PUBLIC HEALTH ASSESSMENT
GOLDEN STRIP SEPTIC TANK
SIMPSONVILLE, GREENVILLE COUNTY, SOUTH CAROLINA
The data presented in this section is from the Remedial Investigation conducted by RMT andrepresents the latest information available for this site. For the purpose of this public healthassessment, the site is characterized as occupying approximately 25% of the central portion of the55-acre farm tract. The site consists of five unlined and inactive lagoons. The remainder of thefarm property will be considered as being off-site.
The tables in this section list the contaminants of concern. We evaluate these contaminants in thesubsequent sections of this public health assessment and determine whether exposure to them haspublic health significance. SCDHEC and ATSDR select and discuss these contaminants based uponthe following factors:
- Concentrations of contaminants on and off the site.
- Field data quality, laboratory data quality, and sample design.
- Comparison of on-site and off-site concentrations with public health assessment comparison values for (1) non-carcinogenic endpoints and (2) carcinogenic endpoints.
- Community health concerns
In the data tables that follow under the On-site and the Off-site Contamination subsections, the listedcontaminant does not mean that it will cause adverse health effects from exposures. Instead, the listindicates which contaminants will be evaluated further in the public health assessment.
|= Cancer Risk Evaluation Guide|
|= Environmental Media Evaluation Guide|
|= Maximum Contaminant Level Goal|
|= Maximum Contaminant Level|
|= Proposed Maximum Contaminant Level Goal|
|= EPA Maximum Contaminant Level|
|= Reference Dose|
|= Lifetime Health Advisory|
|= Reference Dose Media Evaluation Guide|
|= parts per million|
|= parts per billion|
Comparison values for public health assessments are contaminant concentrations in specific mediathat are used to select contaminants for further evaluation. These values include EMEGs, CREGs,and other relevant guidelines. CREGs are estimated contaminant concentrations based on a oneexcess cancer in a million persons exposed over a lifetime. CREGs are calculated from EPA'scancer slope factors. EPA's MCLG is a drinking water health goal. EPA believes that the MCLGrepresents a level at which "no known or anticipated adverse health effect on human health occurswhich allows an adequate margin of safety." PMCLGs are MCLGs that are being proposed. MCLsrepresent contaminant concentration that EPA deems protective of public health (considering theavailability and economics of water treatment technology) over a lifetime (70 years) at an exposurerate of 2 liters of water per day. While MCLs are regulatory concentrations, PMCLGs and MCLGsare not. EPA's RfD is an estimate of the daily exposure to a contaminant that is unlikely to causeadverse health effects. RMEGs are media-specific comparison values derived from EPA referencedoses and are used to select contaminants of concern at hazardous waste sites.
Toxic Chemical Release Inventory (TRI)
The Toxic Chemical Release Inventory (TRI) is developed by the EPA from chemical releaseinformation provided by certain industries. The chemical release information is based oncontaminants found in air, surface water, groundwater, or soil.
Project staff conducted a search of the TRI for the years 1987 and 1988. TRI did not containinformation on toxic chemical release in the area around the GSST site.
RMT collected soil samples from the areas surrounding the lagoons and from the truck turnaroundarea. These soils contained the greatest concentrations of contaminants on the site. However, thesesamples do not represent surface soil samples as defined by ATSDR (0" - 3" in depth). Surface soilsamples are needed to characterize the extent of soil contamination that would most likely representan exposure pathway for this media.
RMT collected soil samples S-18 through S-34 from on-site locations 0' - 2' in depth, and classifiedthem as "surface soil samples". Table 2 presents the contaminants of concern identified in thesesamples. Little, if any, contamination was detected in samples collected from locations further awayfrom the lagoons (26).
Soil boring samples were collected at depths of greater than 2 feet to 14 feet. These samples werecollected to investigate the horizontal and vertical extent of waste deposition within the five lagoons(all samples were collected from on-site locations). Soils were sampled continuously until wastewas encountered and a sample of the waste was collected. The boring was then advanced to depthsof three to five feet below the waste, and samples were again collected. If no waste was encounteredin a boring, another location was sampled. Table 3 presents the contaminants identified as beingof concern in this media.
