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PUBLIC HEALTH ASSESSMENT

FAIRFIELD COAL GASIFICATION PLANT
FAIRFIELD, JEFFERSON COUNTY, IOWA


ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS

The tables in this section list the contaminants selected for further evaluation. These contaminantsare evaluated in subsequent sections of the public health assessment to determine if exposures areof public health significance. The following criteria are used for selecting contaminants:

  1. Concentrations of contaminants on and off-site.
  2. Field data quality, laboratory data quality, and sample design.
  3. Comparison of on-site and off-site concentrations with background concentrations, if available.
  4. Comparison of on-site and off-site concentrations with comparison values developed forspecific environmental media.
  5. Community health concerns.

In the following sections, On-Site Contamination and Off-Site Contamination, the listing of acontaminant does not mean that it will cause adverse health effects. Instead, the list indicatescontaminants that were further evaluated for plausible health impact.

The data tables include the following acronyms:

EMEG=Environmental Media Evaluation Guide (ATSDR)
CREG=Cancer Risk Evaluation Guide (ATSDR)
RMEG=Reference Dose Media Evaluation Guide (ATSDR)
LTHA=Long Term Health Advisory (EPA)
MCLG=Maximum Contaminant Level Goal (EPA)
MCL=Maximum Contaminant Level (EPA)
ppm=parts per million for soil and sediment samples (equivalent tomilligram per kilogram, mg/kg)
ppb=parts per billion for water samples (equivalent to microgram perliter, µg/L)

Comparison values (CVs) are contaminant concentrations in specific media that are used to selectcontaminants for further evaluation. EMEGs are media-specific values derived from ATSDR'sMinimal Risk Levels (MRLs). RMEGs are derived from EPA's Reference Doses (RfDs). CREGsare media-specific values derived from EPA's Cancer Slope Factors to serve as an aid in selectingcontaminants for follow-up that are potential carcinogens. Cancer Slope Factors provide anindication of the relative carcinogenic potency of a particular chemical.

MCLGs include safety factors and represent levels of contaminants at which no known oranticipated adverse health effects should occur upon exposure. Maximum Contaminant Levels(MCLs) are contaminant concentrations set for public drinking water supplies that EPA or theIowa Department of Natural Resources (IDNR) deem protective of public health (considering theavailability and economics of water treatment technology) over a lifetime (70 years) at anexposure rate of 2 liters of water per day. While MCLs are regulatory concentrations, EMEGs,CREGs, RMEGs, and MCLGs are not.

Tables in this section list selected contaminants at the Fairfield Coal Gasification site. Exposureto these contaminants is evaluated in subsequent sections of this document.

INTRODUCTION

Samples of environmental media were collected and analyzed during the PreliminaryInvestigation, the Expanded Site Investigation, and during the RI/FS conducted from July 1986-January 1990. Samples were collected from waste material, subsurface soil, sediment, surfacewater, and groundwater. On-site and off-site sampling locations are shown in Figures 4A and 4Bof the Appendices. Groundwater flow directions and groundwater elevations are shown onFigure 3A.

Groundwater beneath the site is contained in a localized perched water system which is overlainby fill material (3 to 5 feet deep) in an unconfined drift aquifer composed of sand lenses within theglacial till. Beneath the surficial water table are three deep aquifers: Mississippian aquifer atdepths of 180 to 480 feet; Devonian aquifer at depths of 780 to 1,000 feet; and theCambrian-Ordovician aquifer (Jordan Aquifer) at depths of 1,300 to 2,100 feet. These deepaquifers are separated by limestone and dolomite aquicludes. The RI/FS reported thatgroundwater flow at the site is generally south-southeast and south-southwest (Figure 3A). Groundwater data in the RI/FS indicate that contaminants have leached or migrated from the gasholder pit, the former tar separator tank, and the relief gas holder tank. As a result, the on-siteperched water system and in the on-site and off-site drift glacial aquifer have been contaminated(Figures 5A-5C).21,22

