PUBLIC HEALTH ASSESSMENT

ROSS METALS INCORPORATED
ROSSVILLE, FAYETTE COUNTY, TENNESSEE

APPENDICES

APPENDIX A - FIGURES

Figure 1. Site Location Map

Figure 2. Site Map

Figure 3. Intro Map

APPENDIX B - TABLES

List of Acronyms Appearing in Tables

CREG -	Cancer Risk Evaluation Guide for 1x10-6 excess cancer risk
EEP -	State of Tennessee Environmental Epidemiology Program
EMEG -	Environmental Media Evaluation Guide (ATSDR)
iEMEG -	intermediate Environmental Media Evaluation Guide (ATSDR)
LTHA -	Lifetime Health Advisory for drinking water (EPA)
MCLG -	Maximum Contaminant Level Goal (EPA)
MRL -	Minimal Risk Level (ATSDR)
RCRA -	Resource Conservation and Recovery Act
RMEG -	Reference Dose Media Evaluation Guide
SRSC -	Superfund Remedial Site Characterization
STCR -	Superfund Time-Critical Removal

Appendix B, Table 1 - Contaminants Detected in On-site Surface Soil (0"-6") Samples, Above Environmental Screening Values and Eastern U.S. Background Values in the Operational Area at the Ross Metals, Inc. National Priorities List Site - Rossville, Fayette County, Tennessee

Contaminant	Concentration Range (mg/kg)		Sample Date	Reference	Sample Location	Screening Value (mg/kg)		Cancer Class
	Minimum	Maximum				Value	Source
Antimony	20UJ	270J	11/20/96	SRSC	Grass area	20	RMEG
Arsenic	24J	230J	11/20/96	SRSC	Grass area	20 0.5	EMEG CREG	A
Lead	4,100	43,000	11/20/96	SRSC	Grass area	400	EPA	B2

Appendix B, Table 2 - Contaminants Detected in On-site Surface Soil (Landfill Area) Samples, Above Environmental Screening Values and Eastern U.S. Background Values at the Ross Metals, Inc. National Priorities List Site - Rossville, Fayette County, Tennessee

Contaminant	Concentration Range (mg/kg)		Sample Date	Reference	Screening Value (mg/kg)		Cancer Class
	Minimum	Maximum			Value	Source
Antimony	5U	75J	11/19/96	SRSC	20	RMEG
Arsenic	7J	76J	11/19/96	SRSC	20 0.5	EMEG CREG	A
Lead	260	50,800	07/01/97	EEP	400	EPA	B2

Appendix B, Table 3 - Contaminants Detected in On-site Groundwater (Monitoring Wells), Above Environmental Screening Values at the Ross Metals, Inc. National Priorities List Site - Rossville, Fayette County, Tennessee

Contaminant	Concentration Range (µg/L)		Sample Date	Reference	Screening Value (µg/L)		Cancer Class
	Minimum	Maximum			Value	Source
Antimony	20U	60U	06/13/95	STCR	4	RMEG
Arsenic	5U	110	05/09/90	RCRA	3 0.02	EMEG CREG	A
Chromium	2U	77	05/09/90	RCRA	50	RMEG	A
Lead	2U	500	05/09/90	RCRA	15	EPA	B2
Manganese	3U	5,600	11/21/96	SRSC	50	RMEG
Vanadium	10U	160	05/09/90	RCRA	30	iEMEG

Appendix B, Table 4 - Contaminants Detected in Off-site Surface Soil (0"-6") Samples, Above Environmental Screening Values and Eastern U.S. Background Values at the Ross Metals, Inc. National Priorities List Site - Rossville, Fayette County, Tennessee

Contaminant	Concentration Range (mg/kg)		Sample Date	Reference	Sample Location	Screening Value (mg/kg)		Cancer Class
	Minimum	Maximum				Value	Source
Antimony	3.3UJ	51J	11/19/96	SRSC	Woodland	20	RMEG
Arsenic	5.3J	86J	11/19/96	SRSC	Woodland	20 0.5	EMEG CREG	A
Lead	89J	12,000	11/19/96	SRSC	Woodland	400	EPA	B2