Range - ppm
|Arochlor 1254||ND - 0.27||S-31||0.3||EMEG|
ND = not detected
Range - ppm
|N-nitroso-di-n-propylamine||ND - 1.1||SB-08||0.1||CREG|
|Arochlor 1254||ND - 0.21||SB-05||0.3||EMEG|
|Cadmium||ND - 3140||SB-07||40||EMEG|
|Chromium||7.7 - 35,800||SB-08||300||RMEG|
|Copper||ND - 15,300||SB-08||NONE|
|Cyanide||ND - 1790||SB-07||1000||RMEG|
|Lead||6.9 - 345||SB-08||NONE|
|Manganese||78.1 - 2900||SB-07B||300||RMEG|
|Nickel||ND - 1690||SB-08||NONE|
ND = Not detected
Surface Water and Sediments
As part of the RI, surface water samples SW-06 and SW-07 were collected from Lagoons # 1 and#4. These samples detected the presence of metals in the lagoons. Table 4 presents contaminantsidentified as being of concern in this media. RMT samples did not detect contaminants that couldimpact the tributary or Gilder Creek (29).
Stream sediment samples were collected to investigate sediment deposited by the on-site stream oras a result of surface water runoff from the lagoon area. Samples were also collected from thebottoms of gullies and ditches in the vicinity of the lagoons. These gullies and ditches receive wateronly after significant rainfall; therefore, no surface water samples were collected from these areas.
Table 4 presents the contaminants of concern identified in on-site surface water and sedimentsamples.
Range - ppm
|Cadmium||ND - 0.078||SW-06||0.007||EMEG|
|Chromium||ND - 0.498||SW-07||0.05||RMEG|
|Manganese||ND - 0.441||SW-06||0.05||RMEG|
|Manganese||33.3 - 1340||SS-09||300||RMEG|
SW = Surface Water
SS = Sediment
ND = Not detected
GSST is located in the Piedmont physiographic province of South Carolina. This province rangesin elevation from 400 to 1200 feet above mean sea level. The hydrogeological investigationconsisted primarily of the evaluation of seventeen on-site monitoring wells.
The geology on the site consists of residual soils and saprolite (shallow aquifer) composed primarilyof fine-grained silty and clayey sand overlying the bedrock (deep) aquifer. The bedrock aquifervaries in depth, from an approximate 10 to 60 feet below the ground surface, throughout the site.
Topographic data of the site indicate that much of the site slopes to the west and northwest towardthe on-site stream. The stream originates at a spring located near the southwest corner of the site. West of this stream, the land surface rises steeply. Topographic elevations ranges from anapproximate 850 feet above mean sea level (msl) at the southeastern edge of the site to anapproximately 775 feet msl where the stream leaves the site to the north.
Groundwater samples collected during the RI were intended to define the groundwater plume and/orpattern of contamination. RMT measured water levels for seven consecutive months between Apriland October 1990. The RI concluded that groundwater in the vicinity of the site occurs underunconfined conditions and the water table tends to mimic the general contour of the ground surface. The RI also concluded that groundwater flow on the site is primarily to the northwest over most ofthe site. Drainage is toward the unnamed tributary, that flows from south to north. In the area westof the stream, groundwater flows to the northeast, toward the stream.
During the RI, RMT installed seventeen groundwater monitoring wells. These wells were installedto investigate the horizontal groundwater flow rate and direction, the vertical groundwater flowcomponents, and water quality conditions. Table 5 presents contaminants identified as being ofconcern in this media.
Samples collected from monitoring wells in the immediate vicinity of the lagoons indicate thatgroundwater has been minimally affected by waste constituents from past disposal activities. Contaminants of concern were identified in these areas; however, there is no discernible plume ofwaste constituents. Groundwater resources at the site have not been adversely affected by past wastedisposal activities beyond the immediate area of the lagoons. No other on-site areas appear to havebeen impacted by past disposal activities.
