PUBLIC HEALTH ASSESSMENT
LEONARD CHEMICAL COMPANY INC.
CATAWBA, YORK COUNTY, SOUTH CAROLINA
Data in this section are from the 1992 Remedial Investigation report. This represents the latestinformation for this site.
The tables in this section list the contaminants of concern. We evaluate these contaminants inthe subsequent sections of this public health assessment and determine whether exposure to themhas public health significance. SCDHEC and ATSDR select and discuss these contaminantsbased upon the 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, thelisted contaminant does not mean that it will cause adverse health effects from exposures. Instead, the list indicates which contaminants will be evaluated further in the public healthassessment.
|= 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 specificmedia that are used to select contaminants for further evaluation. These values include EMEGs,CREGs, and other relevant guidelines. CREGs are estimated contaminant concentrations basedon a one excess cancer in a million persons exposed over a lifetime. CREGs are calculated fromEPA's cancer slope factors. EPA's MCLG is a drinking water health goal. EPA believes that theMCLG represents a level at which "no known or anticipated adverse effect on human healthoccurs which allows an adequate margin of safety." PMCLGs are MCLGs that are beingproposed. MCLs represent contaminant concentrations that EPA deems protective of publichealth (considering the availability and economics of water treatment technology) over a lifetime(70 years) at an exposure rate of 2 liters of water per day. While MCLs are regulatoryconcentrations, PMCLGs and MCLGs are not. EPA's RfD is an estimate of the daily exposureto a contaminant that is unlikely to cause adverse health effects. RMEGs are media-specificcomparison values derived from EPA RfDs and are used to select contaminants of concern at hazardous waste sites.
Various metals (e.g. aluminum, arsenic, iron, manganese, nickel, cobalt, copper, and vanadium)were detected in soil, groundwater, and surface water at the LCC site. The presence of thesemetals in the different media may be similar to the background levels of these metals commonlyfound in this area.
Toxic Chemical Release Inventory (TRI)
TRI is developed by the EPA from chemical release information provided by certain industries. The chemical release information is based on contaminants found in air, surface water,groundwater, or soil.
Project staff conducted a search of the TRI for the site and local area for the years 1988, 1989,and 1990. The search included a 1-mile radius around the site. As the site was not active inthese years, no listing was found. TRI located one other facility, the Georgia-PacificCorporation Catawba Hardboard, within a 1-mile radius of the site. Available data cannot linkreleases from this company to contaminants detected in media on or near the LCC site.
An initial survey of on-site soils was conducted to help define the extent of soil contamination,to assess the background soil quality, and to identify possible contaminant sources. Thelocations of the soil samples are presented in Figure 4. Sampling focused primarily on three on-site areas: the truck turn-around/process area, the former landfill area, and the storage area. Agrid system consisting of 14 north-south trending lines and 12 east-west trending lines with 50-foot spacings was laid out across the site (Figure 3). The results of this field soil screening werelater used to assist in finalizing site and background monitoring well locations and subsequent soil borings.
The soils on the site consist of fill, alluvial, and residual soils. Fill soils are those that have beenreworked or disturbed and deposited by unnatural means. Alluvial soils are those commonlylocated in flood plains and formed by erosion and deposition caused by the stream or river. Residual soils are formed by mechanical and chemical weathering. The fill soils on the site arerestricted to the truck turn-around area; where the fill soil was probably used to facilitate trucktraffic. Below the fill soils of the truck turn-around area and along Ferry Branch creek there arealluvial soils. The alluvial soils range in depth from 0 to 10 feet thick. The primary soils on thesite are residual soils; these ranged from 0 to an approximate 65 feet thick. Residual soils areweathered gradually and transitioned into partially weathered rock (PWR) then to the bedrock(deep) aquifer. The depth of the bedrock varies from approximately 45 feet below surface in the southeastern portion of the site to over 100 feetbelow the surface in the western portion of the site.
Soil contamination is predominately restricted to the three operational areas. Contaminantsdetected in these areas include volatile compounds, semi-volatile compounds, metals, PCBs andpesticides. Beyond the limits of these operational areas, little degradation of soils has occurred. In general, the highest concentration of contaminants were detected in the truck turn-aroundarea. Remnants of drums were found buried in this area during the RI, suggesting that disposalof materials had occurred in this area. This area is topographically the lowest area on the siteand the depth to groundwater is approximately 10 feet.
The area of the former landfill is topographically lower than the storage area. It was loweredthrough excavations that occurred as a result of preliminary remedial actions in 1983. Thecontamination in this area appears to be concentrated between 0 to 5 feet below the groundsurface and decreases with depth.
Two background samples (A2-00 and A2-03) were collected from one on-site location near theentrance of the site (Figure 4). These samples were analyzed to determine the typicalconcentrations of metals at the site. The RI reports that all metals detected at the site are withinlevels expected in soils in the eastern United States.
Data collected for soil samples are reported in this public health assessment under three tables. Table 2 presents contaminants for Surface Soil (0 to 3 inches), Table 3 presents contaminants forSubsurface Soil (greater than 3 inches to 2 feet), and Table 4 presents contaminants for Subsurface Soil (greater than 2 feet).
- Surface Soil
Nine soil samples meeting ATSDR's definition of surface soil (0" - 3") were collected at variouson-site locations on September 12, 1991 (Figure 4). These samples were collected to furtherdefine the areal extent of contamination on the site. Contaminants identified as being of concernfor this media are presented in Table 2.
Mercury and vanadium were detected at levels lower than background concentrations. Thebackground concentration for mercury was 0.31 ppm and vanadium was 184 ppm.Polychlorinated biphenyls (PCBs), arsenic, and beryllium were also detected in on-site soil and found to exceed the comparison values.
Range - ppm
|Aroclor 1254 (PCBs)||ND - 0.3||D3.5-00||0.09||CREG|
|Aroclor 1260 (PCBs)||ND - 2.8||I.56-00||0.09||CREG|
|Arsenic||1.2 - 1.5||H.52-00||0.4||CREG|
|Beryllium||0.15 JN - 0.73 JN||G5.5-00||0.2||CREG|
|Cobalt||5.8 J - 21.6||B7.5-00||No Value|
|Dimethyl phthalate||ND - 5.7||I.56-00||No Value|
|Iron||16,600 - 57,700||G5.5-00||No Value|
|Lead||11.2 - 757||D3.5-00||No Value|
|Mercury||ND - 0.22||I.56-00||No Value|
|Nickel||2.1 J - 9.8||I.56-00||No Value|
|Vanadium||28.2 - 164||G5.5-00||No Value|
J = Estimated value
JN = Presumptive evidence of presence of material
ND = Not detected
Subsurface soil samples were collected and analyzed to better define the areal and vertical extentof contamination. These samples were collected during the summer of 1991 and were presented in the 1992 RI report.
Beryllium, mercury, and vanadium were detected at levels lower than backgroundconcentrations. The background concentration for beryllium was estimated at 0.7 ppm, mercurywas 0.31 ppm, and vanadium was 184 ppm.
