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September 22, 2004

Appendix E: ATSDR Glossary of Terms

The Agency for Toxic Substances and Disease Registry (ATSDR) is a federal public health agency with headquarters in Atlanta, Georgia, and 10 regional offices in the United States. ATSDR's mission is to serve the public by using the best science, taking responsive public health actions, and providing trusted health information to prevent harmful exposures and diseases related to toxic substances. ATSDR is not a regulatory agency, unlike the U.S. Environmental Protection Agency (EPA), which is the federal agency that develops and enforces environmental laws to protect the environment and human health. This glossary defines words used by ATSDR in communications with the public. It is not a complete dictionary of environmental health terms. If you have questions or comments, call ATSDR's toll-free telephone number, 1-888-42-ATSDR (1-888-422-8737).


Occurring over a short time [compare with chronic].

Acute exposure
Contact with a substance that occurs once or for only a short time (up to 14 days) [compare with intermediate duration exposure and chronic exposure].

Adverse health effect
A change in body function or cell structure that might lead to disease or health problems

Surrounding (for example, ambient air).

A substance measured in the laboratory. A chemical for which a sample (such as water, air, or blood) is tested in a laboratory. For example, if the analyte is mercury, the laboratory test will determine the amount of mercury in the sample.

Background level
An average or expected amount of a substance or radioactive material in a specific environment, or typical amounts of substances that occur naturally in an environment.

Plants and animals in an environment. Some of these plants and animals might be sources of food, clothing, or medicines for people.

Cancer risk
A theoretical risk for getting cancer if exposed to a substance every day for 70 years (a lifetime exposure). The true risk might be lower.

A substance that causes cancer.

Occurring over a long time [compare with acute].

Chronic exposure
Contact with a substance that occurs over a long time (more than 1 year) [compare with acute exposure and intermediate duration exposure]

Comparison value (CV)
Calculated concentration of a substance in air, water, food, or soil that is unlikely to cause harmful (adverse) health effects in exposed people. The CV is used as a screening level during the public health assessment process. Substances found in amounts greater than their CVs might be selected for further evaluation in the public health assessment process.

Completed exposure pathway [see exposure pathway].

Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA)
CERCLA, also known as Superfund, is the federal law that concerns the removal or cleanup of hazardous substances in the environment and at hazardous waste sites. ATSDR, which was created by CERCLA, is responsible for assessing health issues and supporting public health activities related to hazardous waste sites or other environmental releases of hazardous substances. This law was later amended by the Superfund Amendments and Reauthorization Act (SARA).

The amount of a substance present in a certain amount of soil, water, air, food, blood, hair, urine, breath, or any other media.

A substance that is either present in an environment where it does not belong or is present at levels that might cause harmful (adverse) health effects.

Referring to the skin. For example, dermal absorption means passing through the skin.

Dermal contact
Contact with (touching) the skin [see route of exposure].

Detection limit
The lowest concentration of a chemical that can reliably be distinguished from a zero concentration.

Dose (for chemicals that are not radioactive)
The amount of a substance to which a person is exposed over some time period. Dose is a measurement of exposure. Dose is often expressed as milligram (amount) per kilogram (a measure of body weight) per day (a measure of time) when people eat or drink contaminated water, food, or soil. In general, the greater the dose, the greater the likelihood of an effect. An "exposure dose" is how much of a substance is encountered in the environment. An "absorbed dose" is the amount of a substance that actually got into the body through the eyes, skin, stomach, intestines, or lungs.

Dose (for radioactive chemicals)
The radiation dose is the amount of energy from radiation that is actually absorbed by the body. This is not the same as measurements of the amount of radiation in the environment.

Environmental media
Soil, water, air, biota (plants and animals), or any other parts of the environment that can contain contaminants.

Eosinophilic Meningitis
Meningitis is an infection of the fluid of a person's spinal cord and the fluid that surrounds the brain. People sometimes refer to it as spinal meningitis. Meningitis is usually caused by a viral or bacterial infection. Eosinophilic Meningitis is a form of meningitis commonly associated with parasites. In humans, this form of meningitis is most commonly acquired by purposeful or accidental ingestion of infective larvae in terrestrial mollusks, planaria and fresh-water crustacea. There is no effective specific treatment. During and just after WWII the parasite was introduced, and/or spread passively from South and Southeast Asia into the Western Pacific islands and eastward and southward through Micronesia, Melanesia, Australia and into Polynesia, sequestered in shipments of war material and facilitated by post-war commerce. In the 1950s numerous cases were identified for the first time on Sumatra, the Philippines, Taiwan, Saipan, New Caledonia, and as far east as Rarotonga and Tahiti. Then cases were detected in Vietnam, Thailand, Cambodia, Java, Sarawak, the New Hebrides, Guam and Hawaii during the 1960s (Source:

United States Environmental Protection Agency.

