PUBLIC HEALTH ASSESSMENT
GEORGIA-PACIFIC CORPORATION HARDWOOD SAWMILL
PLYMOUTH, WASHINGTON COUNTY, NORTH CAROLINA
The Georgia-Pacific Corporation Hardwood Sawmill site is comprised of approximately 24 acres along the Roanoke River in Plymouth, Washington County, North Carolina. The site is located one quarter of a mile east of the downtown area of Plymouth and has an estimated population of 400 people residing in the area surrounding the site. The nearest off-site residence is located 800 feet east of the facility. Atlas Plywood Company owned the property before 1950.
Georgia-Pacific Corporation Hardwood Sawmill produced and treated hardwood lumber and railroad ties at the site from 1950 until1983. In 1983, the facility burned and was permanently closed. The property was deeded to Decatur Partnerships by the Georgia-Pacific Corporation on January 2, 1985. Hazardous waste disposal practices while the site was in operation are unknown. The sawmill was served by an on-site production well and septic system during the period of operation and employed seventy-five workers.
Chemical and physical hazards on site have been removed through the Removal Action conductedby the EPA. The removal action data collected at the site was evaluated and no significant levels ofcontamination expected to cause adverse health effects were detected in the soil.
Based upon available data reviewed and observations made, the Georgia-Pacific Hardwood SawmillSuperfund Site is currently categorized by the Agency for Toxic Substances and Disease Registry(ATSDR) as a No Apparent Public Health Hazard. The current completed exposure pathway isoff-site biota through recreational fishing in the Roanoke River. Fish tested showed elevated levelsof dioxin. A fish consumption advisory is in effect along the river. Past exposures occurred on-siteto former workers and trespassers via contact with contaminated soil containing metals, pesticides,volatile organics, semi-volatile organics and dioxin. The contaminated soil 0" - 6" was removedduring a post soil removal action by the EPA in June of 2000. The data does not indicate thathumans have been exposed to levels of contamination on-site that would be expected to cause adverse health effects.
In this public health assessment, The Agency for Toxic Substances and Disease Registry (ATSDR),evaluates the public health significance of the formerly proposed Georgia-Pacific CorporationHardwood Sawmill National Priorities List (NPL) site in Plymouth, North Carolina. ATSDR hasreviewed available environmental and health outcome data and community health concerns todetermine whether adverse health effects are possible. In addition, this public health assessmentrecommends actions to reduce, prevent, or identify more clearly the possibility for site-relatedadverse health effects. ATSDR, in Atlanta, Georgia is one of the agencies of the U.S. Public HealthService. The Superfund law (Comprehensive Environmental Response, Compensation, andLiability Act of 1980 [CERCLA] as amended by the Superfund Amendments and ReauthorizationAct of 1986 [SARA]) requires ATSDR to conduct public health assessments of hazardous wastesites within 1 year of the site's proposal for the NPL.
The Georgia-Pacific Corporation Hardwood Sawmill site comprises approximately 24 acres alongthe Roanoke River in Plymouth, Washington County, North Carolina. The site is located onequarter of a mile east of the downtown area of Plymouth, and has a estimated population of 400people residing in the area surrounding the site. The Plymouth High School is located 0.27 milesouth of the site. The nearest off-site residence is located 800 feet east of the facility.
Atlas Plywood Company owned the property before 1950. Georgia-Pacific Corporation HardwoodSawmill produced and treated hardwood lumber and railroad ties at the site from 1950 until 1983(1). In 1983, the facility burned and was permanently closed. The property was deeded to DecaturPartnerships by the Georgia-Pacific corporation on January 2, 1985. Hazardous waste disposalpractices at the site while in operation are unknown. The sawmill was served by an on-siteproduction well and septic system during the period of operation and employed seventy-five workers(2). Drinking water from the on-site production well was not consumed by workers while the sitewas operational. Decatur Partnerships leased a portion of the site to an asphalt mixing companywhich ceased operation in June 1995. The site is presently unoccupied.