Appendix B, Table 5 - Contaminants Detected in Off-site Surface Soil (Composite Samples), Above Environmental Screening Values and Eastern U.S. Background Values at the Ross Metals, Inc. National Priorities List Site - Rossville, Fayette County, Tennessee

Contaminant	Concentration Range (mg/kg)		Sample Date	Reference	Screening Value (mg/kg)		Cancer Class
	Minimum	Maximum			Value	Source
Antimony	6.0U	22	11/28/90	RCRA	20	RMEG
Arsenic	8.4	20	11/28/90	RCRA	20 0.5	EMEG CREG	A
Lead	290	2,400	11/28/90	RCRA	400	EPA	B2

Appendix B, Table 6 - Contaminants Detected in Off-site Groundwater (Monitoring Wells), Above Environmental Screening Values at the Ross Metals, Inc. National Priorities List Site - Rossville, Fayette County, Tennessee

Contaminant	Concentration Range (µg/L)		Sample Date	Reference	Screening Value (µg/L)		Cancer Class
	Minimum	Maximum			Value	Source
Antimony		20U	11/21/96	SRSC	4	RMEG
Arsenic	5U	40U	11/21/96	SRSC	3 0.02	EMEG CREG	A
Lead	2U	1,400	11/20/96	SRSC	15	EPA	B2

Appendix B, Table 7 - Contaminants Detected in Off-site Surface Water Samples, Above Environmental Screening Values at the Ross Metals, Inc. National Priorities List Site - Rossville, Fayette County, Tennessee

Contaminant	Concentration Range (µg/L)		Sample Date	Reference	Screening Value (µg/L)		Cancer Class
	Minimum	Maximum			Value	Source
Antimony	20	130U	06/14/95	STCR	4	RMEG
Arsenic	7U	150	06/14/95	STCR	3 0.02	EMEG CREG	A
Cadmium	14	120	06/14/95	STCR	7	EMEG	B1
Lead	57	16,000	06/14/95	STCR	15	EPA	B2
Manganese	300	1,400	11/20/96	SRSC	50	RMEG
Thallium	5U	100	05/09/90	RCRA	0.4	LTHA

APPENDIX C - ENVIRONMENTAL EXPOSURE PATHWAYS

Appendix C, Table 1 - Completed Environmental Exposure Pathways at the Ross Metals, Inc. National Priorities List Site, Rossville, Fayette County, Tennessee

On-Site Completed Exposure Pathways Elements
Source	Environmental Medium	Pathway Status	Point of Exposure	Route of Exposure	Exposed Populations	Number Exposed
Site related activities	Soil less than 6 inches below the surface	Past, Current, Future	Operational area	Inhalation, Dermal absorption, Incidental ingestion	On-site Workers and Persons visiting or trespassing upon the site	Not Known
Site-related and Non-site-related Activities	Soil less than 6 inches below the surface	Past, Current, Future	Landfill area	Inhalation, Dermal absorption, Incidental ingestion	Anyone who comes into contact with the contaminated soil without using proper personal protective equipment or taking personal hygiene measures	Not Known
Physical Hazards	Discarded site equipment, dumped waste	Past, Current, Future	Operational and Landfill areas of the site	Inhalation, Dermal absorption, Incidental ingestion	Anyone who trespasses upon the site property and comes into contact with the contaminated materials and equipment	Not Known
Site-related and Non-site-related Activities	Air	Past	Outdoors	Inhalation	On-site Workers and Residents in the vicinity of the site	Less than 750 persons
Off-site Completed Exposure Pathway Elements
Site-related and Non-site-related Sources	Soil less than 6 inches below the surface	Past, Current, Future	Woodland and wetland areas next to the site	Inhalation, Dermal absorption, Incidental ingestion	Recreational users of the land next to the site	Not Known
Site-related and Non-site-related Sources	Soil less than 6 inches below the surface	Past	Residential areas adjacent to the site	Inhalation, Dermal absorption, Incidental ingestion	Residents and visitors of homes with contaminated soil	Less than 50 persons

Appendix C, Table 2 - Potential (Possible) Environmental Exposure Pathways at the Ross Metals, Inc. National Priorities List Site, Rossville, Fayette County, Tennessee

