Samples collected during the SRI are indicated by a date following the location the sample was
taken.
ATSDR uses several types of medium-specific screening values to assist in selecting the
contaminants that will be evaluated for public health significance. For this assessment, the
specific screening values include Environmental Media Evaluation Guides (EMEGs), Cancer
Risk Evaluation Guides (CREGs), and Reference Dose Media Evaluation Guides (RMEGs).
EMEGs are media-specific estimates that pose a minimal risk to humans. They are based on
ATSDR's minimal risk levels (MRLs) or EPA's reference doses (RfDs). 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 (12). CREGs are estimated contaminant concentrations that are based on
one excess cancer for a million persons exposed over a lifetime and are calculated from EPA's
cancer slope factors. RMEGs are calculated from EPA's Reference Doses and are based on their
estimates of the daily exposure to a contaminant that is unlikely to cause adverse health effects.
| Appendix C, Table 1 - Completed Environmental Exposure Pathways at the ICG Iselin Railroad Yard National Priorities List Site, Jackson, Madison County, Tennessee |
| On-Site Exposure Pathways Elements |
| Source |
Environmental
Medium |
Pathway
Status |
Point of
Exposure |
Route of
Exposure |
Exposed
Populations |
Number
Exposed |
| Site Activities |
Soils less than 3" below
the surface |
Past, Present, Future |
Areas near former site
operations and
maintenance buildings;
Rail Tie Pile/Dump |
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 |
| Site-Related and
Non-Site-Related
Activities |
Air |
Past, Present, Future |
Outdoors |
Inhalation |
On-site workers and
Residents in the vicinity
of the site |
Less than 1000
persons |
| Old Floor Drainage
System;
Wastewater
Lagoon; and
Site-Related
Activities |
Surface Water
Sediment |
Past, Present, Future |
Drainage ways;
Intermittent Tributary;
Jones Creek |
Inhalation, Dermal
absorption, Incidental
ingestion |
People who come into
contact with
contaminated water
bodies and sediments |
Not Known |
| Off-Site Exposure Pathways Elements |
| Site and Non-Site
Related Sources |
Surface Water
Sediment |
Past, Present, Future |
Jones Creek |
Incidental ingestion
(surface water only),
Dermal absorption,
Inhalation |
People using Jones Creek
for recreational purposes |
Not Known |
Not Known
(assumed to be
background) |
Soil on Terrace above
site |
Past, Present, Future |
Outside in vicinity of
Washington-Douglas
Elementary School |
Incidental ingestion,
Inhalation, Dermal
Absorption |
Residents in the vicinity
of the
Washington-Douglas
Elementary School, esp.
children |
Less than 1000 |
| Appendix C, Table 2 - Possible Environmental Exposure Pathways at the ICG Iselin Railroad Yard National Priorities List Site, Jackson, Madison County, Tennessee |
| On-site Exposure Pathways Elements |
| Source |
Environmental
Medium |
Pathway
Status |
Point of
Exposure |
Route of
Exposure |
Exposed
Populations |
Number
Exposed |
| Former Site Activities
and Other Sources |
Groundwater
(On-site) |
Future |
Water Exit Point |
Ingestion, Dermal
absorption, Inhalation |
People who use water
from the
contaminated aquifer |
None Currently
Known |
| Lye Vat |
Sludge |
Past (prior to
pollution abatement
system installation) |
On-site Drainage
Ditches |
Incidental ingestion,
Dermal absorption,
Inhalation |
People on the site in
the area of drainage
ditches |
Not known |
| Site Activities |
Soil more than 3"
below the surface |
Past , Present, Future |
Areas near former site
operations and
maintenance
buildings; Rail Tie
Pile/Dump |
Inhalation, Dermal
absorption; Incidental
ingestion |
Anyone who digs into
the soil, unless the
contaminated soils are
removed from the site |
None Known |
| Off-Site Exposure Pathways Elements |
| Groundwater |
Groundwater |
Past, Present, Future |
Water Exit Point |
Inhalation, Incidental
ingestion, Dermal
absorption |
Anyone who puts a
well into the
contaminated aquifer |
None Known |
| Groundwater |
Municipal Water |
Past |
At Sampling Point |
Inhalation, Dermal
absorption, Incidental