Wood preserving operations at the facility consisted of passing wood along a conveyor belt andthrough a dip vat. The dip vat contained a mixture of wood treatment chemicals and pesticides.When wood passed through the dip vat any excess preservative on the finished wood spilled to theground in the vicinity of the conveyor. The contaminated soil was periodically burned in the on-siteboilers (2).
The following is a record of investigations conducted at the site:
* December 1985, preliminary assessment conducted by NC Division of Health Services,
* October 1989, Phase I Screening Site Inspection completed by NUS Corporation,
* September 1991, Greenhorne & O'Mara , Inc. Conducted a Phase II Screening Site Inspection,
* April 1994, Dynamac Corporation conducted a Site Inspection Prioritization , and
* June 1995, the NC Department of Environment, and Natural Resources (NCDENR) conducted an expanded site inspection (ESI) at the facility.
Soil samples collected from the dip vat area during the ESI contained metals, lindane, polychlorinated biphenyls, dioxins, furans, pentachlorophenol, and pyrene at elevated concentrations (1). Sediment samples collected in the Roanoke River during the ESI containedelevated concentrations of metals, dioxins, furans, pentachlorophenol, and lindane, compared withbackground samples taken one mile upstream. Dioxins were detected in sediment samples collected and analyzed during the ESI and RI.. The background samples were taken during aconcurrent NCDENR inspection of a Weyerhaeuser Corporation facility. The river is commerciallyand recreationally fished from Plymouth, NC, to Albermarle Sound (1).
The EPA conducted a public availability meeting and interviewed citizens in Plymouth, NC on May25-29, 1998 (3). The majority of the people were aware of the City's plan for eco-tourism andredevelopment of the site. Some people remembered when the site operated, but did not recall anyproblems associated with the site. ATSDR representatives attempted to answer questionsconcerning the potential health threat the site posed to the Roanoke River.
Representatives from ATSDR and EPA conducted site visits on June 29-30, 1999 (4). Access to the former Georgia-Pacific facility from Plywood Road is restricted by a gate with a "no trespassing" sign posted. No property boundary fences were identified during the site visit.
The approximate population living within one mile of the site is 2,531 residents. The entirepopulation of Plymouth totaled 4,314 as of the 1997 Claritas Survey (3). The racial mixture in thecity of Plymouth, NC, is 2,448 Black; 1,814 White; 22 Asian; 29 Hispanic; 1 other nationality (5).
Industries in the Plymouth area include: Weyerhaeuser Paper Company, Mackey's Ferry Sawmill,Yamato Lumber, Plymouth Fertilizer Company, Plymouth Garment, Plymouth Pallet, SmithBrother Chemical Company, and Tyson Carolina (3). Drinking water is provided via the city's municipal water system.
ATSDR has evaluated all of the available environmental monitoring data to determine whatenvironmental contaminants and which specific areas on the site may be a concern. ATDSR usedcomparison values to determine which contaminants and areas should be examined more closely. Comparison values (CV) are health-based thresholds below which no known or anticipated adverseeffect on the health of persons should occur. The values allow an adequate margin of safety. Thecontaminant tables in this section identify the comparison values for each contaminant. Appendix Acontains a description of the comparison values used in this Public Health Assessment.
A contaminant is evaluated further if the contaminant level in a valid environmental sample exceeds comparison values. The presence of a chemical in the contaminant tables does not mean that exposures to the contaminant or adverse health effects have occurred or will occur. Later sections of this Public Health Assessment contain more detailed discussions of the potential for adverse human health effects as a result of any exposures to the known contaminants of concern.
This document focuses on those contaminants which pose a reasonable potential for human exposure.
In 1999, EPA collected soil samples (0"-6") on-site and analyzed for metals, pesticides, volatile andsemi-volatile organic contaminants and dioxin. (TCDD). Forty chemicals were detected in surfacesoil and 10 were detected in the stockpile area. The chemicals detected, in the surface soil and in thestockpile area had at least one concentration above the CV. These chemicals are identified in Tables1-4, Appendix C. Those chemicals above the CV are evaluated further in the Pathways Analysissection. An on-site production well was in service during the site's operational period. Water fromthe on-site production well was reportedly not consumed by workers while the site was operational.