Range - ppm
|Aluminum||7,120 - 19,800||E4-1||No Value|
|Antimony||ND - 850 N||J7-015||20||RMEG-Child|
|Aroclor 1260 (PCBs)||ND - 33||B6-05||0.09||CREG|
|Arsenic||0.68 JN - 1.6 JN||B6-05||0.4||CREG|
|Beryllium||0.11 J - 0.58 J||E2-05||0.2||CREG|
|Bis(2-Ethylhexyl)Phthalate||ND - 720||J7-015||50||CREG|
|Butyl-Benzyl-Phthalate **||ND - 66||B6-05||1000||RMEG-Child|
|Cadmium||ND - 96||J7-015||10||EMEG-Child|
|Chromium||35.5 - 788||I7-05||300||RMEG-Child|
|Cobalt||5.6 B - 35.7||I7-05||No Value|
|4,4-DDT||ND - 2.1||J7-015||2||CREG|
|1,2-Dichlorobenzene **||ND - 210||B6-05||5000||RMEG-Child|
|Dimethyl phthalate||ND - 490||J7-015||No Value|
|Lead||9.9 - 4,280||01-05||No Value|
|Manganese||29.8 - 835||E2-05||300||RMEG-Child|
|Mercury||ND - 0.3||B6-05||No Value|
|Methyl Ethyl Ketone||ND - 4,800||J7-015||No Value|
|Naphthalene||ND - 44J||J7-015||No Value|
|Nickel||3.9 J - 938||J7-015||No Value|
|Tetrachloroethene||0.006 J - 7,700||J7-015||10||CREG|
|Toluene||0.006 - 22,000||J7-015||10,000||RMEG-Child|
|1,1,1-Trichloroethane||ND - 380 J||J7-015||No Value|
|1,1,2-Trichloroethane||ND - 7,600||J7-015||10||CREG|
|Trichloroethene||ND - 6,700||J7-015||60||CREG|
|Vanadium||43.3 - 85.2||E2-05||No Value|
** = Selected due to cancer classification
J = Estimated value
JN = Presumptive evidence of presence of material; estimated value
N = Presumptive evidence of presence of material
ND = Not detected
Subsurface soil samples were collected at depths greater than two feet; however, the PathwaysAnalyses section of this public health assessment has eliminated contaminants in subsurface soilat depths greater than 2 feet as a public health concern at this time. Contaminants detected insubsurface soil greater than two feet are listed in Appendix B.
The groundwater investigation conducted during the RI was intended to determine the horizontaland vertical extent of contamination in groundwater, to determine the hydraulic relationshipbetween the saprolite (shallow) and the bedrock (deep) aquifers, to establish groundwater flowpatterns, and to establish background levels of inorganic compounds.
Groundwater - Monitoring Wells
Eleven on-site groundwater monitoring wells were installed during the 1992 RemedialInvestigation (Figure 5). Seven of these wells were constructed in the shallow aquifer and fivewere constructed in the deep aquifer. The shallow monitoring wells were advanced in soil sothat the bottom of the well screens were located five feet below the water table. The deep wellswere installed in bedrock. Hydraulic testing was conducted after the installation of themonitoring wells to evaluate the hydraulic characteristics of the shallow and deep aquifersbeneath the site. Contaminants identified as being of concern are in Table 5.
SCDHEC installed five shallow monitoring wells on the site in 1983. These consisted ofmonitoring wells (MW) 4, 5, 6, 7, and 8. Monitoring wells 4 and 5 were sampled as part of theRI. Monitoring wells 1A, 2, 3, and 7 were not sampled due to questionable constructionmethods. MW-4 was sampled, however, the results of this sampling are questionable due tounknown construction methods and well integrity. Monitoring wells 6 and 8 were not sampledas part of the RI because their locations are relative to the locations of the monitoring wellsinstalled during the RI and were not considered to provide useful groundwater data needed for the RI.
Groundwater contamination is associated primarily with volatile organic compounds (VOCs)detected in the shallow and deep aquifers. The shallow groundwater plume has been identified. The extent of the bedrock groundwater plume has been determined for the northern, western,and eastern sides. The southern limit of the bedrock aquifer contaminant plume has not beenfully determined. The vertical extent of groundwater impact has not been defined to date.
LCC is located in the Piedmont Physiographic Province of north-central South Carolina. Thesite is underlain by 20-40 feet of weathered rock called saprolite that is formed from the physicaland chemical weathering of the underlying metamorphic rock. This rock type is a medium grademetamorphic rock with a high mica content. The outcrops of these rocks near the site trendnortheasterly and the dip is nearly vertical. The geologic and topographic structure of thebedrock (deep aquifer) are the dominant factors that control the movement and occurrence ofgroundwater in the Piedmont Physiographic Province. Groundwater in the area occurs withinthe joints, fractures, and faults of the crystalline rocks and in the pore spaces of the overlying,unconsolidated residual and alluvial soil deposits. Groundwater flow at the site is primarilytoward Ferry Branch creek. The depth to groundwater on the site is approximately 15 to 35 feetin the western area of the site to approximately 5 feet adjacent to Ferry Branch creek.
Groundwater - Temporary Wells
One temporary monitoring well, designated as TW-4, was installed on the LCC site (Figure 6). TW-4 is located upgradient of monitoring well MW-4. This location was chosen to determinethe presence or absence of vinyl chloride in the shallow aquifer. Three additional temporarywells were constructed off-site. All temporary wells were properly sealed in accordance withstate guidelines after sampling.
The 1992 RI reports that vinyl chloride was detected at 4,390 ppb at temporary monitoring well TW-4. An EMEG (Child) of 0.2 ppb has been established for vinyl chloride.
Range - ppb
|Acetone||ND - 27,000||MW7A||2000||EMEG-Child|
|Aluminum||536 - 27,200||MW11||No Value|
|Arsenic||ND - 13.2||MW07A||0.02||CREG|
|Beryllium||ND - 1.57||MW11||0.008||CREG|
|Bis(2-Ethylhexyl)Phthalate||ND - 17||MW10D||3||CREG|
|Cadmium||ND - 5.99||MW07A||2||EMEG-Child|
|Cobalt||ND - 41.20 J||MW09||No Value|
|1,2-Dichloroethane||ND - 810||MW04||0.4||CREG|
|1,1-Dichloroethene||ND - 710||MW04||90||EMEG-Child|
|Iron||ND - 83,000||MW-07A||No Value|
|Isophorone||ND - 21||MW07A||9||CREG|
|Lead||ND - 9.25||MW07A||50||MCL|
|Manganese||4.28 J - 8920||MW07A||50||RMEG-Child|
|Methyl-Iso-Butyl-Ketone||ND - 13,000||MW07A||No Value|
|Methylene Chloride||ND - 12,000||MW09||600||EMEG-Child|
|Naphthalene||ND - 29||MW05||20||LTHA|
|Tetrachloroethene||ND - 11,000||MW04||0.7||CREG|
|Toluene||ND - 18,000||MW07A||2000||RMEG-Child|
|1,1,1-Trichloroethane||ND - 1300||MW04||200||LTHA|
|1,1,2-Trichloroethane||ND - 9800||MW04||0.6||CREG|
|Trichloroethene||ND - 2400||MW09||3||CREG|
|Vanadium||2.68 J - 42.4 J||MW11D||20||LTHA|
|Vinyl Chloride||ND - 2700||MW04||0.2||EMEG-Child|
J = Estimated value
ND = Not detected
On-Site Surface Water and Sediments
Surface water drainage on the site trends generally toward the east and southeast toward FerryBranch creek. Drainage also occurs at the former landfill area and trends east and drains intoFerry Branch. Ferry Branch flows east and southeast and meets the Catawba River,approximately 2.4 miles downstream from the site.