Contact with a substance by swallowing, breathing, or touching the skin or eyes. Exposure may be short-term [acute exposure], of intermediate duration, or long-term [chronic exposure].

Exposure assessment
The process of finding out how people come into contact with a hazardous substance, how often and for how long they are in contact with the substance, and how much of the substance they are in contact with.

Exposure pathway
The route a substance takes from its source (where it began) to its end point (where it ends), and how people can come into contact with (or get exposed to) it. An exposure pathway has five parts: a source of contamination (such as an abandoned business); an environmental media and transport mechanism (such as movement through groundwater); a point of exposure (such as a private well); a route of exposure (eating, drinking, breathing, or touching), and a receptor population (people potentially or actually exposed). When all five parts are present, the exposure pathway is termed a completed exposure pathway.

Water beneath the earth's surface in the spaces between soil particles and between rock surfaces [compare with surface water].

A source of potential harm from past, current, or future exposures.

Hazardous waste
Potentially harmful substances that have been released or discarded into the environment.

Health consultation
A review of available information or collection of new data to respond to a specific health question or request for information about a potential environmental hazard. Health consultations are focused on a specific exposure issue. Health consultations are therefore more limited than a public health assessment, which reviews the exposure potential of each pathway and chemical [compare with public health assessment].

Health education
Programs designed with a community to help it know about health risks and how to reduce these risks.

Indeterminate public health hazard
The category used in ATSDR's public health assessment documents when a professional judgment about the level of health hazard cannot be made because information critical to such a decision is lacking.

The act of swallowing something through eating, drinking, or mouthing objects. A hazardous substance can enter the body this way [see route of exposure].

The act of breathing. A hazardous substance can enter the body this way [see route of exposure].

Intermediate duration exposure
Contact with a substance that occurs for more than 14 days and less than a year [compare with acute exposure and chronic exposure].

Lowest-observed-adverse-effect level (LOAEL)
The lowest tested dose of a substance that has been reported to cause harmful (adverse) health effects in people or animals.

Maximum Contaminant Level (MCL)
The maximum concentration of a specific contaminant that is allowed under the Federal Safe Drinking Water Act. MCLs ensure that drinking water does not pose either a short-term or long-term health risk. EPA sets MCLs at levels that are economically and technologically feasible.

Milligram per kilogram.

Milligram per square centimeter (of a surface).

Milligram per cubic meter; a measure of the concentration of a chemical in a known volume (a cubic meter) of air, soil, or water.

Moving from one location to another.

Minimal risk level (MRL)
An ATSDR estimate of daily human exposure to a hazardous substance at or below which that substance is unlikely to pose a measurable risk of harmful (adverse), noncancerous effects. MRLs are calculated for a route of exposure (inhalation or oral) over a specified time period (acute, intermediate, or chronic). MRLs should not be used as predictors of harmful (adverse) health effects [see reference dose].

National Priorities List for Uncontrolled Hazardous Waste Sites (National Priorities List or NPL)
EPA's list of the most serious uncontrolled or abandoned hazardous waste sites in the United States. The NPL is updated on a regular basis.

No apparent public health hazard
A category used in ATSDR's public health assessments for sites where human exposure to contaminated media might be occurring, might have occurred in the past, or might occur in the future, but where the exposure is not expected to cause any harmful health effects.

No-observed-adverse-effect level (NOAEL)
The highest tested dose of a substance that has been reported to have no harmful (adverse) health effects on people or animals.

No public health hazard
A category used in ATSDR's public health assessment documents for sites where people have never and will never come into contact with harmful amounts of site-related substances.

NPL [see National Priorities List for Uncontrolled Hazardous Waste Sites]

A volume of a substance that moves from its source to places farther away from the source. Plumes can be described by the volume of air or water they occupy and the direction they move. For example, a plume can be a column of smoke from a chimney or a substance moving with groundwater.