Range - ppm
|Bis(2-ethylhexyl)phthalate||ND - 0.12||MW-06A||0.003||CREG|
|Chromium||ND - 0.061||MW-06||0.007||EMEG|
|Nickel||ND - 5.30||MW-04||0.1||LTHA|
|Zinc||ND - 0.055||MW-06||3||RMEG|
ND = Not detected
1,2-Dichloroethene, Bis(2-ethylhexyl)phthalate, and metals were detected in lagoons # 1 and # 4. These lagoons remain uncovered. Table 6 presents the contaminants identified as being of concernin this media. All the contaminants of concern identified in this media were found in lagoon #1.
The highest concentrations of heavy metals were found in sample W-01 (lagoon #1). This may berelated to the close proximity of the sample location to a discharge area used during past activitiesat the site and to the increased depth of lagoon #1 in the area of W-01.
Methylene Chloride was detected in W-01 and is presented in Table 7. However, this compoundwas also found in the analytical method blank during analysis of samples W-01 and W-02. Thesecompounds may be laboratory artifacts.
Range - ppb
|Lead||12.1 - 1900||W-01||NONE|
|Nickel||ND - 6140||W-01||NONE|
ND = Not detected
N = Spiked sample recovery not within control limits
RMT collected air samples to investigate the presence of airborne particulate matter, hydrocarbons,and other compounds at the site. Air monitoring consisted of background (off-site) and on-sitemonitoring during field activities. No contaminants were detected on-site (26).
RMT collected soil samples S-01 to S-17 from off-site locations. Off-site locations are classifiedas the locations outside of the 25% area that comprise the site. These locations are still within the55-acre tract of farm land. No soil samples were collected from outside these 55-acres. Soilsamples were collected from 0' to 2' in depth. RMT classified these samples as "surface soil". However, these do not represent surface soil samples for the purposes of this public healthassessment. ATSDR defines surface soil as soil from 0" to 3" in depth. This definition of surfacesoil enables us to evaluate the contaminant concentration found in soil that would serve as the mostlikely route of exposure. This also enables us to evaluate the health effects that could be associatedwith exposures to a specific contaminant concentration.
Table 7 presents the contaminants identified as being of concern in this media.
Range - ppm
|Tetrachloroethene||ND - 0.23||S-17||10||CREG|
|Bis(2-ethylhexyl)phthalate||ND - 130||S-17||50||CREG|
|Aldrin||ND - 0.44||S-16||2||EMEG|
|Dieldrin||ND - 0.46||S-16||0.04||CREG|
|Antimony||ND - 154N||S-17||20||RMEG|
|Cadmium||ND - 798||S-17||40||EMEG|
|Chromium||20.5 - 7530||S-17||300||RMEG|
|Copper||ND - 6200||S-16||NONE|
|Lead||10.7 - 5290||S-17||NONE|
|Manganese||30.1 - 410||S-24||300||RMEG|
|Nickel||ND - 262||S-16||NONE|
ND = Not detected
N = Spiked sample recovery was not within control limits
Surface Water and Sediments
As part of the RI, RMT collected samples from five locations (SW-1 to SW-5) of the stream. Oneof these samples, Surface water sample 1 (SW-1), was collected from an upgradient location, toprovide a background information for surface water quality. Stream surface water and sediment donot appear to have been affected by past disposal activities.
Stream sediment sample 1 (SS-01) was collected at the groundwater seep that serves as the originof the unnamed stream and was considered to be a background sample for the RI. Table 9 presentscontaminants identified as being of concern in off-site sediments.
Range - ppm
|Cadmium||ND - 86.5||SS-06||40||EMEG|
|Chromium||10.9 - 474||SS-06||300||RMEG|
|Copper||ND - 662||SS-06||NONE|
|Lead||2.7 - 221||SS-06||NONE|
|Nickel||ND - 16.6||SS-06||NONE|
ND = Not detected
As part of the RI, groundwater monitoring wells (MW) 9 and 9A were installed to characterizegroundwater flow and water quality conditions. They were also installed to develop verticalgroundwater flow gradient components around and downgradient of the lagoon area and potentialsurface and groundwater discharge areas.
MW #2 and #2A were installed to obtain gradient water quality data. They were used asbackground samples. Table 9 presents the contaminants identified as being of concern in this media. No off-site groundwater plume has been identified to date. Sampling conducted to date do notindicate groundwater contaminant migration (29).