Precipitation filtrating through the waste material and soil has dissolved contaminants from thecoal-tar and formed a leachate that has migrated into the groundwater. These contaminants haveleached from the coal-tar and contaminated the soil located below the groundwater table. VOCshave leached into the groundwater at a greater rate than PAHs. VOC concentration in thegroundwater is much higher than PAHs (Table II). This variation in concentration is possiblycaused by the higher water solubility of VOCs in groundwater and the greater affinity of PAHs toabsorb to coal-tar and organic matter in soil. A downward vertical gradient is present betweenmonitoring wells FI-3 and FI-3D, indicating that the site overlies a groundwater recharge area forthe glacial till aquifer. Migration of contaminants to the upper bedrock is minimal. The singlegroundwater sample and single soil sample from monitoring well FI-3D (a depth of 75 feet)contained only trace concentrations of PAHs.

Tables I and II list on-site contaminants found in subsurface soil and groundwater at levels abovecomparison values. Tables III and IV list off-site contaminants found in subsurface soil andgroundwater at levels above comparison values.

A. On-Site Contamination

On-site samples were collected from waste material, subsurface soil, sediment, and groundwater.

Subsurface and Surface Soils

Table I lists contaminanted subsurface soils found during EPA sampling events. Soil borings,representing subsurface soils from 0 to12.5 feet deep and below 12.5 feet were collected andanalyzed during the RI/FS. Subsurface soil samples were analyzed for total metals, cyanide,VOCs (of which benzene, ethylbenzene, toluene, and xylene are collectively referred to asBETX), base-neutral-acids (BNAs), and PAHs. Soil boring locations are shown in Figure 4A.

Maximum concentrations of carcinogenic and noncarcinogenic PAHs in subsurface soils werefound in boring B-21 and B-22, located near the relief gas holder tank. Subsurface soil collectedat a depth of 22 to 24 feet from boring B-21, contained 1,800 mg/kg benzene and 58.6 mg/kgcarcinogenic PAHs. Soil collected at 4.5 to 5.5 feet from boring B-22 contained 40.9 mg/kgcarcinogenic PAHs. Subsurface soil collected at depths of 35.5 to 36.5 feet from boring FI-8,located on the northern edge of the relief gas holder tank, contained trace concentrations of 0.119mg/kg carcinogenic PAHs and 0.069 mg/kg toluene. A subsurface soil sample from boring B-29,collected at 26 to 27 feet, contained 6.6 mg/kg benzene, 27 mg/kg ethylbenzene, 170 mg/kgtoluene, and 210 mg/kg xylene.

A surface soil sample collected next to the east side of the gas holder pit during the 1987Expanded Site Investigation contained higher levels than the soil comparison values forcarcinogenic and noncarcinogenic PAHs and arsenic. During additional surface soil sampling in1992, a sample was collected next to the southeast end of the operations building which contained11.2 mg/kg arsenic, 4.5 mg/kg beryllium, and 4,910 mg/kg manganese.18 The soil comparisonvalues for arsenic, beryllium, and manganese are 20 EMEG, 0.2 CREG, and 300 RMEG,respectively.

EPA's surface soil sampling is conducted from 0 - 6 inches in depth. ATSDR uses 0 - 3 inches todefine surface soils because we feel that people are more likely to come into contact with 0 -3inches of soil rather than to a depth of 6 inches.

Table I*

On-Site Subsurface Soil (mg/kg)


ContaminantConcentrationLocationComparison
Value

Arsenic18B-230.4 CREG
Beryllium3B-250.2 CREG
Manganese1,500B-20300 RMEG

Benzene

1,800

B-21

20 CREG

Benz(a)anthracene

1.9

FI-7

nc
Benzo(a)pyrene6.1JB-220.1 CREG
Benzo(b)fluoranthene13J B-22nc
Benzo(g,h,i)perylene3.3JB-22none
Benzo(k)fluoranthene16JB-21nc
Chrysene40JB-21nc
Dibenz(a,h)anthracene0.76JB-26nc
Indeno(1,2,3-cd)pyrene2.9JB-22nc
Naphthalene250JB-21none
Phenanthrene37JB-22none

nc- noncarcinogen.
None- none listed
J- compound detected, quantity estimated.
*From Remedial Investigation/Feasibility Studies. Fairfield Coal Gasification Site, Fairfield, Iowa, July 28, 1989. Prepared by B & W WasteScience and Technology Corporation.