Point of exposure
The place where someone can come into contact with a substance present in the environment [see exposure pathway].

A group or number of people living within a specified area or sharing similar characteristics (such as occupation or age).

Potentially responsible party (PRP)
A company, government, or person legally responsible for cleaning up the pollution at a hazardous waste site under Superfund. There may be more than one PRP for a particular site.

Parts per billion.

Parts per million.

Actions that reduce exposure or other risks, keep people from getting sick, or keep disease from getting worse.

Public availability session
An informal, drop-by meeting at which community members can meet one-on-one with ATSDR staff members to discuss health and site-related concerns.

Public comment period
An opportunity for the public to comment on agency findings or proposed activities contained in draft reports or documents. The public comment period is a limited time period during which comments will be accepted.

Public health action
A list of steps to protect public health.

Public health advisory
A statement made by ATSDR to EPA or a state regulatory agency that a release of hazardous substances poses an immediate threat to human health. The advisory includes recommended measures to reduce exposure and reduce the threat to human health.

Public health assessment (PHA)
An ATSDR document that examines hazardous substances, health outcomes, and community concerns at a hazardous waste site to determine whether people could be harmed from coming into contact with those substances. The PHA also lists actions that need to be taken to protect public health [compare with health consultation].

Public health hazard
A category used in ATSDR's public health assessments for sites that pose a public health hazard because of long-term exposures (greater than 1 year) to sufficiently high levels of hazardous substances or radionuclides that could result in harmful health effects.

Public health hazard categories
Public health hazard categories are statements about whether people could be harmed by conditions present at the site in the past, present, or future. One or more hazard categories might be appropriate for each site. The five public health hazard categories are no public health hazard, no apparent public health hazard, indeterminate public health hazard, public health hazard, and urgent public health hazard.

Public health statement
The first chapter of an ATSDR toxicological profile. The public health statement is a summary written in words that are easy to understand. The public health statement explains how people might be exposed to a specific substance and describes the known health effects of that substance.

Reference dose (RfD)
An EPA estimate, with uncertainty or safety factors built in, of the daily lifetime dose of a substance that is unlikely to cause harm in humans.

Remedial investigation
The CERCLA process of determining the type and extent of hazardous material contamination at a site.

Resource Conservation and Recovery Act (1976, 1984) (RCRA)
This Act regulates management and disposal of hazardous wastes currently generated, treated, stored, disposed of, or distributed.

RfD [see reference dose]

The probability that something will cause injury or harm.

Route of exposure
The way people come into contact with a hazardous substance. Three routes of exposure are breathing [inhalation], eating or drinking [ingestion], or contact with the skin [dermal contact].

Safety factor [see uncertainty factor]

A portion or piece of a whole. A selected subset of a population or subset of whatever is being studied. For example, in a study of people the sample is a number of people chosen from a larger population [see population]. An environmental sample (for example, a small amount of soil or water) might be collected to measure contamination in the environment at a specific location.

Sample size
The number of units chosen from a population or an environment.

A liquid capable of dissolving or dispersing another substance (for example, acetone or mineral spirits).

Source of contamination
The place where a hazardous substance comes from, such as a landfill, waste pond, incinerator, storage tank, or drum. A source of contamination is the first part of an exposure pathway.

Special populations
People who might be more sensitive or susceptible to exposure to hazardous substances because of factors such as age, occupation, sex, or behaviors (for example, cigarette smoking). Children, pregnant women, and older people are often considered special populations.

A branch of mathematics that deals with collecting, reviewing, summarizing, and interpreting data or information. Statistics are used to determine whether differences between study groups are meaningful.

A chemical.

Superfund [see Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) and Superfund Amendments and Reauthorization Act (SARA)

Superfund Amendments and Reauthorization Act (SARA)
In 1986, SARA amended the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) and expanded the health-related responsibilities of ATSDR. CERCLA and SARA direct ATSDR to look into the health effects from substance exposures at hazardous waste sites and to perform activities including health education, health studies, surveillance, health consultations, and toxicological profiles.

Surface water
Water on the surface of the earth, such as in lakes, rivers, streams, ponds, and springs [compare with groundwater].

Toxicological profile
An ATSDR document that examines, summarizes, and interprets information about a hazardous substance to determine harmful levels of exposure and associated health effects. A toxicological profile also identifies significant gaps in knowledge on the substance and describes areas where further research is needed.

