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PUBLIC HEALTH ASSESSMENT

MARION (BRAGG) DUMP
MARION, GRANT COUNTY, INDIANA



ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS

The tables in this section list the contaminants of concern. We evaluate these chemicals in the subsequent sections of this public health assessment and determine whether exposure to them has public health significance. ATSDR selects and discusses a chemical as a contaminant of concern based upon the following factors:

  1. the chemical has no comparison value and/or may be toxic to humans at specified levels;


  2. the comparison of on-site and off-site concentrations with public health assessment comparison values for 1) noncarcinogenic endpoints and 2) carcinogenic endpoints;


  3. an evaluation of the field data quality, laboratory data quality, and sample design;


  4. community health concerns related to a particular chemical.

In the data tables that follow under the On-site Contamination and Off-site Contamination subsections, the listed chemical does not mean that it will cause adverse health effects from exposures. Instead, the list indicates which chemicals will be evaluated further in the public health assessment.

Comparison values for this public health assessment are contaminant concentrations in specific media that are used to select contaminants for further evaluation. Sample data provided are documented in the Final RI report.

The data tables include the following acronyms:

CREG = Cancer Risk Evaluation Guide. CREGs are estimated contaminant concentrations based on a one excess cancer in a million persons exposed over a lifetime. They are calculated from EPA's cancer slope factors.

EMEG = Environmental Media Evaluation Guide. EMEGs are media-specific comparison values that are used to select chemicals of concern at hazardous waste sites. They are derived from the minimal risk level.

MCL = Maximum Contaminant Level (for drinking water). MCLs represent contaminant concentrations that EPA deems protective of public health (considering the availability and economics of water treatment technology) over a lifetime (70 years) at an exposure rate of 2 liters of water per day. While MCLs are regulatory concentrations, PMCLGs and MCLGs are not.

NAS = National Academy of Sciences. It has been suggested by the NAS, that where water supplies contain more than 20 ppm, dietary restriction to less than 1 g is difficult to achieve and maintain.

ppm = Parts per million

ppb = Parts per billion

RMEG = Reference Dose Media Evaluation Guide. RMEGs are media-specific comparison values that are used to select chemicals of concern at hazardous waste sites. They are derived by ATSDR from the reference dose level.

The Toxic Chemical Release Inventory (TRI) is an EPA database that contains information on chemical releases of industries in the United States. It is used to determine the potential sources of contamination near NPL sites. A computer search was conducted of the most recent Toxic Chemical Release Inventory (TRI 89) data to review a listing of those industrial chemicals generated or accidentally released within the city of Marion. No industries reported either generating or releasing any of the chemicals of concern present on the site.

All chemicals found in sampled media have been assessed for adverse health effects.

Preliminary field work for the site (including sampling) preceded the RI. Sampling was also conducted during both phases of the RI. The results have been combined to characterize the extent of contamination found at the site.

A. On-Site Contamination

The waste boring and on-site soil samples collected during the RI do not fit the ATSDR definition for surface soil (less than 3 inches in depth) and subsurface soil (greater than 3 inches in depth). Although the waste boring and on-site soil samples are considered separately under the soil subheading, the depths at which the samples were taken should be noted.

Waste Borings and Natural Soil

Waste boring samples were taken of the fill material in the site at three locations. Samples were taken at four fill waste depths (0-8 feet, 6-12 feet, 8-16 feet, and 16-24 feet). Natural soil samples were collected at four locations at depths of 16-18 feet, 20-22 feet, 20-23 feet, and 24-26 feet (see Figure 2).


Figure 2. On-site Sampling Locations

Contaminants of concern found in the waste boring samples are shown in Table 1. Waste boring samples from boring locations WB01, WB02, and WB03 indicated the presence of volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs) at concentrations above background levels. The only pesticide detected was chlordane. However, most of the pesticide analyses were invalidated by the EPA data reviewer based on quality assurance protocols; therefore, this result may not be representative of pesticides present at the site. In all cases, the concentration of chemicals in the natural soil beneath the fill were significantly less than the concentrations found in the fill. It can be concluded that contaminants are present in the fill at concentrations above background levels typically found in the Eastern United States. However, the concentrations of these chemicals were below the levels of health concern except for cadmium. In addition, copper and lead were found at elevated levels and will be evaluated in subsequent sections of this document (3).

