GEORGETOWN STEEL CORPORATION
GEORGETOWN, GEORGETOWN COUNTY, SOUTH CAROLINA
BACKGROUND AND STATEMENT OF ISSUES
Staff from the Waccamaw District office of the South Carolina Department of Health and
Environmental Control (SCDHEC) asked for a review of monitoring data collected in Georgetown,
Georgetown County, South Carolina. These data were collected as part of the Georgetown Air
Quality Study (GAQS) started in 2000. This health consultation will address the potential health
effects of the iron-oxide (red staining) and other particulate matter observed (specifically PM 2.5 and
PM 10) near the Georgetown Steel Corporation. The issue of the potential health effects of the iron-oxide will be included as part of the Georgetown Air Quality Study. Even though the iron-oxide is
also particulate matter, it will be discussed separately from the discussion of the PM 2.5 and PM 10
particulate matter. The Office of Environmental Community Health prepared this health
consultation under cooperative agreement with the Agency for Toxic Substances and Disease
Registry (ATSDR).
In the early 1970's, SCDHEC (then referred to as the South Carolina Pollution Control Authority)
began investigating complaints of staining on structures in downtown Georgetown, South Carolina.
The initial complaints coincided with the startup of two steel production facilities in the area,
Georgetown Steel Company (GSC) and Georgetown Ferreduction (later purchased by GSC). Both
facilities were built at the corner of Fraser and Front Streets, less than a block from downtown
businesses and homes. Soon after the companies opened, residents within several blocks of the
facilities reported problems with staining, specifically red staining, on the exterior surfaces of homes,
businesses, cars, and boats. The complainants believed that the staining resembled emissions
generated by the steel facilities. Several times during the 1970's, 1980's, and 1990's, SCDHEC
investigated complaints, documented air permit violations, and brought enforcement actions against
the company. The company did take steps through the years to reduce and control particulate matter
emissions at the facility. Some of these improvements included upgrading ductwork for better
collection of dust, installation of baghouses to increase the control of emissions from various stages
in the production, paving plant roads to reduce fugitive dust emissions, and closing roof louvers and
openings in the melt shop. Red staining continues to be a problem in the downtown Georgetown
area (SCDHEC, 2003).
Through the years, the Georgetown community has expressed concerns about possible health
problems associated with the material that was causing the red stain. In a 1996 study, SCDHEC's
Division of Air Quality Analysis identified the stain as goethite. Goethite is an oxidation product
of iron (SCDHEC, 2003).
In 1996, SCDHEC's Division of Air Quality Analysis (DAQA) and Waccamaw EQC District air
staff began a special air quality study (Project Plan and Final Report for "What Changed the Color
of My Boat?"). Three sampling monitors were placed around the city of Georgetown to collect
samples, specifically the red stain. SCDHEC's Division of Air Quality Analysis identified the stain
as goethite. Goethite is an oxidation product of iron (SCDHEC, 2003). The 1996 report concluded
that a primary contributor to the staining of the fiber glass plates was Georgetown Steel Corporation.
The study raised the question as to whether other mechanisms and/or components, such as other
industrial pollutants, might be involved with the formation of the red stain.
SCDHEC staff contacted the Air Pollution Control Departments in Florida and Pittsburgh to
determine if the red stain is simply a byproduct of steel production. The red staining problem did not
occur around steel mills in either of these areas. During the same time period, SCDHEC conducted
air quality inspections at several major facilities in the Georgetown area. Only minor violations were
noted during these inspections.
Since 1996, Waccamaw District air staff have increased air quality surveillance in Georgetown by
conducting unannounced visits to the area at different times of the day and night. Filters collected
from DAQA's particulate samplers set up in the Georgetown area have been analyzed to determine
their content. Special air sampling conducted during the shutdown of several area plants has also
been performed. The results of these efforts proved to be informative, but did not provide enough
information to determine what stage or stages of the manufacturing process emitted the particles
necessary for the stain to result and if other pollutants were involved in the formation of the red
staining (SCDHEC, 2003). To attempt to resolve this question, SCDHEC began a Bi-State Study
with Alabama in September 2000.
