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ATSDR (1993). Public Health Assessment Guidance Manual. Atlanta, Georgia.

ATSDR (1997). Toxicological Profile for Benzene. Atlanta, Georgia.

ATSDR (1998). Toxicological Profile for Methyl Tert-Butyl Ether. Atlanta, Georgia.

Belpoggi, F. et al. (1997). Results of Long-Term Experimental Studies on the Carcinogenicity of Methyl Tert-Butyl Ether. Annals of the New York Academy of Sciences, vol. 837, p. 77-95.

EPA (1997). Drinking Water Advisory: Consumer Acceptability Advice and Health Effects Analysis on Methyl Tertiary‑Butyl Ether (MTBE). U. S. Environmental Protection Agency. Office of Water.

EPA (1999). Achieving Clean Air and Clean Water: The Report of the Blue Ribbon Panel on Oxygenates in Gasoline. U.S. Environmental Protection Agency.

EPA (2000). Risk-Based Concentration Table. U.S. Environmental Protection Agency. Philadelphia, Pennsylvania.

IARC (1987). World Health Organization, International Agency for Research on Cancer. Overall Evaluations of Carcinogenicity to Humans. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, vol. 1 to 73. Suppl. 7, 38-74. Lyons, France.

MA DEP (1995). Guidance for Disposal Site Risk Characterization. MA DEP Office of Research and Standards.

MA DEP (1998). Letter from MA DEP/WERO to Ronald Leonard re: notification of responsibility and designations as a PRP. October 22, 1998.

MA DEP (1999). (personal communication with Anthony Kurpaska, March 24, 1999 and April 29, 1999).

MA DEP (2001). Drinking Water Standards and Guidelines for Chemicals in Massachusetts Drinking Waters. Spring 2001. MA DEP Office of Research and Standards, Bureau of Strategic Policy & Technology.

Maxymillian Technologies (1999a). Immediate Response Action Plan and Imminent Hazard Evaluation. January 1999. Pittsfield, Massachusetts.

Maxymillian Technologies (1999b). Immediate Response Action Status Report. February 1999. Pittsfield, Massachusetts.

Maxymillian Technologies (1999c). Immediate Response Action Status Report. April 1999. Pittsfield, Massachusetts.

Maxymillian Technologies (1999d). July 1, 1999 Letter from Daneille Rice to Chau Vu of MDPH requesting for information on the Hatchery Road site.

Maxymillian Technologies (1999e). Phase I Initial Site Investigation Report. October 1999. Pittsfield, Massachusetts.

Maxymillian Technologies (1999f). (personal communications with Robert MacLean on May 11, 1999, June 29, 1999).

Maxymillian Technologies (2000a). Immediate Response Action Plan Status Report. Pittsfield, Massachusetts.

Maxymillian Technologies (2000b). (personal communications with Robert MacLean on May 10, 2000).

Maxymillian Technologies (2001). Immediate Response Action Completion Report, Method 3 Risk Characterization and Response Action Outcome. August 2001. Pittsfield, Massachusetts.

MDPH (2001). Cancer Incidence in Massachusetts 1994-1998: City/Town Supplement. Massachusetts Department of Public Health, Bureau of Health Statistics, Research and Evaluation, Massachusetts Cancer Registry.

New Marlborough Board of Assessors (1999) (personal communications with Marsha Pshenishny, June 23, 1999 re: construction date and length of residency at four Hartsville homes; and June 28 and August 17, 1999 re: residency status of current residents at four Hartsville homes).

Olin, SS (1999). Exposure to Contaminants in Drinking Water. Estimating Uptake through the Skin and by Inhalation. Risk Science Institute, International Life Sciences Institute. Washington, DC.

Squillace PJ, et al. (1996). A preliminary Assessment of the Occurrence and Possible Sources of MTBE in Groundwater of the United States, 1993-94. Environmental Science and Technology, vol. 30, no. 5, p. 1721-1730.

U.S. Bureau of the Census. 2001. 2000 Census Population: Characteristics of the Population. Washington: US Department of Commerce.