EPA sampled off-site surface soil in 1999 and collected eight samples from residential yards and 10from the ball fields and the school south of the site. Elevated levels above the comparison valuewere identified in two samplings. The sample located at the boy scouts center south of the sitecontained pentachlorophenol at 2.4 parts per million (ppm). Lead at 467 ppm was detected at ahome in the residential area ( 7).
Analytical results from surface water and sediment samples did not find any contaminants abovecomparisons values (CVs).
The Roanoke River, Chowan River/HWY 17, and Albemarle Sound fish study found elevateddioxin levels in fish along the Roanoke River (17). A fish consumption advisory based on the dioxinstudy was issued and includes a 15-mile section of the river. The study found levels from non-detect to 16.5 parts per trillion (ppt) in all species of fish.
The main access to the former Georgia-Pacific facility from Plywood Road is restricted by a gatewith a "no trespassing" sign posted. No property boundary fences were identified during the sitevisit. The site is surrounded by thick swampy woodlands on the southern border, dense woodlandson the east and west borders and the Roanoke River to the north. The EPA Emergency Responseand Removal Branch has completed removal of all buildings on the site.
This section presents evaluations of the possible environmental pathways that help determinewhether individuals have been, are being, or will be exposed to site-related contaminants. Environmental pathways can be completed or potential. A completed pathway indicates thathuman exposure to contaminants has occurred in the past or is occurring (8). A potential exposurepathway indicates that human exposure to contaminants could have occurred in the past, could beoccurring, or could occur in the future. An exposure pathway that is not completed indicates thathuman exposure did not occur during that time period. An exposure pathway can be eliminatedfrom consideration if exposure has never occurred and never will occur. If there is uncertainty abouthow the contaminants of concern are related to the site in an exposure pathway, the pathway will be evaluated as if the contaminants were related.
Completed On-Site Soil Exposure Pathway
Table 1 (Appendix D) lists the components of the Georgia-Pacific site, with soil being the onlycompleted environmental pathway. This pathway is considered complete because exposure tochemicals at levels above the comparision value occurred in the past to workers and trespassers fromcontact with contaminated soil when the site was operational. Metals, pesticides, volatile organics,semi-volatile organics and dioxin (TCDD) are the contaminants found in the soil. The possiblehealth impact of this completed exposure pathway is evaluated in the Public Health Implications section.
Completed Off-Site Biota Exposure Pathway
Table 2 (Appendix D) lists the components of the completed environmental exposure pathway andthe estimated number of individuals in that pathway. Data samples collected from the RoanokeRiver showed elevated levels of dioxin in fish. Biota is a completed pathway because of therecreational activities on the Roanoke River such as fishing. A fish consumption advisory has beenin effect along the river since 1996. The completed exposure pathway will be further evaluatedwhen more data becomes available.
Potential Off-Site Surface Soil Exposure Pathway
Table 2 (Appendix D) lists the components of the potential environmental exposure pathway and theestimated number of individuals in that pathway. Surface soil sampling of off-site data showedelevated levels of contaminants in two areas sampled. It is possible for people to have been exposedto the contaminants found in the residential area and the boy scouts center via incidental ingestion,inhalation, or dermal contact during recreational activities which may have resulted in disturbing of the soil.
Not Completed On-Site Ground Water Exposure Pathway
On-site ground water is considered a "not completed" pathway because ground water from the sitewas not used for drinking by the workers while the site was operational. Therefore it is unlikely thatpeople could have been exposed to any "site related" contaminants via this pathway.
Not Completed Off-Site Ground Water Exposure Pathway
The majority of the residents in the vicinity of the former Georgia-Pacific facility are served by themunicipal water system which is located approximately 1.5 miles from the site. The nearestresidential well is located approximately 1.3 miles from the site. It is unlikely that site relatedcontaminants could enter these wells and thereby expose residents to ground water contamination ifit is present.
