BUNKER HILL MINING AND METALLURGICAL
KELLOGG, SHOSHONE COUNTY, IDAHO
|Comparison of Bunker Hill ROW Contamination by Sampling Year and Location|
0 to 1 inch
1 to 6 inches
0 to 1 inch
1 to 6 inches
0 to 1 inch
1 to 6 inches
|mg/kg - milligrams per kilogram|
Evaluation Strategy Explained
Evaluation Strategy (5)
ATSDR evaluates hazards associated with environmental contaminants in two phases. The firstphase is a screening phase which may consist of several steps, and the second phase is based onprofessional judgment. In the first step of the screening phase, ATSDR compares theconcentrations of contaminants to which the community could be exposed to health comparisonvalues. Exposures at levels less than or equal to these comparison values are not expected tomake people sick and are thus considered to be "safe" levels, even under the conditions ofmaximum exposure. For example, comparison values for chronic-duration (long-term)exposures are based on lifelong, continuous exposure. While it is unlikely that anyone would beexposed this frequently or for this duration, it represents a worse case condition. If a contaminantconcentration does not exceed a comparison value, ATSDR generally does not need to evaluatethe contaminant any further, because even under the maximum conditions of exposure, anindividual would not be expected to get sick.
If a contaminant concentration exceeds a comparison value, but is below levels where adversehealth effects have been reported, ATSDR performs a more in-depth evaluation using realisticexposure scenarios. This is a way to describe the exposure, relative to other exposures. It doesnot predict whether an individual will get sick. For example, if an individual were exposed to acontaminant half as much as another individual, his risk would be half as great. This risk doesnot mean that the individual would get sick. ATSDR does not know if either individual wouldget sick, but ATSDR uses this way of describing an individual's risk of getting sick from aspecific exposure.
ATSDR used the maximum concentration of contaminants in order to determine the estimatedexposure. Use of the maximum concentration will result in the most protective evaluation forhuman health. For soil the ingestion rates used are 50 milligrams per day (mg/day) for adults,200 mg/day for young children, and 500 mg/day for toddlers. A small child (aged 1 to 3 yearsold) may on occasion ingest up to 5000 mg/day (one teaspoon per day of contaminated soil). However this is unlikely to have occurred since the medium being evaluated in this public healthconsultation is surface soils on and in the immediate vicinity of ROWs. Standard body weightsfor adults, young children, and toddlers are 70 kilograms (kg), 16 kg, and 10 kg, respectively. Some exposures may be intermittent or irregularly timed. For those exposures, an exposurefactor (EF) is calculated which averages the dose over the exposed period. When unknown, thebiological absorption from the environmental medium is assumed to be 100%. Lifetime cancerrisk (70 years) was also evaluated.
ATSDR Plain Language Glossary
of Environmental Terms
ATSDR Plain Language Glossary
of Environmental Health Terms
- How a chemical enters a person's blood after the chemical has beenswallowed, has come into contact with the skin, or has been breathed in.
- Contact with a chemical that happens once or only for a limited period of time. ATSDR defines acute exposures as those that might last up to 14 days.
- A response to a chemical mixture, or combination of substances, that might be expected if the known effects of individual chemicals, seen at specific doses, were added together.
Adverse Health Effect:
- A change in body function or the structures of cells that can lead to disease or health problems.
- A response to a mixture of chemicals or combination of substances that isless than might be expected if the known effects of individual chemicals,seen at specific doses, were added together.
- The Agency for Toxic Substances and Disease Registry. ATSDR is a federal health agency in Atlanta, Georgia that deals with hazardous substance and waste site issues. ATSDR gives people information about harmful chemicals in their environment and tells people how to protect themselves from coming into contact with chemicals.
- An average or expected amount of a chemical in a specific environment. Or, amounts of chemicals that occur naturally in a specific environment.
- A group of diseases which occur when cells in the body become abnormal and grow, or multiply, out of control.
- Any substance shown to cause tumors or cancer in experimental studies.
- See Comprehensive Environmental Response, Compensation, andLiability Act.