In order to evaluate cancer incidence a statistic known as a standardized incidence ratio (SIR) was calculated for each cancer type. An SIR is an estimate of the occurrence of cancer in a population relative to what might be expected if the population had the same cancer experience as some larger comparison population designated as "normal" or average. Usually, the state as a whole is selected to be the comparison population. Using the state of Massachusetts as a comparison population provides a stable population base for the calculation of incidence rates. As a result of the instability of incidence rates based on small numbers of cases, SIRs were not calculated when fewer than five cases were observed.

Specifically, an SIR is the ratio of the observed number of cancer cases to the expected number of cases multiplied by 100. An SIR of 100 indicates that the number of cancer cases observed in the population evaluated is equal to the number of cancer cases expected in the comparison or "normal" population. An SIR greater than 100 indicates that more cancer cases occurred than expected and an SIR less than 100 indicates that fewer cancer cases occurred than expected. Accordingly, an SIR of 150 is interpreted as 50% more cases than the expected number; an SIR of 90 indicates 10% fewer cases than expected.

Caution should be exercised, however, when interpreting an SIR. The interpretation of an SIR depends on both the size and the stability of the SIR. Two SIRs can have the same size but not the same stability. For example, an SIR of 150 based on 4 expected cases and 6 observed cases indicates a 50% excess in cancer, but the excess is actually two cases. Conversely, an SIR of 150 based on 400 expected cases and 600 observed cases represents the same 50% excess in cancer, but because the SIR is based upon a greater number of cases, the estimate is more stable. It is very unlikely that 200 excess cases of cancer would occur by chance alone.

To determine if the observed number of cases is significantly different from the expected number or if the difference may be due solely to chance, a 95% confidence interval (CI) was calculated for each SIR. A 95% CI assesses the magnitude and stability of an SIR. Specifically, a 95% CI is the range of estimated SIR values that has a 95% probability of including the true SIR for the population. If the 95% CI range does not include the value 100, then the study population is significantly different from the comparison or "normal" population. "Significantly different" means there is less than 5% percent chance that the observed difference is the result of random fluctuation in the number of observed cancer cases.

For example, if a confidence interval does not include 100 and the interval is above 100 (e.g., 105-130), then there is statistically significant excess in the number of cancer cases. Similarly, if the confidence interval does not include 100 and the interval is below 100 (e.g., 45-96), then the number of cancer cases is statistically significantly lower than expected. If the confidence interval range includes 100, then the true SIR may be 100, and it cannot be concluded with sufficient confidence that the observed number of cases is not the result of chance and reflects a real cancer increase or decrease. Statistical significance is not assessed when fewer than five cases are observed.

In addition to the range of the estimates contained in the confidence interval, the width of the confidence interval also reflects the stability of the SIR estimate. For example, a narrow confidence interval (e.g., 103--115) allows a fair level of certainty that the calculated SIR is close to the true SIR for the population. A wide interval (e.g., 85--450) leaves considerable doubt about the true SIR, which could be much lower than or much higher than the calculated SIR. This would indicate an unstable statistic.


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).

The process of taking in. For a person or animal, absorption is the process of a substance getting into the body through the eyes, skin, stomach, intestines, or lungs.

Occurring over a short time [compare with chronic].

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

Additive effect:
A biologic response to exposure to multiple substances that equals the sum of responses of all the individual substances added together [compare with antagonistic effect and synergistic effect].

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

Requiring oxygen [compare with anaerobic].

Surrounding (for example, ambient air).

Requiring the absence of oxygen [compare with aerobic].

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.

Analytic epidemiologic study:
A study that evaluates the association between exposure to hazardous substances and disease by testing scientific hypotheses.

Antagonistic effect:
A biologic response to exposure to multiple substances that is less than would be expected if the known effects of the individual substances were added together [compare with additive effect and synergistic effect].

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.

Decomposition or breakdown of a substance through the action of microorganisms (such as bacteria or fungi) or other natural physical processes (such as sunlight).

Biologic indicators of exposure study:
A study that uses (a) biomedical testing or (b) the measurement of a substance [an analyte], its metabolite, or another marker of exposure in human body fluids or tissues to confirm human exposure to a hazardous substance [also see exposure investigation].