Table 1. Chemicals of Concern in On-Site Waste Borings, Marion (Bragg) Dump.

Chemical Maximum
Concentration
(ppm)
Depth
(Feet)
Date Comparison Value
ppm Source
cadmium 403 12-20 03-86 1 EMEG
copper 5,850 16-24 03-86 - *
lead 5,870 6-12 03-86 - *

* No health comparison value available


Soil - Surface

Investigation of on-site surface soil contamination (February 1986) involved the collection of six composite samples of the top 6 inches of soil from representative locations across the site (see Figure 2) (3). The on-site surface soil was found to be essentially free of VOCs. Comparison background samples were taken from four off-site locations (see Off-site Contamination subsection).

Polynuclear aromatic hydrocarbons (PAHs), which are SVOCs, were found at two locations above background concentrations. One location is in the fill area; the second location is on-site, but is off the fill area. The source of PAHs found at location SS07 is unknown. The possible source of PAHs found at location SS04 is runoff from a "cold mix" asphalt road patch storage pile on the Marion Paving area.

One pesticide (4,4'-DDT at 76 ppb) was found at one of the six sample locations. The presence of this pesticide does not appear to be widespread and was not a health concern.

Three inorganic chemicals (cadmium, lead, and mercury) were found in the surface soil at concentrations above background levels. Only cadmium at 13 ppm was present at levels of health concern. Contaminants of concern found in the surface soil samples are shown in Table 2 (3).

Table 2. Summary of On-Site Surface Soil Sample Results, Marion (Bragg) Dump, February 1986

Chemical Maximum
Concentration
(ppm)
Comparison Value
ppm Source
benzo(a)anthracene 7.6 - *
benzo(a)pyrene 7.2 0.1 CREG
benzo(b)fluoranthene 11 - *
benzo(k)fluoranthene 11 - *
cadmium 13 1 EMEG
chrysene 5.2 - *
dibenzo(a,h)anthracene 1.4 - *
indeno(1,2,3-cd)pyrene 5.5 - *
lead 80 - *

* No health comparison value available


Groundwater - Monitoring Wells

Seventeen monitoring wells were sampled during the RI. Three of the monitoring wells were installed by the EPA Field Investigation Team (FIT) several years prior to the RI. The remaining 14 wells were installed as part of the RI by the EPA contractor. Seven of the monitoring wells are screened at the top of the upper aquifer (shallow wells); five wells are screened at the bottom of the upper aquifer (intermediate wells); and one is screened at the top of the lower aquifer (deep well). These 13 wells are generally along the perimeter of the site. The remaining four of the 17 monitoring wells are off-site, upper aquifer, background wells (see Figure 3 in Off-site Contamination subsection).

Two aquifers have been identified at the site. The upper (water table) aquifer consists of sand and gravel outwash deposits and is isolated from the lower aquifer by a glacial till layer. In certain areas of the site, fill is below the water table and, therefore, is within the upper aquifer. The lower aquifer is composed of limestone bedrock. Groundwater from each aquifer was sampled during the RI. Samples were collected from 12 wells within the upper aquifer and a single well within the lower aquifer.

Sample results were compared to concentrations detected in background wells considered to be unaffected by chemicals at the site. The lower aquifer sample had no corresponding background well sample, and therefore, samples from an off-site water supply well of equivalent depth were used as background for the lower aquifer (3).

Upper Aquifer

The background well samples contained no detectable concentrations of chemicals except benzoic acid, bis(2-ethylhexyl)phthalate, and sodium. The chemicals detected in the upper aquifer at the site are possibly site-related. Several chemicals were detected in only one of the 21 monitoring well samples. Benzene, benzoic acid, and bis(2-ethylhexyl)phthalate were detected in three or more samples. In addition, arsenic and sodium were also detected. The concentrations of benzene, bis(2-ethylhexyl)phthalate, and arsenic exceeded health concern levels (Table 3). The level (253,000 ppb) of sodium found would be a health concern for individuals ingesting this water on a routine basis who have high blood pressure or who are on a sodium restricted diet (3).