On-Site Potential Exposure Pathways Elements
Source	Environmental Medium	Pathway Status	Point of Exposure	Route of Exposure	Exposed Population	Number Exposed
Site Activities	Soil more than 6 inches below the surface	Past, Current, Future	Operational and Landfill areas of the site	Inhalation, Dermal absorption, Incidental ingestion	Anyone who digs into the soil, unless the contaminated soils are removed from the site	None Known
Former Site Activities	Groundwater (on-site)	Future	Water exit point	Ingestion, Dermal absorption, Inhalation	People who use water from the contaminated aquifer	None Currently Known
Off-Site Potential Exposure Pathway Elements
Surface Runoff	Surface Water	Past, Current, Future	Wetlands area near site	Incidental ingestion, Dermal absorption, Inhalation	Residents and anyone who uses the wetlands area adjacent to the site for recreational purposes	Not Known

Appendix C, Table 3 - Eliminated (Non-Apparent) Environmental Exposure Pathways at the Ross Metals, Inc. National Priorities List Site, Rossville, Fayette County, Tennessee

Eliminated On-Site Exposure Pathway Elements
Source	Environmental Medium	Pathway Status	Point of Exposure	Route of Exposure	Exposed Population	Number Exposed
Former Site Activities	Groundwater (on-site)	Past, Current	Water exit point	Ingestion, Inhalation, Dermal absorption	None Expected	None Known
Eliminated Off-Site Exposure Pathway Elements
						None Known
Site-related and Non-site-related activities	Surface soil	Current, Future	None Expected	Incidental ingestion, Dermal absorption, Inhalation	Residents	None Known

APPENDIX D - HEALTH GUIDELINES, EXPOSURE DOSE ESTIMATION, AND RISK ESTIMATES

Health Guidelines

Health guidelines provide a basis for comparing estimated exposures with concentrations of contaminants in different environmental media (soil, air, water, and food) to which people might be exposed.

Non-Cancer Health Effects

ATSDR has developed a Minimal Risk Level (MRL) for contaminants commonly found at hazardous waste sites. The MRL is an estimate of daily exposure to a contaminant below which non-cancer, adverse health effects are unlikely to occur. MRLs are developed for different routes of exposure, like inhalation and ingestion, and for lengths of exposure, such as acute (less than 14 days), intermediate (15-364 days), and chronic (365 days or greater). Oral MRLs are expressed in units of milligrams of contaminant per kilogram of body weight per day (mg/kg/day). Because ATSDR has no methodology to determine amounts of chemicals absorbed through the skin, the Agency has not developed MRLs for dermal exposure. The method of deriving MRLs does not include information about cancer, therefore, an MRL does not imply anything about the presence, absence, or level of cancer risk. If an ATSDR MRL is not available as a health value, then EPA's Reference Dose (RfD) is used. The RfD is an estimate of daily human exposure to a contaminant for a lifetime below which (non-cancer) health effects are unlikely to occur (9).

Cancer Health Effects

The EPA classifies chemicals as Class A, Class B, Class C, Class D, or Class E. This classification defines a specific chemical's ability to cause cancer in humans and animals. According to EPA, Class A chemicals are known human carcinogens, and Class B chemicals are probable human carcinogens. Class B is further subdivided into two groups:  Group B1 consists of chemicals for which there is limited evidence of carcinogenicity from epidemiologic studies in humans; and Group B2 consists of chemicals for which there is sufficient evidence of carcinogenicity in animals, but inadequate evidence or no data available from epidemiologic studies in humans. Group C chemicals are possible human carcinogens. Group D chemicals are not classifiable as to human carcinogenicity and Group E chemicals are those for which there is evidence that they are not carcinogenic to humans. For carcinogenic substances, EPA has established the Cancer Slope Factor (CSF) as a guideline. The CSF is used to determine the number of excess cancers resulting from exposure to a contaminant. The National Toxicology Program in its Annual Report on Carcinogens classifies a chemical as a "known human carcinogen" based on sufficient human data. Its classification of a chemical as being "reasonably anticipated to be a carcinogen" (RAC) is based on limited human or sufficient animal data. ATSDR considers the above physical and biological characteristics when developing health guidelines.

