FINAL TECHNICAL REPORT
SDMS DocID 2104498
FMC Corporation
Baseline Human Health Risk Assessment OU-7 Ground Water
Avtex Fibers Superfund Site
Front Royal, Virginia
23 September 2008
Environmental Resources Management 200 Harry S Truman Parkway
Suite 400 Annapolis, MD 21401
ERM. AR303500
TABLE OF CONTENTS
EXECUTIVE SUMMARY ES-1
1.0 INTRODUCTION 1
2.0 SELECTION OFcCONSTITUENTS OF POTENTIAL CONCERN 2
3.0 EXPOSURE ASSESSMENT 4
3.1 CALCULATION OF EXPOSURE POINT CONCENTRATION 4
3.2 EXPOSURE PARAMETERS 5
3.2.2 Ingestion 6 3.2.3 Dermal 6 3.2.4 Inhalation 7
4.0 TOXICITY ASSESSMENT 8
5.0 RISK CHARACTERIZATION 10
5.1 RISK CHARACTERIZATION FOR LEAD 10
5.2 RISKS FROM NONCARCINOGENIC CONSTITUENTS 11
5.2.1 Ingestion and Dermal Pathways 11 5.2.2 Inhalation Pathway 11 5.2.3 Hazard Indices 11
5.3 RISKS FROM CARCINOGENIC CONSTITUENTS 12 5.3.1 Ingestion and Dermal Pathways 12 5.3.2 Inhalation Pathway 12 5.3.3 Cancer Risk 12
5.4 RISK CHARACTERIZATION FOR VOLATILE CONSTITUENTS RELEASED TO AMBIENT AIR 13
5.5 PCBS IN GROUND WATER 13
6.0 UNCERTAINTY 15
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6.1 GENERAL METHODOLOGICAL UNCERTAINTIES 15 6.1.1 Site Characterization 15 6.1.2 Toxicological Information 16 6.1.3 Exposure Assumptions 16
6.1.4 Dermal Contact Pathivay 17
6.2 RISK CHARACTERIZATION 17
7.0 CONCLUSIONS 18
8.0 REFERENCES 21
LIST OF FIGURES
1 LOCATION OF GROUND WATER WELLS USED IN BASELINE HUMAN HEALTH ASSESSMENT
2 FLOW DIAGRAM FOR SELECTION OF CONSTITUENTS OF POTENTIAL CONCERN (COPCS)
LIST OF TABLES
1 OCCURRENCE, DISTRIBUTION AND SELECTION OF CONSTITUENTS OF POTENTIAL CONCERN
2 SELECTION OF EXPOSURE PATHWAYS
3 MEDIUM-SPECIFIC EXPOSURE POINT CONCENTRATION SUMMARY
4A VALUES USED FOR DAILY INTAKE CALCULATIONS - ADULT RESIDENT, INGESTION AND DERMAL
4B VALUES USED FOR DAILY INTAKE CALCULATIONS - ADULT RESIDENT, INHALATION
4C VALUES USED FOR DAILY INTAKE CALCULATIONS - CHILD RESIDENT, INGESTION AND DERMAL
4D VALUES USED FOR DAILY INTAKE CALCULATIONS - CHILD RESIDENT, INHALATION
5A NON-CANCER TOXICITY DATA-ORAL/DERMAL
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TABLE OF CONTENTS (CONTINUED)
5B NON-CANCER TOXICITY DATA - INHALATION
6A CANCER TOXICITY DATA - ORAL/DERMAL
6B CANCER TOXICITY DATA-INHALATION
7A CALCULATION OF NON-CANCER HAZARDS - ADULT RESIDENT
7B CALCULATION OF NON-CANCER HAZARDS - CHILD RESIDENT
7C CALCULATION OF CANCER RISKS - ADULT RESIDENT
7D CALCULATION OF CANCER RISKS - CHILD RESIDENT
8A RISK SUMMARY - ADULT RESIDENT
8B RISK SUMMARY - CHILD RESIDENT
9 RISK SUMMARY - CHILD/ADULT RESIDENTS
LIST OF APPENDICES
A ANALYnCAL DATA
B SUPPORTING CALCULATION FOR RISK ASSESSMENT
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EXECUTTVE SUMMARY
The baseline human health risk assessment (HHRA), provided herein, evaluates a hypothetical future residential scenario for exposure to both on-site and off-site ground water. This risk assessment assesses potential risk that exists without remediation or institutional controls, and conforms to the standards of the Risk Assessment Guidance for Superfund, Part D guidance (U.S. EPA 1998).
All three possible routes of exposure to ground water—ingestion, dermal absorption, and inhalation of volatile compounds—were included in this HHRA. As the first step in the HHRA, the constituents of potential concern (COPC) screening analysis identified 23 constituents as COPCs. These constituents were carried through the exposure and toxicity assessment, and the risk calculations.
Risks from lead were evaluated using the lEUBK model, with the maximum reported concentration of 31.2 lig/L as the drinking-water concentration, and a site-specific 95% UCL background soil lead concentration of 14.9 mg/kg. The predicted geometric mean blood lead concentration is 3.8 |ig /dL, with 1.9 percent of the population predicted to exceed 10 ^g/dL, which is well below the EPA goal of no more than 5 percent of the population having blood lead levels exceeding 10 fjg/dL, (U.S. EPA 2002). Therefore, lead in the ground water does not pose a risk at this site.
Tables 8a and 8b presents the summary of non-cancer and cancer risk estimates for all exposure pathways for adults eind children, and also presents the risk estimates for noncarcinoger\s whose hazard quotient (HQ) contributes to an organ-specific hazard index (HI) greater than one, and the carcinogeriic risk estimates greater than 1x10^. For non-cancer health effects via the ingestion and dermal pathways, three constituents (carbon disulfide, arsenic, and rnercury) contribute over 90% of the calculated risk, with mercury being the most significant contributor (70% of calculated risk). For noncarcinogenic health effects via the inhalation pathway, mercury was also the main risk driver, contributing 94% of the risk. The total HI summed across all pathways and all constituents is 290 for adults and 410 for children.
The total cancer risk for the adult resident potential exposure associated with domestic use of water is 8.2 x 10-' and 4.8 x 10-' for the child resident, resulting in a cumulative lifetime cancer risk of 1.3 x 10-2- as shown in Table 9. For carcinogenic effects via the ingestion and dermal pathways.
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arsenic contributes virtually all of the carcinogenic risk (99%). None of the volatile COPCs are carcinogenic via the inhalation pathway.
Risks associated with potential exposure to COPCs that may volatilize and imgrate from ground water to ambient air and into on-site maintenance buildings were also considered. As such, vapor intrusion is not just an issue when buildings are directly over the ground water plume, but also when a structure is within 100 feet of a ground water VOC plume (USEPA, 2002). This would consist of on-site areas east of the South Fork Shenandoah River but west of the Norfolk-Southern railroad right-of-way and on-site areas west of the South Fork Shenandoah River (River).
Iri the event that buildings could be constructed as part of future on-site activities, new construction must adhere to the requirements of the "Conservation and Environmental Protection Easement and Declaration of Restrictive Covenants" (Conservation Easement), which could include structures such as maintenance and/or similar type structures. As stated in the Conservation Easement, buildings considered to be ciistomary and appropriate for park usage, such as ranger's stations, bathrooms, and maintenance buildings, are permissible; To address potential concerns regarding vapor intrusion into these structures, any new construction will be required to include a vapor barrier or vapor intnision mitigation system in the design. This approach eliminates the uncertainly associated with predicting air concentrations based on isoil vapor data. '
For the area west of the River, including parcels that are privately -bwTied, the remedied alternatives identified in the OU-7 FSAvill include an evaluation of potential vapor iritrusion concerns for this ar^a during the remedial design phase if the alternative is selected in the Record of Decision for the OU-7 remedy,
FMC is proceeding with an investigation of PCBs iri ground water in the vicinity of the former Polymer Plant building beca;use of the detected presence of PCBs in soil at this location. The scope of the'investigation will include analysis of ground water samples for specific PCB congeners. Future ground water quality data collected from overburden monitoring wells installed at the Polymer plant will be evaluate to determine if PCBs are at levels that could pose a risk to a future construction worker. FMC will address potential risks to PCBs in grourld water as part of the reporting of the Polymer Plant ground water data.
In summary, this risk assessment for potential future domestic use of on-site and off-site groxind water indicates that arsenic and mercury present the greatest threat to a hypothetical future ground water user.
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1.0 INTRODUCTION
FMC Corporation has been directed by the U.S. Environmental Protection Agency (USEPA) to conduct a risk assessment to provide an analysis of baseline human health risk associated with ground water from the Avtex Fibers Superfund Site (Site). This baseline human health risk assessment (HHRA) assesses potential risk that exists without remediation or institutional controls. The HHRA addresses all potential users of the Site that would have the potential to contact contaminated ground water in the future if the Site was not remediated and an institutional control preventing ground water use was not put in place.
The HHRA includes a hypothetical future residential scenario, which consists of the domestic use of ground water by either on-site or off-site users that could come in contact with contaminated ground water. Domestic use of ground water may result in exposures via direct water ingestion, and also via dermal absorption and inhalation during showering (the inhalation pathway applies to volatile constituents only). All of these exposure pathways, as presented in Table 1, are included in this assessment. In addition, EPA Region III asked that consideration of risk be given for a trespasser/recreational scenario and maintenance worker scenario. For both of these scenarios, potential exposures could occur if the receptors were exposed to impacted ground water at Viscose Basins 9 through 11 while trespassing or recreating, or conducting operations and maintenance activities in the proposed conservancy area in some areas overlying impacted ground water.