The study of the harmful effects of substances on humans or animals.

Uncertainty factor
Mathematical adjustments for reasons of safety when knowledge is incomplete. For example, factors used in the calculation of doses that are not harmful (adverse) to people. These factors are applied to the lowest-observed-adverse-effect-level (LOAEL) or the no-observed-adverse-effect-level (NOAEL) to derive a minimal risk level (MRL). Uncertainty factors are used to account for variations in people's sensitivity, for differences between animals and humans, and for differences between a LOAEL and a NOAEL. Scientists use uncertainty factors when they have some, but not all, the information from animal or human studies to decide whether an exposure will cause harm to people [also sometimes called a safety factor].

Urgent public health hazard
A category used in ATSDR's public health assessments for sites where short-term exposures (less than 1 year) to hazardous substances or conditions could result in harmful health effects that require rapid intervention.

Volatile organic compounds (VOCs)
Organic compounds that evaporate readily into the air. VOCs include substances such as benzene, toluene, methylene chloride, and methyl chloroform.

Other glossaries and dictionaries:
Environmental Protection Agency

National Center for Environmental Health (CDC)

National Library of Medicine (NIH)

For more information on the work of ATSDR, please contact:
Office of Policy and External Affairs
Agency for Toxic Substances and Disease Registry
1600 Clifton Road, N.E. (MS E-60)
Atlanta, GA 30333
Telephone: (404) 498-0080

Appendix F: Other Potential Sources of Pollution in the Mongmong Area

Mongmong, a village of about 1,000 people, takes pride in its landscaped properties and well-kept houses. Because it is so well-kept, some sources of environmental pollution are not obvious. Sources of environmental pollution include both old military properties and unpermitted waste disposal areas. A brief summary of each of the potential source areas identified are provided below:

1. Agana Power Plant. PCBs were found in soils on and off the plant and in the Agana Swamp. It is unknown if other contaminants were generated from previous power sources and discharged from large smoke stacks in the early days of the plant's operation. Additionally, a 1945 area allocation map for Mongmong shows an area designated as "113" (Commonly known as Fifth Base Depot) allocated to an unit with an illegible name ("A--? C---? Force?"). The Agana Power Plant is part of former area designated as "113". Agana Power Plant was built in 1949 on the former 5th Field Marine Depot. Navy documents (Odgen, 1996, Earthtech, 2000) indicate that the area has also been occupied by the U.S. Navy Mobile Construction Battalion 10 (Ogden, 1996).