Biologic monitoring:
Measuring hazardous substances in biologic materials (such as blood, hair, urine, or breath) to determine whether exposure has occurred. A blood test for lead is an example of biologic monitoring.

Biologic uptake:
The transfer of substances from the environment to plants, animals, and humans.

Biomedical testing:
Testing of persons to find out whether a change in a body function might have occurred because of exposure to a hazardous substance.

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

Body burden:
The total amount of a substance in the body. Some substances build up in the body because they are stored in fat or bone or because they leave the body very slowly.

See Community Assistance Panel.

Any one of a group of diseases that occurs when cells in the body become abnormal and grow or multiply out of control.

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.

Case study:
A medical or epidemiologic evaluation of one person or a small group of people to gather information about specific health conditions and past exposures.

Case-control study:
A study that compares exposures of people who have a disease or condition (cases) with people who do not have the disease or condition (controls). Exposures that are more common among the cases may be considered as possible risk factors for the disease.

CAS registry number:
A unique number assigned to a substance or mixture by the American Chemical Society Abstracts Service.

Central nervous system:
The part of the nervous system that consists of the brain and the spinal cord.

[see Comprehensive Environmental Response, Compensation, and Liability Act of 1980]

Occurring over a long time (more than 1 year) [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].

Cluster investigation:
A review of an unusual number, real or perceived, of health events (for example, reports of cancer) grouped together in time and location. Cluster investigations are designed to confirm case reports; determine whether they represent an unusual disease occurrence; and, if possible, explore possible causes and contributing environmental factors.

Community Assistance Panel (CAP):
A group of people, from a community and from health and environmental agencies, who work with ATSDR to resolve issues and problems related to hazardous substances in the community. CAP members work with ATSDR to gather and review community health concerns, provide information on how people might have been or might now be exposed to hazardous substances, and inform ATSDR on ways to involve the community in its activities.

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.

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.

Delayed health effect:
A disease or injury that happens as a result of exposures that might have occurred in the past.

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

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

Descriptive epidemiology:
The study of the amount and distribution of a disease in a specified population by person, place, and time.

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

Disease prevention:
Measures used to prevent a disease or reduce its severity.

Disease registry:
A system of ongoing registration of all cases of a particular disease or health condition in a defined population.

United States Department of Defense.

United States Department of Energy.

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.

Dose-response relationship:
The relationship between the amount of exposure [dose] to a substance and the resulting changes in body function or health (response).

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

Environmental media and transport mechanism:
Environmental media include water, air, soil, and biota (plants and animals). Transport mechanisms move contaminants from the source to points where human exposure can occur. The environmental media and transport mechanism is the second part of an exposure pathway.

United States Environmental Protection Agency.

Epidemiologic surveillance:
The ongoing, systematic collection, analysis, and interpretation of health data. This activity also involves timely dissemination of the data and use for public health programs.

The study of the distribution and determinants of disease or health status in a population; the study of the occurrence and causes of health effects in humans.

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-dose reconstruction:
A method of estimating the amount of people's past exposure to hazardous substances. Computer and approximation methods are used when past information is limited, not available, or missing.

Exposure investigation:
The collection and analysis of site-specific information and biologic tests (when appropriate) to determine whether people have been exposed to hazardous substances.

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.

Exposure registry:
A system of ongoing followup of people who have had documented environmental exposures.

Feasibility study:
A study by EPA to determine the best way to clean up environmental contamination. A number of factors are considered, including health risk, costs, and what methods will work well.

Geographic information system (GIS) :
A mapping system that uses computers to collect, store, manipulate, analyze, and display data. For example, GIS can show the concentration of a contaminant within a community in relation to points of reference such as streets and homes.

Grand rounds:
Training sessions for physicians and other health care providers about health topics.