The waters of Ferry Branch and the Catawba River are classified as being suitable for secondaryrecreation and being suitable as a source for drinking water supply after conventional treatmentin accordance with SCDHEC requirements. These waters are also suitable for the propagationof fish and for industrial and agricultural purposes.Surface water and sediment samples (SW/SS) were collected from Ferry Branch at threelocations during the RI (Figure 7). The purpose of these samples was to help determine thepresence or absence of contamination in Ferry Branch creek and to compare the quality ofsurface water and sediments migrating onto and off the site.
Samples collected from SW/SS-01 were intended to provide background information of thestream quality upgradient of the site. Samples from SW/SS-03 provided data of the streamquality prior to leaving the site area. SW/SS-01 and SW/SS-03 data will be discussed in theOff-site Surface Water and Sediments section of this public health assessment.
The samples collected from SW/SS-02 will be considered as on-site samples in this public healthassessment. These samples were collected from stream locations in the northern portion of thesite. Data from these samples generally provide information about surface water and sedimentquality in the stream as it enters the site. No contaminants were detected above comparisonvalues at this location.
Air monitoring was performed during all phases of the field activities. The purpose of the airmonitoring was to protect the site workers from adverse conditions during various activities. Airmonitoring data were not included in the RI report and are not available for review. This publichealth assessment recommends that air monitoring continue during on-site remedial activitiesand that data be provided for review.
No off-site soil samples were collected during the Remedial Investigation. This public healthassessment recommends that off-site soil be sampled to better characterize the extent of site-related soil contamination, if any, from the LCC site.
Groundwater - Monitoring Wells
Nine off-site monitoring wells (Monitoring wells 13, 13D, 14, 15, 16, 17, 17D, 18, and 18D)were installed during the Remedial Investigation. Six of these wells were constructed as shallowwells and three were was constructed as a deep monitoring well (Figure 5). Five of thesemonitoring wells (Monitoring wells 13, 13D, 14, 15, and 16) were consideredbackground/upgradient monitoring wells and were sampled to provide an indication of the background concentrations of site constituents.
Range - ppb
|Aluminum **||ND - 12,700||MW13||No Value|
|Arsenic||ND - 0.94 J||MW18D||0.02||CREG|
|Beryllium **||ND - 2.33 J||MW16||0.008||CREG|
|Bis(2-Ethylhexyl)Phthalate**||ND - 10J||MW15||3||EMEG|
|Cadmium||3.1B - 3.73 J||MW18D||2||CREG|
|Cobalt **||ND - 7.09||MW13||No Value|
|Iron **||223 - 19,400||MW13||No Value|
|Lead||2.72 J - 15||MW18||No Value|
|Manganese **||59.1 - 318||MW14||50||RMEG-Child|
|Tetrachloroethene||ND - 21||MW17D||0.7||CREG|
|Trichloroethene||ND - 3 J||MW17D||3||CREG|
|Vanadium||2.30 J - 60.1||MW13||20||LTHA|
** = These samples are considered to be background levels
J = Estimated value
ND = Not detected
Bis(2-ethylhexyl)phthalate was reported at an estimated value in monitoring well 15. The RIstates that this is a common laboratory artifact and could be in this case as the monitoring welladjacent to MW-15 did not detect this compound. Additionally, aluminum, beryllium, cobalt,and manganese were detected in the background wells at levels of concern. Contaminantsidentified as being of concern for this media are presented in Table 6.
Groundwater - Temporary Wells
Three temporary wells (TW-1, TW-2, and TW-3) were installed south of the site to better definethe placement of monitoring well pair MW-17/MW-17D (Figure 6). Samples collected fromthese wells on May 5, 1992 were analyzed for 32 volatile organic compounds. However, no contaminants were detected above comparison values.
Groundwater - Private Wells
Private drinking water wells used by residents living near the site were not sampled during theRI. However, SCDHEC sampling in the area prior to the RI showed that private water drinkingwells were not impacted by contaminants from the site. However, more recent sampling data isneeded to determine the quality of potable water used from private wells near the site.
Off-site Surface Water and Sediments
Surface water and sediment samples were collected from Ferry Branch in three locations (Figure7). Surface Water/Sediment (SW/SS) location 01 provided information about the upstreamquality of the surface water; SW/SS-02 represented the quality as it entered the site; and SW/SS-03 indicated the quality of the surface water as the creek leaves the site. The purpose of thesesamples was to help determine the presence or absence of contamination in Ferry Branch.
Contaminants identified in off-site surface water and sediment samples are presented in Tables 7and 8 respectively. Aluminum was detected at the highest concentration in the downgradientsurface water sample from SW-03, it was also detected upstream and in the on-site location.Cobalt, copper, and vanadium were detected in sediment samples upgradient from the site(SS01). Cobalt was also detected in downstream locations. Copper was detected in allsediment samples, with the highest concentration being found in the upstream location. Vanadium was found in all sediment sample locations.
Bis(2-ethylhexyl)phthalate, 1,2-dichloroethene, iron, methyl-iso-butyl-ketone, tetrachloroethene,and trichloroethene were detected in surface water samples downgradient from the site (SW03). These chemicals were only found in the downstream location (SW-03).
1,2-Dichloroethene, methyl-iso-butyl-ketone, and trichloroethene were detected at estimatedvalues. Toluene was also detected at an estimated concentration that did not exceed thecomparison value. These compounds were detected in on-site groundwater. This public health assessment recommends additional sampling in order to better characterize the extent, ifany, of site-related contaminants migrating to the creek.
Range - ppb
|Aluminum||170 J - 245||SW03||No Value|
|Bis(2-Ethylhexyl)Phthalate||ND - 29||SW03||3||CREG|
|1,2-Dichloroethene||ND - 2 J||SW03||0.4||CREG|
|Iron||564 - 616||SW03||No Value|
|Methyl-Iso-Butyl-Ketone||ND - 10 J||SW03||No Value|
|Tetrachloroethene||ND - 7||SW03||0.7||CREG|
|Trichloroethene||ND - 3 J||SW03||3||CREG|
J = Estimated value (organic chemicals) ND = Not detected
Range - ppm
|Cobalt||ND - 0.95 J||SD01||No Value|
|Copper||1.5 J - 2.3 J||SD03||No Value|
|Vanadium||0.82 J - 3.95 J||SD01||No Value|
J = Estimated value
ND = Not detected
In June 1992, Aquaterra, Inc. released the results of a soil gas survey they conducted for theLeonard site. The soil gas survey was conducted to provide information about the horizontalextent that groundwater may have been impacted by volatile organic compounds due to pastactivities at the site. It was also intended to aid in the delineation of the contaminant plume inorder to determine the necessity and locations of additional monitoring wells. The survey wasperformed east across Ferry Branch and in the northern area of the site (Figure 8).