Not Completed Off-Site Surface Water and Sediment Exposure Pathway
Off-site surface water and sediment pathways are considered "not completed"pathways because contaminants detected in the media were not above the comparisons values (CVs).
This section contains information on the contaminants to which certain people have been, are, ormay become exposed and that may cause adverse health effects. Although the relative toxicity of achemical is important, the response of the human body to chemical exposure is actually determinedby several additional factors, including the magnitude of exposure (how much), the duration ofexposure (how long), and the route of exposure (i.e., breathing, eating, drinking, or skin contact). Lifestyle factors (i.e., occupation and personal habits) have a major impact on the likelihood,magnitude, and duration of exposure. In addition, individual characteristics such as age, sex,nutritional status, overall health, and genetic constitution affect how a contaminant is absorbed,distributed, metabolized, and eliminated from the body. Accordingly, the probability that exposure-related adverse outcomes will actually occur does not depend solely on concentrations inenvironmental media.
From evaluations of metal contaminants above the comparisons values (Tables 1, 2 and 3) andexposure pathways (Tables 1 and 2), ATSDR determined that exposures to several contaminants toon-site workers, and residents off site warranted more detailed toxicological evaluation anddiscussion in this section. Air quality data pertinent to Georgia Pacific's operations are not available,so inhalation exposure could not be evaluated; also, preliminary sampling data indicate that soilcontaminants and associated potential exposures may extend beyond the site onto adjacentproperties.
Past Exposures: Former workers
The former workers are assumed to have been on site five days a week, 50 weeks per year, for 30years, and to have ingested 50 milligrams of soil or stockpile material a day. There were two mainexposure scenarios for the former workers at the site who might have accidentally ingested smallamounts of contaminated soils and tar/soil mixture of stockpile.
One exposure scenario involves plant workers who were likely to have been accidentally exposedoccasionally to arsenic, chromium, copper, lead, polyaromatichydrocarbons ( PAHs) and pesticidesthrough ingestion of, and skin contact with, contaminated soils on site (Tables 1 and 2). Thisexposure would have been added to that from process air emissions, which cannot be evaluatedbecause relevant data are not available. The amounts of arsenic, chromium, copper, pesticides andPAHs this group of workers were potentially exposed to are below levels known to cause adversehealth effects (9,10, 11,12,13,14,15).
The highest level of lead the group of workers were probably exposed to is below the 400 ppmscreening value of lead in soil as proposed by the EPA Superfund screening value.
The other exposure scenario is associated with former workers who worked close to the ground. Thisgroup of former workers were likely exposed to metals, PAHs and pesticides in surface soil (Tables1 and 2), as well as several PAHs in soil/tar stockpile material on site (Table 3). Health studies haveprovided little insight about the health effects resulting from human exposure to multiplecontaminants in soil. However, our evaluation indicates that the levels of individual contaminantsthis group of workers were possibly exposed to in soil and soil/stockpile material on site are belowlevels known to cause adverse health effects (9,10,12,13,14,15).
Current Exposures: Fish Eaters
Residents who ate fish from the Roanoke River were exposed to dioxins and furans in fish tissue(17). Levels of 2,3,7,8- and total- tetrachlorinated dioxins (TCDDs) and furans (TCDFs) weremeasured in several game fish and catfish species from several locations along the Roanoke Riverbasin. The concentrations of the dioxins and furans were totaled and reported as dioxin toxicityequivalent quotient (TEQ), which are measured in parts per trillion (ppt). Each dioxin and furancongener represented the potential toxicity of 2,3,7,8- TCDD. The TEQs reported for fish from theRoanoke River, therefore, represents the concentrations of 2,3,7,8- TCDD and 2,3,7,8- TCDF.