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

Half-life (t1/2):
The time it takes for half the original amount of a substance to disappear. In the environment, the half-life is the time it takes for half the original amount of a substance to disappear when it is changed to another chemical by bacteria, fungi, sunlight, or other chemical processes. In the human body, the half-life is the time it takes for half the original amount of the substance to disappear, either by being changed to another substance or by leaving the body. In the case of radioactive material, the half life is the amount of time necessary for one half the initial number of radioactive atoms to change or transform into another atom (that is normally not radioactive). After two half lives, 25% of the original number of radioactive atoms remain.

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

Hazardous Substance Release and Health Effects Database (HazDat):
The scientific and administrative database system developed by ATSDR to manage data collection, retrieval, and analysis of site-specific information on hazardous substances, community health concerns, and public health activities.

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.

Health investigation:
The collection and evaluation of information about the health of community residents. This information is used to describe or count the occurrence of a disease, symptom, or clinical measure and to estimate the possible association between the occurrence and exposure to hazardous substances.

Health promotion:
The process of enabling people to increase control over, and to improve, their health.

Health statistics review:
The analysis of existing health information (i.e., from death certificates, birth defects registries, and cancer registries) to determine if there is excess disease in a specific population, geographic area, and time period. A health statistics review is a descriptive epidemiologic study.

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 number of new cases of disease in a defined population over a specific time period [contrast with prevalence].

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].

In vitro:
In an artificial environment outside a living organism or body. For example, some toxicity testing is done on cell cultures or slices of tissue grown in the laboratory, rather than on a living animal [compare with in vivo].

In vivo:
Within a living organism or body. For example, some toxicity testing is done on whole animals, such as rats or mice [compare with in vitro].

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.

Medical monitoring:
A set of medical tests and physical exams specifically designed to evaluate whether an individual's exposure could negatively affect that person's health.

The conversion or breakdown of a substance from one form to another by a living organism.

Any product of metabolism.

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].

State of being ill or diseased. Morbidity is the occurrence of a disease or condition that alters health and quality of life.

Death. Usually the cause (a specific disease, condition, or injury) is stated.

A substance that causes mutations (genetic damage).

A change (damage) to the DNA, genes, or chromosomes of living organisms.

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.

[see National Priorities List for Uncontrolled Hazardous Waste Sites]

Physiologically based pharmacokinetic model (PBPK model):
A computer model that describes what happens to a chemical in the body. This model describes how the chemical gets into the body, where it goes in the body, how it is changed by the body, and how it leaves the body.

A craving to eat nonfood items, such as dirt, paint chips, and clay. Some children exhibit pica-related behavior.

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.

Prevalence :
The number of existing disease cases in a defined population during a specific time period [contrast with incidence].

Prevalence survey:
The measure of the current level of disease(s) or symptoms and exposures through a questionnaire that collects self-reported information from a defined population.

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

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 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 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.

Public meeting:
A public forum with community members for communication about a site.

An unstable or radioactive isotope (form) of an element that can change into another element by giving off radiation.

Any radioactive isotope (form) of any element.

[see Resource Conservation and Recovery Act (1976, 1984)]

Receptor population:
People who could come into contact with hazardous substances [see exposure pathway].

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.

Registry :
A systematic collection of information on persons exposed to a specific substance or having specific diseases [see exposure registry and disease registry].

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.

RCRA Facility Assessment. An assessment required by RCRA to identify potential and actual releases of hazardous chemicals.

See reference dose.

The probability that something will cause injury or harm.

Risk reduction:
Actions that can decrease the likelihood that individuals, groups, or communities will experience disease or other health conditions.

Risk communication:
The exchange of information to increase understanding of health risks.

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]

[see Superfund Amendments and Reauthorization Act]

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 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 person, group, or community who has an interest in activities at a hazardous waste site.

Statistics :
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.

Substance-specific applied research:
A program of research designed to fill important data needs for specific hazardous substances identified in ATSDR's toxicological profiles. Filling these data needs would allow more accurate assessment of human risks from specific substances contaminating the environment. This research might include human studies or laboratory experiments to determine health effects resulting from exposure to a given hazardous substance.

Superfund Amendments and Reauthorization Act (SARA):
In 1986, SARA amended 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].

[see epidemiologic surveillance]

A systematic collection of information or data. A survey can be conducted to collect information from a group of people or from the environment. Surveys of a group of people can be conducted by telephone, by mail, or in person. Some surveys are done by interviewing a group of people [see prevalence survey].