SCDHEC attempted to determine the extent and magnitude of the red staining and to determine if
other components or mechanisms played a significant role in the development of the stain. The part
of the study to determine extent of staining was inconclusive. Apparent staining showed a wide
variability and no study area could be defined (SCDHEC, 2003). To determine whether or not other
factors contribute to the staining problem, SCDHEC and the Alabama Department of Environmental
Management completed a joint state study. The intent of the Bi-State Study was to compare the red
stain observed in Georgetown to the red stain observed around the DRI facility located in Mobile,
Alabama. The main objective of this study was to determine if goethite (red staining) staining
resulted from emissions generated at a DRI facility without the influence of other industrial
components present in Georgetown. It was determined that the goethite from the Alabama monitors
was found to be optically similar to the goethite found on the Georgetown monitor. These
similarities indicated that some element of the DRI process at GSC contributed significantly to the
red staining found in the Georgetown area (SCDHEC, 2003).
Currently, there are four monitoring stations in the Georgetown area. A summary table of data
collected during the last five years is presented below. A more complete listing of the data are
presented in Appendix A. The iron is measured as elemental iron on the total suspended particulate
filters at each of the locations. Iron is reported as micrograms per cubic meter or µg/m3.
Georgetown Area
Iron Concentrations in Particulate Filters
1996-2000
Site Name
Range Concentration (µg/m3)
Mean Concentration
(µg/m3)
Howard High School
0.05-16.55
1.45
Georgetown CMS
0.05-26.38
2.95
Maryville Power Sub Station
0.05-3.92
0.32
Winyah
0.07-73.72
3.21
The station at Winyah is between Dozier Street and Cleland Street. The station was placed to
measure the greatest impact of emissions from Georgetown's primary industries. The Maryville Sub
Station is a Santee Cooper electrical substation at the intersection of Power Avenue and Ward Street.
The Maryville Sub Station serves as a local background monitoring station. Georgetown CMS, the
Georgetown Continuous Monitoring station, is south of the Georgetown Steel Corporation. The
Howard High School station is at Howard Adult & Community Education Center located at 500 S.
Kaminski Street.
The only standards available to use for comparison are those that have been developed for use in
occupational settings. Occupational settings typically involve much higher exposures and exposure
to many materials. The American Conference of Government Industrial Hygienists (ACGIH)
recommend an exposure limit of 5,000 µg/m3 time weighted average measured as iron. The United
States Occupational Safety and Health Administration (OSHA) limits permissible exposure to
10,000 µg/m3 measured as total iron particulates.
Particulate matter is a complex mixture of small particles and liquid droplets. Fine particles can be
emitted directly from sources such as diesel engines, wood burning activities, and other industrial
and commercial combustion processes (U.S.EPA, 2003). The size of the particulate is very important
to understanding the likelihood of exposure. Generally fine particulate matter is more likely to be
inhaled into the lungs. Exposure to high levels of fine particulate matter has the potential to cause
adverse health effects. Asthmatics, senior citizens, and people with respiratory disease and heart
disease can be particularly sensitive to the effects of particulates.
Particulate data (PM 2.5) has been collected in the Georgetown area (Winyah station) since 1999.
The sampler runs every three days for 24 hours, midnight to midnight. There are no continuous PM
2.5 monitors in Georgetown. The annual average for the Winyah station has only slightly exceeded
the national annual standard for PM 2.5 once (15.5 µg/m3) since SCDHEC started measuring PM
2.5. The national standard is 15 µg/m3 for an annual average. The 24-hour maximum standard (65
µg/m3) has not been exceeded at the Winyah station. The levels of PM 2.5 for the Winyah station
are similar to other parts of the state with annual averages across the state ranging from 11 to 15 µg/m3.