Table 3. Chemicals of Concern in On-Site Upper Aquifer Samples,
Marion (Bragg) Dump, July 1986.

Chemical Maximum
Concentration
(ppb)
Comparison Value
ppb Source
arsenic 78 3 EMEG
benzene 12 1 CREG
bis(2-ethylhexyl)phthalate 1,000 3 CREG
sodium 253,000 20 NAS

Lower Aquifer

Sampling data for the lower aquifer indicated the presence of three inorganic chemicals (acetone, methylene chloride, and trichloroethene). Acetone and methylene chloride are common laboratory contaminants and are considered suspect. Inorganic chemicals were also found in the samples taken from the lower aquifer. None of the chemicals found in the lower aquifer samples were at levels of health concern (3).

Leachate Wells

Three leachate wells were installed where waste boring sampling occurred. During both sampling phases of the RI, one leachate well was not sampled because it was dry. Therefore, only data from two wells are available for evaluation (see Figure 2).

Eleven chemicals (Table 4) were detected in the leachate well samples at levels of a health concern. Three other chemicals (aluminum, calcium, and cobalt) were found at elevated levels and will be evaluated in subsequent sections of this document. Benzene was detected in both wells. Bis(2-ethylhexyl)phthalate was detected in only one of the two wells. With the exception of benzene and bis(2-ethylhexyl)phthalate, the presence of the other chemicals are likely the result of former on-site operations. It is not possible to determine at this time the degree to which benzene and bis(2-ethylhexyl)phthalate are related to site activities (3).

Table 4. Chemicals of Concern in On-Site Leachate Well Samples, Marion (Bragg) Dump, March 1986.

Chemical Maximum
Concentration
(ppb)
Comparison Value
ppb Source
aluminum 186,000 - *
antimony 61 4 RMEG
arsenic 524 3 EMEG
benzene 42 1 CREG
bis(2-ethylhexyl)phthalate 1,000 3 CREG
cadmium 626 7 EMEG
calcium 683,000 - *
chromium 696 50 RMEG
cobalt 353 - *
copper 4,730 1,300 MCL
lead 5,090 15 MCL
nickel 1,900 200 RMEG
vanadium 696 30 RMEG
zinc 10,100 3,000 RMEG

* No health comparison value available

Surface Water - On-Site Pond

Samples were collected approximately 2 feet above the pond bottom and along the shore of the pond (see Figure 2). No chemicals were detected in the on-site pond at a concentration of health concern in the August 1985 samples.

Sediment - On-Site Pond

Cadmium (8,000 ppb) was the only compound detected at concentrations of health concern in on-site pond sediment samples (Table 5) (see Figure 2). However, mercury (140 ppb) was also found at significantly elevated levels compared to background and will be evaluated in subsequent sections of this document (3).

Leachate Seep Water and Sediment

Two investigative samples, one quality control (QC) duplicate and two QC blanks, were collected (see Figure 2) during Phases I and Phase II. Samples from four off-site groundwater monitoring wells were used as background samples. All samples were unfiltered and were analyzed for the standard field measurements (pH, temperature, specific conductance and organic vapor readings).

Cadmium and lead were detected at levels of health concern in the leachate seep water (Table 5) (3).

Table 5. Chemicals of Concern in On-Site Leachate Seep Water/Pond Sediment Samples, Marion (Bragg) Dump, July 1986.

Chemical Maximum Concentration (ppb) Comparison Value
Leachate Seep
Water
Sediment ppb Source
cadmium 28 8,000 2 EMEG
lead 88 - 50 MCL
mercury - 140 20 EMEG

Fifteen chemicals were detected in the leachate seep sediment samples at concentrations exceeding background soil concentrations. Only three (antimony, selenium, tin) were found at concentrations of a health concern (Table 6) (3).

Table 6. Chemicals of Concern in On-Site Leachate Seep Sediment Samples, Marion (Bragg) Dump, February 1986.