Groundwater

On-site groundwater samples were collected during the RI/FS from nine permanent monitoringwells, two temporary monitoring wells, two extraction wells, and one private well (FI-3). Samples were taken from monitoring wells at depths ranging from 9 to 49 feet and from theextraction wells at depths ranging from 20 to 40 feet. Monitoring well water samples wereanalyzed for total metals, cyanide, pesticides, polychlorinated biphenyls (PCBs), BETX and otherVOCs, BNAs, and PAHs. Water samples from extraction wells EX-1 and EX-2 were analyzedfor total metals, VOCs, and BNAs. Residential well (FI-3) was analyzed for total metals, BETX,and PAHs. Table II lists on-site groundwater contaminants found above comparison values andalso lists those contaminants for which no comparison values are available.

Table II*

On-Site Groundwater (µg/L)


ContaminantsConcentrationLocationComparison
Value

Arsenic77B-240.02 CREG
Barium2,000B-24700 RMEG
Cadmium5.6B-245 RMEG
Lead450B-2415 MCL
Mercury4.7B-242 LTHA
Nickel200B-24100 LTHA
Vanadium230B-2420 LTHA
Cyanide910B-24200 RMEG

Benzene

74,000

FI-9

1 CREG
Ethylbenzene1,300JFI-91,000 RMEG
Toluene24,000FI-92,000 RMEG
Styrene1,700JFI-9100 LTHA

2,4-dimethylphenol

4,100

FI-3

200 RMEG
Phenol6,300FI-36,000 RMEG

Benzo(a)anthracene

36J

FI-3

nc
Benzo(a)pyrene23FI-30.005 CREG
Benzo(b)fluoranthene18JFI-9nc
Benzo(k)fluoranthene18JFI-9nc
Benzo(g,h,i)perylene9JFI-3none
Chrysene36JFI-3nc
Dibenzo(a,h)anthracene2.9JFI-3nc
Indeno(1,2,3-cd)pyrene7.0JFI-3nc
Naphthalene4,500FI-920 LTHA
Phenanthrene320JFI-3none

nc- noncarcinogen.
None- none listed.
J- compound detected, quantity estimated.
*From Remedial Investigation/Feasibility Studies. Fairfield Coal Gasification Site, Fairfield, Iowa, July 28, 1989. Prepared by B & W WasteScience and Technology Corporation.

The maximum concentration of metals in on-site groundwater was found in temporary monitoringwell B-24 at a depth of 9 feet. The maximum concentrations of VOCs, PAHs, and phenoliccompounds were found in monitoring wells FI-3 and FI-9 at a depth of approximately 40 feet. Agroundwater sample from monitoring well FI-3D, collected at a depth of 78 feet (which is the topof the upper bedrock), contained 0.07 µg/L noncarcinogenic PAHs. Monitoring well FI-2,screened at 70 feet, contained 320 µg/L benzene and 0.9 µg/L noncarcinogenic PAHs.

Air Emissions and Air Monitoring

On March 31, 1993, ATSDR attended a meeting at the request of EPA Region VII concerningsoil remedial activities and air monitoring plans at the site. The meeting was held at Region VIIHeadquarters in Kansas City, Kansas. Representatives from EPA, IE, and the contractor (Blackand Veatch) working on the site clean-up were in attendance. ATSDR's recommendationsincluded: obtain monitoring data for air emissions around the site perimeter; usesampling/monitoring equipment capable of reliably and accurately detecting benzene atconcentrations as low as 1 ppb; and provide the monitoring data to ATSDR as early as possiblefor determination of possible health risk to the sorrounding residential population (Appendix B).

Eight air monitoring events were conducted during the removal of the relief gas holder tank (Maythrough November 6, 1993). The initial event established background levels for the componentsbeing monitored. Subsequent sampling events were conducted during worst-case scenarios over24-hour sampling periods. The first five air sampling events were conducted upwind anddownwind for particulates (less than 10 microns), PAHs, and VOCs. Sampling events 6 through8 were conducted for VOCs only.