The PM 10 data are monitored at the Winyah station as well as at Howard High. The samplers at
these locations run samples every six days. Data have been collected since 1997 (1991 at
Georgetown CMS). The annual average for the Georgetown area monitoring stations range from
23 µg/m3 to 30 µg/m3. The level of PM 10 measured in Georgetown are consistently below the
national annual standard of 50 µg/m3. The level of PM 10 particulate data for the Georgetown area
are consistent with the rest of South Carolina with state-wide annual averages ranging from 20 to
24 µg/m3. The maximum level of PM 10 in the Georgetown area never exceeded the U.S.EPA 24-hour standard (150 µg/m3).
DISCUSSION
SCDHEC has been monitoring the iron content of the total suspended particulate (TSP) filters since
1996. The American Conference of Government Industrial Hygienists (ACGIH) recommend an
exposure limit of 5,000 µg/m3 time weighted average measured as iron. At this level, exposure is
unlikely to result in the accumulation of particles in the lung and x-ray changes. The United States
Occupational Safety and Health Administration (OSHA) limits permissible exposure to 10,000
µg/m3 measured as total particulates, to prevent the iron oxide accumulation in the lungs. The levels
of iron found in particulate matter in Georgetown are orders of magnitude less than the occupational
exposure limits. The maximum level of iron in the last five years was 73 µg/m3 found at the Winyah
monitoring station. The average iron concentrations over the last five years is less than 5.0 µg/m3, which is also much lower then the available standard. Iron oxide is generally not considered to
be a toxic material (Boyd and Shanas, 1963; Boyd and Shanas, 1967).
Red staining is a common by-product of the DRI process. The movement, stockpiling, and
processing of iron ore fines creates iron dust. Many occupations involve exposure to iron oxide and
iron including iron ore miners, miners, welders, caulker/burners, metal dressers, oxyacetylene
cutters, pigment workers, turners, grinders, fettlers, steel and iron rolling mill workers and silver
polishers. Welders particularly, can be exposed to high levels of iron oxide dust and fumes. Typical
occupation exposures are around 3,000-50,000 µg/m3. The accumulation of iron oxide in the lungs
can be associated with the development of a condition called siderosis. Siderosis is considered a
benign condition that resolves over a number of years once exposure stops. Siderosis is generally
considered a condition of overload, where the exposure to the dust is in excess of the lungs ability
to clear the particles (Flahive, 2001; Lay et al. 1999).
Most, if not all, of the information about adverse health effects of exposure to iron is obtained from
workplace studies and a few studies with human volunteers. Workplace exposures likely involve
simultaneous inhalation exposures to other materials. In general, iron-oxide is not very toxic and
is more of an irritant than a toxic material. In workers, who are exposed to much higher levels of
iron-oxide than the general public, siderosis may contribute to reduced lung function and patchy
fibrosis. Over time the iron-oxide dust is slowly cleared from the lungs (Flahive, 2001).
Based on the available iron data generated from the TSP filters over the past few years, it does not
appear as though the iron concentrations in the Georgetown area are at levels that would pose risks
to area residents. The concentrations are far below current health based (occupational) standards.
Although inhalation of iron has been linked with a condition that can decrease lung function, it
seems to only be associated with workplace exposures and not with other types of exposures (Lay
et al., 2001). Area residents would not develop this condition even if they were exposed to the
average level of iron measured in the community.
The levels of particulates (PM 2.5 and PM 10) in the Georgetown area are low and are consistent
with the rest of the State of South Carolina. At no time in the last seven years of monitoring, have
particulates exceeded the 24-hour maximum standard for either PM 2.5 or PM 10. Only once did
PM 2.5 exceed the annual average standard level and then it was only slightly exceeded. The
inhalation of fine particulate matter has been associated with lung function decreases, airway
inflammation, and respiratory symptoms. Senior citizens, children, asthmatics, and people with
ongoing lung or heart problems can be particularly sensitive to the effects of inhaled particulates.
Particulate levels in Georgetown are low and there is no reason for the general population living in
Georgetown area to experience adverse health effects from inhaling particulates.