Range - ppm
|Manganese||ND - 5.30||MW-07||0.05||RMEG|
** = EPA Action Level
ND = Not detected
RMT collected air samples to investigate the presence of airborne particulate matter, hydrocarbons,and other compounds at the site. Air monitoring consisted of background (off-site) and on-sitemonitoring during field activities. The initial background samples were collected to characterizeroutine exposure at the site prior to field activities.
Off-site air monitoring samples were collected from four locations. A sample was collected upwind,downwind, and at each crosswind. Based on the air sampling results, RMT reports that there is noapparent impact. Off-site background samples showed no indications of contamination (26).
Conclusions drawn for this health assessment are determined by the availability and reliability ofthe referenced information. SCDHEC assumes that adequate quality assurance and quality controlmeasures were followed with regard to chain of custody, laboratory procedures, and data reporting.
Duplicate samples, rinsate blanks, and water supply samples were collected as part of the QA/QCprocedures utilized at the site. Additional QA/QC was gained through the use of field blanks andtrip blanks.
Lagoons #1 and #4 still remain open; these constitute a physical hazard on the site.
To determine whether nearby residents are exposed to contaminants migrating from the site,ATSDR evaluates the environmental and human components that lead to human exposure. Thispathways analysis consists of five elements: A source of contamination, transport through anenvironmental medium, a point of exposure, a route of human exposure, and an exposed population.
ATSDR categorizes an exposure pathway as a completed or potential exposure pathway if theexposure pathway cannot be eliminated. Completed pathways have all five elements and indicatethat exposure to a contaminant has occurred in the past, is currently occurring, or will occur in thefuture. Potential pathways, however, have at least one of the five elements missing, but couldbecome completed. Potential pathways indicate that exposure to a contaminant could have occurredin the past, could be occurring now, or could occur in the future. An exposure pathway can beeliminated if at least one of the five elements is missing and will never be present. No completedexposure pathways were identified for the GSST site; however, Table 10 identifies the potentialexposure pathways. The discussion that follows incorporates only those pathways that are importantand relevant to the site. We also discuss some of those exposure pathways that have beeneliminated.
No completed exposure pathways were identified for the GSST site.
Contaminants of concern do not appear to have migrated from the site via surface water, sediments,groundwater, soil, or air. Therefore, the residents in the area would not be exposed to contaminantsof concern. The only potential for exposures to nearby residents is if they visit the site. Therefore,no potential exposure pathways were identified for off-site locations and media.
|Exposure Pathway Elements||Time|
Past, current, and future exposures to contaminated soil may have resulted at the GSST site. In thefuture, only the on-site lagoon areas could represent likely points of exposure.
In the past, exposure to contaminants at the GSST site could have occurred to anyone who may haveentered the site or to on-site workers. However, no data are available about the possible exposuresand/or length of exposures; therefore, adverse health effects from past exposures to on-site soilcannot be evaluated. The routes of exposure could have been through dermal contact with, ingestionof, or inhalation of soil particles.
Currently, contaminants of concern have been identified in on-site and off-site soils. The highestconcentrations of contaminants appear to be concentrated around the lagoon area which is fencedoff. Persons entering the lagoon area could be exposed to contaminants of concern throughingestion or dermal contact with contaminated soil. However, there is thick vegetation and groundcover on the site making exposures currently unlikely. Surface soil (0" - 3") samples would beuseful to ascertain the possibility for exposures to contaminants found in the surface soil should thiscover be eliminated or reduced. Exposures to contaminants at the GSST site could be occurring;however, the site is restricted by a fence and is not easily accessible. Therefore, the possibility ofpeople wandering onto the site is considered minimal.
In the future, potential exposure pathways could become completed if the site is developed. However, due to the nature and current status of the site, this pathway is considered unlikely.
No soil samples were collected from beyond the 55-acre tract of farm land; since contamination wasdetected in 0' - 2' soil samples off-site on the farm, it is possible that there could be contaminationof the surface soil outside the farm land. This possibility cannot be evaluated without additionalsurface soil sampling.