The samples were analyzed for volatile organic compounds. Preliminary results showed thepresence of aromatic hydrocarbon compounds. The RI report suggests that this may indicatethat the contaminant plume may have migrated south of the site along Ferry Branch.
The results of the soil gas survey prompted the placing of MW-18, 18D, and 19. Monitoringwells 17 and 17D were located south of the site based on the soil gas survey and analyticalresults from groundwater grab samples collected from temporary shallow monitoring wells.
Aquaterra, Inc. concluded that "the contaminant plume in Area A may have migrated alongFerry Branch creek to the southern extent of the survey area (approximately 800 feet)." This isconsistent with the site topography and flow direction at the site.
The data in this section are from the 1992 Remedial Investigation report. Thus, this reportcontains the latest information for this site. Quality Control and Quality Assurance (QA/QC)conclusions drawn for this public health assessment are determined by the validity of theanalysis and conclusions made and the availability and reliability of the referenced information. SCDHEC assumes that adequate quality assurance and quality control measures were followedwith regard to chain-of-custody, laboratory procedures, and data reporting.
Overall, the data appears to be reliable. All data have undergone a laboratory quality assurancereview. The following describes inconsistencies noted in the RI pertaining to groundwatersamples at the LCC site.
The RI states that monitoring well MW-10D was resampled due to a high pH measured duringinitial sampling. Resampling of the well provided data coinciding with previous samplingresults. However, methylene chloride and carbon disulfide were detected in the new samples butwere not detected previously.
The RI states that problems arose while drilling the boreholes for monitoring wells 7D and 10D,from soil caving into the drilling. To prevent this, drilling mud was used to replace water as thecirculating fluid.
The RI states that monitoring well MW-13 was constructed using stainless steel instead of PVCas were the other wells. This was done so that MW-13 would serve as a control well to providea means for evaluating the effects that PVC may have on groundwater samples.
SCDHEC installed five shallow monitoring wells on the site in 1983. Of the wells installed bySCDHEC, only monitoring wells MW-4 and MW-5 were sampled during the RI. The RI statesthat the other wells were not samples due to questionable construction methods or due to theirrelative location to newer wells. The RI also states that data results from monitoring well MW-4are questionable because the construction methods used for this well are unknown and the integrity of the well is questionable.
Acetone and methylene chloride were detected in groundwater samples and were shown inQA/QC samples to be laboratory artifacts. However, acetone was stored on-site for many yearsand possible health effects from exposure to this compound will be evaluated later in this publichealth assessment. Acetone and bis(2-ethylhexyl)phthalate were detected at concentrations of 12parts per billion (ppb) and 29 ppb respectively in surface water samples. These compounds werenot detected in the primary sample and are both common laboratory artifacts; however,additional sampling is needed for this media. Bis(2-ethylhexyl)phthalate was also detected inon-site in other on-site media.
The LCC property is highly vegetated with brush, hardwoods, and pines. During the 1993 sitevisit, project staff noted that access roads had been cleared throughout the site. Informationgathered after the site visit indicated that these roads had been cleared during the RemedialInvestigation. Project staff visited the site following a weekend of severe weather consisting ofsnow and cold temperatures. Project staff noted several downed trees and limbs on the site.
The site contains various industrial equipment, old refrigerator/freezers, the remains of an oldautomobile, metallic sheds housing student desks, and a variety of other debris. Project staffalso noted approximately 100 fiber drums on wood pallets on the site. Some of these drumswere covered by tarps; uncovered drums are in a deteriorated condition. Project staff noted alarge tarp, approximately 25' x 25', covering unknown materials located adjacent to the on-sitegenerator. The preceding conditions pose a physical hazard to people who may wander onto thesite and to on-site workers.
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 exposedpopulation.
ATSDR categorizes an exposure pathway as a completed or potential exposure pathway if theexposure pathway cannot be eliminated. Completed pathways have all five elements andindicate that exposure to a contaminant has occurred in the past, is currently occurring, or willoccur in the future. Potential pathways, however, have at least one of the five elements missing,but could become completed. Potential pathways indicate that exposure to a contaminant couldhave occurred in the past, could be occurring now, or could occur in the future. An exposurepathway can be eliminated if at least one of the five elements is missing and will never bepresent. No completed exposure pathways were identified for the LCC site; however, Table 9identifies the potential exposure pathways. The discussion that follows incorporates only thosepathways that are important and relevant to the site. We also discuss some of those exposurepathways that have been eliminated.
Because we could not define a receptor population, we do not believe that exposure is occurring. Therefore, no completed exposure pathways exist at the Leonard site.
|Exposure Pathway Elements||Time|
At the LCC site, contaminants may have migrated or may migrate in the future from the formeroperations areas. Contamination detected during the RI may have originated from spills fromprevious operations and/or leaking drums or containers that were deposited in these areas. Contaminants identified in surface soils are considered to be of concern because they represent themost likely route of human exposures to site-related contaminants. Exposures could occurthrough direct contact with the soil. Contamination was also found in subsurface soils. Thesecontaminants could migrate into groundwater through leaching and could subsequently betransported in groundwater. Contaminants were also detected in groundwater, surface water andsediments. In this section, we will discuss the potential for human exposures to contaminantsfound in these media.
Past, current, and future exposures to contaminated soil may have resulted at the LCC site. Whilethe future development of the site could lead to exposure pathways in the future, we believe thatonly on-site areas represent likely points of exposure.
In the past, exposure to contaminants at the LCC site could have occurred to anyone who mayhave wandered onto the site or to on-site workers. Mr. Leonard stated that at different times hemay have had as many as 12 on-site workers. Mr. Leonard stated these employees woreprotective clothing; however, we have no documentation to indicate what type of dermal orrespiratory protective equipment was used by these employees. No data are available about thepossible exposures and/or length of exposures; therefore, adverse health effects from pastexposures to on-site soils cannot be evaluated. The routes of exposure could have occurredthrough dermal contact with, ingestion of, or inhalation of soil particles.
Currently, contaminants of concern have been detected in surface and subsurface soil at the LCCsite. Exposure to contaminants at the LCC site could be occurring. The site is restricted by afence and the site is not easily assessable; therefore, the possibility of people wandering onto thesite is considered minimal. The current routes of human exposure include ingestion or dermalcontact with contaminated soil.
On-site subsurface soil samples (greater than 2' in depth) were collected and analyzed during theRI. As the site is not active, the potential for human exposures to soils at a depth greater thantwo feet are considered unlikely. Therefore, this public health assessment eliminates this exposurepathway at this time. Should the area be excavated in the future, this pathway will be reevaluated.
In the future, potential exposure pathways could become completed if the site is developed. However, due to the nature of the site topography and the location of the site, this pathway isconsidered unlikely.
No data are available for review concerning off-site soil; therefore, exposure pathways from thismedia cannot be further evaluated. This Public Health Assessment recommends that off-site soilsamples be collected and analyzed to better characterize the extent of contamination in off-sitesoil.