Synergistic effect:
A biologic response to multiple substances where one substance worsens the effect of another substance. The combined effect of the substances acting together is greater than the sum of the effects of the substances acting by themselves [see additive effect and antagonistic effect].

Teratogen :
A substance that causes defects in development between conception and birth. A teratogen is a substance that causes a structural or functional birth defect.

Toxic agent:
Chemical or physical (for example, radiation, heat, cold, microwaves) agents that, under certain circumstances of exposure, can cause harmful effects to living organisms.

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.

An abnormal mass of tissue that results from excessive cell division that is uncontrolled and progressive. Tumors perform no useful body function. Tumors can be either benign (not cancer) or malignant (cancer).

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)


The public comment period for the New Marlborough/Hatchery Road Public Health Assessment (PHA), ended on September 5, 2000. MDPH received comments on several different issues. Some comments were editorial i.e., concerning spelling or sentence syntax, and were incorporated. A discussion of the more substantive comments follows:

Comment 1a: The last paragraph on page 1 of the PHA stated that Mount Everett Landscaping and Excavation Inc. is the potentially responsible party (PRP) when in fact the owner of Mount Everett has been designated as a PRP.

Response: MDPH has changed the language in the PHA to read:

"On October 16, 1998, the Massachusetts Department of Environmental Protection (MA DEP) was notified of a gasoline release at the Mount Everett Landscaping and Excavating Company (MT 1999a). On October 22, 1998, MA DEP sent a letter to the owner of the Mount Everett property notifying him of his responsibilities as a PRP for the Hatchery Road site (MA DEP 1998, MT 1999a). An environmental consulting firm was hired by the Mount Everett property owner to address the release, determine the extent of contamination and conduct remedial activities."

Comment 1b: The first paragraph of page two of the PHA refers to the source of contamination. The commentator cites the results of an investigation of the 300-gallon aboveground gasoline tank, following its removal from the Mount Everett property, which indicated that no point(s) of leakage were identified and suggests that this "demonstrate[s] that the tank was not the source of the release that is the subject of the PHA." The investigation indicated that the primary release at the site appears to have occurred approximately 50 feet west of Mount Everett's building and the tank. (MT, October 1999e, 18, 40).

Response: The PHA did not attempt to specify any particular source of the contaminants at the site, e.g. the 300-gallon aboveground gasoline tank. Rather, the PHA evaluated soil and groundwater data related to the site for purposes of exposure and health assessment. The samples referred to that were collected to age date the material were said to have been taken in an "area" where a gasoline release "might have happened." The text in the PHA did not identify the tank itself as "the" source or refer to the condition of the tank, and thus, there is no need to alter the text. Language has been added to this paragraph describing general site investigation/clean-up efforts and remedial actions as follows:

"Following the initial environmental sampling to identify the area and extent of groundwater contamination, a series of immediate response actions (IRAs) were conducted to prevent further contamination and potential exposure. These activities included intensive water sampling and installation of carbon filtration systems, on-site treatment of the contaminated groundwater and provisions for an alternative water supply for residents whose wells were contaminated. In August 2001 a response action outcome completion report (RAO) was filed with the MA DEP, signifying that levels of oil or hazardous materials were below Massachusetts' guidelines and standards (MT 2001)."

Comment 2: On page 10 the PHA states that a few of the many surface water samples collected in the Konkapot River were found to contain low levels of gasoline-related compounds. The PHA recognizes that the constituents were detected at levels below MCLs and MMCLs. The PHA fails, however, to explain that the low levels of gasoline constituents are more likely due to road wash than to the release at the site. Based on the sampling results and the lack of a consistent detection of MTBE in the river, Maxymillian has concluded that the low level of constituents detected in the river are more likely the result of road wash (MT 1999e, p. 27).

Response: MDPH did not attempt to assess the possible source(s) of the gasoline-related contaminants detected in the surface water samples from the river although run-off from road wash could be a contributor. The main point is that low levels of compounds found in surface water samples did not exceeded MCLs. Therefore, no changes are needed in the PHA.