Ingestion |
Anyone who comes
into contact with the
contaminated water
prior to treatment |
None Known |
| Appendix C, Table 3 - Non-Apparent Environmental Exposure Pathways at the ICG Iselin Railroad Yard National Priorities List Site, Jackson, Madison County, Tennessee |
| On-site Exposure Pathways Elements |
| Source |
Environmental
Medium |
Pathway
Status |
Point of
Exposure |
Route of
Exposure |
Exposed
Populations |
Number
Exposed |
| Neutralization Tank |
Sludge |
Past (since pollution
abatement system
installed), Present,
Future |
Neutralization Tank |
Dermal absorption |
None Expected |
None Known |
| Former Site Activities and
Other Sources |
Groundwater
(On-site) |
Past, Present |
Water Exit Point |
Ingestion, Inhalation,
Dermal absorption |
People who use water
from the contaminated
aquifer |
None Known |
| Site Processes |
Surface Water and
Sediment |
Past Present, Future |
Wastewater Lagoon |
Dermal absorption,
Incidental ingestion,
Inhalation |
None Expected |
None Known |
| Off-Site Exposure Pathways Elements |
| Groundwater |
Municipal Water |
Present, Future |
At Tap |
Ingestion, Dermal
absorption, Inhalation |
None Expected (Water
is treated prior to
reaching end user |
Not Expected |
APPENDIX D
COMPARISON OF ESTIMATED EXPOSURE DOSE
TO HEALTH GUIDELINES
TABLES 1 - 2
| Appendix D, Table 1 - Results of Comparison of Estimated Exposure Dose to Health Guidelines
for Persons Exposed to On-Site Contaminants at the ICG Iselin Railroad Yard National Priorities
List Site, Jackson, Madison County, Tennessee |
| Contaminant |
Pathway
Medium |
Health Guideline (mg/kg/day) |
Cancer
Class |
| Value |
Source |
Exceeded by
Estimated
Exposure Dose |
| 2-Hexanone |
Surface Soil
Surface Water |
|
Unknown |
|
|
| 2-Methylnaphthalene |
Surface Soil |
|
Unknown |
|
|
| 4-Methyl-2-pentanone |
Surface Water |
|
Unknown |
|
|
| Naphthalene |
Surface Soil |
|
Unknown |
|
|
| Carbazole |
Surface Soil |
|
None |
|
|
| Dibenzofuran |
Surface Soil |
|
Unknown |
|
|
| Dieldrin |
Surface Soil
Sediment |
0.00005 |
MRL |
NO
NO |
B2 |
| carcinogenic PAHs |
Surface Soil
Sediment |
0.1 |
aMRL |
NO
NO |
B2 |
| Aluminum |
Sediment |
|
Unknown |
|
|
| Antimony |
Surface Soil
Sediment |
0.0004 |
RfD |
NO |
|
| Arsenic |
Surface Soil
Sediment |
0.0003 |
MRL |
NO
NO |
A |
| Cadmium |
Surface Soil
Sediment |
0.0007 |
MRL |
NO
NO |
B1 |
| Chromium |
Surface Soil
Sediment |
0.005 |
RfD |
NO
NO |
A |
| Copper |
Surface Soil
Sediment |
|
None |
|
|
| Iron |
Sediment |
|
Unknown |
|
|
| Lead |
Surface Soil
Sediment |
|
None |
|
B2 |
| Manganese |
Surface Water
Sediment |
0.005 |
RfD
None |
NO |
|
| Mercury |
Sediment |
0.002 |
iMRL |
NO |
|
| Appendix D, Table 2 - Results of Comparison of Estimated Exposure Dose to Health Guidelines
for Persons Exposed to Off-Site Contaminants At and Near the ICG Iselin Railroad Yard National
Priorities List Site, Jackson, Madison County, Tennessee |
| Contaminant |
Pathway
Medium |
Health Guideline (mg/kg/day) |
Cancer
Class |
| Value |
Source |
Exceeded by
Estimated
Exposure Dose |
| Tetrachloroethene |
Municipal Well Water |
0.01 |
RfD |
NO |
B2 |
| Aluminum |
Sediments
Terrace Area Soils |
|
Unknown |
|
|
| Antimony |
Terrace Area Soils |
0.0004 |
RfD |
NO |
|
| Arsenic |
Sediments
Terrace Area Soils |
0.0003 |
MRL |
NO
NO |
A |
| Barium |
Sediments
Terrace Area Soils |
0.07 |
RfD |
NO
NO |
|
| Copper |
Sediments |
|
None |
|
|
| Iron |
Sediments
Terrace Area Soils |
|
Unknown |
|
|
| Lead |
Sediments
Terrace Area Soils |
|
None |
|
B2 |
| Manganese |
Surface Water
Sediments
Terrace Area Soils |
0.005 |
RfD
None
None |
NO
|
|
| Vanadium |
Sediments
Terrace Area Soils |
0.0003 |
iMRL |
NO
NO |
|
Unknown = Health guideline not available aMRL = ATSDR's acute Minimal Risk Level
MRL = ATSDR's Minimal Risk Level
RfD = EPA's Reference Dose
iMRL = ATSDR's intermediate Minimal Risk Level * = Health guideline for Benzo(a)pyrene
None = Health guideline not available |
APPENDIX E
RESPONSE TO PUBLIC COMMENTS
The data from the Supplemental Remedial Investigation (RI) Report, submitted on May
17, 1996, need to incorporated into this document.