CHILD HEALTH CONSIDERATIONS
SCDHEC's evaluation contained within this document considered children as a susceptible
subpopulation. There is no information to indicate whether or not children are more or less
susceptible to exposure to iron-oxide. However, the levels of iron measured in air around
Georgetown are an order of magnitude less than the federal standard. Children can be more sensitive
to the effects of particulates. The level of particulates in the Georgetown area are low and there is
no reason to expect that area children are exposed to levels of iron-oxide or other particulates that would pose a risk to their health.
CONCLUSIONS
It is unlikely that residents living in the area with the red staining problem are exposed to levels of
iron or particulates associated with the development of health effects. The levels of iron monitored
over a four year period are much lower than the established standards for iron. Particulate levels in
Georgetown are low and there is no reason for the general population living in Georgetown area to
experience adverse health effects from inhaling particulates.
ATSDR classifies sites as to their public health hazard category. Under ATSDR's classification
system, the inhalation of red staining or iron-oxide and other particulates in residential areas of
Georgetown is not expected to result in adverse health effects and is categorized as a no public health hazard.
RECOMMENDATION
No further public health actions are warranted with regard to the iron-oxide or red staining or other particulate matter.
PUBLIC HEALTH ACTION PLAN
The results of this first health consultation will be provided to the public as part of the presentation of the Summary of the Georgetown Air Quality Study.
REFERENCES
Boyd, Eldon M. and Shanas, M.N. 1963. The Acute Oral Toxicity of Reduced Iron. J. Canad. Med. Assoc. Vol. 89, 171-175.
Boyd, Eldon M. and Shanas, M.N. 1967. Studies on the Low Toxicity of Reduced Iron, B. P. 1932. J. Canad. Med. Assoc. Vol. 96, 1141-1146.
Flahive, Dr. Martyn. Nov. 2001. Summary Paper for the Investigation of the Health Effects of Iron, Iron Oxide and Iron Ore Dusts. Discussion Paper and Literature Review.
Lay, John C., Zeman, Kirby L., Ghie, Andrew J., Bennett, William D. 2001. Effects of Inhaled Iron Oxide Particles on Alvelolar Epithelial Permeability in Normal Subjects. Inhalation Toxicology, 13:1065-1078.
Lay, John C., Williams, D., Bennett, Ghio, Andrew J., Bromberg, Philip A., Costa, Daniel L., Chong, Kim S., Koren, Hillel S., Devlin Robert B. 1999. Cellular and Biochemical Response of the Human Lung after Intrapulmonary Instillation of Ferric Oxide Particles. Am. J. Respir. Cell Mol. Biol. Vol. 20, 631-642.
South Carolina Department of Health and Environmental Control. 2003. Georgetown Air Quality Study. Summary of Findings.
PREPARERS OF REPORT
Tracy Shelley, MS
Program Manager
Office of Environmental Community and Environmental Health
South Carolina Department of Health and Environmental Control
ATSDR Technical Reviewer
Debra Gable
Technical Project Officer
Division of Health Assessment and Consultation
APPENDIX A: GEORGETOWN IRON DATA
Station Name
Site ID
Total # of years
Minimum
Maximum
Average Mean
GEORGETOWN CMS
45-043-0006
5
0.050
154.24
2.955
GEORGETOWN COUNTY HEALTH DEPT
45-043-0001
1
0.360
13.81
3.030
HOWARD HIGH SCHOOL
45-043-0002
5
0.050
59.33
1.450
MARYVILLE
45-043-0007
5
0.010
14.63
0.325
WINYAH
45-043-0009
5
0.070
197.84
3.212
For All Sites
0.010
197.84
2.035
Annual Arith Mean
Min Sample Value
1996
1997
1998
1999
2000
1996
1997
1998
1999
2000
GEORGETOWN CMS
5.477
2.725
2.283
1.728
2.560
0.73
0.18
0.11
0.05
0.37
GEORGETOWN COUNTY HEALTH DEPT
3.030
0.36
HOWARD HIGH SCHOOL
2.123
1.496
1.261
1.414
0.954
0.35
0.10
0.10
0.05
0.07
MARYVILLE
0.518
0.290
0.277
0.237
0.301
0.06
0.01
0.05
0.06
0.05
WINYAH
6.233
2.480
1.963
2.392
2.992
0.35
0.18
0.07
0.21
0.14
1996
1997
1998
1999
2000
Max Sample Value
Max Sample Value
Max Sample Value
Max Sample Value
Max Sample Value
45-043-0006
154.24
63.71
55.16
43.16
73.16
45-043-0001
13.81
45-043-0002
59.33
43.27
38.16
46.43
31.91
45-043-0007
14.63
8.06
6.80
5.22
8.16
45-043-0009
197.84
79.66
58.76
79.71
96.77
APPENDIX B: ATSDR GLOSSARY OF ENVIRONMENTAL HEALTH 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).