Chemicals present in soils at the LCC site may leach into groundwater. Infiltration andprecipitation will aid in leaching the contaminants from soil and transporting them into thegroundwater. Once in the groundwater, contaminants are transported in the direction ofgroundwater flow, but at a slower rate than groundwater. The groundwater flow at the LCC siteis toward the south and southeast into Ferry Branch creek. This creek outflows into the Catawba River.
Past, current, and future exposure pathways may result from contamination of groundwater atseveral points of exposure: undeveloped areas, Ferry Branch creek, and the site. While severalpoints of exposure could occur in the future, we believe that only undeveloped areas representlikely points of exposure. Exposures could occur to anyone who installs a private drinking wellon the site or in the area of groundwater contamination. These exposures would include ingestionor inhalation of groundwater, or dermal contact. Some chemicals present in groundwater couldvolatilize, resulting in inhalation exposure.
The RI concludes that the fracture orientation of the bedrock aquifer appears favorable in that thearea to the south and east (downgradient) of the site do not appear to have any residentialreceptors. Off-site groundwater sampling consisted of shallow and deep aquifer samples collectedby the site entrance that were considered to be background samples. Other sampling locationsincluded samples collected from MW-17 and 17D, approximately 390 feet southeast of the site,toward the groundwater flow path; and samples collected from MW-18 and 18D, approximately180 feet east of the site boundary. No contaminants were detected east of the site; contaminantswere detected to the southeast of the site. Additional groundwater samples should be collectedfrom areas further downgradient of the site toward the groundwater flow path to better define thecontaminant migration.
The RI also concludes that the potential for contamination to residential wells to the north andwest of the site appear low since the potential receptors are hydraulically upgradient from the site. However, the community is concerned about the potential for their private drinking wells to becontaminated. Therefore, this public health assessment recommends that the private wells in thevicinity of the site be sampled to determine if site-related contaminants have migrated to these wells.
Of all the contaminants identified at the LCC site, the volatile organic compounds show morepotential for migration in the subsurface environment. However, the concentrations of somecontaminants would be expected to diminish over time and distance due to dilution, volatilization,and/or biodegradation.
Surface Water/Sediment Pathway
Surface water drainage on the LCC site is toward Ferry Branch creek. The creek is located eastof the site and could be affected by storm water runoff or by contaminants migrating from the siteand discharging into the creek.
During the RI three surface water and sediment sample locations were analyzed forcontamination. One of these locations was considered upgradient from the site, one at the site,and another downgradient from the site. These samples served as representations of contaminantsin Ferry Branch creek that were not site related and some that are site related. On-going samplingis needed as short-term sampling detects only what exists in these media at a particular time. Therecommended on-going sampling would provide information about the contaminant transport inthese media. Therefore, this public health assessment recommends that additional sampling beconducted of the surface water and sediment locations and that additional locations be sampledfor constituents of concern and to better characterize the extent of site-related contaminantsreaching Ferry Branch creek. Bis(2-ethylhexyl)phthalate, 1,2-dichloroethene, methyl-iso-butyl-ketone, tetrachloroethene, and trichloroethene were identified in the surface water samplescollected from the downstream location. Copper was detected in sediment samples collected from the downstream location.
Past, current, and future exposure pathways may result from exposures to contamination ofsurface water and sediment. Currently, there are no known routes of human exposure associatedwith surface water and sediments and no adverse health effects are anticipated. However, thispotential exposure pathway could become completed in the future. Anyone who ingests or hasskin contact with contaminated surface water and sediments may be exposed to the identifiedcontaminants.
During the RI, surface water and sediment samples were taken from one upstream location, oneon-site location, and one downstream location (Figure 7). The purpose of these samples was tohelp determine the presence or absence of contamination in Ferry Branch creek and to comparethe quality of surface water and sediments migrating onto and off the site.
Samples from the upstream location were intended to provide background information of thestream quality upgradient of the site. Downstream samples provided data of the stream qualityprior to leaving the site area. The samples collected from SW/SS-02 were considered as on-sitesamples in this public health assessment. No contaminants were detected above comparison values at the on-site location.
The LCC site as been closed for many years. The RI concludes that considering the number ofyears that the site has been closed and the temperatures around the site, volatile compounds arelikely to have already evaporated from surface soils. However, some of these contaminants havebeen detected in subsurface soils and if excavation occurs in these areas, some volatilization islikely to occur. Of the chemicals detected at the LCC site, the halogenated aliphatics are the mostlikely to volatilize.
While there are no known routes of human exposure to airborne contaminants, this potentialexposure pathway could become a completed exposure pathway if the site becomes developed inthe future. Contaminants found in soil may become airborne and migrate into the air duringexcavation. The soil at the LCC site is very moist and the possibility of soil becoming airborneduring excavations is highly reduced because of this moisture content. Soil could becomeairborne if the wind stirs the soil. In addition, the site is highly vegetative and the site topographyis not conducive to high winds. Therefore, this potential exposure 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 Minimal Risk Levels (MRLs) for contaminantscommonly found at hazardous waste sites. The MRL is an estimate of daily human exposure toa contaminant 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 (greaterthan 365 days). ATSDR presents these MRLs in Toxicological Profiles. These chemical-specific profiles provide information on health effects, environmental transport, humanexposure, and regulatory status.
Acetone is a clear colorless liquid with a distinct smell and sweetish taste that is found naturallyin the environment. It is also produced by industries. Acetone is mostly used to make otherchemicals; these chemicals are then used for making plastics, fibers, drugs, and pharmaceuticals. It is also used in fingernail polish removers.
This public health assessment identified a potential exposure pathway for acetone at the LCCsite. Human exposure to acetone may occur in the future if on-site groundwater contaminatedby acetone is ingested or comes into contact with skin.
ATSDR has established an intermediate oral MRL for acetone at 0.2 milligrams per kilogramper day (mg/kg/day). The MRL is based on the results from animal studies. The studiesconcluded that rats exposed to 200 mg/kg/day of acetone developed abnormalities in their blood. The MRL established by ATSDR does not imply that these effects will occur in humans who areexposed to acetone but, is designed to be protective of human health. Humans exposed to highlevels of acetone (2241 mg/kg/day) have experienced sore throat, coma, and diabetes-like symptoms.
Ingestion of on-site groundwater by children and adults would result in exposure to acetoneslightly above the MRL. However, the level of exposure children and adults would receive isconsiderably less than levels known to cause adverse health effects in humans or animals. Morestudies are needed to evaluate what health effects, if any, will occur in humans from exposure tolow levels of acetone.
Dermal exposure to acetone levels detected in groundwater on-site may result in skin irritation.
Arsenic is a naturally-occurring element in the earth's crust. Pure arsenic is a gray metal-likematerial, but this form is not common in the environment. Arsenic is usually found combinedwith other elements. Most arsenic compounds are white or colorless powders that do notevaporate. They have no smell, and most have no special taste. Thus, you usually cannot tell ifarsenic is present in food, water, or air. Arsenic is used as a preservative for wood and as apesticide.