This risk assessment conforms to the standards of the Risk Assessment Guidance for Superfund (RAGS) Part D guidance (USEPA 1998), with all standardized tables found at the end of the document. The following sections contain discussions of the screening for Constituents of Potential Concern (COPCs), exposure assessment, toxicity assessment, risk characterization, and conclusions. Thorough documentation of ground water data quality, analytical methods, and sampling details, along with site history, are presented in the following documents and are not duplicated here:
• Supplemental Field and Laboratory Data Report for Operable Unit 7 (Exponent 2001); and
• Second Supplemental Field and Laboratory Data Report for Operable Unit 7: Deep Ground Water Investigation and Pumping Test (ERM 2007).
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2.0 SELECTION OF CONSTITUENTS OF POTENTIAL CONCERN
As the first step in the risk assessment process, ground water constituent concentrations were screened to determine the Constituents of Potential Concern (COPCs) which are retained for further evaluation in the HHRA. Figure 2 illustrates the COPCs selection process. The data used to identify ground water COPCs were taken from sampling events conducted in 2000, 2002 and 2003. Data collected from bedrock monitoring wells in 2000 included MW-3, MW-9, GM-8, GM-9,116, 216, 316, PW-2, 205, 305, 181, GM-2A, GM-2B, 177, 215 and PZ-11. Two duplicate samples were collected from 116 and MW-9 during this sampling event. Data collected in 2002 included samples taken from monitoring wells 336 and 602, and samples collected from monitoring well 603 were collected in 2003. The location of the monitoring wells is provided in Figure 1. The ground water analytical data used in this screening analysis are provided in Appendix A, Table A-1. Each constituent provided in Table A-1 with at least one positive detection was retained for the screening analysis. Note that none of the constituents were eliminated based on the comparison to background concentrations. The constituent concentration data, screening concentrations, the selected COPCs, and the rationale for including or excluding constituents as COPCs are presented in Table 1. The procedure used to select COPCs is described as follows.
The first step in the screening process consisted of comparing the maximum reported constituent concentrations to screening criteria. The screening criteria consisted of the EPA Region III Risk-Based Concentrations (RBCs) for tap water (EPA Region III April 2007a). The non-cancer RBC values were adjusted to a Hazard Quotient of 0.1 (i.e., non-cancer RBCs were divided by 10) and the carcinogenic RBCs set at a cancer risk of 1 x 10"̂ were used for screening purposes.
For some of the constituents, RBCs were not available on the EPA Region III April 2007 table. These included cobalt, mercury, and phenanthrene. The tap water screening criteria for cobalt was taken from an earlier version of the Region III RBC April, 2004 table, as this metal is no longer listed on the current table. The RBC for methylmercury was used as a surrogate for total mercury and the anthracene RBC was used as a surrogate for phenanthrene. Also, the essential human nutrients calcium, magnesium, potassium and sodium do not have RBCs. Due to their low toxicities, these constituents were eliminated from further consideration as COPCs (USEPA 1989).
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As shown in Table 1, constituents for which the maximum reported value was below the screening criteria were not retained as COPCs. All remaining constituents identified as COPCs by this screening process were retained for further evaluation in the HHRA as specified under RAGS Part D. The final list of COPCs for the ground water risk assessment includes 23 constituents: 15 inorganics, 6 semivolatile organics, and 2 volatile organic constituents (see Table 1).
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3.0 EXPOSURE ASSESSMENT
The sections below describe the calculation of appropriate exposure-point concentrations (EPCs) and the determination of the relevant input parameters for each exposure pathway. This information is presented in this order to be consistent with the tables specified in RAGS Part D.
As discussed in the Introduction and shown in Table 2, the primary exposure scenario evaluated in this risk assessment is the future residential use of ground water. In addition to potential exposure with ground water, EPA Region III has requested that all reasonably expected exposure be included within this assessment including a trespasser/recreational scenario and a maintenance worker scenario. For these scenarios, EPA has indicated that Viscose Basins 9 through 11 currently pose risks to trespassers and would pose risks to recreational users of the site if the risks are not mitigated in the future. Additionally, EPA has indicated that potential exposure for maintenance workers who performed activities in the conservancy area that overlay impacted ground water and Viscose basins 9 through 11 could also occur.
As noted in Table 2, direct contact exposures with surface soil by the trespasser /recreational receptors and the maintenance worker were evaluated in the Final Baseline Human Health Risk Assessment for Avtex Fibers Superfund Site (Gradient 2002). Consequently, these potential risks will not be considered herein. However, potential exposures via inhalation of vapors originating from the ground water to ambient air for the conservancy area and Viscose basins 9 through 11 are qualitatively evaluated in Section 5.4.
3.1 CALCULATION OF EXPOSURE POINT CONCENTRATION
To characterize future residential exposure, EPCs were derived from the ground water data provided in Appendix A, Table A-1. The data obtained from the field duplicate results were averaged with its associated sample before any other calculations were performed. For averaging, non-detects were handled in the following rnanner: if all results were non-detects, the lowest detection limit was used. If there was a mixture of detects and non-detects for a constituent, the detected values were averaged with one-half the detection limit for the non-detected values.
The deep wells 336, 602 and 603 on the west side of the river have been sampled at multiple depth intervals. Use all of the data from the 15
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intervals could bias the statistical analysis based on these wells. Only the highest concentration for each detected constituent from wells from 336 and 603 were included in the statistical analysis to estimate the EPCs.
For the exposure point concentration (EPC) used in risk calculations, the EPA recommends using the 95 percent upper confidence limit of the mean (95% UCL), which represents an upper bound of the long-term average concentration to which the receptor might be exposed. The 95% UCL was obtained using EPA's ProUCL software (version 4.0) (USEPA 2007b). The software package allows for the handing of left-censored data sets (i.e., data sets that include non-detected values). Historically, EPA has recommended that non-detected concentrations be included within the statistical analysis and represented as one-half the reporting limit. This procedure is no longer recommended and is believed to generate EPCs that are biased low, which could ultimately underestimate actual risk estimates. The ProUCL software handles left-censored data sets to avoid this issue when greater than 50 percent of the samples within the dataset report a positive detection. For some of the constituents evaluated herein, less than 50 percent of the samples reported a positive detection. For those constituents, the maximum reported concentration was used in the risk assessment (USEPA 1992). The resulting EPC values are presented in Table 3.
3.2 EXPOSURE PARAMETERS
The exposure scenario for this risk assessment involves a hypothetical future residential scenario, which consists of the domestic use of ground water by either on-site or off-site users that could come in contact with contaminated ground water. Exposure pathways that are included in the exposure assessment and risk calculations include ingestion, dermal contact with the water, and inhalation of volatile compounds. For all three exposure routes, an adult and child receptor were selected. The pathway-specific input parameters are described below. A summary of values used for daily intake calculations for each receptor are provided in Tables 4a through 4b.
Standard default exposure parameters were obtained from the Exposure Factors Handbook (USEPA 1997), the Standard Default Exposure Factors guidance (USEPA 1991), Updated Dermal Exposure Assessment Guidance (USEPA Region III 2003) and RAGS Part E guidance (USEPA 2004). These parameters are detailed below.
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3.2.2 Ingestion
An upper-bound estimate of average daily water ingestion of 2 L/day was selected for the adult resident and 1 L /day was selected for the child resident. These values are frequently incorporated as an upper-bound estimate of water consumption in risk-based assessments (USEPA 2007a). Values used to calculate ingestion exposures for adults are presented in Table 4a and for children in Table 4c.
3.2.3 Dermal
The first step in assessing exposures via the dermal route was to determine wrhich constituents might result in dermal exposures that were significant relative to ingestion exposures. EPA's Final Dermal Guidance (USEPA 2004) calculates a constituent-specific ratio of dermal to oral exposure using standard residential input parameters. Specifically, this guidance compares the potential constituent exposures that might occur from ingestion of 2 L of water per day to dermal exposures that might result from showering for 35 minutes per day. The calculated ratio is expressed as a percentage of the ingestion dose that might result from dermal exposure. For this assessment, dermal exposure to a particular constituent is included in the exposure and risk calculations only if the constituent-specific dermal/oral ratio exceeds 10 percent.
To determine the possible dermal doses for these constituents, the site-specific chronic oral ingestion dose was multiplied by the constituent-specific dermal-to-oral ratios from ratios from Exhibits B-3 and B-4 of the EPA guidance. This approach yields the same results as doing the typical calculation, because the default exposure parameters for both oral and dermal intakes were deemed appropriate for the evaluation of potential future exposures to ground water from the site.
A value of 100 percent would indicate that dermal exposures are calculated to be equal to ingestion exposures under the EPA assumptions. A value of 10 percent would indicate that the calculated dermal exposures for a specific constituent are estimated to be only one-tenth of the exposures that would occur from direct ingestion of the water. This approach yields the same results as doing the typical calculation, because the default exposure parameters for both oral and dermal intakes were deemed appropriate for the evaluation of potential future exposures to ground water from the site. Values used to calculate dermal exposures for adults are presented in Table 4a and for children in Table 4c.