Absorption:
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.
Acute:
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].
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.
Aerobic:
Requiring oxygen [compare with anaerobic].
Ambient:
Surrounding (for example, ambient air).
Anaerobic:
Requiring the absence of oxygen [compare with aerobic].
Analyte:
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.
Biodegradation:
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.
Biota:
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.
CAP:
See Community Assistance Panel.
Cancer:
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 of for getting cancer if exposed to a substance every day for 70 years (a lifetime
exposure). The true risk might be lower.
Carcinogen:
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.
CERCLA:
[see Comprehensive Environmental Response, Compensation, and Liability Act of
1980]
Chronic:
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.
Concentration:
The amount of a substance present in a certain amount of soil, water, air, food, blood, hair, urine,
breath, or any other media.
Contaminant:
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.
Dermal:
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.
DOD:
United States Department of Defense.
DOE:
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.
EPA:
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.
Epidemiology:
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.
Exposure:
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.
Groundwater:
Water beneath the earth's surface in the spaces between soil particles and between rock surfaces
[compare with surface water].
Half-life (t½):
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.
Hazard:
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.
Incidence:
The number of new cases of disease in a defined population over a specific time period [contrast
with prevalence].
Ingestion:
The act of swallowing something through eating, drinking, or mouthing objects. A hazardous
substance can enter the body this way [see route of exposure].
Inhalation:
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.
Metabolism:
The conversion or breakdown of a substance from one form to another by a living organism.
Metabolite:
Any product of metabolism.
mg/kg:
Milligram per kilogram.
mg/cm2:
Milligram per square centimeter (of a surface).
mg/m3:
Milligram per cubic meter; a measure of the concentration of a chemical in a known volume (a cubic
meter) of air, soil, or water.
Migration:
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].
Morbidity:
State of being ill or diseased. Morbidity is the occurrence of a disease or condition that alters health
and quality of life.
Mortality:
Death. Usually the cause (a specific disease, condition, or injury) is stated.
Mutagen:
A substance that causes mutations (genetic damage).
Mutation:
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.
NPL:
[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.
Pica:
A craving to eat nonfood items, such as dirt, paint chips, and clay. Some children exhibit pica-related behavior.
Plume:
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].
Population:
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.
ppb:
Parts per billion.
ppm:
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.
Prevention:
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.
Radioisotope:
An unstable or radioactive isotope (form) of an element that can change into another element by
giving off radiation.
Radionuclide:
Any radioactive isotope (form) of any element.
RCRA:
[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.
RFA:
RCRA Facility Assessment. An assessment required by RCRA to identify potential and actual
releases of hazardous chemicals.
RfD:
See reference dose.
Risk:
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]
SARA:
[see Superfund Amendments and Reauthorization Act]
Sample:
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.
Solvent:
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.
Stakeholder:
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.
Substance:
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].
Surveillance:
[see epidemiologic surveillance]
Survey:
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 which, 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.
Toxicology:
The study of the harmful effects of substances on humans or animals.
Tumor:
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.
The South Carolina Department of Health and Environmental Control's Office of Environmental
Community Health prepared this Georgetown County health consultation under a 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 health consultation was begun.
Debra Gable
Technical Project Officer
Superfund Site Assessment Branch (SSAB)
Division of Health Assessment and Consultation (DHAC)
ATSDR
The Division of Health Assessment and Consultation, ATSDR, has reviewed this health consultation, and concurs with its findings.