- A contact with a substance or chemical that happens over a long period of time. ATSDR considers exposures of more than one year to be chronic.
Completed Exposure Pathway:
- See Exposure Pathway.
Comparison Value (CVs):
- Concentrations or the amount of substances in air, water, food, and soil that are unlikely, upon exposure, to cause adverse health effects. Comparison values are used by health assessors to select which substances and environmental media (air, water, food and soil) need additionalevaluation while health concerns or effects are investigated.
Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA):
- CERCLA was put into place in 1980. It is also known as Superfund. This act concerns releases of hazardous substances into the environment, and the cleanup of these substances and hazardous waste sites. ATSDR was created by this act and is responsible for looking into the health issues related to hazardous waste sites.
- A belief or worry that chemicals in the environment might cause harm to people.
- How much or the amount of a substance present in a certain amount ofsoil, water, air, or food.
- See Environmental Contaminant.
Delayed Health Effect:
- A disease or an injury that happens as a result of exposures that may haveoccurred far in the past.
- A chemical getting onto the skin. (see Route of Exposure).
- The amount of a substance to which a person may be exposed, usually on a daily basis. Dose is often explained as "amount of substance(s) per body weight per day".
Dose / Response:
- The relationship between the amount of exposure (dose) and the change in body function or health that results.
- The amount of time (days, months, years) that a person is exposed to a chemical.
- A substance (chemical) that gets into a system (person, animal, or the environment) in amounts higher than that found in Background Level, or what would be expected.
- Usually refers to the air, water, and soil in which chemicals of interest are found. Sometimes refers to the plants and animals that are eaten by humans. Environmental Media is the second part of an Exposure Pathway.
U.S. Environmental Protection Agency (EPA):
- The federal agency that develops and enforces environmental laws to protect the environment and the public's health.
- The study of the different factors that determine how often, in how many people, and in which people disease will occur.
- Coming into contact with a chemical substance.(For the three ways peoplecan come in contact with substances, see Route of Exposure.)
- The process of finding the ways people come in contact with chemicals, how often and how long they come in contact with chemicals, and the amounts of chemicals with which they come in contact.
- A description of the way that a chemical moves from its source (where it began) to where and how people can come into contact with (or get exposed to) the chemical.
ATSDR defines an exposure pathway as having 5 parts:
- Source of Contamination,
- Environmental Media and Transport Mechanism,
- Point of Exposure,
- Route of Exposure, and
- Receptor Population.
When all 5 parts of an exposure pathway are present, it is called aCompleted Exposure Pathway. Each of these 5 terms is defined in this Glossary.
- How often a person is exposed to a chemical over time--for example, every day, once a week, twice a month.
- Substances that have been released or thrown away into the environment and, under certain conditions, could be harmful to people who come into contact with them.
- ATSDR deals only with Adverse Health Effects (see definition in this Glossary).
Indeterminate Public Health Hazard:
- The classification used in Public Health Assessment documents to describe sites at which important information is lacking (missing or has not yet been gathered) about site-related chemical exposures.
- Swallowing something, as in eating or drinking. It is a way a chemical can enter the body (See Route of Exposure).
- Breathing. It is a way a chemical can enter your body (See Route of Exposure).
- Lowest Observed Adverse Effect Level. The lowest dose of a chemical in a study, or group of studies, that has caused harmful health effects in people or animals.
- Minimal Risk Level. An estimate of daily human exposure-by a specifiedroute and length of time-to a dose of chemical that is likely to be without a measurable risk of adverse, noncancerous effects. An MRL should not be used as a predictor of adverse health effects.
- The National Priorities List. (Part of Superfund.) A list kept by the U.S. Environmental Protection Agency (EPA) of the most serious, uncontrolled or abandoned hazardous waste sites in the country. An NPL site needs to be cleaned up or is being looked at to see if people can be exposed to chemicals from the site.
- No Observed Adverse Effect Level. The highest dose of a chemical in a study, or group of studies, that did not cause harmful health effects in people or animals.