The levels of TCDD in fish fillets ranged from non-detect to 16.5 (ppt). The highest level of TCDDdetected in fish fillets is lower than levels known to cause adverse health effects (16). That level isalso lower than the Food and Drug Administration's (FDA's) 25 ppt level of concern. Moreover, allof the TEQs in fish at the site were below TEQs in some 200 fish samples reported by the EPA in anational fish survey. Although we do not know the plasma TCDD lipid levels of residents who eatfish from the Roanoke River, the plasma TCDD lipid levels of Swedish fishermen who consumedbaltic salmon containing 30-90 TEQs daily, had plasma lipid TCDD levels well within the rangereported for the American population. Although a few catfish samples had TEQs above the NorthCarolina 3 ppt advisory level for fish consumption, the overall TEQs have remained below advisorylevel. The site records and information indicate that TEQ concentrations have continued to decline.The highest dioxin amount of ingested by residents is some 3,000 times lower that caused noobserved adverse effects in animal primates after four years of long-term exposure to dioxin. TheEPA, the International Agency for Research on Cancer (IARC) and the Department of Health andHuman Services (DHHS) consider TCDD to be a human carcinogen based on animal studies (16).However, residents are unlikely to develop excess cancer because of exposure to the low levels ofTCDD in fish fillets.
Residents in Nearby Homes and Institutions
Preliminary samplings of off-site surface soils located adjacent to the site detected 467 parts permillion (ppm) lead in residential soil and 2.4 (ppm) pentachlorophenol at a Boy Scouts Center. According to EPA officials, comprehensive soil data for off-site areas will soon be available forinclusion into this document. The preliminary data indicate that site-related contaminants may havemigrated to off-site areas. Contaminants can migrate or move from one location to another by rain,melting snow, ice or wind. However, the level of lead detected in soil from one residential yard, isbelow levels that have been shown to cause adverse health effects (12). The amounts ofpentachlorophenol ingested by adults and soil pica children (children that have contact with soil viahand to mouth contact) play are some 13 to 8,000 times lower than ATSDR's maximum risk levels(MRLs) or EPA's reference dose (RfD). While these levels of exposure are not likely to cause adversehealth effects for adults and children, this evaluation is based on limited preliminary informationonly. ATSDR will re-evaluate current exposure to contaminants in residential soil when the comprehensive off-site soil data is available.
The state does not compile health outcome data for the specific groups of potentially affectedpopulations being evaluated in this assessment (e.g., people on and near the site). Hence, site-specific health outcomes cannot be evaluated from the available data.
During ATSDR's public availability meeting on March 2, 2000, the following health concerns were posed:
*Are the pollutants affecting the fish in the river (3)?
Response: Yes, the North Carolina State Health Department recommended a fish consumptionadvisory along a 15-mile area of the Roanoke River. However, the levels of dioxinsdetected in fish fillets is lower than levels known to cause adverse health effects.
*What are the pollutants found in the river (3)?
Response: Elevated levels of dioxin were found in fish tissue. Dioxin is created when materialsare manufactured such as paper products, disinfectants and certain pesticides. Dioxins are also created when materials are burned at low temperatures such aschemical products, leaded gasoline, plastic, wood, and paper (6).
*Will the wetland ditch area surrounding the site be cleaned-up?
Response: The wetland ditch area will be cleaned if environmental testing shows thatcontaminates have reached the area.
The responses were those provided by ATSDR.
- The Georgia Pacific Corporation Hardwood Sawmill site presents a No Apparent Public Health Hazard. Recreational fishing in the Roanoke River presents a current completed exposure pathway off-site. Evaluations of relevant environmental and toxicologic data indicate that, under site-specific conditions of on-site exposure, exposure to site contaminants in the past, present, or future is not likely to result in any adverse impact on human health.
- Former on-site workers were likely exposed to several metals, pesticides, and PAHs in soil.Prior to the removal of contaminated soils, levels exceeding EPA Action Levels for a number of contaminants including dioxin that existed at levels known to cause adversehealth effects.