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3.2.4 Inhalation
A receptor could be exposed to constituents in ground water via inhalation if the constituent volatilizes into the air, such as when showering. Inhalation exposures were assessed for the COPCs that are considered volatile, defined as having a molecular weight less than 200 g/mol, and a Henry's Law constant greater than or equal to 1x10"^ atm-m^/mole (USEPA 2007a). Based on these criteria, four COPCs were identified as volatiles: ammonia, acetone, carbon disulfide, and naphthalene.
The chronic daily intake from inhalation exposure was calculated using the formula from Foster and Chrostowski (1987). This exposure pathway is appropriate for the adult resident, but may overestimate inhalation exposures for children who are more likely to bath rather than shower. Nonetheless, this exposure pathway was conservatively evaluated for the child resident. Tables 4b and 4d presents the input parameters for adults and children, respectively, and the equation used to calculate the chronic daily intake via inhalation.
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4.0 TOXICITY ASSESSMENT
The purpose of the toxicity assessment is to evaluate the potential for site-related constituents to cause adverse health effects in exposed individuals, and to define, to the extent possible, the relation between the degree of exposure to a hazardous constituent and the likelihood of any adverse health effects.
In this assessment, the potential for noncarcinogenic health effects was evaluated for long-term average exposures (i.e., as would occur over a year) by comparing estimated chronic daily intakes with constituent-specific reference dose (RfD) values from the EPA. RfDs represent daily intakes at which no adverse effects are expected to occur over a lifetime of exposure, even in sensitive subpopulations. Carcinogenic slope factors (CSFs) were used to estimate the incremental lifetime risk of developing cancer that corresponds to the estimated exposure levels calculated in the exposure assessment. Both RfDs and CSFs are specific to the route of exposure (e.g., ingestion or inhalation exposure —for dermal exposures, oral toxicity factors are used, and adjusted to absorbed dose, if appropriate).
Values for RfDs and CSFs from the USEPA's Integrated Risk Information System (IRIS; USEPA 2007c) were used preferentially when available. This computerized database contains EPA-verified toxicity values and EPA regulatory information for many constituents commonly detected at hazardous waste sites. EPA extensively reviews and verifies RfDs and CSFs derived for risk assessment and, once verified, they represent agency consensus. If toxicity values were not available from IRIS, then values were obtained from the RBC table (USEPA 2007a).
The toxicity values used to assess the noncarcinogenic health effects of the COPCs for the Avtex site are presented in Tables 5a and 5b, along with uncertainty factors and the primary target organ. Toxicity values for the carcinogenic COPCs are presented in Tables 6a and 6b, along with the weight-of-evidence classification, which indicates the adequacy of the data that support designation of a constituent as a carcinogen. Constituent-specific adjustments or substitutions are documented in the tables.
Dermal toxicity values are listed only for all constituents being assessed via that route of exposure. Based on EPA guidance (USEPA 2004), when evaluating risks from dermal absorption of constituents, toxicity values may need to be adjusted to account for absorbed dose (rather than
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administered dose). EPA guidance indicates that constituents with dermal to oral ratios of greater than 10 percent should be included in the dermal exposure assessment. Nonetheless, all constituents were retained for further evaluation.
USEPA has not developed RfDs specifically for the dermal pathway. As a surrogate for dermal RfDs, oral values were adjusted to account for absorption through the skin to allow comparison with calculated dermal doses which consider absorption (USEPA 1989, 2004; USEPA Region III 2003). Specifically, oral RfDs were multiplied by a Region recommended dermal absorption factor as shown on Exhibit 4a (USEPA 2004). These adjusted RfD values were used to evaluate dermal contact risks.
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5.0 RISK CHARACTERIZATION
In risk assessments, two types of potential health effects are characterized — noncarcinogenic and carcinogenic. For noncarcinogenic health effects, risk estimates are provided in the form of Hazard Quotients (HQs) and Hazard Indices (His). The HQ represents the estimated exposure for a specific constituent divided by the reference dose (RID), expressed in mg/kg-day. As such, HQs indicate the site-related exposure in comparison to an exposure level that is unlikely to result in adverse health effects. If an HQ value is less than one, then it can reasonably be assumed that the constituent exposure will not be associated with toxicity. As HQ values increase above one, the potential for toxicity increases. An HI value represents the sum of HQs across constituents and across all exposure pathways. The constituent-specific HQ values are summed into an HI only if it can be established that the constituent-specific endpoint of toxicity would be additive with the toxicities of other constituents.
For carcinogenic constituents, risk estimates are calculated by multiplying the average lifetime daily dose by the carcinogenic slope factor (CSF), expressed in (mg/kg-day) -i. This yields a unitless estimate of risk, and should be interpreted as the probability of increased incidence of cancer in a lifetime. Therefore, a cancer risk estimate of 1 x 10'^ indicates a probability of 1 in 1,000,000, or 1 cancer in a population of 1,000,000 people exposed to the average lifetime daily dose, assuming that all individuals have reasonable maximum exposure (RME).
5.1 RISK CHARACTERIZATION FOR LEAD
Risks for lead are not calculated by the same method as other constituents, thus, a separate calculation was performed to determine the potential risk from lead exposure. The Integrated Exposure Uptake Biokinetic (lEUBK, version 1.0) Model for Lead in Children was run using the maximum ground water concentration of 31.2 ug/L, and with a site-specific 95% UCL background soil lead concentration of 14.9 mg /kg (see Appendix A, Table A-2). Background lead soil concentrations were calculated using 110 soil samples collected from the fly ash stockpile and SoccerPlex areas. Using these site-specific parameters, and all other inputs set at model defaults, the predicted geometric mean blood lead concentration is 3.8 ^g/dL, with 1.9 percent of the population predicted to exceed 10 |ag/dL. The EPA goal is that no more than 5 percent of the population should have blood lead levels exceeding 10 |ag/dL, (USEPA 2002). Therefore, lead in the ground water does not pose a risk at this site.
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5.2 RISKS FROM NONCARCINOGENIC CONSTITUENTS
Calculated non-cancer hazards for oral, dermal and inhalation exposure for an adult and child resident are presented in Tables 7a and 7b, respectively. The non-cancer risks for the adult and child residents are also sunuT^arized in Tables 8a and 8b, respectively.
5.2.1 Ingestion and Dermal Pathways
For the adult resident, the calculated HI summed across all constituents for the ingestion and dermal pathways is 146 (see Table 8a). The specific constituents for which the calculated HQ exceeds one are antimony, arsenic, chromium, manganese, mercury, vanadium, phenol and carbon disulfide. For ingestion and dermal exposures, the primary contributors to the non-cancer risk (i.e., collectively representing more than 90 percent of the non-cancer risk) are carbon disulfide (HQ= 46), arsenic (HQ=53), and mercury (HQ= 8).
For the child resident, the calculated HI value summed across all constituents for the ingestion and dermal pathways is 343 (see Table 8b). The specific constituents for which the calculated HQ exceeds one are antimony, arsenic, chromium, cobalt, manganese, mercury, nickel, vanadium, phenol and carbon disulfide. For ingestion and dermal exposures, the primary contributors to the non-cancer toxicity risk (i.e., collectively representing more than 90 percent of the non-cancer risk) are carbon disulfide (HQ= 107), arsenic (HQ=120), and mercury (HQ= 18).
For these constituents, the non-cancer risk is primarily associated with ingestion exposures for both the adult and child receptors, with dermal absorption making a negligible contribution to total exposure.
5.2.2 Inhalation Pathway
The total HI for inhalation of vapors during showering for adults and children is 140 and 76, respectively. For this exposure pathway, HQ values for three of the constituents evaluated exceed unity (i.e., HQ >1) which included mercury, naphthalene, and carbon disulfide. Of the total non-cancer inhalation risk, approximately 80 percent was contributed from mercury.
5.2.3 Hazard Indices
The calculated HI value for adults indicates that across all constituents and exposure routes, the non-cancer risk associated with domestic use of ground water is 290. The three body organs or systems with the highest
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HI summed across all pathways and constituents are the nervous system (HI=200), impacts to blood (HI=22) and the kidney (HI=12).
Similarly for children, the calculated HI value across all constituents and exposure routes, the non-cancer risk associated with domestic use of ground water is 410. The three body organs or systems with the highest HI summed across all pathways and constituents are the nervous system (HI=200), impacts to blood (HI=52) and the kidney (HI=33).
5.3 RISKS FROM CARCINOGENIC CONSTITUENTS
Calculated carcinogenic risks for oral, dermal and inhalation exposure for an adult and child resident are presented in Tables 7c and 7d, respectively. The carcinogenic risks for the adult and child residents are also summarized in Tables 8a and 8b, respectively.
5.3.1 Ingestion and Dermal Pathways
The calculated carcinogenic risk for the ingestion and dermal pathways, summed across all constituents, is 8.2 x lO-̂ for the adult resident and 4.8 x 10-3 for children. For both receptors, over 99 percent of the cancer risk is attributed to arsenic. The other carcinogenic constituents present in ground water, namely bis(2-ethylhexyl)phthalate and pentachlorophenol, contribute an insignificant level of risk when compared to the total cancer risk for these pathways.
5.3.2 Inhalation Pathway
None of the constituents present in ground water that could be volatilized and be inhaled during showering are considered to be carcinogenic. Consequently, this pathw^ay does not contribute to the total cancer risk for ground water.
5.3.3 Cancer Risk
The total cancer risk for the adult resident potential exposure associated with domestic use of water is 8.2 x 10-3 and 4.8 x 10"̂ for the child resident, resulting in a cumulative lifetime cancer risk of 1.3 x 10- '̂ as shown in Table 9. If risks are summed across all three pathways, arsenic contributes 99 percent to the total calculated risk.