No Apparent Public Health Hazard:
- The category is used in ATSDR's Public Health Assessment documents for sites where exposure to site-related chemicals may have occurred in the past or is still occurring but the exposures are not at levels expected to cause adverse health effects.
No Public Health Hazard:
- The category is used in ATSDR's Public Health Assessment documents for sites where there is evidence of an absence of exposure to site-related chemicals.
- Public Health Assessment. A report or document that looks at chemicalsat a hazardous waste site and tells if people could be harmed from coming into contact with those chemicals. The PHA also tells if possible further public health actions are needed.
Point of Exposure:
- The place where someone can come into contact with a contaminated environmental medium (air, water, food or soil). For example: the area of a playground that has contaminated dirt, a contaminated spring used for drinking water, the location where fruits or vegetables are grown incontaminated soil, or the backyard area where someone might breathe contaminated air.
- A group of people living in a certain area; or the number of people in a certain area.
- Potentially Responsible Party. A company, government or person that isresponsible for causing the pollution at a hazardous waste site. PRPs are expected to help pay for the clean up of a site.
Public Health Assessment(s):
- See PHA.
Public Health Hazard:
- The category is used in PHAs for sites that have certain physical features or evidence of chronic, site-related chemical exposure that could result in adverse health effects.
Public Health Hazard Criteria:
- PHA categories given to a site which tell whether people could be harmed by conditions present at the site. Each is defined in the Glossary. The categories are:
- - Urgent Public Health Hazard
- Public Health Hazard
- Indeterminate Public Health Hazard
- No Apparent Public Health Hazard
- No Public Health Hazard
- People who live or work in the path of one or more chemicals and could come into contact with them (See Exposure Pathway).
Reference Dose (RfD):
- An estimate, with safety factors (see safety factor) built in, of the daily, life-time exposure of human populations to a possible hazard that is not likely to cause harm to the person.
Route of Exposure:
- The way a chemical can get into a person's body. There are three exposure routes:
- - breathing (also called inhalation),
- eating or drinking (also called ingestion), and
- getting something on the skin (also called dermal contact).
- Also called Uncertainty Factor. When scientists don't have enough information to decide if an exposure will cause harm to people, they use "safety factors" and formulas in place of the information that is not known. These factors and formulas can help determine the amount of a chemical that is not likely to cause harm to people.
- The Superfund Amendments and Reauthorization Act in 1986 amendedCERCLA and expanded the health-related responsibilities of ATSDR. CERCLA and SARA direct ATSDR to look into the health effects from chemical exposures at hazardous waste sites.
- The number of people that are needed for a health study.
- A small number of people chosen from a larger population (See Population).
Source (of Contamination):
- The place where a chemical comes from, such as a landfill, pond, creek, incinerator, tank, or drum. Contaminant source is the first part of an Exposure Pathway.
- People who may be more sensitive to chemical exposures because of certain factors such as age, a disease they already have, occupation, sex, or certain behaviors (like cigarette smoking). Children, pregnant women, and older people are often considered special populations.
- A branch of the math process of collecting, looking at, and summarizing data or information.
- See NPL.
- A way to collect information or data from a group of people (population). Surveys can be done by phone, mail, or in person. ATSDR cannot do surveys of more than nine people without approval from the U.S. Department of Health and Human Services.
- A health effect from an exposure to more than one chemical, where one of the chemicals worsens the effect of another chemical. The combined effect of the chemicals acting together are greater than the effects of the chemicals acting by themselves.
- Harmful. Any substance or chemical can be toxic at a certain dose (amount). The dose is what determines the potential harm of a chemical and whether it would cause someone to get sick.
- The study of the harmful effects of chemicals on humans or animals.
- Abnormal growth of tissue or cells that have formed a lump or mass.
- See Safety Factor.
Urgent Public Health Hazard:
- This category is used in ATSDR's Public Health Assessment documents for sites that have certain physical features or evidence of short-term (less than 1 year), site-related chemical exposure that could result in adverse health effects and require quick intervention to stop people from being exposed.