Chemical Maximum
Concentration
(ppm)
Comparison
Value
ppm Source
antimony 33 0.8 RMEG
selenium 6.3 6 EMEG
tin 35 - *

* No health comparison value available

B. Off-Site Contamination

Surface Water - Mississinewa River

The Mississinewa River water samples were collected in March 1986 (Phase I) and July 1986 (Phase II) from eight locations. Samples were taken at five locations along the perimeter of the site to determine whether or not there has been any detectable impact on river water quality (see Figure 4). With the exception of one sample location, all samples were collected from the main channel of the river. The one exception was a sample taken in a ponded backwater channel. Water did not flow through this backwater channel unless the river was above normal stage. Three sample locations were upstream from the site and were used as background locations. Phase I samples were collected during a period of high-water levels, but less than flood stage. Phase II samples were collected during a period of low water levels. Sodium was the only chemical detected in near-site samples of river water at levels above those found in upstream samples (Table 7). The level found during Phase II (23,500 ppb) would be a health concern for those individuals ingesting this water on a routine basis and who have high blood pressure, or are on a sodium restricted diet (3).


Figure 3. Off-site Sampling Locations
of Groundwater Monitoring Wells for
Marion (Bragg) Dump Site

Sediment - Mississinewa River

Three river sediment samples were taken (March 1986) at the same locations as the three river water samples. There was no corresponding river water sample location for one of the river sediment sample locations. Three river sediment sample locations were upstream from the site and were sampled for use as background samples (see Figure 4).


Figure 4. Off-site Sampling Locations for Marion (Bragg) Dump site

The chemicals beryllium (300 ppb) and silver (3,400 ppb) were found in concentrations above background levels in one out of four river sediment samples. However, only beryllium is present at levels of health concern (Table 7). The river sediment does not appear to have been adversely impacted by the site except for the one location noted above (3).

Fish - Off-Site Pond

Skin-on fillets of fish taken from the off-site pond were found to contain 4.5 ppm of mercury (Table 7). This level is of concern for persons who may consume fish from the off-site pond.

Surface Water - Off-Site Pond

Two water samples were collected (one in March 1986) from the large off-site pond immediately south of and adjacent to the site (see Figure 4). Samples were collected 2 feet above the sand bottom and along the shore of the pond. Samples were collected in order to determine whether or not pond sediment had been contaminated by the site. The pond is upgradient from the site, and because of its proximity to the site, sampling was warranted. Background samples were taken from three small ponds in the Eastside Cove area. These background locations are upgradient from the site and in depressions remaining from gravel pit operations, just as the large off-site and on-site ponds were formed.

Only mercury (2 ppb) was detected in the off-site pond water (Table 7). This concentration could be a health concern since the lifetime drinking water health advisory (LTHA) level is equal to the level detected. However, a duplicate sample taken from the same location did not confirm the original concentration (3).

Sediment - Off-Site Pond

In samples collected in February/March 1986 (see Figures 4), the off-site pond sediments contained two chemicals, bis(2-ethylhexyl)phthalate (882 ppb) and mercury (130 ppb), at concentrations above background levels. However, the levels of bis(2-ethylhexyl)phthalate are below levels of health concern. Mercury, which was detected in only one out of three samples (Table 7), has no appropriate health comparison value (in soil/sediment) and, therefore, will be further evaluated in subsequent sections of this document (3).

Table 7. Chemicals of Concern in Off-site Samples from River & Pond Surface Water, River & Pond Sediment, and Pond Fish; February, March, & July 1986.

Medium Chemical Maximum
Concentration
(ppb)
Comparison
Value
ppb Source
Surface Water

(River)

(Pond)

sodium

mercury

23,500

2

20

-

NAS

*

Sediment

(River)

(Pond)

beryllium

bis(2-ethylhexyl)phthalate
mercury

300

882
136

0.008

3
-

CREG

CREG
*

Fish

(Pond)

methyl mercury 4.5 ppm 2 FDA

* No health comparison value available

Asphalt Plant Effluent Water

The asphalt plant (Marion Paving Company) effluent water sample was collected directly from the pipe that was discharging this effluent onto the ground where it then flowed overland into the on-site pond. Part of the asphalt plant process train included drying of the gravel used in manufacturing asphalt. The gravel dryer was equipped with a scrubber which used water from the pond to remove particulates from the dryer exhaust gasses. One investigative sample was collected directly from a 10-inch diameter steel pipe. Samples from four off-site groundwater monitoring wells were used as background samples (see Figure 2).