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5.4 RISK CHARACTERIZATION FOR VOLATILE CONSTITUENTS RELEASED TO AMBIENT AIR
EPA requested that a qualitative assessment of the potential exposure to COPCs that may volatilize and migrate from ground water to ambient air be included in this assessment. It is important to note that of the COPCs identified at the site, only four constituents are sufficiently volatile to migrate from the subsurface into ambient air. These COPCs include ammonia, naphthalene, acetone and carbon disulfide. As such, vapor intrusion is not just an issue when buildings are directly over the ground water plume, but also when a structure is within 100 feet of a ground water VOC plume (USEPA, 2002). This would consist of on-site areas east of the South Fork Shenandoah River but west of the Norfolk-Southern railroad right-of-way and on-site areas west of the South Fork Shenandoah River (River).
In the event that buildings could be constructed as part of future on-site activities, new construction must adhere to the requirements of the "Conservation and Environmental Protection Easement and Declaration of Restrictive Covenants" (Conservation Easement), which could include structures such as maintenance and/or similar type structures. As stated in the Conservation Easement, buildings considered to be customary and appropriate for park usage, such as ranger's stations, bathrooms, and maintenance buildings, are permissible. To address potential concerns regarding vapor intrusion into these structures, any new construction will be required to include a vapor barrier or vapor intrusion mitigation system in the design. This approach eliminates the uncertainly associated with predicting air concentrations based on soil vapor data.
For the area west of the River, including parcels that are privately -owned, the remedial alternatives identified in the OU-7 FS will include an evaluation of potential vapor intrusion concerns for this area during the remedial design phase if the alternative is selected in the Record of Decision for the OU-7 remedy.
5.5 PCBS IN GROUND WATER
FMC is proceeding with an investigation of PCBs in ground water in 2008 in the vicinity of the former Polymer Plant building because of the detected presence of PCBs in soil at this location. The scope of the investigation will include analysis of ground water samples for specific PCB congeners. Future ground water quality data collected from overburden monitoring wells installed at the Polymer plant will be evaluate to determine if PCBs are at levels that could pose a risk to a
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future construction worker. FMC will address potential risks to PCBs in ground water as part of the reporting of the Polymer Plant ground water data.
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6.0 UNCERTAINTY
The carcinogenic risk and noncarcinogenic hazard estimates presented in this HHRA are not intended to be calculations of absolute risk or hazard to individuals who may use the Site currently or in the future. Uncertainties in underlying data prevent exact determination of risk to receptor populations. The goal of the risk assessment was to provide reasonable, conservative risk estimates to guide decision-making. By using standardized methodology guidelines, in particular, RAGS Part D (USEPA 2001), and standardized default exposure factors provided in USEPA (1997) risk assessments for Superfund Sites provide a basis for determining whether remediation should be considered.
USEPA (1991) states that, "Where the cumulative carcinogenic Site risk to an individual based on reasonable maximum exposure for both current and future land use is less than lO"*, and the non-carcinogenic hazard quotient is less than 1, action generally is not warranted unless there are adverse environmental impacts." Moreover, USEPA guidance (USEPA 1989, 2001) acknowledges that uncertainty in a risk assessment can cause differences in the numerical results of more than an order of magnitude. Therefore, it is important to document and discuss the types of uncertainties that may affect the risk estimates calculated in the previous section.
Risk is broadly a function of exposure and toxicity. Therefore, uncertainties in characterizing either of these result inaccuracy in risk estimates. Specific sources of uncertainty can be divided into two groups: methodological and Site-specific. These types of uncertainties are described in the following subsections. Their effect on final risk estimates is discussed, where possible.
6.1 GENERAL METHODOLOGICAL UNCERTAINTIES
6.1.1 Site Characterization
It is sometimes impossible to completely characterize heterogeneous environmental media from a statistical standpoint. Soil constituent concentrations may vary by orders of magnitude over intervals of an inch or less; air constituent concentrations vary greatly over space and time. In some cases, only a few samples are available to evaluate a particular medium or potential source area. Risk estimates based on a limited sample database may not be representative of actual contamination, as is the case for this Site. Samples were concentrated in those areas suspected
15 OU-7 GROUND WATER BASELINE HHRA-9/23/2008
AR303520
to have come in contact with site-related constituents, and therefore are considered a conservative representation of the impacts due to former site activities.
6.1.2 Toxicological Information
Toxicity data used in human health risk assessments can be limited. Much of the data used to generate health criteria are derived from animal studies. Uncertainties result given that:
• Both endpoints of toxicity (effect or target organ) and the doses at which effects are observed are extrapolated from animals to humans;
• Results of short-term exposure studies are used to predict the effects of long-term exposures;
• Results of studies using high doses are used to predict effects from exposures to low doses usually expected at hazardous waste Sites; and
• Effects exhibited by homogeneous populations of animals (or humans) are used to predict effects in heterogeneous populations with variable sensitivities (e.g., the young, elderly or infirm).
In addition, thorough toxicity data are not available for all constituents detected at many Sites. Often the toxicity value for the most potent constituent in a group is used as a surrogate for structurally similar compounds. This may result in the overestimation of risk.
USEPA and other regulatory agencies attempt to account for these sources of uncertainty by including uncertainty factors in the determination of health criteria such as RfDs. In addition, the level of confidence in RfDs for noncarcinogenic effects and the weight of evidence for carcinogenic effects are specified for each constituent. These qualifiers have been discussed in the dose-response section of this risk assessment.
6.1.3 Exposure Assumptions
Evaluating exposure to environmental constituents requires a number of different inputs and assumptions. These include the types of exposed populations, including their ages and health conditions; average lifespans; activity patterns such as time spent indoors versus outdoors, time spent at different locations; time spent working or residing in the area of the Site; contact rates for contaminated media; skin surface area for dermal contact; and absorption rates via the skin and digestive tract. There are significant uncertainties regarding the extent to which a constituent is absorbed from soil through the skin.
ERM 1 6 OU-7 GROUND WATER BASELINE HHRA-9/23/2008
AR303521
Current USEPA guidance for conducting risk assessments at Superfund Sites recommends values to be used for many of these parameters. This serves to reduce unwarranted variability in exposure assumptions used to perform baseline risk assessments across different sites.
Because values specified in guidance documents are often conservative, upper-bound figures, they would rarely lead to underestimating risks. Site-specific exposure parameters should be used over standard default exposure parameters when they are known to prevent masking of Site-specific variations.
Baseline risk assessments also estimate current and future exposure scenarios based on constituent concentrations detected at the Site during the Site investigation. In general, no attenuation or degradation of constituents over space or time is assumed. This also typically results in a conservative estimate of risk, especially for organic constituents that are typically subjected to natural degradation processes such as biodegradation, volatilization and oxidation/reduction. Iri some cases, natural degradation processes result in daughter products more toxic than the parent compound.
6.1.4 Dermal Contact Pathway
The use of adjusted toxicity values for the assessment of dermal risks is another source of uncertainty in the risk assessment. Adjusted oral toxicity values were generated based on USEPA Region Ill-recommended oral absorption factors. Oral absorption factors are based primarily on animal studies that are not always the same species associated with the toxicity study.
6.2 RISK CHARACTERIZATION
Constituent-specific risks are generally assumed to be additive. This oversimplifies the fact that some constituents are thought to act synergistically (1 + 1 > 2) while others act antagonistically (1 + 1 < 2). The overall effect of these mechanisms on multi-constituent, multi-media risk estimates is difficult to determine but the effects are usually assumed to balance.
17 OU-7 GROUND WATER BASELINE HHRA-9/23/2008
AR303522
7.0 CONCLUSIONS
This baseline human health risk assessment evaluates a hypothetical future residential scenario for exposure to both on-site and off-site ground water. This risk assessment assesses potential risk that exists without remediation or institutional controls, and conforms to the standards of the RAGS Part D guidance (USEPA 1998), with all standardized tables found at the end of the document.
All three possible routes of exposure to ground water—ingestion, dermal absorption, and inhalation of volatile compounds — were included in this assessment. The COPC screening analysis identified 23 constituents as COPCs, and these constituents were carried through the exposure and toxicity assessment, and the risk calculations.
Risks from lead were evaluated using the lEUBK model, using the maximum concentration of 31.2 |ag/L as the drinking-water concentration, and a site-specific 95% UCL background soil lead concentration of 14.9 mg/kg. The predicted geometric mean blood lead concentration is 3.8 lag /dL, with 1.9 percent of the population predicted to exceed 10 | ig/dL, which is well below the EPA goal of no more than 5 percent of the population having blood lead levels exceeding 10 |ag/dL, (USEPA 2002). Therefore, lead in the ground water does not pose a risk at this site.
Tables 8a and 8b presents the summary of non-cancer and cancer risk estimates for all exposure pathways for adults and children, and also presents the risk estimates for noncarcinogens whose HQ contributes to an organ-specific HI greater than one, and the carcinogenic risk estimates greater than 1x10" .̂ For non-cancer health effects via the ingestion and dermal pathways, four constituents (carbon disulfide, arsenic, and mercury) contribute over 90% of the calculated risk, with mercury being the most significant contributor (70% of calculated risk). For noncarcinogenic health effects via the inhalation pathway, mercury was also the, main risk driver, contributing 94% of the risk. The total HI summed across all pathways and all constituents is 290 for adults and 410 for children.