Excavation of the source material and contaminated soil started in June 1993 with the removal ofthe relief gas holder tank. The excavation activities generated significant off-site odor emissions. Nearby residents complained of odors, reported health effects, and requested a public meetingwith EPA to address these issues.

Air monitoring for VOCs was conducted during on-site remedial activities on July 21 and 22,1993. Some of the chemicals believed present in the air included benzene, toluene, xylene,cresols, phenols, and PAHs. The downwind monitoring station was located immediately west ofthe relief gas holder tank, within the fence. The highest concentration of benzene (110 ppb) wasobtained from this monitoring station. This level is below the Occupational Safety and HealthAdministration's (OSHA's) permissible exposure limit (PEL) of 1,000 ppb for benzene. OSHAPELs are time-weighted average (TWA) concentrations that must not be exceeded during any 8-hour work shift in a 40-hour work week. TWAs are established to be protective of healthy adultworkers in occupational exposure settings. To allow for variations in sensitivity to any toxiceffects of benzene among a more heterogenous population, a 24-hour per day exposure wasextrapolated by ATSDR, and results were presented in a health consultation issued on July 9,1993 (Appendix B). ATSDR recommended that the 24-hour average benzene concentrations inair not exceed 24 ppb, and that the benzene air concentration at no time should exceed 1 ppm. Those levels were exceeded in sampling rounds 2 and 4, but the levels were not exceeded insubsequent sampling events (those conducted after release of the health consultation).

Toluene was also present at a 24-hour concentration of 130 ppm, which is below the 300 ppmdetermined by ATSDR to be protective of human health for continuous exposures up to 14 days. Styrene was measured at a concentration of 140 ppm, which is approximately 0.6 milligrams percubic meter (mg/m3). This level is below EPA's inhalation reference dose concentration of 1mg/m3 of air. Air measurements for all other organic compounds (at the downwind monitoringstation) and all other organic compounds sampled at the other two monitoring stations werebelow any regulatory standards or health-based guidelines. A total of 18 PAHs were analyzedduring air monitoring conducted in May and June 1993. Only seven non-carcinogenic PAHs inthe air were detected. ATSDR considered the levels non-threatening to human health (AppendixB). Excavation activities continued until November 1993 at which time the constructioncontractors demobilized for the 1993 winter season.

Remedial actions for the soils operable unit were completed in May 1995. IE furnishes EPA withmonthly status reports. The February 1996 status report indicated that soil removed from the siteis currently stored in facilities located in Iowa Falls and Marshalltown, Iowa, awaiting treatment. On February 12, 1996, IE received EPA's response outlining the proposal for disposal ofnonhazardous contaminated soil at Heartland Cement in Independence, Kansas. Copies of themonthly status reports are located in the Fairfield Public Library.

B. Off-site Contamination

Subsurface Soil, Surface Soil, and Sediment

Table III lists contaminants in subsurface soils found during EPA sampling events. Soil borings,representing subsurface soils from 0 to12.5 feet deep and below 12.5 feet were collected andanalyzed during the RI/FS. Subsurface soil samples were analyzed for total metals, cyanide,VOCs, including BETX, BNAs, and PAHs. Soil boring locations are shown in Figure 4A.

Maximum concentrations of carcinogenic PAHs, benzene, ethylbenzene, toluene, and xylene werefound in samples from soil borings B-29 and B-31 collected at depths ranging from 3 to 4 feet and26 to 27 feet, respectively. Bore holes B-29 and B-31 are near the former drainage ditch.

Surface soil samples collected near the CRI&P railroad tracks across Burlington Avenue (north ofthe site) during the 1987 Expanded Site Investigation contained carcinogenic and noncarcinogenicPAHs.