- Nearby residents who eat fish from the Roanoke River basin are likely exposed todioxins/furans in fish. However, the amounts of pesticide residues in some fish species arebelow levels known to cause adverse health effects and some are above levels consideredsafe for consumption. The fish are safe for consumption if eaten in accordance with the fish advisory issued by the state of North Carolina.
- Potential exposure to site-related contaminants in the future is below health concerns. In theevent that the planned land use for a eco-tourism and historical development changes in the future to include residential development, pica child health issues should be re-evaluated.
Site Characterization Recommendations:
ATSDR concurs with the on going comprehensive study of the Roanoke River basin to furthercharacterize fish, surface water and river bank soils. ATSDR will consider amending this section ifpertinent information arises during the document review process:
- It appears that TCDD concentrations in fish have decreased, the fish advisory should remainin effect while more data is collected on fish to certify that public health is being protected in the Roanoke River.
- The wetland ditch area surrounding the site should be tested for possible contamination because of overland flow from the site.
ATSDR's Child Health Initiative recognizes that the unique vulnerabilities of infants and childrendemand special emphasis in communities faced with contamination of their water, soil, air, or food. Children are at greater risk than adults from certain kinds of exposures to hazardous substancesemitted from waste sites and emergency events. They are more likely to be exposed because theyplay outdoors and they often bring food into contaminated areas. They are more likely to come intocontact with dust, soil, and heavy vapors close to the ground. Also, they receive higher doses ofchemical exposure due to lower body weights. The developing body systems of children can sustainpermanent damage if toxic exposures occur during critical growth stages.
Evaluations have not identified specific child health issues associated with this site. In the event thatthe planned land use for a eco-tourism and history development center changes, and the site isdeveloped for residential use, child health issues should be re-evaluated.
The Public Health Assessment (PHA) for the Georgia-Pacific Corporation Hardwood Sawmill sitewas made available for public review and comment on November 24, 2000, at the repository in theWashington County Library in Plymouth, North Carolina. The release of the PHA was announcedin the Roanoke-Beacon and Washington Daily News papers. The comment period ended onDecember 26, 2000. ATSDR did not receive any comments.
A major purpose of a public health assessment is the identification of the actions needed to protectpublic health, evaluate whether exposure is occurring or could occur, or identify whether there aresite-related health effects.
The following have been identified:
Completed Public Health Actions
- ATSDR, and the EPA visited the Georgia-Pacific Superfund site on June 29-30, 1999, to verify site conditions and to gather pertinent information and data for the site.
- ATSDR conducted a public availability meeting on March 3, 2000.
- ATSDR reviewed the on-site environmental data from the EPA post soil removal. The post soil removal data indicated that exposure to on-site surface soil in the present and future is not likely to result in any adverse impact on human health.
- ATSDR provided the public an opportunity to comment on a draft of this public healthassessment. The public comment period was from November 24, through December 26,2000. No comments were received.
Planned Public Health Actions
- ATSDR will review all future off-site environmental data from the EPA remedialinvestigations when it becomes available.
Wayne Hall, MPH
Environmental Health Scientist
Superfund Site Assessment Branch
Division of Health Assessment and Consultation
Agency for Toxic Substances and Disease Registry
Moses Kapu, Ph.D.
Environmental Health Scientist
Superfund Site Assessment Branch
Division of Health Assessment and Consultation
Agency for Toxic Substances and Disease Registry
Health Education Specialist
Division of Health Education and Promotion
Agency for Toxic Substances and Disease Registry
Community Involvement Specialist
Division of Health Assessment and Consultation
Agency for Toxic Substances and Disease Registry
ATSDR Region IV
- U.S. Environmental Protection Agency, National Priorities List (NPL), Georgia-Pacific Hardwood Sawmill, January 1999.
- State of North Carolina, Department of Environment, Health, and Natural ResourcesDivision of Waste Management Superfund Section, Expanded Site Inspection, January1997.