The total cancer risk for the adult resident potential exposure associated with domestic use of water is 8.2 x lO-̂ and 4.8 x 10-̂ for the child resident, resulting in a cumulative lifetime cancer risk of 1.3 x 10-2' ^g shown in Table 9. For carcinogenic effects via the ingestion and dermal pathways, arsenic contributes virtually all of the carcinogenic risk (99%). None of the volatile COPCs are carcinogenic via the inhalation pathway.
18 OU-7 GROUND WATER BASELINE HHRA-9/23/2008
AR303523
Risks associated with potential exposure to COPCs that may volatilize and migrate from ground wjater to ambient air and into on-site maintenance buildings were also considered. As such, vapor intrusion is not just an issue when buildings are directly over the ground water plume, but also when a structure is within 100 feet of a ground water VOC plume (USEPA, 2002). This would consist of on-site areas east of the South Fork Shenandoah River but west of the Norfolk-Southern railroad right-of-way and on-site areas west of the South Fork Shenandoah River (River).
In the event that buildings could be constructed as part of future on-site activities, new construction must adhere to the requirements of the "Conservation and Environmental Protection Easement and Declaration of Restrictive Covenants" (Conservation Easement), w^hich could include structures such as maintenance and/or similar type structures. As stated in the Conservation Easement, buildings considered to be customary and appropriate for park usage, such as ranger's stations, bathrooms, and maintenance buildings, are permissible. To address potential concerns regarding vapor intrusion into these structures, any new construction will be required to include a vapor barrier or vapor intrusion mitigation system in the design. This approach eliminates the uncertainly associated with predicting air concentrations based on soil vapor data.
For the area west of the River, including parcels that are privately -owned, the remedial alternatives identified in the OU-7 FS will include an evaluation of potential vapor intrusion concerns for this area during the remedial design phase if the alternative is selected in the Record of Decision for the OU-7 remedy.
For releases to ambient air, volatile constituent would readily dissipate into the atmosphere by the wind blowing across the site posing an insignificant risk to trespassers or recreators at the site. Vapors could also migrate from ground water or soil gas into on-site buildings constructed in the future, and therefore will require further evaluation. Should on-site maintenance and/or similar-type buildings be constructed in an area overlying the ground water plume, FMC will evaluate whether vapor intrusion into the building would be a concern by collecting empirical soil gas data.
FMC is proceeding with an investigation of PCBs in ground water in 2008 in the vicinity of the former Polymer Plant building because of the detected presence of PCBs in soil at this location. The scope of the investigation will include analysis of ground water samples for specific PCB congeners. Future ground water quality data collected from overburden monitoring wells installed at the Polymer plant will be evaluate to determine if PCBs are at levels that could pose a risk to a
19 OU-7 GROUND WATER BASELINE HHRA-9/23/2008 AR303524
future construction worker. FMC will address potential risks to PCBs in ground water as part of the reporting of the Polymer Plant ground water data.
In summary, this risk assessment for potential future domestic use of on-site and off-site ground water indicates that arsenic and mercury present the greatest threat to a hypothetical future ground water user.
20 OU-7 GROUND WATER BASELINE HHRA-9/23/2008
AR303525
8.0 REFERENCES
ERM. 2007. Second Supplemental Field and Laboratory Data Report for Operable Unit 7: Deep Ground Water Investigation and Pumping Test (ERM 2007). Prepared for FMC Corporation, Philadelphia, PA. ERM, Annapolis, MD.
Exponent. 2000. Feasibility study work plan: Avtex Fibers Superfund site. Operable Unit 7. Prepared for FMC Corporation, Philadelphia, PA. Exponent, Boulder, CO.
Exponent. 2001. Supplemental field and laboratory data report for Operable Unit 7, Avtex Fibers Superfund Site, Front Royal, Virginia. Prepared for FMC Corporation, Philadelphia, PA. Exponent, Boulder, CO.
Foster, S. and P. Chrostowski. 1987. Inhalation Exposures for Volatile Organic Contaminants in the Shower. Presentation a[t the Annual Meeting of APCA, New York. June 21-24,1987.
Gradient. 2002. Baseline Human Health Risk Assessment for the Avtex Fibers Superfund Site, Front Royal, Virginia. Prepared for FMC Corporation, Philadelphia, PA. Gradient Corporation, Cambridge, MA.
U. S. EPA. 1989. Risk Assessment Guidance for Superfund: Volume I -Human Health Evaluation Manual (Part A), Office of Solid Waste and Emergency Response. EPA/540/1-89/002.
USEPA, 1991. Human Health Evaluation Manual, Supplemental Guidance: Standard Default Exposure Factors. U.S. Environmental Protection Agency, Office of Solid Waste and Emergency Response, Washington, DC. Directive 9285.6-03. June 25.
USEPA. 1992. Supplemental Guidance to RAGS: Calculating the Concentration Term. Volume 1, Number 1. U.S. Environmental Protection Agency, Office of Emergency and Remedial Response, Washington, DC. Publication 9285.7-081.
USEPA. 1996. Soil Screening Guidance: Technical Background Document. Office of Solid Waste and Emergency Response. Washington, DC. EPA/540/R-95/128.
21 OU-7 GROUND WATER BASELINE HHRA-9/23/2008
AR303526
USEPA. 1997. Exposure Factors Handbook, Volumes 1-3. U.S. Environmental Protection Agency, Office of Research and Development, Washington, DC. EPA/600-P-95/002Fa,b,c. August.
USEPA. 1998. Risk Assessment Guidance for Superfund, Volume I: Human Health Evaluation Manual, Part D, Standardized Planning, Reporting and Review of Superfund Risk Assessments, Interim. U.S. Environmental Protection Agency, Office of Solid Waste and Emergency Response, Washington, DC. EPA/540/R197/033. January.
USEPA. 2002. Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children. U.S. Environmental Protection Agency, Washington, DC. EPA 540/R-93-081.
USEPA, Region III. 2003. Updated Dermal Exposure Assessment Guidance.
USEPA. 2004. Risk Assessment Guidance for Superfund, Volume I: Human Health Evaluation Manual, Part E, Supplemental Guidance for Dermal Risk Assessment, Final. U.S. Environmental Protection Agency, Office of Solid Waste and Emergency Response, Washington, DC. EPA/540/R99/005. September.
USEPA. 2004. Risk-Based Concentration (RBC) Table. U.S. Environmental Protection Agency, Region III, Philadelphia, PA.
USEPA. 2007a. Risk-Based Concentration (RBC) Table. U.S. Environmental Protection Agency, Region III, Philadelphia, PA.
USEPA. 2007b. ProUCL Version 4.0. Office of Research and Development. Washington, DC. Publication 600/R-038.
USEPA. 2007c. Integrated Risk Information System (IRIS). Online electronic data files (http://www^.epa.gov/iriswebp/iris/index.html). U.S. Environmental Protection Agency, Office of Research and Development, National Center for Environmental Assessment, Cincinnati, OH.
22 OU-7 GROUND WATER BASELINE HHRA-9/23/2008
AR303527
http://www%5e.epa.gov/iriswebp/iris/index.html
Figures
AR303528
FIGURES
AR303529
• MW-03
B02-:
336-5'GM-02B
> MW-09
PW-02 yp.a -±- "̂ ^ ,305
4?
4̂ PZ-11
216,316
GM-08 116
^ GM-09
w Figure 1. Location of Ground Water Wells Used in Baseline Human Health
i5° Assessment ERM
AR303530
Data from specific, ^Wells sampled in 2000, 2002,^
and 2003
Was chemical ever detected?
Is maximum detected concentration >RBC (carcinogens)? >RBC/10 (noncarcinogens)?
Is chemical likely to be site related?
NO
YES
NO Was chemical detected >5% of the time?
Is detected chemical reasonably present in
groundwater?
Chemicals of Potential Concern
(COPC) for HHRA
Figure 2. Flow Diagram for Selection of Chemicals of Potential Concern (COPCs) Avtex Fibers Superfund Site, Front Royal, Virginia.
AR303531
Tables
AR303532
TABLES
AR303533
Table 1 Occurrence, Distribution, and Selection of Constituents of Potential Concern Avtex Fibers Superfund Site, Front Royal, Virginia
'Scenario Timeframe: Current and Future Use Medium: Ground Water Exposure Medium; Groundwater Exposure Point: Tap Water
CAS
Number
TAL Inorganics
7429-90-5
7664-11-7
7440-36-0
7440-38-2
7440-39-3
744043-9
7440-70-2
18540-29-9
7440-18-4
7440-50-8
57-12-5
7439-89-6
7439-92-1
7439-95-t
7439-96-5
7439-97-6
7440-02-0
744009-7
7782-19-2
7440-23-5
7440-62-2
7440*6-6
Constituent *"
(Total)
A luminum
Ammonia
Antimony
Arsenic
Barium
Cadmium
Calcium
Chromium
Cobalt
Copper
Cyanide
Iron
U a d
Magnesium
Manganese
Mercury
Nickel
Potassium
Selenium
Sodium
Vanadium
Zinc
Min imum
Concentration
250
0.35
1.5
3.3
26.9
0.98
2,840
4.6
13.2
5.5
6.3
190
7.3
147
7.3
• 28.3
132
640
12
67,900
3.2
74
Min imum
Qualifier
; )K .