Chemicals present in soils at the GSST site may leach into groundwater. Infiltration andprecipitation will aid in leaching contaminants from soil and transporting them into groundwater. Once in groundwater, contaminants are transported in the same direction as groundwater flow, butat a much slower rate. The RI also concluded that groundwater flow on the site is primarily to thenorthwest over most of the site. Drainage is toward the unnamed tributary, that flows from southto north. In the area west of the stream, groundwater flows to the northeast, toward the stream.
In the future, human exposure to contaminated on-site groundwater could occur if the site isdeveloped for residential or commercial uses. Exposures could occur if people ingest on-sitegroundwater. However, due to the nature and status of the site, this pathway is considered unlikely.
Groundwater sampling results, presented in the RI, indicate that this pathway is not completed fromthe site to residential private well users. Additionally, all of the newer homes in the subdivisionshave municipal water. A few of the older homes are using private wells as their drinking watersource. Contaminated groundwater has been detected on-site, and we have no indication thatcontaminants have not migrated off-site. MW-7 on the edge of the property showed detectablelevels of site contaminants, and the plume has not been fully defined. It is possible that some off-site private wells may be contaminated. Identification and sampling of private wells is needed tofully evaluate this pathway. The owner receives water from a spring; this spring is also the sourcefor the unnamed tributary. No contamination has been detected in the spring and no drinking waterwells exist on-site.
If it has not already occurred, groundwater contamination could migrate to off-site private wells. Better characterization of the groundwater plume is needed to determine this possibility.
Surface Water/Sediments Pathways
- Unnamed Tributary
Recreational users of the unnamed tributary to Gilder Creek could be exposed to contaminants ofconcern in stream sediments and surface water. Exposures could occur to anyone who may wadein the tributary. However, the lagoons are secured by fences and the probability of peoplewondering into the open lagoons is considered unlikely. The tributary is not large enough tosupport swimming or the existence of fish; therefore, accidental ingestion of this water is notconsidered a pathway of concern.
- Lagoon Areas
Children or adolescents playing in, or near, the lagoons have a risk of exposure from ingestion orabsorption. The site is restricted by a secure fence and signs are posted throughout the perimeter.
Contaminants of concern were identified in two lagoons (#1 and #4). Persons ingesting this materialwould be exposed. However, this is considered unlikely.
Because of the thick vegetation and ground cover on the GSST site, the airborne release ofcontaminants of concern is not considered a pathway of concern at this time.
In the future, this pathway could become a potential if site activities lead to volatilization ofcontaminants of concern. Exposures could occur through inhalation of contaminants of concern. However, this pathway is considered unlikely.
In this section, we will discuss the health effects in persons exposed to specific contaminants,evaluate state and local health databases, and address specific community health concerns. Toevaluate health effects, ATSDR has developed a Minimal Risk Level (MRL) for contaminantscommonly found at hazardous waste sites. The MRL is an estimate of daily human exposure to acontaminant below which non-cancer, adverse health effects are unlikely to occur. MRLs aredeveloped for each route of exposure, such as ingestion and inhalation, and for the length ofexposure, such as acute (less than 14 days), intermediate (15 to 364 days), and chronic (greater than365 days). ATSDR presents these MRLs in Toxicological Profiles. These chemical-specificprofiles provide information on health effects, environmental transport, human exposure, andregulatory status.
Aldrin and Dieldrin
These compounds were widely used as insecticides from the 1950's to the early 1970's. Dieldrin hasalso been used for wood treatment, for mothproofing woolen products, and as a sheep dip. TheUnited States has banned most uses of these compounds (1). Aldrin and dieldrin were detected intwo (of 19) soil samples at depths of 0' to 2' at the GSSt site. No surface soil (0"-3") samples werecollected at or around the site; therefore, human exposure pathways cannot be evaluated for this media.
Human studies have shown that brief exposures to high levels of aldrin or dieldrin may produceheadaches, dizziness, irritability, loss of appetite, nausea, muscle twitching, convulsions, and a lossof consciousness. These symptoms disappear with time after the exposure ceases. Long-termoccupational exposure to fairly low levels of these compounds have not resulted in adverse healtheffects (1).