Comment 3: On page 13 the PHA stated that the residents moved out of 8 Hatchery Road on November 28, 2000. The PHA stated on page 21 that these residents moved out on November 21. In the context of litigation brought by these residents against the Mount Everett property owner, the residents have asserted that they moved out of the residence on November 16, 1998.

Response: The commenter in his letter referred to November 28, 2000; however, we believe that he meant to write November 28, 1998 in his comments as that is the year referred to in the pages of the draft PHA that he is citing. MDPH received information directly from the resident with regard to occupancy. On March 24, 1999, a letter from a resident of 8 Hatchery Road to Ms. Suzanne Condon of MDPH, stated that the then resident lived at 8 Hatchery Road from March 1, 1997 to November 15, 1998, approximately 20 ½ months. All references in the PHA to the date of occupancy have been edited to correct this. A footnote has been added to clarify the information provided to MDPH by the resident. It is important to note that this slight change in date, when these residents moved out of the property on 8 Hatchery Road would not affect the calculations of exposure and health concerns for the tenants. Thus, the conclusions of the PHA do not change.

Comment 4: The PHA states on page 17, with respect to water sampling conducted at the point of entry treatment systems, as follows: "All samples have shown that contaminated levels are much higher at the pre-carbon point than the post-carbon point." This suggests that all levels of contaminants at the pre-carbon filters are high, which is inaccurate. The commenter recommends: "All samples have shown that contaminant levels are much lower at the post-carbon point than the pre-carbon point."

Response: MDPH added language to PHA narrative that clarifies details as follows:

"Based on sampling results for these five residences for pre-carbon, mid-carbon, and post-carbon water summarized in tables 5a through 5e, the water treatment systems appear to be working effectively in removing compounds from the water supply to the houses. MTBE, the primary contaminant of concern in these samples, ranges from nondetectable to 3,600 ppb prior to filtration and nondetectable to 29 ppb after filtration." Thus, levels of contaminants at the post-carbon point have been significantly lower than pre-carbon and also lower than comparison values. Except for methylene chloride detected as a laboratory contaminant for 1553 Hartsville/New Marlborough Road, there were no exceedances of MCLs or guidance values post treatment for drinking water in all these houses.

Comment 5: On page 19, the PHA includes a section regarding "Physical and Other Hazards", which in sum asserts that trucks, tractors and heavy construction equipment utilized by Mount Everett as part of its landscaping business "could present a physical hazard to trespassers." First, the equipment poses no greater risk of physical hazard to anyone than many other things in the area, including such things as trees, roads, fences or traffic. More importantly, whether such equipment poses any potential risk of physical hazard is wholly irrelevant to the purpose of the PHA, to evaluate potential risks posed by a release of gasoline at the site and, perhaps, activities relating to that release.

Response: PHAs do evaluate physical hazards, so physical hazards are relevant and are required to be discussed in all PHAs. According to ATSDR's published guidelines for doing public health assessments, besides evaluating potential risks posed by chemical contamination in the environment, the PHA also needs to have a section specifying any physical hazards at the site, the potential health threat that they represent and the populations at risk from these hazards. The heavy construction equipment and machinery located at the front of the Mount Everett building could pose a threat to any trespassers, including teenagers. The site was accessible, i.e. it was not fenced in. Consequently, the potential for physical hazards did exist at the site. A sentence has been added to this section such that it now reads as follows:

"At the time of the site visit in May 1999, there were trucks, tractors and heavy construction equipment at the 'unfenced' area in front of the landscaping building. 'This is a site of commercial activity, the nature of which requires heavy equipment. While these potential concerns are not the primary focus of the public health assessment, which was to evaluate potential health and exposure concerns related to exposure opportunities to chemicals,' this equipment could present a physical hazard to trespassers. There are no other known physical hazards to the general public at the site."

Comment 6: On pages 21 and 22, the PHA states that several of the houses in the vicinity of the site have been owned by one family since they were built. With respect to the houses at 1352 Hartsville/Mill River and 1553 Hartsville/New Marlborough, the Mount Everett property owners do not believe those statements regarding ownership are accurate. In addition, they felt that such statements appear to be irrelevant.