)K
JL
I
-i J J
JL
) L
)
J
Maximum
Concentrahon
4,000
13,000
747
1,170
190
3
281,000
398
833
130
733
13,000
31.2
134,000
2,080
28.3
1,950
152,000
171
14,300,000
721
6,580
Maximum
Qualifier
J
) J
L
1 K
I
.1
Units
m/i-m/i-Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Location
of Maximum
Concentration
603-6
305
116
MW-09
603-8
GM-08
CM-09
CM-08
GM-08
603-8
PW-02
305
PZ-11
603D
GM-09
116
CM-08
116
MW-09
CM-08
MW-09
GM-08
Detection
Frequency'"
5/23
16/24
20/23
22/23
20/23
3/23
23/23
16/23
16/23
13/23
11/16
19/21
5/16
23/23
22/23
1/23
16/Z3
23/23
2/23
23/23
12/23
16/23
Range of
Detection
Limits
19-200
1-10
076 - 5
1.2-5
100
0.9-3
1.6-5
7 1 - 5 0
2.7-25
4 - 2 0
9.8
2.5
0.048-18
8.4-50
3.5
2.6 - 20
8.6-
Concentration
Used for
Screening™
4,000
13,000
747
1,170
190
3
281,000
398
833
130
733
13,000
31.2
134,000
2,080
28.3
1,950
152,000
171
14,300,000
721
6,580
Screening
Toxicity Value
( N / Q ™
3,700 N
21 N
1.5 N
0.045 C
730 N
1.8 N
N U T ' "
11 N "
73 N ' "
150 N
7 3 N
2,600 N
15™
NUT™
73 N
0.37 N " " '
73 N
N U T " "
18 N
N U T " '
3.7 N
MOON
Potential
ARAR/TBC
Value
----— -
• -
--— -------— ---—
Potential
ARAR/TBC
Source
---------------------—
COPC
Flag
. (Y /N)
Y
Y
Y
Y
N
Y
N
Y
Y
N
Y
Y
Y
N
Y
Y
Y
N
N
N
Y
Y
Rationale foi
Selection or
Deletion
ASL
ASL
ASL .
ASL
BSL
ASL
NUT
ASL
ASL
BSL
ASL
ASL
ASL
NUT
ASL
ASL
ASL
NUT
BSL
NUT
ASL
/WL
Page 1 of 2
AR303534
Table 1 Occurrence, Distribution, and Selection of Constituents of Potential Concent Avtex Fibers Superfund Site, Front Royal, Virginia
Scenario Timeframe: Current and Future Use
Medium: Ground Water
Exposure Medium: Groundwater
Exposure Point: Tap Water ^
CAS
Number
TCL SVGAs
105-67-9
95-57-8
95-18-7
106-44-5
117-81-7
78-59-1
91-20-3
87.«6-5
85-01-8
108-95-2
TCL VOAs
75-34-3
78-93-3
108-10-1
67-64-1
75-15^
108-88-3
Constituent *"
2,4-Dimelhylphenol •
2-Chlorophenol
2-MethyIphenol (o-Cresol)
4-Methylphenol (p-CresoI)
bis(2-Ethylhexyl)phthaIate
Isophorone
Naphthalene
Pentachlorophenol
Phenanthrene
Phenol
1,1-Dichloroethane
2-Butanone (MEK)
4-Methyl-2-pentanone
Acetone
Carbon disulfide
Toluene
Min imum
Concentrahon
4
2
2
3
3
2
65
6
18
3
18
7
3
13
6
8
Min imum
Qualifier
L
Maximum
Concentration
11
2
470
280
12
2
65
6
18
34,000
18
53
42
5,300
540,000
16
Maximum
Qualifier
J
L
1 L
J J
J
) J
J
Units
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
MR/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Location
of Maximum
Concentration
MW-09
116
MW-09
MW-09
GM-08
PW-02 and 205
MW.03
MW-03
MW-09
MW-09
' 116
305
116
116
MW-03
603-6
Detection
Frequency'-'
3/16
1/16
10/16
9/16
3/16
2/16
1/16
1/16
1/16
13/16
1/38
2/38
3/38
15/38
33/38
7/38
Range of
Detection
Limits
0.9-1
0.9-1
0 .9-1
3
2 -20
0.9-10
0.9-10
3-31
0.9-1
0.9-1
1-250
3-500
3-500
6-2000
5
1-500
Concentration
Used for
Screening"'
11
2
470
280
12
2
65
6
18
34,000
18
53
42
5,300
540,000
16
Screening
Toxicity Value
( N / Q ' "
7 3 N
3.0 N
180 N
18 N
4.8 C
70 C
065 N
056 C •
37N '= '
1,100 N
9 0 N
700 N
630 N
550 N
100 N
230N
Potential
ARAR/TBC
Value
---- •
------
------
Potential
ARAR/TBC
Source
----------
-----
• -
COPC
Flag
(Y /N)
N
N
Y
Y
Y
N
Y
Y
N
Y
N
N
N
Y
Y
N
Rationale for
Selection or
Deletion
BSL
BSL
ASL
ASL
ASL
BSL
ASL
ASL
BSL
ASL
BSL
BSL
BSL
ASL
ASL
BSL
(1) Constituents wi th at least one positive detection included in the screening analysis; all data from packer wells included
(2) B Qualified data vk'ere not included as a detection.
(3) Maximum concentration used for screening.
(4) EPA Region Ml RBCs for tap water (Apri l 6, 2007). RBC values for noncarcinogens were divided by 10 for use in screening.
( "C = carcinogenic, "NC" = non
Table 2 Selection of Exposure Pathways Avtex Fibers Superfund Site, Front Royal, Virginia
Scenario
Timeframe
Current
Medium
Groimdwater
•
Soil
SoU
Exposure
Medium
Grovmdvk'ater
Air
Surface SoU
Surface Soil
Exposure
Point
Tap water
Showerhead vapors
Volatiles released from Ground
Surface
Viscose Basins 9 -11
Viscose Basins 9 -11
Receptor
Population
Resident
Resident
Trespasser / Recreational / Meuntenance
Worker
Trespasser / Recreational
Maintenance Worker
Receptor
Age
Adult/(3uld
Adult/Child
Adult/Child
Adult/Child
Older Youth/Adult
Older Youth/Adult
Older Youth/Adult
Adult
Adult
Adult
Exposure
Route
Ingestion
Dermal
Inhalation
Inhalation
Ingestion
Dermal
Inhalation
Ingestion
Dermal
Inhalation
On-Site/
Off-Site
Off-Site
Off-Site
Off-Site
On-Site / Off-Site
On-Site
On-Site
On-Site
On-Site
On-Site
On-Site
Type of
/Analysis
None
None
None
Qualitative
None
None
None
None
None
None
Rationale for Selection or Exclusion
of Exposure Pathway
No drinking water wells currently drawing from affected groundwater
No drinking water weUs currently drawing from affected groundwater
No drinking water wells currently drawing from affected groundwater
Constituents present in ground water could volatUze and be released to ambient air at ground surface.
Direct contact exposures evaluated in Baseline Human Health Risk Assessment (Gradient, 2002
Direct contact exposures evaluated in Baseline Himian Health Risk Assessment (Gradient, 2002
Direct contact exposures evaluated in BaseUne Human Health Risk Assessment (Gradient, 2002
Direct contact exposures evaluated in Baseline Human Health Risk Assessment (Gradient, 2002
Direct contact exposures evaluated in Baseline Human Health Risk Assessment (Gradient, 2002
Direct contact exposures evaluated in Baseline Hvmian Health Risk Assessment (Gradient, 2002
Page 1 of 2
AR303536
Table 2 Selection of Exposure Pathways Avtex Fibers Superfund Site, Front Royal, Virginia
Scenario
Timeframe
Future
Medium
Groundwater
Exposure
Medium
Groundwater
Ail
Exposure
Point
Tap water
Showerhead vapors
Volatiles released from Ground
Surface
Receptor
Population
Resident
Resident
Trespasser / Recreational / Maintenance
Worker
Receptor
Age
Adult/ChUd
Adult/Child
Adult/Child
Adult/Child
Exposure
Route
Ingestion
Dermal
Inhalation
Inhalation
On-Site/'
Off-Site
On-Site / Off-Site
On-Site / Off-Site
On-Site / Off-Site
On-Site / Off-Site
Type of
Analysis
Quantitative
Quantitative
Quantitative
Qualitative
Rationiile for Selection or Exclusion
of Exposure Pathway
Concern for future residential development; risks estimated using on-site data
Concern for future residential development; risks estimated using on-site data
Concern for futiu'e residential development; risks estimated using on-site data
Constituents present in ground water could volatilze and be released to ambient air at ground surface.
Page 2 of 2
AR303537
Table 3 Medium-Specfic Exposure Point Concentration Summary Reasofmble Maximum Exposure Avtex Fibers Superfund Site, Front Royal, Virginia
Scenario Timeh-ame; Future
Medium: Ground Water
Exposure Medium: Groundwater
Exposure Point: Tap Water
Exposure Point
' —
Constituent of
Potential Concern
Aluminum
Ammonia
Antimony
Arsenic
Cadmium
Chromium
Cobalt
Cyanide
Iron
Lead
Manganese
Mercury
Nickel
Vanadium
Zinc
2.Methylphenol
4-MethyIptienol
bis(2-Elhylhexyl)phthalate
Naphthalene
Pentachlorophenol
Phenol
Acetone
Carbon disulfide
Units
Mg/L .