2. 5th Field Marine Depot. This was located south-southwest of NAS Agana and north-northeast of Agana Swamp. It encompassed a large area of the village of Mongmong and extended into Toto. Aerial photos show that the 1st and 5th Marine Task Force, 5th Marine Depot, 5th Field, used the area. The 5th Field was used during World War II and as a staging area during the Korean Conflict. It may have incorporated areas identified in 1945 as area "115" for storage, warehouses, and other operations. Old aerial photos on file with Guam EPA reportedly show roads leading into the swamp. The bulleted items below give examples of recent discoveries on the old 5th Field property.
  • In late 1999, on a private property northwest of APP (209 South Biang Street, Lot 1121-1-R1), the property owner found chemical warfare material, chemical identification sets (CAIS) (with 40 ml vials of phosgene and other non-weapon-grade chloroform-diluted war gases) and one piece of double fused unexploded ordnance. None of the CAIS was found to have leaked and all were safely removed. High levels of metals were also detected in the surrounding soils and reportedly cleaned up.
  • Another private property-a limestone quarry that was once part of the 5th Field Marine Depot-has a 6- to 8-inch layer of calcium hypochlorite ampules (containing chlorine gas) that could have been used to disinfect drinking water according to a 1985 report.
  • According to 1985 report by B.G. Karole and T.B. McGrath, during military downsizing after World War II, an undetermined amount and type of surplus material items were landfilled in low spots and depression areas.
  • Munitions were discovered when a person dug up a half-track truck in the summer of 2000 near South Biang Street.
  • Dozens of small glass vials initially believed to be filled with a substance known as "White Phosphorus," ordnance left over from World War II, were uncovered behind a Toto apartment in January 2001. The glass vials were later identified as calcium hypochlorite, which is used to purify water.
  • In 2001, a property owner unearthed what was suspected to be military debris from an area that was previously part of the 700-acre 5th Field Marine Supply Depot. The debris included Jeep parts, scrap metal, and other material such as tires. The burial depth and amount of material was not reported. The USACE's Honolulu office decided that since the debris contained no apparent toxic material (i.e., lead, arsenic, cadmium, hydraulic fluid, or asbestos), and since it had been buried, the area was not a threat to human health or the environment. Therefore, the area was not eligible for funding under the restoration program.
3. Northwest of the APP, including the village of Toto. The following bullets list potential pollution sources in this area.
  • Naval Air Station, Agana: Groundwater movement in water bearing rocks between Mongmong and the Naval Air Station, Agana, has not been fully characterized. Trichloroethylene (TCE) and other chlorinated hydrocarbons, fuels, and cleaning solvents could be in the groundwater, potentially moving toward Mongmong. Low concentrations of TCE have been found in nearby community production wells. The utilities are sampling water (with oversight from GEPA) to ensure that it is safe to drink. The TCE's source is still unknown. GEPA is collecting additional information on potential sources in the area.
  • Area 17: Area 17 was used as Naval Supply Drum Storage as well as other unspecified uses.
  • Non-military trash piles and landfill areas: One resident reportedly started putting old cars and other materials in a limestone fracture or pit. The landfill, which contained tires, caught on fire. Multiple trash piles and significant surface trash were observed by ATSDR during the May 2000 visit to Mongmong and surrounding villages.
1. Northeast side (toward Sinajana) of the Agana River, including Agana Springs. The following bullets list potential pollution sources in this area.
  • 178th Coast Artillery Battalion and VHF Station: The 1945 area allocation map shows that the 178th Coast Artillery Battalion and VHF Station, and areas with illegible area numbers, were across from Mongmong on the other side of the swamp, upgradient from Agana Springs.
  • Naval Reservation: A current United States Fish and Wildlife Service wetland map identifies an old (World War II-era) naval reservation. It does not identify the reservation's name or use.
  • UXO locations: Community members have told GEPA that there is unexploded ordnance (associated with the U.S. liberation of Guam) near the Spanish Dykes National Historic Landmark. This area is currently on USACE list to be investigated.
  • Coca Cola/Pepsi Cola: Areas in the swamp were used by Coca Cola/Pepsi Cola.
  • Drummed wastes: A recent spill of drums of plating chemicals, including chromium compounds/acids, was cleaned up.
  • Sewage lines and lift stations, septic tanks, seepage from garbage and trash piles, stormwater, and other outfalls: Bacterial contamination has been reported since the 1960s in Agana Springs.

Appendix G: Reducing Inhalation Exposure During Swamp Fires

Tips for Minimizing Smoke-Related Health Problems From Fires in the Agana Swamp and Other Locations

Swamp fires can become more of a hazard in dry conditions. During drought, fires can become intense and long-lived if the organic portion (dead plant matter) begins to burn creating hard-to-control muck fires. These muck fires can be difficult to control and typically produce a lot of smoke which is a potential health and traffic hazard.

Usually, healthy adults are not at risk from breathing smoke. Most symptoms (e.g., running nose, coughing, etc) subside after the smoke clears. Breathing smoke can be of greater concern for the elderly, for children, and for those with pre-existing conditions such as asthma and heart and lung disease. ATSDR has prepared the following list of actions that you can take to help protect your health if you are in a smoky environment:
  • Stay indoors with the windows closed when the air is smoky.
  • Run the air conditioner in recycle mode, if available.
  • Keep your homes air filters clean.
  • Decrease physical activity during smoky periods and consider rescheduling outdoor athletic events
  • .
  • Avoid any activity producing smoke inside your home.
  • If you have asthma or another health condition, take your medications as prescribed.
  • Call your physician if you have difficulty breathing
  • .
  • Drink plenty of fluids.
  • Use nasal moisturizing spray if nasal passages become irritated.
  • Use a humidifier to ease irritation caused by smoke.
  • Antihistamines may ease symptoms caused by exposure to smoke. However, this may cause additional drying of nasal passages and increased nasal irritation.
  • Facility managers and property owners seeking more information on protecting air quality in buildings can consult the U.S., Environmental Protection Agency (EPA) publication, "Building Air Quality: A Guide for Building Owners and Facility Managers," available at: or call 1-800-438-4318. A number of other EPA indoor air publications are also available online at

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