Seven chemicals were detected at above background levels in the asphalt plant effluent water at levels of health concern (Table 8). Aluminum, which was also found at levels exceeding background, has no appropriate health comparison value (in water) and, therefore, will be further evaluated in subsequent sections of this document. The asphalt plant effluent may have added a few contaminants at low levels to the on-site pond (3).

Asphalt Plant Effluent Sediment

Effluent from the Marion Paving Company asphalt plant flowed over the ground and into the on-site pond and deposited its sediment load in a low area forming a delta where the water entered the pond. One sediment sample was collected from this area. Sediment concentrations were compared to background pond sediment concentrations (see Figure 2).

Methylene chloride was detected at above background levels but not at a level of health concern. Aluminum and tin were also found at levels above background (Table 8) and will be further evaluated in subsequent sections of this document (3).

Table 8. Chemicals of Concern in Asphalt Plant Effluent Water & Sediment Samples, July 1986.

Chemical Maximum Concentration (ppb) Comparison Value
Water Sediment ppb Source
aluminum 156,000 5,430 - *
arsenic 150 - 3 EMEG
chromium 244 - 50 RMEG
lead 210 - 15 MCL
manganese 12,300 - 50 RMEG
nickel 419 - 200 RMEG
tin - 28 - *
vanadium 554 - 30 EMEG

* No health comparison value available

C. Quality Assurance and Quality Control

In preparing this public health assessment, ATSDR relies on the information provided in the referenced documents and assumes that adequate quality assurance and control measures were followed with regard to chain-of-custody, laboratory procedures, and data reporting. The validity of the analysis and conclusions drawn for this document are determined by the completeness and reliability of the referenced information. Some of the information provided in the summary tables of the RI did not correlate with the raw data provided in the Appendix of the RI.

As previously stated, mercury contamination of the off-site pond could not be confirmed due to conflicting sample results. This is an identified data gap. Generally, all other data were deemed acceptable for use.

D. Physical and Other Hazards

As discussed in the Site Visit subsection, a 6-foot chain-link fence has been erected around the site by the contractor to restrict access to the site. During the site visit, several areas bordering the Mississinewa River were not fenced and access to the on-site pond was possible. Since the site visit, however, the entire site has been fenced.

There have been several allegations by local individuals regarding the possible dumping of chemicals in the off-site pond. With the exception of the mercury contamination, there are no data to support these allegations.

PATHWAYS ANALYSES

To determine whether nearby residents are exposed to contaminants migrating from the site, ATSDR evaluates the environmental and human components that lead to human exposure. This pathways analysis consists of five elements: 1) a source of contamination, 2) transport through an environmental medium, 3) a point of exposure, 4) a route of human exposure, and 5) an exposed population.

ATSDR categorizes an exposure pathway as a completed or potential exposure pathway if the exposure pathway cannot be eliminated. Completed pathways require that the five elements exist and indicate that exposure to a contaminant has occurred in the past, is currently occurring, or will occur in the future. Potential pathways, however, require that at least one of the five elements is missing, but could exist. Potential pathways indicate that exposure to a contaminant could have occurred in the past, could be occurring now, or could occur in the future. An exposure pathway can be eliminated if at least one of the five elements is missing and will never be present. Table 9 identifies the completed exposure pathways, and Table 10 identifies the potential exposure pathways. The discussion that follows these two tables incorporates only those pathways that are important and relevant to the site. We also discuss some of those exposure pathways that have been eliminated.

A. Completed Exposure Pathways

On-Site Pond

The surface water from the on-site pond has not been shown to contain any contaminants at levels of health concern. In addition, fish tissue data do not reveal the presence of any health threat for persons who may consume fish from the pond. However, elevated levels of cadmium and mercury have been measured in the pond sediments. In the past, children and adults have been observed using the pond for swimming and fishing. Therefore, it is likely that human exposure to cadmium and mercury from the sediments has occurred in the past. Under such conditions, persons (especially children) may have been exposed to contaminants in the pond sediments through skin contact and incidental ingestion. Exposure to contaminants from water and fish in the on-site pond is also possible, even though past sampling has not confirmed contamination in these media.