Exposure Dose Estimation

To link the site's human exposure potential with health effects that may occur under site-specific condition, ATSDR estimates human exposure to the site contaminant from ingestion and/or inhalation of different environmental medium (9). The following relationship is used to determine the estimated exposure to the site contaminant:

ED = (C x IR x EF) / BW

ED = exposure dose (mg/kg/day)
C = contaminant concentration
IR = intake rate
EF = exposure factor
BW = body weight

Standard body weights for adults, young children, and toddlers are 70 kg, 16 kg, and 10kg, respectively. The maximum contaminant concentration detected at a site for a specific medium is used to determine the estimated exposure. Use of the maximum concentration will result in the most protective evaluation for human health. For soil the ingestion rates used are 50 mg/day for adults, 100 mg/day for on-site workers and trespassers, and 200 mg/day for school-aged children. Exposure doses for children exhibiting pica behavior were evaluated for soils off-site in the residential area next to the site because one of the homes currently operates as an unlicensed day care facility. A small child (aged 1 to 3 years old) may on occasion ingest 5000 mg/day (one teaspoon per day) of contaminated soil. Some exposures are intermittent or irregularly timed. For those exposures, an exposure factor (EF) is calculated which averages the dose over the exposed period. When unknown the biological absorption from the environmental media (soil, water) is assumed to be 100%.

How Risk Estimates are Made

Non-Cancer Risks

For noncarcinogenic health risks, the contaminant intake was estimated using exposure assumptions for the site conditions. This dose was then compared to a risk reference dose (estimated daily intake of a chemical that is likely to be without an appreciable risk of health effects) developed by ATSDR or EPA.

Noncarcinogenic effects, unlike carcinogenic effects are believed to have a threshold, that is, a dose below which adverse health effects will not occur. As a result, the current practice is to identify, usually from animal toxicology experiments, a no-observed-adverse-effect-level (NOAEL). This is the experimental exposure level in animals at which no adverse toxic effect is observed. The NOAEL is then divided by an uncertainty factor (UF) to yield a risk reference dose. The UF is a number which reflects the degree of uncertainty that exists when experimental animal data are extrapolated to the general human population. The magnitude of the UF takes into consideration various factors such as sensitive subpopulations (for example; children, pregnant women, and the elderly), extrapolation from animals to humans, and the incompleteness of available data. Thus, exposure doses at or below the risk reference dose are not expected to cause adverse health effects because it is selected to be much lower than dosages that do not cause adverse health effects in laboratory animals.

The measure used to describe the potential for non-cancer health effects to occur in an individual is expressed as a ratio of estimated contaminant intake to the risk reference dose. If exposure to the contaminant exceeds the risk reference dose, there is concern for potential non-cancer health effects. As a rule, the greater the ratio of the estimated contaminant intake to the risk reference dose, the greater the level of concern. A ratio equal to or less than one is generally considered an insignificant (minimal) increase in risk.

Cancer Risks

Increased cancer risk were estimated by using site-specific information on exposure levels for the contaminant of concern and interpreting them using cancer potency estimates derived for that contaminant by EPA. An increased excess lifetime cancer risk is not a specific estimate of expected cancers. Rather, it is an estimate of the increase in the probability that a person may develop cancer sometime in his or her lifetime following exposure to that contaminant.

There is insufficient knowledge of cancer mechanisms to decide if there exists a level of exposure to a cancer-causing agent below which there is no risk of getting cancer, namely, a threshold level. Therefore, every exposure, no matter how low, to a cancer-causing compound is assumed to be associated with some increased risk. As the dose of a carcinogen decreases, the chance of developing cancer decreases, but each exposure is accompanied by some increased risk.

There is no general consensus within the scientific or regulatory communities on what level of estimated excess cancer risk is acceptable. Some have recommended the use of the relatively conservative excess lifetime cancer risk level of one in one million because of the uncertainties in our scientific knowledge about the mechanism of cancer. Others feel that risks that are lower or higher may be acceptable, depending on scientific, economic, and social factors. An increased lifetime cancer risk of one in one million or less is generally considered an insignificant increase in cancer risk.