Potential human exposure pathways have been identified for arsenic. Human exposure mayoccur in the future if on-site surface soil, on-site subsurface soil (greater than 3 inches to 2 feet),or on-site groundwater contaminated with arsenic are ingested or come into contact with skin.
ATSDR has not established an MRL for arsenic; however, EPA has established a reference dose(RfD) for arsenic at 0.0003 mg/kg/day. Ingestion of contaminated soil by children or adultswould not exceed the RfD. Children and adults who ingest on-site groundwater would be exposed to arsenic levels slightly above the RfD.
The levels associated with the LCC site are below levels known to cause adverse health effectsin humans. At much higher levels, the ingestion of arsenic by humans over many years(typically 10 years or more) has caused irritation of the gastrointestinal tract, affected the levelsof red and white blood cells, caused abnormal heart function, damaged blood-vessels, andimpaired nerve function. Long-term oral exposure to inorganic arsenic can also cause a patternof skin changes including the darkening of the skin and the appearance of small "corns" or"warts" on the palms, soles, and torso.
Arsenic is classified by the EPA as a known human carcinogen. A human carcinogen is achemical that has sufficient evidence from human epidemiological studies that it causes cancer. Humans that ingest arsenic at the LCC site for 10 years would develop a "low increased risk" ofdeveloping cancer.
Direct skin contact with arsenic compounds may cause the skin to become irritated with someredness and swelling. However, it does not appear that skin contact with arsenic is likely to leadto any serious internal effects.
Bis(2-ethylhexyl)phthalate, also known as di(2-ethylhexyl)phthalate or DEHP, is a liquid used tomake plastic more flexible. These plastics are used in a variety of consumer products such asimitation leather, rainwear, footwear, upholstery, flooring, tablecloths, shower curtains, foodpackaging materials, and children's toys. It is also used as a hydraulic fluid and as a dielectricfluid in electrical capacitors.
Potential exposure pathways were identified for DEHP at the LCC site. Human exposure mayoccur in the future if on-site soil and groundwater, or off-site groundwater and surface watercontaminated by DEHP is ingested or comes into contact with skin.
The EPA reference dose for DEHP is 0.02 mg/kg/day. Most of what is known about the healtheffects of DEHP comes from animal studies, especially studies in rats and mice. Because DEHPappears to affect rats and mice differently than it affects humans and other animals, it is difficultto predict health effects in humans using information from animal studies.
While human studies are not available, laboratory animals exposed to high doses of DEHP haveexperienced liver damage and male reproductive system damage. Reproduction in these animalswas affected and birth defects were more likely. However, none of these effects have beendocumented in humans. Human absorption of DEHP in the body is different from that of rodents. Therefore, many of the effects seen in animals after exposures to DEHP may not occurin humans.
DEHP is classified as a probable human carcinogen. A probable human carcinogen is a categoryfor which there is sufficient evidence of carcinogenicity in animals, but inadequate evidence orno data from human epidemiologic studies. DEHP has also been shown to cause an increasedincidence of cancer in rats and mice. Exposure to the levels of DEHP related to the LCC siterepresent an "insignificant risk" of cancer.
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 including metal plating, pigments, batteries, and plastics.
This public health assessment identified potential exposure pathways for cadmium. Thepathways may become completed in the future if humans ingest or have skin contact with on-sitesubsurface soil, groundwater, or off-site groundwater contaminated by cadmium.
ATSDR has established a chronic oral MRL for cadmium of 0.0002 mg/kg/day. Childreningesting contaminated groundwater would be exposed to a concentration that slightly exceedsthe MRL. If the site is excavated and children accidently ingest on-site subsurface soil, theywould incur an exposure level that would exceed the MRL.
Available studies do not indicate that adverse health effects occur in humans at levels ofcadmium detected at the LCC site. The MRL was established to be protective of kidney effectsin humans. There is strong evidence that suggests that the kidney is the target organ of cadmiumtoxicity following extended exposures to the compound. However, available studies indicatethat the effects occur only after extended exposure to cadmium at levels greater than those at theLCC site.
Human and animal studies do not represent adverse health effects associated with dermal exposure to cadmium.
1,2-Dichloroethane is a clear, man-made liquid that is not found naturally in the environment. Itevaporates at room temperature and has a pleasant smell and a sweet taste. 1,2-Dichloroethanewas formerly used as a component in cleaning solutions, pesticides, adhesives, paint, varnish,and finish removers. Today, it is mostly used to make other chemical products.
A potential pathway for 1,2-dichloroethane was identified. Human exposure could occur in the future if on-site groundwater is ingested or if it comes into contact with skin.
ATSDR has not developed an MRL and EPA has not developed a reference dose for 1,2-dichloroethane. Health effects in animals were noted at levels far greater than the levels foundin on-site groundwater.
EPA has classified 1,2-dichloroethane as a probable human carcinogen. A probable humancarcinogen categorizes chemicals for which there is sufficient evidence of carcinogenicity inanimals, but inadequate evidence or no data from available human studies. Human ingestion ofon-site groundwater contaminated by 1,2-dichloroethane would represent a "low increased risk"of developing cancer.
Dermal exposure to 1,2-dichloroethane in on-site groundwater is not anticipated to result in adverse health effects.
Iron is an essential metal in the human diet. The Recommended Daily Allowance (RDA) foriron is 10 to 15 mg/day. However, excess iron in the diet may result in adverse health effects. Ingestion of large doses of iron may cause vomiting, liver damage, and renal failure. Excessiveiron in the diet over time may lead to the accumulation of iron in the liver, disturbance of liverfunction, and even cardiovascular effects (Klaassen 1986).
This public health assessment identified potential exposure pathways for iron. Human exposuresmay occur in the future if on-site surface soil, on-site groundwater, off-site groundwater, or off-site surface water is ingested or comes into contact with skin.
Human ingestion of on-site groundwater would result in exposure to iron above the RDA. However, the levels of iron in on-site groundwater are below levels known to cause mild ironpoisoning in children and adults. However, some individuals may be genetically sensitive toiron (e.g., Wilson's disease). Individuals should consult their physician before ingesting highlevels of iron.
Isophorone is a clear liquid with a peppermint-like odor. It is a man-made chemical, also foundnaturally in cranberries. It is used as a solvent in some printing inks, industrial paints, lacquers,and adhesives.
This public health assessment identified a potential exposure pathway for isophorone. Humanexposure may occur in the future if on-site groundwater contaminated by isophorone is ingestedor if it comes into contact with skin.
ATSDR has established a chronic oral MRL of 0.2 mg/kg/day and an intermediate oral MRL of3 mg/kg/day. Human ingestion of on-site groundwater contaminated by isophorone wouldexceed the chronic oral MRL but not the intermediate MRL. The chronic MRL is based on ananimal study where high doses (250 mg/kg/day) of isophorone affected the kidneys in mice. While no evidence suggests that these effects will occur in humans, the MRL is designed toprotect against them. The levels of isophorone in groundwater are significantly less than thelevels used in the animal study.