Table 9. Completed Exposure Pathways

PATHWAY EXPOSURE PATHWAY ELEMENTS TIME
SOURCE ENVIRONMENTAL
MEDIA
POINT
OF
EXPOSURE
ROUTE OF
EXPOSURE
EXPOSED
POPULATION
On-site pond Marion (Bragg) Dump Sediment Pond Incidental ingestion,
Skin contact
Local population
using on-site pond
Past
Present
Future

B. Potential Exposure Pathways

Off-Site Pond

The surface water from the off-site pond may currently pose a health threat based on the limited data collected, especially the high level of mercury discovered at the pond. Skin-on fillets of fish taken from the off-site pond were found to have a concentration of 4.5 ppm of mercury. This concentration of mercury in fish tissue is of concern. The off-site pond is not currently fenced, and there is a possibility that swimming and fishing could be occurring. The high levels of mercury found in the pond sediments and fish tissue may present an exposure pathway. However, because of the insufficient information (data gap) available regarding the off-site pond, it is difficult to make definite conclusions regarding the health threat. Therefore, additional monitoring of the pond water, sediment, and fish is recommended.

Mississinewa River

The surface water from the Mississinewa River does not currently pose a health threat. Current data shows the contaminant levels are not elevated and they do not currently pose a threat. In addition, contaminants are not likely to be found in the river because of the relatively small number and relatively low concentration of the contaminants found, and the high dilution rate afforded by the river. However, because the contaminated groundwater flows toward the river, there may be a health concern if the contaminant levels increase in the river. Individuals who use the Mississinewa River for fishing and swimming may have incidental ingestion or dermal absorption during recreational activities to contaminants in the river if the level of the contaminants increases.

Groundwater/Private Well

There are two aquifers identified in the area which are separated by a glacial till that confines the lower aquifer from the upper aquifer. The upper aquifer is contaminated. The hydraulic gradient in the upper aquifer is toward the Mississinewa River, which is acting as a hydraulic barrier to prevent the groundwater from flowing beyond the river. Under the present conditions, the groundwater exposure pathway is not complete and, therefore, is not currently of concern. However, in the future, there would be concern regarding groundwater contamination if the area is used for recreational or residential purposes and if wells are constructed in the upper aquifer on-site. If wells are installed on-site into the shallow aquifer, persons may be exposed to groundwater contaminants through ingestion, inhalation, and dermal absorption.

Soil

Under present conditions, there are no current health concerns from contaminated soil because the site is fenced, and there is minimal access to the site. Also, contaminated soil on the site is currently capped with a clay cover. In the future, however, if the site is converted to a recreational or residential area, the contaminated subsurface soil may be uncovered. Under such conditions, an exposure pathway may be created through the soil. If the site is developed, construction workers may be exposed to subsurface soil through dermal absorption and incidental ingestion of the contaminated soil; or, if the area is converted to a residential area, residents may be exposed to the contaminants through incidental ingestion and dermal absorption.

Table 10. Potential Exposure Pathways

PATHWAY EXPOSURE PATHWAY ELEMENTS TIME
SOURCE ENVIRONMENTAL
MEDIA
POINT OF
EXPOSURE
ROUTE OF
EXPOSURE
EXPOSED
POPULATION
Off-site pond Marion (Bragg)
Dump
Surface water,
sediments, and fish
Pond Ingestion and
Skin contact
Local population
using off-site pond
or ingesting fish
Past
Present
Future
Mississinewa River Marion (Bragg)
Dump
Surface water River Incidental
ingestion,
Skin contact
Local population
using river
Future
Groundwater/Private
Well
Marion (Bragg)
Dump
Groundwater Residential wells Incidental
ingestion,
Inhalation,
Skin contact
Residents on-site Future
Soil Marion (Bragg)
Dump
Soil (subsurface) On-site
construction
areas and
residential yards
Incidental
ingestion,
Skin contact
Construction
workers, residents
on-site
Future

PUBLIC HEALTH IMPLICATIONS

In this section we will discuss the health effects of persons exposed to specific chemicals, evaluate state and local health databases, if available, and address any existing community health concerns.