Sources of Heath Guideline Information

ATSDR has prepared toxicological profiles for many substances found at hazardous waste sites. Those documents present and interpret information on the substances. Health guidelines, such as ATSDR's MRL and EPA's RfD and CSF are included in the toxicological profiles. Those health guidelines are used by ATSDR health professionals in determining the potential for developing adverse non-carcinogenic health effects and/or cancer from exposure to a hazardous substance. Preparers of this public health assessment have reviewed the profiles for the contaminants of concern at the Ross Metals, Inc. National Priorities List site.

APPENDIX E - COMPARISON OF ESTIMATED EXPOSURE DOSE TO HEALTH GUIDELINES

Appendix E, Table 1 - Results of Comparison of Estimated Exposure Dose to Health Guidelines for Persons Exposed to Contaminants in On-Site Surface Soil at the Ross Metals, Inc. National Priorities List Site, Rossville, Fayette County, Tennessee

Contaminant	Health Guideline (mg/kg/day)			Cancer Class
	Value	Source	Exceeded by Estimated Exposure Dose
Antimony	0.0004	RfD	No
Arsenic	0.0003	MRL	No	A
Lead		None		B2

Appendix E, Table 2 - Results of Comparison of Estimated Exposure Dose to Health Guidelines for Persons Exposed to Contaminants in Off-Site Surface Soil near the Ross Metals, Inc. National Priorities List Site, Rossville, Fayette County, Tennessee

Contaminant	Health Guideline (mg/kg/day)			Cancer Class
	Value	Source	Exceeded by Estimated Exposure Dose
Antimony	0.0004	RfD	No
Arsenic	0.0003	MRL	No	A
Lead		None		B2

APPENDIX F - EXPOSURE INVESTIGATION

Summary

The purpose of this Exposure Investigation (EI) was to determine whether the residents of the house immediately adjacent to the Ross Metals site, on Railroad Street, were exposed to lead level which would be of health concern. Staff from ATSDR conducted an EI in May 30, 1998. One out of the six participants, a three year old child had a slightly elevated blood lead level; this child does not permanently reside at this residence. None of the soil and dust samples tested in this EI contained lead in excess of the EPA screening level.

Background

The Ross Metals Inc. site, which has been an inactive secondary lead smelting plant since 1992, is located on a five-acre tract of land in Rossville, Fayette County, Tennessee. It is bordered on the west side by a waste water treatment facility, the north side by woodland and wetlands, the south by Southern Railroad tracts and the Kellogg Corporation property, the east side by wetlands and the southeast ( along Railroad Street ) by residences. There are seven residences lining that street, with the closest one about 10 feet from the fence of the site.

Numerous inspections and sampling investigations have been conducted at the site. From 1979 until December 1988, blast slag ( a glassy residue generated by the melting of metallic ores ) was disposed of in the on-site landfill located on the north portion of the RMI site. In November 1988, RMI submitted a Resource Conservation Recovery Act (RCRA), part B application for disposal of what was thought to be non hazardous blast furnace slag into an on-site landfill. EPA conducted two sampling investigations, respectively on December 7, 1988 and May 9, 1990 to determine if the wasted generated by the facility should be regulated and if the smelting and landfill activities were causing adverse environmental health effects. In June 1990, RCRA part B request was denied when blast slag was classified by EPA as a hazardous waste.

EPA conducted a site investigation during the week of November 28, 1990, during which they analyzed samples taken from the landfill for metals; results indicated lead contamination in all media sampled. The site stopped operation in 1992. EPA conducted a Superfund Time -Critical removal of soil, from October 1994 through June 1995, because of high concentrations of lead. EPA requested ATSDR to review and comment on soil samples taken from the residential yard adjacent to RMI facility; ATSDR determined that the concentration of lead in soil (950 - 1740 mg/kg ) posed a potential public health hazard. ATSDR recommended that the residents be dissociated from contaminated soils. In June 1995, EPA removed an unknown quantity of soil from the residential yard.

In December 1995, ATSDR determined that lead contamination in residential soil near the site had not been properly characterized and recommended that soil sampling be done at the residences near the site with emphasis on homes occupied by children with elevated blood levels. According to the Health Assessors, there were no other available data on further testing and results, prior to presenting this site for an EI in 1997.

One month, prior to actual sampling, members of ATSDR conducted a public meeting to explain the Exposure Investigation and answer questions.

