil, coal, or natural gas, derived from fossils.

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fungi

any of a large group of simple plants characterized by lack of chlorophyll as the mold, mildews, mushrooms, rusts, and smuts. Most have a filamentous body and subsist on organic matter.

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fungicide

an agent which kills or inhibits the growth of fungi

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gingivitis

swollen of the oral cavity gums.

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half life

the time it takes certain materials, such as mercury, to become chemically altered

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heavy metal

any metal with a density of 5.0 or greater, especially one that is toxic to organisms, as lead, mercury, copper, and cadmium.

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herbicide

chemicals used to kill undesirable vegetation

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humic

of or pertaining to the humus

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humus

dark material in the soil consisting principally of organic matter.

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hydrograph

a graph which illustrates hydrologic measurements over a period of time, such as water level, discharge or velocity

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hydrologic cycle

the circulation of water in and on the earth and through earth's atmosphere through evaporation, condensation, precipitation, runoff, groundwater storage and seepage, and re-evaporation into the atmosphere

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hydrosphere

water held in oceans, rivers, lakes, glaciers, groundwater, plants, animals, soil, and air.

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hydroxide

a compound formed by the union of a metal or a radical with one or more hydroxyl (OH) groups, as sodium hydroxide (NaOH).

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igneous

produced under conditions involving intense heat, as rocks of volcanic origin.

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incinerator

a crematory instrument for the combustion (incineration) of organic material, leaving only ash.

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inorganic

not containing carbon or compounds of carbon. Not of plant or animal origin.

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insecticide

chemicals used to control undesirable insects

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ion

an electrically charged atom or group of atoms formed by the loss of one or more electrons, as a cation (positive ion), which is created by an electron loss, or as an anion (negative ion), which is crated by an electron gain.

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lagoon

water impoundment in which organic wastes are stored or stabilized or both

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landfill

a low area of land that is built up from deposits of solid refuse in layers covered by soil.

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latent heat

the heat (energy) absorbed or released as water changes between the gas (water vapor), the liquid (water droplets), and the solid (ice) states

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lethal dose 50% (LD50)

the dosage of a toxic substance required to kill one half of the organisms under study in a given period of time

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lethal dose (LD)

the amount of a toxic substance required to cause death of an organism under study in a given period of time

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lime

calcium oxide (CaO) or quicklime, prepared by heating calcium carbonate thus driving off carbon dioxide.

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lithosphere

a general term for the outer layer of the earth. A wind blown deposit of silty soil having little or no stratification

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manometer

a device for measuring the pressure exerted by gases or liquids. In its simplest form, it is a U-shaped tube containing a fluid (water or mercury) against which the pressure of an unknown is balanced.

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mantle

a general term for the outer covering of earth material

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mercury (Hg)

a silvery-colored metal, commonly called quicksilver. The term refers to any of the different chemical forms that mercury can take, including methylmercury, Hg zero, and Hg(II)

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mercury two

"mercury two" is the mercury ion. Because it is water soluble and associates with particulates, atmospheric deposition of mercury two is relatively fast, either as dry deposition or in precipitation. Combustion sources can emit both mercury zero and mercury two. Mercury two can be produced in the atmosphere by the oxidation of mercury zero by ozone or other oxidants

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mercury zero

"mercury zero" is the elemental form of mercury, familiar as the silvery liquid. Mercury zero can volatilize to the atmosphere at normal temperatures. Over 90% of mercury in the atmosphere is mercury zero, although other forms may be considerably higher than 10% near sources. Because mercury zero does not adsorb to particulates and is not very water soluble, it is removed from the atmosphere very slowly with a half life in the atmosphere of about a year. Mercury zero liquid or amalgam is not absorbed during digestion, but the vapor is readily absorbed by the lungs.

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metabolism

the chemical or energy changes which occur within a living organism or a part of it which are involved in various life activities.

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metal

any of a class of elementary substances, as gold, silver, or copper, all of which are crystalline when solid, and many of which are characterized by opacity, ductility, conductivity, and a unique luster when freshly fractured. An element yielding positively charged ions in aqueous solution of its salts.

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methylmercury

any of several extremely toxic compounds formed from metallic mercury by the action of microorganisms and capable of entering the food chain.

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natural mercury emissions

the atmospheric emission of geologically bound mercury through natural processes (e.g. emission of mercury from volcanoes)

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neurotoxin

a poisonous substance which affects nervous system.

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nitrate (NO3)

an important plant nutrient and type of inorganic fertilizer (most highly oxidized phase in the nitrogen cycle). In water, the major sources of nitrates are septic tanks, feed lots and fertilizers.

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nitrite (NO2)

product in the first step of the two-step process of conversion of ammonium (NH4) to nitrate (NO3)

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opacity

the state or quality of being opaque.

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ores

a metal-bearing mineral or rock, or a native metal, that can be mined at profit. A mineral or natural product serving as a source of some nonmetallic substance, as sulfur.

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organic

compounds that contain carbon.

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oxidation

the removal of hydrogen from a compound. The loss of electron with an increase in positive valence of an element.

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paralysis

loss of sensation or loss of muscular function usually due to an injury to a nerve or a lesion within the central nervous system.

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pathogen

any disease-producing agent.

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pathology

the scientific study of disease, including causes, symptoms, signs, and various structural and functional alteration which may occur in its course.