Mg/L
Mg/L
M8/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Arithmetic
Mean
465
5.4
240
470
-83
325
240
2,900
22
200
-580
120
2,270
80
72
--
6,000
1,000
58,900
95% UCL
(Disnibution)
2,700 (1)-
6.7 (2)
303 (2)
580 (2)
• 3 (3)
180 (4)
380 (2)
260 (2) •
5,450 (5)
31.2 (6)
1,380 (1)
28.3 (3)
720 (6)
285 (4)
4,046 (4)
355 (1)
77 (6)
12 (3)
65 (3)
6 (3)
15,440 (4)
1,130 (7).
152,600 (4)
Maximum
Concentration
(Qualifier)
4,000
13
641
1,170
3
3981
833)
733
13,000
31.2
• 2,080
28.3 L
1,950)
721
6,580)
470
280
12 L
65 L
6)
34,000
5,250)
540,000
Value
2,700
6.7
303
580
3
180
380
260
5,450
31.2
1,380
28.3
720
285
4,046
355
77
12
65
6
15,440
1,130
152,600
Exposure Point Concentrahon
Units
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Statistic
Non-parametinc
Non-parametric
Non-parametnc
Non-parametnc
Maximum
Non-paramebic
Non-parametric
Non-parametinc
Gamma
Maximum
Non-parametnc
Maximum
Non-parametric
Non-parametric
Non-parametnc
Non-parametric
Non-parametinc
Maximum
Maximum
- Maximum
Non-paramebic
Nori-parametric
Non-parametric
1 Rationale
EPA, 2007
EPA, 2007
EPA, 2007
EPA, 2007
EPA, 1992
EPA, 2007
EPA, 20O7
EPA, 2007
EPA, 2007
EPA, 2007
EPA, 2007
EPA, 1992
EPA, 2007
EPA, 2007
EPA, 20O7
EPA, 2007
EPA, 2007
EPA, 1992
EPA, 1992
EPA, 1992
EPA, 2007
EPA, 2007
EPA, 2007
Notes:
Ground water data used for the calculation of the EPC are provided in Appendix A, Table A-1 .
Prior to calculating the EF^, held and laboratory results were averaged. When available, furnace method data for some metals included in analysis.
EPC = Exposure Point Concentration
UCL = Upper Confidence Limit
B = Not detected substantially above 5 times level reported in lab or field blanks.
Foi- common contaminants (acetone, phthlate esters), not detected above 10 times level reported in lab or field blanks.
J = Estimated concentrahon.
L = Concentration is biased low.
(1) 99% KM (Chebyshev) UCL
(2) 95% K M (0 UCL
(3) Because few detections (less than 50% of the samples) were observed,
the maximum concentration was selected as the exposure point ccncentratiori.
(4) 95% KM (Chebyshev) UCL
(5) 95% Approximate Gamma UCL
(6) 95% KM (Penrentile Bootstrap) UCL -
(7) 95% KM (BCA) UCL
EPA, 2007. ProUCL 4.0. U.S. Ehvirx)nmental Protection Agency, Office of Research and Development. Washington DC. Publication 600/R-07/038.
EPA, 1992. Supplemental Guidance to RAGS: Calculating the Concenti-ation Term. Volume 1. U.S, Environmental Protection Agency, Office of Emergency and Remedial Response, Washington E>C. Publication 9285.7-081.
Page 1 of 1 AR303538
Table 4a Values Used for Daily Intake Calculations - Adult Resident, Ingestion and Dermal Reasonable Maximum Exposure Avtex Fibers Superfund Site, Front Royal, Virginia
Scenario Timeframe: Future
Medium: Ground Water
Exposure Medium; Ground Water
Exposure Point Tap Water
Receptor Population: Resident
Receptor Age: Adult
Exposure Route
Ingestion
Dermal
Parameter
Code
CW
IR-W
EF
ED
CFl
BW
AT-C
AT-N
IF-C
IP-NC
DAD
DA.,„,
SA
EV
EF
ED
CF
BW
AT-C
AT-N
IF-C
IF-NC
Parameter Definition
Constituent Concentration in Water
Ingestion Rate of Water
Exposure Frequency
Exposure Duration
Conversion Factor 1
Body Weight
Averaging Time (Cancer)
Averaging Time (Non-Cancer)
Intake Factor (Cancer)
Intake Factor (Non-
Table 4b Values Used for Daily Intake Calculations - Adult Resident, Inhalation Reasonable Maximum Exposure Avtex Fibers Superfund Site, Front Royal, Virginia
Scenario Timeframe: Future
Medium: Ground Water
Exposure Medium: Air
Exposure Point Showerhead Vapors
Receptor Population; Resident
Receptor Age: Adult
Exposure Route
Inhalation
Parameter
Code
D
EF
ED
AT-C
AT-N
IF-C
IF-NC
Parameter Definition
Inhalation Dose
Exposure Frequency
Exposure Duratioti
Carcinogenic averaging time
Noncarcinogenic averaging time
Carcinogenic Dose
Noncarcinogenic Dose
Value
chemical-specific
350
24
25,550
8,760
chemical-specific
chemical-specific
Units
tng/kg/shower
day/year
year
days
days
mg/kg-day
mg/kg-day
Rationale/
Reference
(see model)
EPA 1991
EPA 1991
EPA 1989
EPA 1989
(see itiodel)
(see model)
CT
Value
-------
CT
Rationale/
Reference
-------
Intake Equation/
Model Name
Foster, SA. and P.C Chrostowski, 1987.
(see Appendix B, Table B-2)
Foster and Chrostowski Model equations and assumptions provided in Appendix B Table B-2.
U.S. EPA. 1991. Human Health Evaluation Manual, Supplemental Guidance: Standard Default Exposure Factors. U.S. Environmental Protection Agency, Office of Solid Waste and Emergency Response.
Directive 9285.6-03. June 25,1991.
Foster, S. and P. Chrostowski. 1987. Inhalation Exposures of Volatile Organic Contaminants in the Shower. Presentation at the Annual
Meeting of APCA, New York. June 21-28,1987.
.Page 1 of 1
AR303540
Table 4c Values Used for Daily Intake Calculations - Child Resident, Ingestion and Dermal Reasonable Maximum Exposure Avtex Fibers Superfund Site, Front Royal, Virginia
Scenario Timeframe: Future
Medium: Ground Water
Exposure Medium; Groundwater
Exposure Point Tap Water
Receptor Population; Resident
Receptor Age; Child
Exposure Route
Ingest ion
Dermal
Parameter
Code
C W
m-w EF
ED
C F l
BW
A T - C
A T - N
IF-C
IF -NC
D A D
D A . „ , „ ,
SA
EV
EF
ED
CF
BW
AT-C
A T - N .
IF-C
IF-NC
Parameter Def in i t ion
Const i tuent Concentrat ion in Water
Ingestion Rate o f Water
Exposure Frequency
Exposure Dura t ion
Conversion.Factor 1
Body Weigh t
Averag ing T ime (Cancer)
Averag ing T ime (Non-Cancer)
Intake Factor (Cancer)
Intake Factor (Non
Table 4d Values Used for Daily Intake Calculations Child Resident, Inhalation Reasonable Maximum Exposure Avtex Fibers Superfund Site, Front Royal, Virginia
Scenario Timeframe: Future Medium: Ground Water Exposure Medium: Air Exposure Point: Showerhead Vapors Receptor Population: Resident Receptor Age: Child
Exposure Route
Inhalation
Parameter
Code
D
EF
ED
AT-C
AT-N
IF-C
IF-NC
Parameter Definition
Inhalation Dose
Exposure Frequency
Exposure Duration
Carcinogenic averaging lime
Noncarcinogenic averaging time
Carcinogenic Dose
Noncarcinogenic Dose
Value
chemical-specific
350
6
25.550
2,190
chemical-specific
chemical-specific
Units
mg/kg/shower
day/year
year
days
days
mg/kg-day
mg/kg-day
Rationale/
Reference
(see model)
EPA 1991
EPA 1991
EPA 1989
EPA 1989
(see model)
(see model)
CT
Value
-------
CT
Rationale/
Reference
-------
Intake Equation/
Model Name
Foster, S.A. and P.C. Chrostowski, 1987.
(see Appendix B, Table B-2)
Foster and Chrostowski Model equations and assumptions provided in Appendix B Table B-2.
U.S. EPA. 1991. Human Health Evaluation Manual, Supplemental Guidance: Standard Default Exposure Factors. U.S. Environmental Protection Agency, Office of Solid Waste and Emergency Response.
Directive 9285.6-03. June 25,1991.
Foster, S. and P. Chrostowski. 1987. Inhalation Exposures of Volatile Organic Contaminants in the Shower. Presentation at the Annual
Meeting of APCA, New York. June 21-28,1987.