METHODS

ATSDR conducted an exposure investigation on May 30, 1998. We limited the environmental and biological sampling for to the house immediately adjacent to the site because the town officials condemned the rest of the residences on that street. Moreover, no one was living there.

We tested six members of the household for blood lead. One of the individuals was a female child whom did not reside there but came to visit frequently and spent at least a week per month at this house.

Prior to testing, each adult participant signed the appropriate informed consent form and each minor and their parent or guardian signed an assent form. We informed the participants that their confidentiality would be protected in accordance with all Federal and States laws.

A licensed phlebotomist from the Tennessee State Health Dept. collected the blood by finger stick after thorough hand washing by the participants. The samples were sent to LabCorp Laboratory, Louisville, KY. Laboratory for lead analysis. We collected composite soil samples, four per location, from the fence line between the site and residence, the front yard by the entrance and by the side entrance. We obtained 1x2 meter vacuum sample, from the floor area by side entrance(kitchen), the front entrance under the floor mat and the bedroom floor. We collected 1/4x 2 inch wet wipes in the following areas: the front of the cabinet by side entrance, front entrance, and bedroom floor. We sent the soil and wipe samples to DataChem Laboratories, (Salt Lake City, Utah) to be analyzed for lead. ATSDR mailed the individual test results to the participants and provided an explanation of their significance.

Results

Blood lead, soil, vacuum dust and wipe samples are shown in Tables I -IV, respectively.

Table I. Blood Lead Results

Participants      µg/dl      ages

# 1	3	44
# 2	4	11
# 3	5	39
# 4	5	3
# 5	7	2
# 6	13	3

reference range: ug/dl(0-9)

Table II. Soil Results:

Field Sample number	PB mg/kg (lead)
S1	200
S1	220
S1	230
S2	34
S3	51

S1:Triplicate Composite soil from the fence between site and residence.
S2: Composite soil from front yard by the entrance.
S3: Composite soil from side yard by side entrance.

Table III. Vacuum dust results:

Field sample number	Pb ug/g	Area m2
V1	69	1
V2	130	1
V2	120	1
V3	100	1
Limit of detection	7

V1: 1x1 m area, of kitchen by side entrance.
V2: 1x1 m area, front entrance under floor mat.(duplicates)
V3: 1x1 m area, bedroom floor.

Table IV. Wipe results:

Field Sample Number	Pb ug	Area inch2
W1	4.8	1/4
W2	2.7	1/4
W3	4.6	1/4
limit of detection	2

W1: 1/4 inch2 of wet wipe of side entrance in front of cabinets
W2: 1/4 inch2 wet wipe of front entrance
W3: 1/4 inch2 wet wipe of bedroom floor.

Discussion

The Centers for Disease Control and Prevention (CDC) consider children to have an elevated level of lead if the concentration of lead is 10 µg/dl or more. The CDC recommends that all children between the ages of six months and six years should be screened for lead poisoning." Compared to adults, children absorb more of the lead that they swallow into their bodies, retain more of the lead that they take in, and are more sensitive to its effects. Lead exposure may decrease intelligence quotient(IQ) scores and reduce the growth of young children. These effects have been seen more often after exposure to high levels of lead than after exposure to low levels".

Of the six individuals screened for lead in this EI,(age range of 2-44), only one person had a value greater than 10 ug/dl. According to the occupants of the residence, this three year old child visits the residence quite frequently, three to four times a week however she does not reside there; she lives in the next county with her mother. Other potential sources of lead exposure for this child were not determined. We attempted unsuccessfully several times to have that child retested for blood lead. The Blood lead level in five out of six participants is within the background range for the general population and would not be expected to cause a health hazard.

The Environmental Protection Agency screening level for lead in residential soil is 400mg/kg .None of the soil and dust samples tested in this EI contained lead in excess of the EPA screening level. The wipes samples collected in this EI are uninterpretable for health assessment purposes; they are only useful as a qualitative indicator of contamination.

Conclusions

Blood lead analysis revealed a slightly elevated lead level in one of the six individuals tested for lead; as discussed above, this child is not a full time resident of the house sampled. The source of excess lead exposure in this individual could not be determined. Environmental soil lead were below EPA screening levels and do not pose a health hazard.