Animals fed dieldrin have developed damage to the liver and immune system. Animal studies alsoshow that exposures of a pregnant female to aldrin and dieldrin has been associated with damageto the fetus. Oral doses of aldrin and dieldrin have caused increased rates of liver cancer in micebut not in rats (1).
Antimony is a metal that occurs naturally in the earth's crust. It is used in electrical devices suchas semi-conductors and in alloys as in batteries, anti-friction metal, and cable sheathing. Antimonyoxides, sulfides, and salts are used in flame-proofing compounds, paints, ceramic enamels, glass,and pottery. It is also used to treat people for certain kinds of parasitic infections (2).
Workers on other hazardous waste sites that were exposed to high levels of antimony salt dust havedeveloped gastrointestinal effects including abdominal pain, diarrhea, vomiting, and ulcers. Otheracute health effects occurred at doses that are significantly higher than those found at GSST(ATSDR Toxicological Profile for Antimony, Table 2-2) (2).
While antimony was detected in off-site soil (0'-2') symptoms of antimony toxicity have occurredafter exposures to much greater doses than those found at the GSST site and through different routesof exposure (2). Therefore, exposures to the levels found at the GSST site do not pose a pathwayof concern at this time.
DEHP is used to make plastics more flexible. It is also used as a hydraulic fluid and as a dielectricfluid in electrical capacitors (9).
Bis(2-ethylhexyl)phthalate was detected in on-site groundwater and off-site soil (0' to 2' in depth). Currently, there are no known exposure pathways occurring from exposures to contaminants in thesemedia. The future potential for adverse health effects from exposures to contaminated soil cannotbe evaluated at this time due to the lack of surface soil samples. In the future, people could beexposed to on-site groundwater contamination through ingestion, inhalation, and/or through dermalcontact with groundwater, if the site is developed. However, this pathway is considered unlikely.
According to ATSDR, there are essentially no studies on the health effects of DEHP in humans. In laboratory animals, high doses of DEHP may produce liver damage and damage to the malereproductive system, it can also affect reproduction, and produce birth defects. DEHP has beencaused an increased incidence of cancer in rats and mice. None of these effects have beendocumented in humans (9).
Cadmium occurs naturally in the earth's crust and is most often encountered in combination withother elements such as oxygen, chlorine, or sulfur. It has a number of industrial applications, as inmetal plating, pigments, batteries, and plastics (3).
Cadmium was detected in samples collected from on-site soil (greater than 2' in depth), in surfacewater collected from the lagoons, and in off-site soil (0' to 2' in depth) and sediments. A potentialexposure pathway was identified for cadmium. There are no known human exposure pathwaysoccurring at this time. If the site is developed in the future, people could be exposed tocontaminants in these media through accidental ingestion, inhalation, or through dermal contact withthe contaminated media.
The kidney is the organ most sensitive to chronic doses of cadmium. Renal disease can lead toskeletal damage. Animals chronically exposed to cadmium have demonstrated high blood pressure. Currently, there is no correlation of this finding to humans. Animals and humans exposed to higherlevels of cadmium, than those found at the GSSt site, may develop damage of the liver, testes,immune system, nervous system, and the blood. Reproductive and developmental effects have alsobeen observed in animals treated with cadmium; these effects have not been reported in humans. Acute oral exposure to high doses of cadmium may produce gastrointestinal symptoms in humansincluding nausea, vomiting, and diarrhea (3).
Chromium is a naturally occurring element found in three different states: chromium 0, chromiumIII (trivalent chromium), and chromium VI (hexavalent chromium). Only trivalent chromium iscommon in nature. Chromium is used to make steel and other alloys, bricks for metallurgicalfurnaces, chrome plating, in the manufacture of pigments, leather tanning, wood treatment, andwater treatment (5).
Chromium III is an essential human nutrient that helps to maintain normal metabolism of glucose(sugar) and fat. It has no established toxicity according to the National Academy of SciencesDrinking Water and Health (23).
Chromium VI is irritating to the skin and nasal passages. In the body it attacks the liver, kidney,and central nervous system. Inhalation of high levels of hexavalent chromium has been associatedwith an increased risk of lung cancer in humans (5).
Chromium was detected in on-site soil (greater than 2' in depth), surface water in the lagoons,lagoon wastes, groundwater, and in off-site soil (0' to 2') and sediments.