This information has already been incorporated into the document (Reference #5).
Please change the name of the Site from "ICG Iselin Railroad Yard" to "Iselin Rail Yard
Site." ICG (Illinois Central Gulf Railroad Company) was only one of several companies to
operate at the Site, and ICG has been reorganized and no longer operates under this name.
The facility has been known as the "Iselin Site" since it began operations in the early
1900s.
ATSDR uses the name the site was given when proposed for the NPL (as stated in the Federal
Register).
Page vi, fourth paragraph, second sentence. Ecological sampling was conducted during the
Phase II Remedial Investigation to assess if adverse conditions existed at the Site.
The sentence has been amended to showed that it refers to human biological data.
Page vi, fourth paragraph, last sentence. Please delete this sentence. Additional air
sampling was conducted at the site during Phase II of the Remedial Investigation. The
additional air sampling is presented in the Supplemental RI Report for the Iselin Rail Yard
Site dated May 1996.
The paragraph has been rephrased. Because historical air data are not available, past exposure to
air contaminants (if any), could not be quantified or qualified. It cannot be determined if any of
the contaminants of concern in the contaminated soil, surface water, and sediments pose a threat
via inhalation exposure because recent air sampling data is limited.
Page vi, fifth paragraph, second sentence. Please delete aluminum, copper, and
phosphorous from this sentence. These constituents are not suspected to be carcinogenic in
humans.
Aluminum has not been classified for carcinogenicity. No studies were located regarding cancer
in humans or animals following chronic exposure via ingestion of or dermal contact with
aluminum or its compounds. The studies regarding cancer following inhalation exposure to
aluminum or its compounds were inconclusive due to the addition of other variables which could
have contributed to the development of the carcinogenic effect. The available information has
not shown that aluminum is a potential carcinogen.
Copper was deleted from the sentence.
Phosphorous is not classifiable as to carcinogenicity due to lack of human and animal data.
Page vi, last paragraph, second sentence. Ground water levels were measured from all
on-Site and off-Site ground water monitoring wells on August 19, 1996. A water table
configuration map was generated from this data and submitted to TDEC-DSF in
September 1996. The natural direction of ground water flow at the Site is well defined, and
information available from JUD should enable ATSDR to assess the influences on ground
water flow at the Site from pumping the JUD wells.
This information had not been made available to ATSDR at the time that the public comment
version of this document was written. ATSDR will attempt to retrieve this information. Thank
you for making us aware of its existence.
Page 2, first paragraph, last sentence. Please clarify that the operations that ceased
producing wastewater in 1986 were limited to railroad activities.
This has been reflected in the document.
Page 2, last paragraph, first sentence. Following this sentence, please add the following
sentence: Field work performed by RMT, Inc., for the Phase II Remedial Investigation
continued through December 1995.
The historical data is given chronologically. Your comment is already in the document. See the
last paragraph of the Site Description and History section.
Page 3, last paragraph, first sentence. Why are racial demographics of neighboring
residents relevant to a health study? Please delete reference to racial percentage.
The public health assessment as defined by ATSDR is not a health study. Demographic data is
required in ATSDR public health assessments. It is one of the elements ATSDR is required to
address under Section 104(i)(6)(A) of the Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA) of 1980, as amended [42 U.S.C. 9604(i)(6)(A)].
Page 4, third paragraph, first sentence. The JUD south well field is not down-gradient of
the Site. Ground water flow is to the south-southwest. The JUD south well field is west
and northwest of the Site.
"Down-gradient" was removed from the sentence.
Page 4, third paragraph, second sentence. Is the number of wells stated (10) all of the JUD
wells or just the number of wells in the JUD south well field? It may be helpful to provide
data on the number of wells in both the JUD south and north well fields.
