BASELINE HUMAN HEALTH RISK ASSESSMENT - OU 7 GROUND … · Baseline Human Health Risk Assessment...

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


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.


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.


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.


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.


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.


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 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


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


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



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


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



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


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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