At GSST, sampling has not determined if the chromium is present in the trivalent or hexavalentstate. Therefore, no further statement may be made about the probable health effects resulting fromchromium at this time.
Copper occurs naturally in rock, soil, water, sediment, and air. The United States penny, electricalwiring, and some water pipes are made with copper. It is an essential element for all livingorganisms, including man (6).
Copper was detected in on-site soil (greater than 2'), and in off-site soil (0' to 2') and sediments. Apotential exposure pathway was identified for copper. People could be exposed through ingestion,inhalation, or through dermal contact with contaminated soil and sediments. Currently, there areno known exposures occurring in these media. In the future, these pathways could becomecompleted if the site is developed and groundwater is utilized for domestic purposes or if surfacesoil samples indicate that contaminants of concern exist in this media. However, no adverse healtheffects are anticipated after exposures to copper contamination at the levels associated with the GSST site.
Cyanides are man-made and naturally-occurring substances. They are found in a number of foodsand plants and are produced by certain bacteria, fungi, and algae. Small amounts in the form ofvitamin B12 (cyanocobalamin) are a necessary part of the human diet. Industrial uses includeelectroplating and metal treatment. Elevated amounts are found in sewage (7).
Cyanide was detected in on-site soil (greater than 2' in depth). A future potential exposure pathwaywas identified for cyanide; however, no current exposures are known to have occurred or to beoccurring. Exposures could occur in the future through inhalation, accidental ingestion, or throughdermal contact with contaminants in this media.
ATSDR has not established an MRL for cyanide; however, the EPA has established a chronic oralreference dose of 0.02 mg/kg/day for cyanide. The estimated adult dose from ingestion of cyanidein off-site soil does not exceed the reference dose and no adverse health effects from humanexposure to cyanide in off-site soil are expected. A child ingesting the level of cyanide present inon-site subsurface soil and human ingestion of cyanide from the on-site lagoons would exceed thereference dose. The levels of cyanide in on-site subsurface soil are not at levels that have resultedin adverse health effects in humans. Adult ingestion of cyanide from the on-site lagoons would notoccur at levels known to cause adverse health effects; however, a child ingesting cyanide from theon-site lagoons may experience vomiting.
Dermal contact with cyanide at the GSST site is not expected to result in adverse health effects.
Lead is a naturally-occurring element found in most environmental media. It has a wide range ofuses including storage batteries (automobile batteries), solders, pipes, various chemicals, andgasoline additives (10).
Lead was detected in on-site soil samples (greater than 2' in depth), in the lagoons, and in off-sitesoil (0' to 2') and sediments. A potential exposure pathway was identified for lead in the future. Currently, there are no known routes of human exposure to lead. Exposures could occur throughingestion, inhalation, or dermal contact with contaminated media in the future, if the site isdeveloped.
Although lead may cause acute and chronic effects, major concern has been focused on two chroniceffects of lead toxicity: irreversible central and peripheral nervous system damage in children(manifested as learning difficulty and hypertension in adult males) (1).
Manganese is a naturally-occurring element. Small amounts of manganese are an essential part ofthe human diet (12). It may be mixed with iron to make various types of steel. Some manganesecompounds are used in the production of batteries, and as a component of some ceramics, pesticides,fertilizers, and nutritional supplements (12).
Manganese was detected in on-site soil (greater than 2' in depth), surface water and sedimentsaround the lagoons, and off-site soil (0' to 2' in depth) and groundwater. A future potential exposurepathway was identified for manganese. People could be exposed to manganese by ingestion,inhalation, or through dermal contact with contaminated media. However, no known exposureshave occurred or are occurring.
Workers exposed to high levels of manganese dust on other hazardous waste sites have developedmental and emotional disturbances. Additionally, their body movements became slow and clumsy (12).
Nickel is a metal found naturally in the form of various minerals. It has been shown to be essentialfor normal growth and reproduction in some animals; small amounts may also be essential inhumans (13). It is used primarily in making various steels and alloys, and in electroplating. It isalso used in ceramics, permanent magnet materials, and nickel-cadmium batteries (13).