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PCB (polychlorinated biphenyl)

a family of highly toxic chemical compounds known to cause skin diseases and suspected of causing birth defects and cancer.

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permeability

the capacity of a porous rock, sediment or soil to transmit a fluid such as water. The more fluid that can be transferred, the more permeable the material.

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pesticide

a chemical substance used to kill or control pests such as weeds, insects, fungus, mites, algae, rodents, and other undesirable agents

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pH

a numerical measure of acidity, or hydrogen ion activity used to express acidity or alkalinity; neutral is pH 7.0, values below 7.0 are acid, and above 7.0 are alkaline.

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pharmaceutical

a chemical drug or medicine.

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photochemistry

the branch of chemistry that deals with the chemical action of light.

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photosynthesis

The process which occurs in the cells of green plants in which simple sugars are formed from carbon dioxide and water in the presence of light and chlorophyll. The basic reaction by which light or radiant energy is converted to chemical energy and stored in the molecules of carbohydrates.

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plankton

aquatic organisms of fresh, brackish, or sea water which float passively or exhibit limited locomotor activity.

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poison

a substance, which upon contact or being introduced into an organism, impairs or prevents normal metabolic processes from taking place, thus altering the normal functioning of organs or tissues.

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point-source pollution (PS)

pollution of water from one place in a concentrated manner that is easy to identify. Ex. leaking underground storage tank or discharge pipe from a sewage treatment plant.

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pollution prevention (P2)

Altering a process or use of materials to reduce environmental release of mercury. Examples of pollution prevention include nonfossil-fuel energy production (e.g. wind energy), more efficient use of fossil-fuel energy, use of low-mercury coal, and use of alternative products (e.g. digital thermometers instead of mercury thermometers). According to the Federal Pollution Prevention Act of 1990, pollution prevention is "any practice which reduces the amount of any hazardous substance, pollutant, or contaminant entering the waste stream or otherwise released into the environment prior to recycling, treatment, or disposal...". Pollution prevention is also called "source reduction".

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pollution reduction

in this program, pollution reduction is the decrease in the use and environmental release of mercury.

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porosity

the degree to which the total volume of soil, gravel, sediment or rock is permeated with pores or cavities through which fluids (including air) can move

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parts per million (ppm)

a common basis for reporting water analysis. One ppm equals one unit of measurement per million units of the same measurement. One ppm equals one milligram per litre. One ppm is approximately the aspirin concentration formed when one aspirin tablet is dissolved in 100 gallons of water.

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precipitation (ppt)

moisture falling from the atmosphere in the form of rain, snow, sleet or hail.

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predatory fish

a fish living by killing and eating other fish.

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prenatal

before birth.

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preservative

a chemical substance used to preserve food or other organic material from decomposition or fermentation.

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reduction

a chemical reaction in which one or more electrons are gain by the substance reduced. The addition of hydrogen atoms or the loss of oxygen atoms.

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refuse

something that is discarded as worthless or useless; rubbish, trash, garbage.

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root zone

the depth of soil penetrated by crop roots. Also called the vadose zone.

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runoff

the flow of water from the land to oceans or interior basins by overland flow and stream channels.

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salinity

the concentration of dissolved salts in water.

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salt

a substance other than water resulting from the reaction between an acid and a base.

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saturated fat

a type of single-bond animal or vegetable fat, as that found in butter, meat, egg yolks, and coconut or palm oil, that in humans tends to increase cholesterol levels in the blood.

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sediment

that which settles to the bottom, as in a lake or a river.

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smelting

fusion or melting process in order to separate metals.

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sorb

to take up and hold either by absorption or adsorption.

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soil moisture content (mc)

the portion of water in a soil that can be readily absorbed by plant roots. It is the amount of water released between in situ field capacity (FC) and the permanent wilting point (WP).

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solvent

a liquid in which a substance is dissolved.

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storage

the temporary deposit of a chemical in body tissue or in an organ. Storage is just one facet of chemical bioaccumulation. The term also applies to other natural processes, sucs as the storage of fat in hibernating animals or the storage of starch in seeds.

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TCDD

a by-product of pesticide manufacture; a toxic compound that is carcinogenic and teratogenic in certain animals.

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teratogenic

capable of interfering with the development of a fetus, causing birth defects.

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textile

any cloth or goods produced by weaving, knitting, or felting.

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threshold

the lowest limit at which a certain phenomenon will occur.

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toxic

of, pertaining to, affected with, or caused by a poison.

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toxicity

the quality, relative degree, or specific degree of being toxic or poisonous.

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turbidity

a measure of water cloudiness caused by suspended solids.

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uptake

it describes the entrance of a chemical into an organism -- such as by breathing, swallowing, or absorbing it through the skin -- without regard to its subsequent storage, metabolism, and excretion by that organism.

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valence

the combining power of an atom; its capacity to combine with other atoms to form a molecule, expressed in terms of the number of hydrogen atoms or their equivalent with which any atom may combine.

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volatilization

loss of a substance through evaporation or sublimation. When manure is spread on a field, ammonia-nitrogen in the manure may volatize quickly and be lost as fertilizer unless it is incorporated into the soil.

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wastewater

water that has been used in washing, flushing, manufacturing, etc.; sewage

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x-rays

also know as Roentgen rays. Radiant energy of short wave length produced by high speed electron striking a metal target in a vacuum.
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zooplankton

the animals of plankton

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