Response: In the "Pathway Analysis" section of the PHA, information regarding occupancy in the residences is not irrelevant, but rather is necessary to determine who may have had opportunities for exposure to contaminants and for what duration. Exposure opportunities may have occurred between the estimated time of the release (late 1996 to early 1997) and December 1998 when point of entry filters were installed at these residences, that is, during an approximate two-year period. MDPH obtained information from the New Marlborough Board of Assessors indicated that the ownership of the two properties mentioned in the comment did not change during this period of interest. The PHA appropriately assumed, therefore, that the occupants at these residences were potentially exposed to contaminants in their drinking water over a period of approximately two years.

Comment 7: In the discussion, the PHA assumes a two-year duration of exposure, based on age-dating results of gasoline constituents, for all residents except these at 8 Hatchery Road, whose exposure duration was estimated at 20 ½ months. The exposure duration needs to be revised to eight months to account for the time necessary for the gasoline constituents to migrate from the source to the wells, particularly since the residents of 8 Hatchery Road who lived closest to the release location did not claim to detect an odor until February 1998. In addition these residents avoided using tap water and instead, used bottled water for drinking, showering and for other household activities. Accordingly, even an eight-month potential exposure period would be a conservative assumption with respect to 8 Hatchery Road.

Response: MDPH is not aware of any information that specifically indicates when contaminants migrated down gradient to affect drinking water wells and the commenter does not provide any new information on this issue. With regard to the residents' use of water, information was included in a letter from a resident of the house to Ms. Suzanne K. Condon, Assistant Commissioner, MDPH on March 24, 1999, which stated that residents of the house

"were still drinking distilled tap water that did have an odor until October 2, 1998 when Berkshire Enviro-Lab said that the water sample smelled like gasoline. The water distiller was an enclosed portable unit, which the environmental consultant [i.e., the environmental consultant for Mount Everett] stated would not remove gasoline components. The [residents of this house] continued to use tap water for bathing and laundry until October 16, 1998 when the [Mount Everett property owner] said that there was definitely gasoline components in the water."

Even if exposure was slightly reduced through the use of distilled, tap or bottled water, exposure was not eliminated. It is also unlikely that residents would have used bottled water for showering. Showering is an activity that is widely acknowledged to present exposure concerns in situations where volatile contaminants have been found in the water. Furthermore, the letter also mentioned that the residents of the house made "frequent trips" to Hatchery Road between November 15, 1998 and April 30, 1999, which may have resulted in further exposure. From this information, MDPH believes it would be reasonable for purposes of health assessment to consider the residents' opportunities for exposure to have been for a few additional months, and because of various activity patterns, e.g., intermittent use of tap and distilled water, frequent visits to the property by former tenants and the uncertainty involved in trying to identify when the contaminants reached the affected wells, MDPH has not changed the exposure duration for the receptors. As stated in the PHA, the exposure estimate for the residents at 8 Hatchery Road is 20 ½ months and two years for the residents of the other houses.

Comment 8: The exposure point concentrations are also overstated. The PHA fails to describe the derivation of such concentrations for each receptor and household. The PHA assumed that dermal and inhalation doses from exposures were equivalent to that of oral doses when estimating health risks (see Section B. Evaluation of Possible Health Effects, Footnote 2). This approach is not an accurate approach and should be revised. With respect to 8 Hatchery Road, because the residents of that house reported not utilizing tap water for many household purposes after detecting odor in their tap water in February 1998 (and, on information and belief, had utilized bottled water even before that date), the exposure assumptions utilized in the PHA with respect to 8 Hatchery Road are overstated even more.

Response: MDPH believes the PHA is very specific about the derivation of exposure point concentrations used for each household, i.e., the average concentrations detected in the tap water of each household (see Section B. Evaluation of Possible Health Effects). The commenter seems to suggest factoring in groundwater concentrations in addition to tap water, but MDPH believes that using average concentrations detected in tap water is most representative of exposure to residents in these homes. This section of the PHA explains how MDPH derived the estimated exposure doses of MTBE for residents of 8 Hatchery Road. The same equations are applied to derive estimated exposure doses of MTBE and benzene for the other receptors in households considered in the PHA.