Recommendations

1) Confirm the elevated blood level detected in the child using a venipuncture blood sample. If elevated, follow recommendations by the Centers for Disease Control.

Reference:

CDC; Screening young children for lead poisoning:
Guidance for State and Local Health Officials,
November 1997.

Gerard I. Bazile, MD

Concurrence: Susan Metcalf, MD

APPENDIX G - RESPONSE TO PUBLIC COMMENTS

The following are written comments on the Ross Metals, Inc. Public Health Assessment received by ATSDR during the public comment period:  March 18, 1999 through May 2, 1999. Comments have been paraphrased by ATSDR. The comment is presented in bold lettering and ATSDR's response is in normal type.

1. There is a discrepancy in the number of residents living near the site on Railroad Street. The report lists only one home (with "approximately" five residents) in the immediate vicinity of the facility. This differs from the observations described in a TDEC DSF Trip Report dated April 13, 1999 that three homes are currently being occupied along Railroad Street in the immediate vicinity of the site.

ATSDR did a door to door survey when preparing for the exposure investigation. At that time only one residence along Railroad Street was occupied. In addition, ATSDR was told by city officials that most of the other homes along Railroad Street had been condemned. However, based upon the TDEC DSF trip report, ATSDR has revised this public health assessment to reflect current conditions in the area.

2. The document mentions that there is a daycare in operation in the immediate vicinity of the site. It is not clear that these "targets" were fully considered in the assessment. ATSDR should make an effort to use this more recent observation when evaluating this site.

ATSDR, when evaluating the potential for adverse health effects, considered young children as the current most susceptible population. A majority of the information presented in this public health assessment, except as noted, considers this group amongst those possibly impacted.

3. Regarding the elevated blood lead level of a child that is "not a permanent residence", TDEC DSF is curious what qualifies a person as a permanent resident? It is possible that a person not considered a permanent resident could spend a significant amount of time at or near the Ross Metals site.

The term "not a permanent resident" was chosen by ATSDR based upon interviews with participants in the blood lead survey. It simply means that the Railroad Street residence is not the participant's primary residence. The amount of time that the child spent at the Railroad Street residence was taken into consideration.

4. Is the area determined to a "No Apparent Public Health Hazard" by ATSDR, the residential property along Railroad Street or is it the Ross Metals facility?

The area considered by ATSDR to be a "No Apparent Public Health Hazard" is the residential yards. This conclusion was based upon exposure data gathered by ATSDR during its exposure investigation. The Ross Metals, Inc. site is considered by ATSDR as a "Public Health Hazard". This is mainly due to the presence of physical hazards and the large piles of slag present on the site. This public health assessment has been revised to more clearly delineate the areas of concern.

5. Has exposure potential of trespassers, remediation workers, and regulators been assess?

Yes these exposure potentials have been assessed. Persons working on or visiting the site (without proper personal protective equipment or not taking appropriate personal hygiene measures to prevent exposure) are likely exposed to lead and other metals in surface soil. Due to the presence of the slag piles and the current conditions on the site there is also the potential to be exposed to lead via the air pathway. ATSDR does not have air quality data to determine the degree at which these exposures are likely occurring. ATSDR recommends that measures be taken to restrict all public access to the site and contaminated areas and that safeguards be maintained to prevent or reduce the migration of fugitive dusts from the slag piles.

6. As stated in the document, arsenic is a Class A carcinogen. This being the case, arsenic should not have been overlooked in the section of the document entitled "Health Outcome Data Evaluation". This section of the document states: "It is unlikely that there is current exposure to the contaminants."

The Health Outcome Data Evaluation subsection of this public health assessment has been revised. It mentions the fact soil samples taken during the ATSDR exposure investigation did not find arsenic at levels of public health significance in the yard of the occupied residence closest to the site. Arsenic was found at levels of environmental significance along the fence which separates the site from the residential property area. However, based upon assumptions made by ATSDR, if a child were to sit right at the fence and play, it is not likely that the amount of contaminated soil ingested and the duration and frequency of exposure would be such that a carcinogenic or non-carcinogenic effect would occur.