The JUD south well field consists of 13 wells.
Page 4, fourth paragraph, fourth sentence. The sentence "Local ground water flow is
toward the JUD south well field" is not correct.
That statement was removed from the document.
Page 4, fourth paragraph, last sentence. The Supplemental RI and other information
available from JUD should enable ATSDR to assess whether pumping the wells in the
South Well Field influences ground water flow at the Site.
Statement removed from the document.
Page 6, last paragraph, first sentence. Please explain that Tables 1 through 13 in Appendix
B list all carcinogens regardless of whether comparison levels were exceeded.
Carcinogens whose maximum concentration exceeded the CREG and those which are known
carcinogens but do not have a CREG are included in the tables of Appendix B.
Page 7, first paragraph, first sentence (continuation from page 6). This sentence states that
it is prudent to compare concentrations of organic and inorganic constituents detected in
surface soils, subsurface soils, and sediments to background or normal soil/sediment levels.
Where is this comparison presented in the assessment? In addition, surface soil samples
collected during the Remedial Investigation at the Site were collected from both 0-6 inches
and 0-3 inches. Soil samples collected from both of these intervals meet the US EPA
criteria for a surficial soil sample.
Unlike the risk assessment conducted by EPA which is quantitative, the ATSDR public health
assessment is a qualitative document. Most public health assessments mention the rationale for
preparing the document, however, the exact numbers and calculations are not always included.
The comparison was made but the numbers were not included in the public health assessment.
ATSDR defines surface soil as soil samples taken from the top 0-3 inches of soil. For the
purpose of this public health assessment any soil sample taken at the depth of 0-6 inches is called
unspecific soil and those samples taken at a depth greater than six inches is called sub-surface
soil.
Page 7, third paragraph, second sentence. Please replace the word "access" with "assess."
Document reflects the change.
Page 7, forth paragraph,, second sentence. Arsenic and manganese are naturally occurring compounds in the soils at the Site.
A sentence acknowledging this fact was added to the paragraph.
Page 7, fifth paragraph, second sentence. Please replace the sentence "The direct push
technology advances a water sampling device directly into the soil to a selected depth
without the need to drill boreholes and without making drill cuttings." with the following
sentence: The direct push technology advances a water sampling device through the soil to
a selected depth below the water table without drilling a borehole or generating drill
cuttings.
Paragraph modified to reflect this change.
Page 8, second paragraph, third and fourth sentences. Not all of the samples collected at
the average depth of 30-feet below land surface or greater detected 1,1-dichloroethene,
trichloroethene, and vinyl chloride. The location of the highest concentration of VOCs
detected in the ground water samples were located on the east side of the Site, up-gradient
from the potential source areas at the Site and down-gradient from the landfill adjacent to
the Site.
The paragraph was modified to reflect this change.
Page 8, third paragraph, first sentence. For the purpose of the Remedial Investigation,
(following the TDEC-DSF approved Work Plan), surface soil samples were collected from
0-6 inches and 0-3 inches. Soil samples collected from both of these intervals meet the US
EPA criteria for a surficial soil sample.
A paragraph was added to the unspecific soil subsection to reflect the samples that were taken in December 1995.
Page 9, second paragraph, seventh sentence. Please provide an explanation of why
chromium is assumed to be hexavalent.
This is a very conservative approach which will allow for the greatest protection of public health.
Page 9, second paragraph, last sentence. Please provide an explanation of why all detected
carcinogenic PAHs were compared to ATSDR's screening value for benzo(a)pyrene.
The paragraph was modified. All carcinogenic PAHs were converted to their relative potency to benzo(a)pyrene.
Page 9, last paragraph, first sentence. Please replace the word "are" with "were." Air
samples collected on that day only show what was present at the time of the sampling.
Document reflects this change.
Page 11, second paragraph, third and fourth sentence. The wastewater treatment facility is
inoperative. It does not receive any process water from the Site. The majority of the rail
tie pile is covered with soil. Additional air sampling was conducted at the Site during
Phase II of the Remedial Investigation. The additional air sampling is presented in the
Supplemental RI Report for the Iselin Rail Yard Site dated May 1996.
The air sampling did not cover the area of the rail tie pile/dump and the wastewater treatment facility.