- Barrett. D. Trip Report on Public Availability and Interview Session for Georgia PacificNPL site on May 25-29, 1998, in Plymouth, NC. Atlanta, GA: U.S. EnvironmentalProtection Agency (EPA). May 1998.
- Hall. W. Site Visit of Georgia Pacific NPL site on June 29-30,1999. Atlanta, GA: Agency for Toxic Substances and Disease Registry (ATSDR). June 1999.
- GIS Georgia-Pacific Corporation Hardwood Sawmill Intro Map. Demographic StatisticsSource, 1990 U.S. Census. 1990
- U.S. Environmental Protection Agency, Hazardous Ranking Score Documentation Record,Georgia-Pacific Corporation Hardwood Sawmill EPA ID# NCD000813592, January 7,1999.
- U.S. Environmental Protection Agency, Remedial Investigation Work Plan, Georgia Pacific Corporation Hardwood Sawmill, Plymouth, NC. August 1998.
- ATSDR. Public Health Assessment Guidance Manual. Atlanta, Georgia: U.S. Department of Health and Human Services, Public Health Service. March 1992. Can be accessed at http://www.atsdr.cdc.gov/HAC/HAGM/.
- Agency for Toxic Substances and Disease Registry. Toxicological Profile for Arsenic. April 1993.
- Agency for Toxic Substances and Disease Registry. Toxicological Profile for Chromium. August 1998.
- Agency for Toxic Substances and Disease Registry. Toxicological Profile for Copper. December, 1995.
- Agency for Toxic Substances and Disease Registry. Toxicological Profile for Lead. July 1997.
- Agency for Toxic Substances and Disease Registry. Toxicological Profile for Mercury. August 1997.
- Agency for Toxic Substances and Disease Registry. Toxicological Profile for Alpha-, Beta-, Gamma- and Delta-Haxachlorocyclohexane. May 1994
- Agency for Toxic Substances and Disease Registry. Toxicological Profile for Polycyclic Aromatic Hydrocarbons (PAHs). August 1995.
- Agency for Toxic Substances and Disease Registry. Toxicological Profile for Chlorinated Dibenzo-p-Dioxins (PAHs). December 1995.
- Roanoke River, Chowan River/Hwy 17, and Albemarle Sound Fish Dioxin NPDES Study. July 1997.
Health Comparison Values
Comparison Values (CVs) are contaminated concentrations found in specific media (air, soil, or water) and used to select contaminants for further evaluation. They are not intended to be used as clean-up levels or indicators of public health effects. Comparison Values are derived from toxicological information, using assumptions regarding body weights, ingestion rates, and exposure frequency and duration. The assumptions are generally very conservative (i.e., worst case). The CVs used in this document are listed below.
Cancer Risk Evaluation Guidelines (CREGs) are estimated contaminant concentrations thatwould be expected to cause no more than one excess cancer in a million persons exposed over alifetime. CREGS are calculated from EPA's cancer slope factors(CFS).
Environmental Media Evaluation Guide (EMEGs) are estimated contaminant concentrations inmedia where there is no chance for non-carcinogenic health effects to occur. The EMEG is derivedfrom U.S. Agency for Toxic Substances and Disease Registry's (ATSDR) minimal risk level(MRL).
EPA Soil Screening Levels (EPA SSL) are estimated contaminant concentrations in soil whereadditional evaluation is needed to determine if action is needed to eliminate or reduce exposure.