Pagel of 1
AR303542
Table 5a NoH-Caticer Toxicity Data — Oral/Dermal Avtex Fibers Superfund Site, Front Royal, Virginia
Const i tuent
of Potential
Concern
A l u m i n u m
A m m o n i a
A n t i m o n y
Arsenic
Cadm ium
C h r o m i u m , hexavalent
Cobalt
Cyanide
Iron
Lead
iManganese
Mercury (methy lmercury)
Nickel
Vanad ium
Zinc
2-Methylphenol
4-Methy lphenol
b is(2-Ethylhexyl)phthaUte
Naphthalene
Pentachlorophenol
Phenol
Acetone
Carbon d isu l f ide
Ch ron i c /
Subchronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chron ic
Chronic
Ora l R fD
Value
l.OE+00
N A
4.0E-04
3.0E-04
5.0E-04
3.0E-03
2.0E-02
2.0E-02
7.0E-01
N A
2.0E-02
1.0E-04
2.0E-02
1.0E-O3
3.0E-01
5.0E-02
5.0E-03
2.0E-02
2.0E-02
3.0E-02
3.0E-01
9.0E-01
1.0E-01
Uni ts
m g / k g / d
" " g / k g / d
m g / k g / d
" i g / k g / d
t n g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
Ora l Absorp t ion
Efficiency for Dermal
(1)
l.OE+00
l.OE+00
1.5E-01
l.OE+00
5.0E-02
2.5E-02
l.OE+00
l.OE+00
l.OE+00
l.OE+00
4.0E-02
l.OE+00
4.0E-fl2
2.6E-02
l.OE+00
l.OE+00
l.OE+00
l.OE+00
, l.OE+00
l.OE+00
l.OE+00
' l.OE+00
l.OE+00
Absorbed RfD for Dermal
Value
l.OE+00
N A
6.0E-05
3.0E-04
2.5E-05
75E-05
2.0E-02
2.0E-02
7.0E-01
N A '
8.0E-04
1.0E-O4
8.0E-04
2.6E-05
3.0E-01
5.0E-02
5.0E-03
2.0E-02
2.0E-02
3.0E-02
3.0E-01
9.0E-0I
1.0E-01
Units
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
m g / k g / d
Pr imary
Target
Organ(s)
developmental nervous system
-blood
sk in, vascular
k idney
none reported
b lood, sk in, respiratory
thy ro id , mye l in
b lood, l iver, G I ti-act
N A
Cenb-al Nervous System (CNS)
N A
k idney, l iver, spleen
k idney
b lood
who le body (decreased weight ) , CNS
CNS, respiratory, who le body (maternal death)
l iver
who le body (decreased weight) , k idney, thymus
l iver, k idney
who le body, fehjs
k idney
fehis
Combined
Unce r ta in t y / ^ ^od i l y i ng
Factors
— - '
1 0 0 0 / 1
3 / 1
1 0 / 1
3 0 0 / 3
-100 / 5
-N A
1 / I
3 0 0 / 1
1 0 0 / 1
3 / 1
1000 / 1
1000 / 1
1000 / 1
3000 / 1
1 0 0 / 1
3 0 0 / 1
1000 / 1
1 0 0 / 1
RfD:Target Organ(s) |
Source(s)
NCEA, Region m
N C E A , Region HI
IRIS
IRIS
IRIS
IRIS
N C E A , Region m
IRIS
N C E A , Region HI
N A
IRIS
N A
IRIS
N C E A , Region m
nus IRIS •
HEAST
IRIS
IRIS
mis mis
IRIS
IRIS
Date(s)
( M / D / Y Y Y Y )
N A
-2 /1 /1991
2 /1 /1993
02 /01 /94
• 09 /03 /98
N A
0 2 / 0 1 / 9 3
N A
N A
05 /01 /96
12 /01 /96
08 /03 /05
09 /01 /90
8 /1 /1993 ( w t i h d r a w n )
0 5 / 0 1 / 9 1
09 /17 /98
02 /01 /93
0 9 / 3 0 / 0 2
07 /31 /03
0 9 / 0 1 / 9 0
IRIS = Intgrated Risk Information System
HEAST = Health Effects Assessment Summary Tables
NCEA = National Center for Environmental Assessment
— = Not Available
RfD = Reference Dose
NA= Not Applicable
(1) Oral absorption efficiencies obtained from EPA 2004; EPA Region m, June 2003.
Date represents: IRIS - date when toxicity information last updated in database; NCEA - article date
Source as cited by US EPA Region III Risk-Based Concentration Table (April, 2007).
US EPA Region 111. Risk-Based Concenti-ation (RBQ Table. US Environmental Protection Agency, Region Ul, Philadelphia, PA.
U.S. EPA. 2004. Risk Assessment Guidance for Superfund, Volume 1: Human Health Evaluation Manual (Part E, Supplemental Guidance for Dermal Risk Assessment). Office of Solid Waste and
Emergency Response, Washington, DC. EPA/540/R/99/005. July.
Page 1 of 1
AR303543
Table 5b Non-Cancer Toxicity Data — Inhalation Avtex Fibers Superfund Site, Front Royal, Virginia
Constituent
of Potential
Concern
Aluminum
Ammonia
Antimony
Arsenic
Cadmium
Chromium, hexavalent
Cobalt
Cyanide
Iron
Lead
Manganese
Mercury (methylmercury)
Nickel
Vanadium
Zinc
2-Methylphenol
4-Methylphenol
bis(2-Ethylhe)(yl)phthalate
Naphthalene
Pentachlorophenol
Phenol
Acetone
Carbon disulfide
Chronic/
Subchronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Inhalation RIC
Value
3.5E-03
l.OE-01
NA
NA
2.0E-04
l.OE-04
2.0E-05
NA
NA
NA
5.0E-05
3.0E-04
NA
NA
NA
NA
NA
NA
3.0E-03
NA
NA
NA
7.0E-01
Units
mg/m^
mg/m?
m g / m '
mg/m^
m g / m '
m g / m '
m g / m '
m g / m '
m g / m '
m g / m '
m g / m '
m g / m '
m g / m '
m g / m '
m g / m '
m g / m '
m g / m '
m g / m '
m g / m '
m g / m '
m g / m '
m g / m '
m g / m '
Extrapola
Value
1.0E-03
2.9E-02
NA
NA
5.7E-05
3.0E-05 •
5.7E-06
NA
. NA
. NA
1.4E-05
g.6E-05
NA
NA
NA
NA
NA
NA
9.0E-O4
NA
NA
NA
2.0E-01
ted RfD
Units
mg /kg /d
mg /kg /d
m g / k g / d
mg /kg /d
mg /kg /d
mg /kg /d
mg /kg /d
mg /kg /d
mg /kg /d
mg /kg /d
mg /kg /d
mg /kg /d
mg /kg /d
mg /kg /d
mg /kg /d
mg /kg /d
mg /kg /d
mg /kg /d
mg /kg /d
mg /kg /d
mg /kg /d
mg /kg /d
mg /kg /d
Primary
Target
Org'an(s)
NA
NA
NA
• NA
respiratory
NA
NA .
NA
NA
CNS
CNS
NA
NA
NA
NA
NA
NA
upper respiratory tract
NA
NA
NA
peripheral nervous system
Combined
Uncertainty/Modifying.
Factors
NA
NA
NA
NA
300/ 1
NA
NA
NA
NA
1000 / 1
3 0 / 1
NA
NA
NA
NA
NA
NA
3000 / 1
NA
NA
NA
3 0 / 1
RfC: Target Organ(s)
Source(s) Date(s)
(MM/DD/YYYY)
NCEA, Region III
NA
NA
NCEA, Region n i
IRIS
NCEA, Region III
NA
NA
NA
IRIS
IRIS
NA
NA
NA
NA
NA
NA
IRIS
NA
NA
NA
IRIS
NA
NA
NA
NA
9/3/1998
NA
NA
NA
NA
12/1/1993
6/1/1995
NA .
NA
NA
NA
NA
NA
9/17/1998
NA
NA
NA
8/1/1995
IRIS = Intgrated Risk Information System
NCEA = National Center for Environmental Assessment
— = Nol Available
RIC = Reference Concentration; RfD = Reference Dose
NA = Not Applicable
Date represents: IRIS - date when toxicity information last updated in database; NCEA - article date
Source as cited by US EPA Region III Risk-Based Concentration Table (April, 2007).
US EPA Region HI. Risk-Based Concentration (RBQ Table. US Environmental Protection Agency, Region III, Philadelphia, PA.
Page 1 of 1
AR303544
Table 6a Cancer Toxicity Data — Oral/Dertnal Avtex Fibers Superfund Site, Front Royal, Virginia
Constituent
of Potential
Concern
Aluminum
Ammonia
Antitnony
Arsenic
Cadmium
Chromium, hexavalent
Cobalt
Cyanide
Iron
Lead
Manganese
Mercury (methylmercury)
Nickel
Vanadium
Zinc
2-Methylphenol
4-Methylphenol
bis(2-Ethylhexyl)phthalate
Naphthalene
Pentachlorophenol
Phenol
Acetone
Carbon disulfide
Oral Cancer
Value
NA
NA
NA
1.5E+00
„ NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
1.4E-02
NA
1.2E-01
NA
NA
NA
Slope Factor
Units
(mg/kg-day)'
(mg/kg-day)'
(mg/kg-day)"'
(mg/kg-day)"'
(mg/kg-day)"'
(mg/kg-day)"'
(mg/kg-day)'
(mg/kg-day)"'
(mg/kg-day)"'
(mg/kg-day)"'
(mg/kg-day)"'
(mg/kg-day)"'
(mg/kg-day)"'
(mg/kg-day)"'
(mg/kg-day)'
(mg/kg-day)'
(mg/kg-day)'
(mg/kg-day)"'
(mg/kg-day)"'
(mg/kg-day)"'
(mg/kg-day)'
(mg/kg-day)"'
(mg/kg-day)"'
Oral Absorption
Efficiency for Dermal
(1)
l.OE+00
l.OE+00
1.5E-01
l.OE+00
5.0E-02
2.5E-02
l.OE+00
l.OE+00
l.OE+00
l.OE+00
4.0E-02
l.OE+00
4.0E-02
2.6E-02
l.OE+00
l.OE+00
l.OE+00
l.OE+00
l.OE+00
l.OE+00
l.OE+00
l.OE+00
l.OE+00
Absorbed Can
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