A. Toxicologic Evaluation

This subsection of the public health assessment assesses the public health implication of contaminants that are associated with an exposure pathway that have not been eliminated in the Pathways Analyses section.

ATSDR has developed toxicological profiles on several chemicals that have been found at this site. These profiles provide information on health effects, environmental transport, human exposure, and regulatory status.

Major chemicals of concern associated with the site include arsenic, bis(2-ethylhexyl)phthalate, and mercury. In addition, sodium may be of concern in groundwater and surface water supplies in the site area.

Introduction

As discussed in the Environmental Contamination and Other Hazards and Pathways Analyses sections, access to the site is restricted by a fence surrounding the site. This helps prevent people from coming in contact with on-site contaminants in the on-site soil and pond.

The direction of the groundwater flow is north toward the Mississinewa River, and no residents live between the site and the river. However, persons who use the river for recreation may come into contact with contaminants in the river. Also, if private wells are installed at the site in the future, exposure to groundwater contaminants is possible.

Arsenic

Inorganic arsenic has been determined to be a cancer causing agent. The single most characteristic effect of long-term oral exposure to inorganic arsenic is a pattern of skin changes. This includes a darkening of the skin and the appearance of small "corns" or "warts" on the palms, soles, and torso. While these skin changes are not considered to be a health concern, a small number of the corns may ultimately develop into skin cancer. Swallowing arsenic has also been reported to increase the risk of cancer in the liver, bladder, kidneys, and lungs (9).

Despite all the adverse health effects associated with inorganic arsenic exposure, there is some evidence that a small amount (10-50 ppb/day) of arsenic in the normal diet may be beneficial to human health.

Arsenic was detected in the upper aquifer of the groundwater at 78 ppb. The estimated ingestion dose for children and adults was lower than the EPA chronic oral RfD. There is no apparent cancer risk for incidental ingestion of this water.

Benzene

Benzene is a naturally-occurring substance produced by forest fires and is present in many plants and animals; but benzene is also a major industrial chemical made from coal and oil. How benzene affects health depends on the level and duration of exposure.

Benzene is harmful to the tissues that form blood cells. It is also a cancer causing agent. Leukemia (cancer of the tissues that form white blood cells) has occurred in some workers exposed to benzene for periods of less than 5 years and up to 30 years. In addition, human studies indicate that benzene is harmful to the immune system, increasing the chance for infections and perhaps lowering the body's defenses against tumors. Human data on adverse reproductive outcomes are limited (10).

Benzene was found in the off-site groundwater at 12 ppb. An estimated ingestion dose was calculated. The value was less than the level of no observed adverse health effects in humans. There is no increased cancer risk if this water were to be incidentally ingested.

Bis(2-ethylhexyl)Phthalate (DEHP)

Bis or di(2-ethylhexyl)phthalate (DEHP) is a manmade chemical that is added to plastics to make them flexible. DEHP dissolves very slowly in water. DEHP does not evaporate easily, and thus, very little will be present in the air even near sources of production. This chemical can enter the body through contaminated food, water, or air. Almost all of the DEHP that enters the body from food, water, or air is taken up into the blood from the lungs and intestines. Small amounts may also enter the body through skin contact (11).

Most of what is known about the health effects of DEHP comes from animal studies, especially studies of rats and mice. Because DEHP appears to affect rats and mice differently than humans and other animals, it is difficult to predict the health effects in humans using information from animal studies. There have been no studies of workers exposed to DEHP that indicate it causes cancer in humans.

DEHP was found at 1,000 ppb in the on-site groundwater. The estimated daily ingestion dose was considerably less than the EPA chronic oral RfD. The incidental ingestion of this water should pose an insignificant increase in the cancer risk to humans.

Mercury

Mercury exposure may be occurring. Mercury released into the environment will stay there for a long time. Some or all released organic mercury will slowly break down to become inorganic mercury. Inorganic mercury can also change back to organic mercury with the help of a substance produced by microorganisms and various chemical processes. There is no chronic RfD for mercury. Methylmercury, an organic form of this chemical, is the major form found in fish. Therefore, the EPA reference dose for methylmercury was used to estimate chronic mercury exposure. The brain, kidney, and the unborn child are the most sensitive to methylmercury exposure (12).