|Contaminant||Concentration Range (mg/kg)||Source (CV)||Cancer Class|
|Contaminant||Concentration Range (mg/kg)||Source (CV)||Cancer Class|
|Contaminant||Concentration Range (mg/kg)||Source (CV)||Cancer Class|
|Benzo(a)pyrene equivalent||ND||0.8458||CREG (0.1)||B2|
|Contaminant||Concentration Range (ng/kg)||Source (CV)||Cancer Class|
|TEQ(Toxic.Equiv,Value, From 1-TEF/89)||550||370,000||CREG (0.1)||B2|
CREG- Cancer Risk Evaluation Guidelines
RMEG- Reference Dose Media Evaluation Guide
EMEG- Environmental Media Evaluation Guide
A Human carcinogen
B2 Sufficient evidence of carcinogenicity in animals, but inadequate evidence or no data from epidemiologic studies
|Pathway Name:||Source||Medium||Exposure |
|Exposure Route||Receptor Population||Time of Exposure||Exposure Activities||Estimated Number Exposed||Chemicals|
|On-Site Soil||Georgia Pacific||Soil||Operational Area||Ingestion Inhalation & Dermal||On-Site Workers and Trespassers||Past||Ingestion of soil on site||100*||See tables 1,2,3|
|Pathway Name:||Source||Medium||Exposure Point||Exposure Route||Receptor Population||Time of Exposure||Exposure Activities||Estimated Number Exposed||Chemicals|
|Off-Site Biota||Roanoke River||Surface Water||Roanoke River||Ingestion||People eating fish from the river||Past , |
|Consumption of fish||Unknown||Dioxin|
|Off-Site Soil||Georgia Pacific||SurfaceSoil||Residential Area Boy Scout Center||Ingestion |
|Residents, Scout Members||Past, |
|Lawn Maintenance, Recreational Activities||Unknown||Pentachlorophenol Lead|
- How a chemical enters a person's blood after the chemical has been swallowed, has come into contact with the skin, or has been breathed in.
- Acute Exposure:
- 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.
- Additive Effect:
- 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.
- Antagonistic Effect:
- A response to a mixture of chemicals or combination of substances that is less 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.
- Background Level:
- An average or expected amount of a chemical in a specific environment. Or, amounts of chemicals that occur naturally in a specific environment.
- Used in public health, things that humans would eat - including animals, fish and plants.
- See Community Assistance Panel.
- 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, and Liability Act.
- Chronic Exposure:
- 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.
- Community Assistance Panel (CAP):
- A group of people from the community and health and environmental agencies who work together on issues and problems at hazardous waste sites.
- 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 additional evaluation 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 of soil, water, air, or food.
- See Environmental Contaminant.
- Delayed Health Effect:
- A disease or injury that happens as a result of exposures that may have occurred far in the past.
- Dermal Contact:
- A chemical getting onto your 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 result.
- The amount of time (days, months, years) that a person is exposed to a chemical.
- Environmental Contaminant:
- 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.
- Environmental Media:
- Usually refers to the air, water, and soil in which chemical 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 will disease occur.
- Coming into contact with a chemical substance.(For the three ways people can come in contact with substances, see Route of Exposure.)
- Exposure Assessment:
- 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.
- Exposure Pathway:
- 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.
- How often a person is exposed to a chemical over time; for example, every day, once a week, twice a month.
- Hazardous Waste:
- 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.
- Health Effect:
- ATSDR deals only with Adverse Health Effects (see definition in this Glossary).
- Indeterminate Public Health Hazard:
- The category is used in Public Health Assessment documents for sites where 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 your 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.
- See Cancer.
- Minimal Risk Level. An estimate of daily human exposure - by a specified route 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. (Which is 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 chemicals at 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.
- A line or column of air or water containing chemicals moving from the source to areas further away. A plume can be a column or clouds of smoke from a chimney or contaminated underground water sources or contaminated surface water (such as lakes, ponds and streams).
- Point of Exposure:
- The place where someone can come into contact with a contaminated environmental medium (air, water, food or soil). For examples:
the area of a playground that has contaminated dirt, a contaminated spring used for drinking water, the location where fruits or vegetables are grown in contaminated 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 is responsible for causing the pollution at a hazardous waste site. PRP's 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 are 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
- Receptor Population:
- People who live or work in the path of one or more chemicals, and who 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
- or getting something on the skin (also called dermal contact).
- Safety Factor:
- 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 amended CERCLA 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.
- Sample Size:
- 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.
- Special Populations:
- 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.
- Superfund Site:
- 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.
- Synergistic effect:
- 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.
- Uncertainty Factor:
- 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.