It is not known whether isophorone causes cancer in humans. The EPA has classifiedisophorone as a possible human carcinogen. A possible human carcinogen is used to classifychemicals that have limited evidence from animal studies and no evidence from human studiesto cause cancer. Ingestion of on-site groundwater contaminated by isophorone would represent a"low increased risk" of developing cancer. However, additional studies are needed to characterize human health effects, if any, from exposure to low levels of isophorone.
Dermal exposure to isophorone is not expected to result in adverse health effects in humans.
Lead is a naturally-occurring element that be found in most environmental media. It has a widerange of uses including storage batteries (automobile batteries), solders, pipes, variouschemicals, and gasoline additives.
This public health assessment identified potential exposure pathways for lead. Human exposuremay occur in the future if on-site surface soil, on-site subsurface soil, on-site groundwater, oroff-site groundwater contaminated by lead are ingested or if they come into contact with skin.
Although lead may cause both acute and chronic effects, major concern has focused on theneurotoxicity of lead in children that may manifest itself as learning disorders. Lead toxicity inadults may contribute to hypertension, particularly in middle-aged males.
ATSDR has not set an MRL for lead. The EPA has not set a reference dose (Rfd) for lead. Although exposure to lead salts has been associated with an increased rate of cancer inlaboratory animals, EPA has not set an estimate of carcinogenic potency of lead.
Methylene chloride, also known as dichloromethane, is a colorless liquid that has a mild sweetodor and evaporates very quickly. It is widely used as an industrial solvent and as a paintstripper. It can also be found in certain aerosols and pesticide products and is used in themanufacture of photographic film. Methylene chloride does not appear to occur naturally in theenvironment.
This public health assessment identified a potential exposure pathway for methylene chloride. Human exposure may occur in the future if on-site groundwater contaminated by methylenechloride is ingested of if it comes into contact with skin.
ATSDR has established a chronic MRL of 0.06 mg/kg/day and EPA has established a referencedose of 0.06 mg/kg/day for methylene chloride. Human exposure to methylene chloride in on-site groundwater would exceed both the MRL and the reference dose. No human studies wereavailable regarding oral exposure to methylene chloride. Health effects in animals occurred atlevels higher than those detected at the LCC site. Therefore, human exposure to methylenechloride at the levels associated with the LCC site are not expected to result in adverse healtheffects. However, additional studies are needed to characterize human health effects, if any,from exposure to low levels of methylene chloride.
Dimethyl phthalate is a member of a chemical family group called phthalate esters. Thesesubstances are used commercially as solvents and as plasticizers. These chemicals have alsobeen used in varnishes, dopes, and in insecticides. They are also used in construction,automotive, household, apparel, toys, packaging, and medical products. Phthalate esters arefound at low concentrations in all environmental media (soil, water, etc.).
Potential pathways were identified for dimethyl phthalate. Human exposures to this chemicalmay occur in the future if on-site surface or on-site subsurface soil are ingested or comes intocontact with skin.
ATSDR has not developed an MRL and EPA has not developed a reference dose for dimethylphthalate. ATSDR has not developed a toxicological profile for dimethyl phthalate. Availableinformation indicates that dimethyl phthalate has a very low acute toxicity in animals. Additional information is needed to evaluate the toxicological properties of this chemical.
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. Aroclor 1254 and Aroclor 1260 were detected at the LCC site.
Since 1974, all uses of PCBs have been confined to closed systems. PCBs have not beenmanufactured in the United States since 1977. PCBs still persist in the environment and humanexposures still occur. This is usually as a result of spillage from older transformers andcapacitors that are still in use.
This public health assessment identified a potential exposure pathway for PCBs. Humanexposure may occur in the future if on-site surface soil is ingested of if it comes into contactwith skin.
ATSDR has established an MRL of 0.000005 mg/kg/day for PCBs. This public healthassessment will address health effects from potential PCB exposure by converting all levels ofPCBs detected at the LCC site to equivalent levels of Aroclor 1260. Child ingestion of on-sitesurface soil contaminated by PCBs would result in an exposure above the MRL.
In animal studies, some PCB mixtures have produced adverse health effects that include liverdamage, skin irritations, reproductive and developmental effects, and cancer. Human studiesshow that skin irritations, such as acne-like lesions and rashes, can occur in PCB-exposedworkers. Occupational studies involve workers who have been exposed to amounts of PCBs farin excess of the normal population. However, possible health effects from exposure to the PCBlevels detected at the LCC site are unknown.
PCBs are classified by the EPA as probable human carcinogens. A probable human carcinogencategorizes chemicals for which there is sufficient evidence of carcinogenicity in animals, butinadequate evidence or no data from available human studies. Humans who may ingest soilcontaminated by PCB at the LCC site would develop a "no apparent increased risk" indeveloping cancer.
Tetrachloroethene is a man-made substance that is widely used for dry cleaning fabrics and formetal-degreasing operations. It is also used to make other chemicals and is used in someconsumer products.
This public health assessment identified potential exposure pathways for tetrachloroethene. Human exposure may occur in the future if on-site subsurface soil, groundwater, or off-sitesurface water are ingested or come into contact with skin.
ATSDR has established an intermediate MRL of 0.1 mg/kg/day for tetrachloroethene. Humaningestion of on-site subsurface soil groundwater would exceed the MRL. The MRL is based onanimal studies involving mice that indicate that exposure to 100 mg/kg/day of tetrachloroethenecaused an increase in liver weight. The dose required to cause this effect in mice is much greaterthan levels detected at the LCC site and available studies are insufficient to establish that theliver is the target organ of toxicity in humans. Health effects from exposure to lower levels oftetrachloroethene are unknown.
Dermal exposure to tetrachloroethene at the LCC site is not expected to result in adverse health effects.
Toluene is a clear, colorless liquid with a sweet smell. It is a gasoline additive along with and isalso used for making other fuels from crude oil. Toluene occurs naturally in crude oil and thetolu tree. It is also used in making coke from coal, and as a by-product in the manufacture ofstyrene. It is used in the making of paints, lacquers, adhesives, rubber, paint thinners, and insome printing and leather tanning processes.
This public health assessment identified potential exposure pathways for toluene. Humanexposure may occur in the future if on-site subsurface soil or groundwater are ingested or comeinto contact with skin.
The EPA has established a reference dose of 0.2 mg/kg/day for toluene. Human ingestion of on-site groundwater would result in exposure to toluene above the reference dose. Ingestion of on-site subsurface soil by children would result in exposure to toluene above the reference dose.
One case study was located on health effects in humans after oral exposure to toluene; however,this case pertained to ingestion of very high levels of toluene that resulted in death. The levelsof toluene at the LCC site are significantly below the levels that caused human death. There arelimited animal data on oral effects.
Dermal exposure to toluene may cause eye or skin irritation.
1,1,1-Trichloroethane is a colorless man-made chemical that does not occur naturally in theenvironment. In the environment, it can be found as a liquid, as a vapor, or dissolved in waterand other chemicals. It is used as a solvent, as spot cleaners, glues, and aerosol sprays.
This public health assessment identified potential exposure pathways for 1,1,1-trichloroethane. Human exposures may occur in the future if on-site subsurface soil or groundwater contaminatedwith 1,1,1-trichloroethane is ingested or if it comes into contact with skin.