High levels of mercury (130 ppb) were detected in the off-site sediment and the surface water (2 ppb). However, a repeat sample did not detect any mercury in the surface water in the off-site pond. The estimated daily ingestion dose for children and adults was more than a thousand times less than the lowest-observed-adverse-effect-level and the cancer effect level seen in animal research. This calculation was based on very conservative assumptions such as an individual being exposed for five days out of the week, for fifty weeks out of the year. The incidental ingestion of these sediments would be unlikely to pose adverse effects in humans.

Fish tissue data revealed concentrations of mercury for which restriction of consumption would be advised. We assumed that children, women, and men ate 5, 13, and 15 grams of fish per meal, respectively. We evaluated the fish consumption rates of one meal per week. Table 11 shows the estimated daily doses of methylmercury compared to the EPA chronic RfD (0.0003 ppm).

Table 11. Health Guideline for Ingestion mg/kg/day

Exposure
Pathway
Health Guideline for Ingestion mg/kg/day
Value Source Exceeded by
Estimated Exposure
Dose
Fish 0.0003 Oral RfD male/female yes
Fish 0.0003 Oral RfD child yes

The level of methylmercury ingested by persons who ate or are eating fish taken from the on- and off-site ponds and the Mississinewa River exceeds the health guideline established by EPA.

Sodium

Long-term ingesting of high concentrations of sodium are believed to be associated with the development of hypertension and would complicate clinical treatment of hypertensive patients on salt-restrict intakes.

Sodium was found at 253,000 ppb in the on-site upper aquifer. These levels are not seen as a health threat to the community because the water is not currently used for human consumption.

Because intake restrictions of sodium are often part of hypertensive therapy, the levels of sodium in the off-site groundwater could represent a significant health concern to past residents who used private wells. Typically, prescribed low-sodium diets attempt to limit sodium intake from food and water to either 2,1, or 5 grams (g) in a 24-hour period. It has been suggested by the National Academy of Sciences (NAS) that, where water supplies contain more than 20,000 ppb, dietary restriction to less than 1 g is difficult to achieve and maintain (13).

B. Health Outcome Data Evaluation

Exposure to phthalates is known to cause cancer in rats and mice, but there are insufficient data to determine if they cause cancer in humans. The ISDH is not aware of any health studies conducted at or near the site available for evaluation. The cancer rates for all causes for Grant County are comparable to state and U.S. rates for all race-gender groups except for increases in rates of leukemia in non-white females and multiple myeloma in non-white males. The chemicals found at this site have not been associated with these types of cancer. Based on a review of the county mortality data, and the site-specific environmental data, the need for additional health studies is not warranted at this time.

C. Community Health Concerns Evaluation

The community health concerns were addressed as follows:

  1. Are there any problems of methane gas development from the dump due to decomposing organic material?

    Any problem regarding development of methane gas was addressed during the RI and has been remediated.



  2. Will there be any monitoring of erosion and wind-blown dusts emanating from the site on Central Avenue?

    The clay soil that will be used to cover the site will not produce contaminated dusts that may be blown into residential areas.



  3. Have the fish in the on-site and off-site ponds been analyzed for chemicals?

    Yes, fish from the ponds have been sampled for chemical contamination. Based on the sampling results, fish taken from the on-site pond were not contaminated. However, the fish samples taken from the off-site pond were found to be contaminated with mercury.



  4. Will the leachate observed entering the river be prevented from further polluting the river?

    Leachate entering the river has been addressed in the RI and is being remediated.



  5. How soon will the decaying barrels that were observed along the riverbanks be cleaned?

    The RI calls for removal of the decaying barrels prior to the installation of the clay cap.



  6. Will the cleanup method selected for the site which involves the sanitary landfill cap be sufficient to prevent any serious threat to the city of Marion through groundwater contamination?

    The direction of groundwater flow is north toward the Mississinewa River, and there are no residences between the site and the river. Any threat from groundwater contamination would be in the future if residences and private wells are allowed to be constructed on-site.

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