Nickel was detected in on-site soil (greater than 2' in depth), lagoon wastes and groundwater, andin off-site soil (0' to 2' in depth) and sediments. A potential exposure pathway was identified fornickel. Exposures to nickel may occur in the future through ingestion, inhalation, and throughdermal contact with the contaminated media; however, no exposures are occurring at this time.
Occupational exposure to nickel refinery dust has been associated with increased risks of lung andnasal cancer, and possibly cancer of the larynx. However, the ingestion of nickel does not appearto be associated with an increased risk of cancer (13).
NDPA occurs as an impurity in several common products such as weed killers and certain rubberitems. People may be exposed to NDPA by eating foods treated with nitrite preservatives such ascheeses and cured meats, by drinking certain alcoholic beverages, or by exposure to tobacco smoke (14).
NDPA was detected in on-site soil (greater than 2' in depth). A potential exposure pathway has beenidentified for NDPA. Exposures to this compound could occur in the future, through ingestion, inhalation, or through dermal contact, if the site is developed. Currently, there are noknown routes of exposure to this contaminant.
In animal studies, exposure to high levels of NDPA in food or drinking water led to liver diseaseand death. It also led to an increased rate of cancer of the liver, esophagus, and nasal cavities. Other than the risk of cancer, chronic oral toxicity data are inadequate for humans and animals tobe definitive. ATSDR has set an acute oral MRL of 0.095 mg/kg/day (14).
Polychlorinated Biphenyls (PCBs)
PCBs have been widely used as coolants and lubricants in transformers, capacitors, and otherelectrical equipment. They are a family of man-made chemicals that contain 209 individualcompounds of varying toxicities. Aroclor is a common trade name for various PCB mixtures. Since1974, all uses of PCB's have been confined to closed systems. PCB's have not been manufacturedin the United States since 1977. However, PCB's still persist in the environment and humanexposures still occur (usually as a result of a spill from older transformers and capacitors that arestill in use) (15).
PCBs (Arochlor 1254) was detected in on-site soil samples (0' to 2' and greater than 2' in depth). Currently, there are no known routes of exposure to this contaminant at the GSST site. In the future,exposures could occur through ingestion, inhalation, or through dermal contact with PCBs, if the site is developed.
In animal studies, some PCB mixtures have produced adverse health effects that include liverdamage, skin irritations, reproductive and developmental effects, and cancer. Human studies showthat skin irritations, such as acne-like lesions and rashes, can occur in PCB-exposed workers. Occupational studies involve workers who have been exposed to amounts of PCBs far in excess ofthe normal population (15).
Zinc compounds are found naturally in the air, soil, water, and food. It is an essential element andis needed by the human body in low doses (16). Its uses include galvanized coatings, alloys,negative electrodes in alkaline batteries, paints, paper defoxing, and the vulcanization of rubber. Large amounts are used in fertilizers and it is also found in certain pharmaceuticals including insulin (16).
Zinc was detected in on-site groundwater. A potential exposure pathway was identified for zinc. Exposure to zinc may occur in the future through ingestion, inhalation, or through dermal contactwith the contaminated media.
The major effects of eating food or drinking water that contains too much zinc, or taking too manyzinc supplements, are digestive problems. Stomach cramps, nausea, and vomiting have resultedfrom taking 2 or 3 capsules (each containing 220 mg zinc sulfate or 50 mg zinc) each day. Higherdoses resulted in more serious problems including alterations in the body's immune system (16). We do not expect any of these results from the levels of zinc found at this site.
No completed exposure pathways are known to exist for the GSST site; therefore, no evaluation ofhealth outcome data can be done at this time.
In 1990, local residents were concerned about the potential of their drinking water to becomecontaminated. These residents signed a petition requesting that the town of Simpsonville providethem with municipal water. The Greenville County supervisor for drinking water reports that mostof the homes in that area are now supplied with municipal water.
Concerned citizens also reported two deaths caused by cancer. Project staff gathered informationfrom SCDHEC Vital Statistics and found that the deceased were males. One individual died of lungcancer, the other individual died from a non-specified lymphoma. We could not access additionalmedical history on these individuals. Residents have not identified additional cases of cancer, norhave they raised any new concerns.