FIGURE 2A: Completed Exposure Pathway Table - ON SITE

Pathway Name:	Source	Medium	Exposure Point	Exposure Route	Receptor Population	Time of Exposure	Exposure Activities	Estimated Number Exposed	Chemicals (identify by name or reference to tables in document)
OperationalArea On site soil	Site related	Soil less than 6 in below surface	Operational area	Inhalation, Dermal Absorption, Incidental Ingestion	On site workers and trespassers	Past, Current, Future	Maintenance and Recreational	Unknown	Antimony, Arsenic, Lead
Landfill Area On site soil	Site related and Non - site related Activities	Soil less than 6 inches below the surface	Landfill area	Inhalation, Dermal Absorption, Incidental, Ingestion	Anyone having contact with soil without proper protective equipment	Past Current, Future	Maintenance and Recreational	Unknown	Antimony, Arsenic, Lead
On site soil Operational and Landfill Areas	Physical Hazards	Discarded site equipment and dumped waste	Operational and Landfill areas	Inhalation, Dermal Absorption, Incidental, Ingestion	Trespassers onto the site that come into contact with contaminated materials	Past Current Future	Recreational	Unknown	Antimony, Arsenic, Lead
On site soil	Site- related and Non-site- related Activities	Air	Outdoors	Inhalation	On-site workers and Residents in the vicinity of the site	Past	Maintenance and recreational	Less than 750 persons	Antimony, Arsenic, Lead

FIGURE 2B: Completed Exposure Pathway Table - OFF SITE

Pathway Name:	Source	Medium	Exposure Point	Exposure Route	Receptor Population	Time of Exposure	Exposure Activities	Estimated Number Exposed	Chemicals (identify by name or reference to tables in document)
Woodland, Wetland Off-site soil	Site related and Non-site related	Soil less than 6 inches below the surface	Woodland and wetland areas next to site	Inhalation, Dermalabsorption, Incidental ingestion	Recreational users of the land next to the site	Past Current Future	Maintenance and Recreational	Unknown	Antimony, Arsenic, Lead
Residential Off-site soil	Site related and Non-site related	soil less than 6 inches below the surface	Residential areas adjacent to the site	Inhalation, Dermal absorption, Incidental ingestion	Residents and visitors of homes with contaminated soil	Past	Maintenance	Less than 50 persons	Antimony, Arsenic, Lead

FIGURE 3A: Potential Exposure Pathway Table - ON SITE

Pathway Name:	Source	Medium	Exposure Point	Exposure Route	Receptor Population	Time of Exposure	Exposure Activities	Estimated Number Exposed	Chemicals (identify by name or reference to tables in document)
On site soil Operationaland Landfill	Site Activities	Soil more than 6 inches below the surface	Operational and Landfill areas of the site	Inhalation, Dermal absorption, Incidental ingestion	Anyone who digs into the soil	Past Current Future	Maintenance and Recreational	UnKnown	Antimony, Arsenic, Lead
Port of exit Ground water	Former Site Activities	Ground water	Water exit point	Inhalation, Dermal absorption, Ingestion	Use of water from contaminated aquifer	Future	Recreational and daily usage	UnKnown	Antimony, Arsenic, Lead, Chromium, Manganese, Vanadium

FIGURE 3B: Potential Exposure Pathway Table - OFF SITE

Pathway Name:	Source	Medium	Exposure Point	Exposure Route	Receptor Population	Time of Exposure	Exposure Activities	Estimated Number Exposed	Chemicals (identify by name or reference to tables in document)
Surface Water	Surface Runoff	Surface Water	Wetlands area near site	Incidental Ingestion, Dermal Absorption, Inhalation	Residents living near the site	Past, Current, Future	Recreational	Unknown	Antimony, Arsenic, Lead, Manganese, Cadmium, Thallium

FIGURE 4. TOTAL POPULATION ESTIMATES TABLE

Pathway Name	Unknown	Estimated Pop. in Pathway	Range Minimum	Range Maximum
Potential Pathways On-site	X
Potential Pathways Off-site	X
Total Potential On and Off-site	X
Completed Pathways On-site		0	0	750
Com0pleted Pathways Off-site		0	0	50
Total Completed On and Off-site		0	0	800
Potential and Completed Pathways On-site		0	0	750
Potential and Completed Pathways Off-site		0	0	50
Total Potential and Completed On and Off-site		0	0	800

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