ATSDR has not developed an MRL and the EPA has not developed a reference dose for 1,1,1-trichloroethane. No human studies establishing whether or not health effects occur from eatingfood or drinking water contaminated with 1,1,1-trichloroethene currently exist. Exposure tohigh levels of this chemical have caused liver damage in animals; however, the levels of 1,1,1-trichloroethane at the LCC site are significantly lower than those presented in these studies.
Dermal exposure to 1,1,1-trichloroethane has caused skin irritation in humans. However, the levels necessary to cause these effects are not available.
1,1,2-Trichloroethane is a colorless, sweet-smelling liquid that does not burn easily. It is usedmostly where 1,1-dichloroethene is made and is also used as a solvent.
This public health assessment identified potential exposure pathways for 1,1,2-trichloroethane. Human exposure to this chemical may occur in the future if on-site subsurface soil or groundwater is ingested of if it comes into contact with skin.
ATSDR has established an intermediate oral MRL of 0.04 mg/kg/day and an acute MRL of 0.3mg/kg/day for 1,1,2-trichloroethane. The acute MRL was established to be protective ofneurological effects seen in animal studies. The intermediate MRL was established to beprotective of liver effects seen in animal studies.
Human ingestion of on-site groundwater contaminated by 1,1,2-trichloroethane would notexceed the MRL. Children ingesting contaminated subsurface soil would be exposed to levelsthat exceed both the acute and intermediate MRLs. However, available studies indicate thatadverse health effects occur in animals at much higher levels than those detected at the LCC site. The effects from human exposure to low levels of 1,1,2-trichloroethane over time are unknown.
Dermal exposure to the levels 1,1,2-trichloroethane at the LCC site are not anticipated to result in adverse health effects.
Vinyl chloride is a colorless vapor with a mild, sweet odor. It can exist in liquid form if it iskept under high pressure. Almost all vinyl chloride is man-made. In the United States, mostvinyl chloride is used to make polyvinyl chloride (PVC). PVC is used to make a variety ofplastic products including pipes, wire and cable coatings, and packaging materials.
This public health assessment identified a potential exposure pathway for vinyl chloride. Humanexposures may occur in the future if on-site groundwater is ingested or if it comes into contactwith skin.
ATSDR has established a chronic MRL of 0.00002 mg/kg/day for vinyl chloride. Humaningestion of on-site groundwater contaminated by vinyl chloride would exceed the MRL. Thelevel of vinyl chloride in on-site groundwater is above levels that have affected animal health. Rats exposed to 0.018 mg/kg/day of vinyl chloride had changes in their liver cells. Humanhealth effects that may occur from exposure the levels of vinyl chloride at the LCC site are unknown.
EPA has classified vinyl chloride as a human carcinogen. A human carcinogen is a chemicalthat has sufficient evidence from human epidemiological studies that it causes cancer.
Dermal exposure to vinyl chloride is not anticipated to result in adverse health effects.
Subsurface Soil Contaminants (greater than 3 inches to 2 feet)
Contaminants identified in subsurface soil (greater than 3 inches to 2 feet) are not considered tobe a likely route of human exposure. Human exposure to contaminants in soil is most likely tooccur at depths ranging from zero to three inches below the land surface. The contaminantsidentified in subsurface soil have been grouped together for us to discuss possible health effectsassociated with human exposure to them.
The only potential exposure pathway identified for chromium, copper, 4,4'-DDT, and methylethyl ketone is through human ingestion or dermal contact with on-site subsurface soil. Exposures to these contaminants is not known to have occurred and future human exposure tothese contaminants is unlikely; however, these conditions may change if on-site excavation ofsoil occurs. SCDHEC will continue to review the sampling data for the LCC site and will revisethese evaluations if necessary.
Chromium is a naturally occurring element which is found in three different states: chromium 0,chromium III (trivalent chromium), and chromium VI (hexavalent chromium). Adverse healtheffects from oral exposure to copper at the LCC site are not anticipated. Skin contact withsubsurface soil contaminated with chromium at the LCC site may cause dermatitis or reddeningof the skin.
Copper occurs naturally in rock, soil, water, sediment, and air. Adverse health effects from oralexposure to copper at the LCC site are not anticipated. Studies indicate that some individualsmay show signs of allergic contact dermatitis from skin contact with materials containingcopper. However, neither the dose nor the duration of exposure necessary to produce this effectwas available.
DDT, also known as 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane, was one of the most widelyused chemicals for controlling insects on agricultural crops and for controlling insects that carrysuch diseases as malaria and typhus. DDT does not occur naturally in the environment. Adversehealth effects from ingestion of DDT at the LCC site are not anticipated. Skin contact with soilcontaminated by DDT may cause rashes or irritate the eyes. EPA classifies DDT as a probablehuman carcinogen. A probable human carcinogen category is given to chemicals for which thereis sufficient evidence of carcinogenicity in animals, but inadequate evidence or no data fromhuman studies. Human ingestion of maximally contaminated soil at the LCC site would result ina "no apparent increased risk" in developing cancer.
Methyl ethyl ketone (MEK), or 2-butanone, is a colorless liquid with a sweet, but sharp odor. ATSDR has not established an MRL and EPA has not established a reference dose for thischemical. Ingestion of this chemical may cause dizziness and vomiting. However, the levelsnecessary to cause these effects are not available and additional studies are needed to fullyevaluate the toxicological properties of this chemical.
Contaminants Not Considered of Public Health Concern
We have determined that several of the contaminants detected at the LCC site are not of publichealth concern at this time. These include aluminum, antimony, beryllium, cobalt, 1,2-dichlorobenzene, 1,1-dichloroethene, 1,2-dichloroethene, manganese, mercury, methyl-iso-butyl-ketone, butyl benzyl phthalate, naphthalene, nickel, trichloroethene, and vanadium. SCDHEC will continue to review sampling data as it becomes available and will revise this list if necessary.
As no health outcome data exists for the Leonard Chemical Company site, there is no further discussion at this time.
OHM conducted a well survey of the area to identify the private wells in closest proximity to thesite and their locations. The Remedial investigation concluded that the groundwater plume isheading toward Bowater and not toward the residences in the area; therefore, the private wellswere not tested.
Local residents were also concerned about previous discharge practices conducted at the site intoFerry Branch creek. The Leonard site was issued a National Pollutant Discharge EliminationSystem (NPDES) permit in June 1978, to expire in June 1983. This permit conditions includedcompliance with effluent standards and restrictions. The discharge of treated groundwater intoFerry Branch required compliance with the provisions identified in the Clean Water Act (CWA)307 (a) for toxic pollutants.
The Remedial Investigation identified contaminants of concern in a surface water and sediments(Figure 7). This public health assessment recommends that additional surface water andsediment samples be conducted of the existing locations and that additional locations be sampledto better characterize the extent of site-related contaminant migration and to better determine theextent of migration that could affect Ferry Branch creek.
EPA provided fact sheets on the LCC site to local residents, officials, environmental groups, andlocal newspapers. The fact sheets were intended to provide an overview of the site activities andthe actions taken on the site to date.