The assumption that inhalation dose, dermal daily dose, and ingestion daily dose are all the same is based on the guidance for disposal site risk characterization established by MA DEP in July 1995. Finally, our response to Comment 7 addresses the concern expressed here regarding how long the residents of the house at 8 Hatchery Road used their drinking water.

Comment 9: On pages 34, 35 and 38 and in Appendix C, the PHA provides analyses for alternative exposure assumptions based on 11-year and 25-year duration. These alternative assumptions were conducted before analysis of the estimated date of release was completed. The alternative assumptions were based on the date that Mount Everett was built--1973 (25 years before the spill was reported) and that former tenants of 8 Hatchery Road, i.e., those residing there before the residents living there at the time of the release, may have been exposed from 1986-1997 (11 years). The PHA recognizes that those scenarios are unlikely, hypothetical assumptions, and should not include them since they only serve to cause confusion and misunderstanding.

Response: In Appendix F of the January IRA, a report by Friedman & Bruya, the environmental consultants who conducted the product-dating analysis, indicates that "the spill occurred within a two year period from the sample date" (MT 1999a). Since the publication of the "Public Comment" draft of the PHA, the Response Action Outcome (RAO) Completion report has been released (August 2001). In the RAO, the environmental consultant cites this report by Friedman & Bruya indicating that this is the best estimate for the gasoline release (MT 2001 p.16). Furthermore, DEP agrees that this is a reasonable estimate regarding the time of the spill (Kurpaska, MA DEP, personal communication, 2001). Therefore, MDPH agrees that the 11-year and 25-year exposure assumptions are not necessary and has removed them from the PHA.

Comment 10: The PHA uses comparisons of groundwater data to maximum contaminant levels (MCLs) as a health-based screening tool to determine compounds of concern. While it may be appropriate to use MCLs as a screening tool, many MCLs are not health-based but are instead based on such considerations as technical cleanup feasibility or method detection limits.

Response: As the commenter correctly noted, MDPH initially compared groundwater concentration to MCLs as a screening tool. MCLs are based on a number of factors, including health concerns, technical feasibility and cost. [Under the Safe Drinking Water Act, MCLs are designed to be protective of health to the "extent feasible.] The following changes have been made on pg. 7 of the PHA to clarify that MCL are not always solely based on health.

Old: These comparison values include environmental media evaluation guides (EMEG), reference dose media evaluation guides (RMEG), and cancer risk evaluation guides (CREG) and maximum contaminant levels for drinking water (MCL). These comparison values have been scientifically peer reviewed and published by ATSDR and/or EPA.

New: Comparison values include environmental media evaluation guides (EMEG), reference dose media evaluation guides (RMEG), and cancer risk evaluation guides (CREG). These comparison values have been scientifically peer reviewed or were derived from scientifically peer-reviewed values and published by ATSDR and/or the EPA. Health assessors also use the maximum contaminant levels (MCLs) for drinking water established by the EPA (or MMCLs established by MA DEP) as comparison values. Under the Safe Drinking Water Act, MCLs are protective of public health "to the extent feasible", i.e., they are established with consideration for public health, economic impact and technological feasibility of implementation.

This document was prepared by the Bureau of Environmental Health Assessment of the Massachusetts Department of Public Health. If you have any questions about this document, please contact Suzanne K. Condon, Director of BEHA/MDPH, 7th Floor, 250 Washington Street, Boston, Massachusetts 02108.


This Hatchery Road Site Public Health Assessment was prepared by the Massachusetts Department of Public Health, under cooperative agreement with the Agency for Toxic Substances and Disease Registry. It is in accordance with approved methodology and procedures existing at the time the public health assessment was begun.

Gail D. Godfrey
Technical Project Officer, SPS, SSAB, DHAC

The Division of Health Assessment and Consultation, ATSDR, has reviewed this public health Assessment and concurs with the findings.

Roberta Erlwein

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