Page 11, Section 1, Ground Water. Please include a discussion describing the TDEC
ground water investigation at the former landfill located up-gradient of the Site. Volatile
Organic Compounds (VOCs) have been detected in the ground water monitoring wells
installed by TDEC up-gradient of the Site at the adjacent landfill, and the VOCs have been
determined to be migrating onto the Iselin Rail Yard Site.
Paragraph modified.
Page 11, last paragraph, seventh sentence. Delete the Seventh Sentence. See the
Supplemental RI for additional data.
The Supplemental RI was used to make the indicated determination.
Page 12, fifth paragraph, second sentence. It should not be stated that the samples were
contaminated unless the levels measured are significantly greater than average
concentrations for these metals in the region. Also, please delete the word "heavy" in this
sentence. Not all of the metals listed are heavy metals.
The levels of the indicated metals were above normal background so only change to the
statement was deletion of "heavy".
Page 15, second paragraph, second sentence. Please state if there is evidence that children
younger than six years old have played at the Site.
This information is based on conversations with local residents during the ATSDR public
availability sessions. At the time of the ATSDR site visit, children were not observed playing on the site.
Page 15, third paragraph, first sentence. Please add the word "possibly" between "site" and
"were." There is no historical air analysis available showing that exposure to constituents in air actually occurred by nearby residents or persons on Site.
In addition, there is no evidence to show that nearby residents or persons on the Site were not
exposed to constituents in the air. It is quite likely that during the time the site was in full
operation, workers and others were exposed to airborne constituents. It is also quite likely that
some of these airborne constituents traveled beyond the Site's boundary.
"Likely" was inserted instead of "possibly".
Page 15, third paragraph, fifth sentence. Please change the word "release" to "released."
Document reflects this change.
Page 15, third paragraph, eighth sentence. Constituents that are not Site-related should
not be discussed in this assessment. As stated under "Pathways Analysis" on page 14,,
"...the possible environmental exposure pathways are evaluated to help determine whether
individuals have been, are being, or will be exposed to site-related contaminants." The first
element required in this analysis is that the contaminant of concern is possibly related to
the Site.
In the sentence to which you refer, the sources are on-site exposure points, releases, and activities
which may have contributed to airborne releases.
Document not modified.
Page 15, last paragraph, first sentence. There is no known "on-site waterbodies"
associated with the Site.
Based upon the documents reviewed by ATSDR, portions of Jones Creek and the Unnamed
Intermittent Tributary are on the site. It is possible that children while trespassing upon the site at the very least waded in these waterbodies.
Page 16, second paragraph. It is not appropriate to discuss contamination that is not
related to the Iselin Site in this assessment. Please delete this entire paragraph.
The soils in the area of the school are discussed because the concentration of some of the
contaminants exceeded ATSDR environmental screening values. Since the school houses a
headstart program, the participants are considered to be a highly susceptible population.
Document not modified.
Page 16, third paragraph, second sentence. New ground water sampling data presented in
the Supplemental RI should assist in making this determination.
Document has been modified.
Page 17, first paragraph, last sentence. Please replace "potable purposes" with "a primary
water supply." Potable purposes would most likely exclude dermal contact. Also, please
state that TDEC-DSF would not allow a water supply well to be installed at the Site.
Document reflects these changes.
Page 17, last paragraph, second sentence. Please replace the sentence "Contaminants from
the site may enter the aquifer and therefore be transported to nearby wells" with the
following: Contaminants from the Site may enter this aquifer, and therefore be transported
to the nearby wells.
Modification made.
Page 18, first paragraph. Please state that PCE has never been detected in the ground
water at the Site. Also, if the PCE is not thought to be Site-related, exposure to PCE
through the JUD distribution system should not be mentioned in this assessment.
The municipal wells are discussed in this document because a concern had been raised about
VOCs in the water. Recently available data seems to support the statement that the site is not
responsible for the VOC contamination in the wells.
Page 20, Exposure Dose Estimation. Where are the calculated exposure doses presented in
the report? Also, example calculation for each exposure pathway would be beneficial to
include in the assessment for the benefit of the public who may not be familiar with these
calculations.
The public health assessment is a qualitative document, therefore, those calculations are not
included in most of the documents. The general formula for oral exposure was included in this
document and summary tables to show the results of the comparison of the estimated exposure
doses to health guidelines are presented in Appendix D.
Page 20, Exposure Dose Formula. What method was used to calculate the contaminant
concentration for use in the exposure dose (ED) calculation?
As stated in the text, the maximum concentration of the contaminant found in the specified
medium of the specified pathway was used.
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