A surface soil sample collected near the corner of 7th street and Washington Avenue during theExpanded Site Investigation contained 94 mg/kg arsenic, 12,000 mg/kg barium, and 3,800 mg/kglead. Soil comparison values for arsenic and barium are 20 mg/kg EMEG and 4,000 mg/kgRMEG, respectively. No soil comparison value for lead is available. However, surface soilconcentrations exceeding 500 to 1,000 mg/kg are undesirable for residential areas.10 Additionalsurface soil sampling activities taken close to the previous sample (conducted by IE in April andJune of 1992) contained 5.6 mg/kg arsenic, 0.79 mg/kg beryllium, and 467 mg/kg manganese.18


Table III*

Off-Site Subsurface Soil (mg/kg)

ContaminantsConcentrationLocationComparison
Value

Arsenic21B-3420 EMEG
Beryllium1.3B-290.2 CREG
Manganese910B-34300 RMEG

Benzene

66

B-29

20 CREG

Benzo(a)anthracene

8.7

B-31

nc
Benzo(a)pyrene14B-310.1 CREG
Benzo(b)fluoranthene2.9JB-29nc
Benzo(g,h,i)perylene3B-31none
Benzo(k)fluoranthene13B-31nc
Chrysene7.7JB-29nc
Dibenzo(a,h)anthracene0.95JB-29nc
Indeno(1,2,3-cd)pyrene5.2B-31nc
Naphthalene110JB-29none
Phenanthrene36JB-31none

nc- noncarcinogen.
None- none listed.
J-compound detected, quantity estimated.
*From Remedial Investigation/Feasibility Studies. Fairfield Coal Gasification Site, Fairfield, Iowa, July 28, 1989. Prepared by B & W WasteScience and Technology Corporation.

Sediment samples were collected near the former drainage ditch in 1987 during the Expanded SiteInvestigation. The concentration of carcinogenic and noncarcinogenic PAHs in off-site sedimentsamples at SL1 and SL2 (along the drainage ditch) were found above comparison values. The samplewas collected prior to installation of a culvert and soil covering.

Groundwater

Groundwater samples were collected from seven off-site monitoring wells and 44 off-site residentialwells. The monitoring well samples were collected at depths ranging from 28 to 70 feet. Fourmonitoring well water samples were analyzed for metals, BETX, VOCs, BNAs, and PAHs. Twomonitoring well water samples were analyzed for metals, BETX, and PAHs. One monitoring wellwater sample was analyzed for metals, PAHs, and VOCs. Forty residential well samples wereanalyzed for total coliform, BETX, nitrates, and PAHs. Three residential well samples were analyzedfor BETX and PAHs. One residential well sample was analyzed for metals, BETX, and PAHs. Contaminants that exceeded comparison values are listed in Table IV.

During the Preliminary Site Investigation, Expanded Site Investigation, and RI/FS, 44 off-site privatewells were analyzed for selected PAHs. The maximum levels of carcinogenic PAHs were found inwater from residential well PW-38. Well depth information is not available for PW-38, but the well isconsidered to be shallow (not more than 40 feet deep). A groundwater sample collected in July 1985from PW-38 contained 200 µg/L chrysene. Another sample collected in September 1985 fromPW-38 contained 0.6 µg/L benzo(a)pyrene. In 1989, PW-38 was resampled, and an estimated 0.22µg/L benzo(g,h,i) perylene was detected in the water. The well is believed to be cross-gradient of thesite and is not used for domestic purposes.

The maximum concentrations of benzene, lead, and manganese in private well water samples were38.0 µg/L, 41 µg/L, and 660 µg/L, respectively. These concentrations were found in residential wellFI-A. Well FI-A was screened at a depth of 25.3 feet and is located on the southeast corner ofWashington Avenue and 7th street.

An off-site groundwater sample collected in June 1985, (during the Preliminary Assessment andExpanded Site Investigation) from a Fairfield Water Works municipal well (depth 2,155 feet)contained 1.4 µg/L xylene and 0.036 µg/L chrysene. Neither xylene nor chrysene were present abovecomparison values. The municipal well is located more than a mile from the site and is believed to beup-gradient.

Surface water

The off-site drainage ditch was sampled during the Preliminary Assessment prior to filling the ditch. The surface water sample contained 16.3 µg/L carcinogenic PAHs and 1.3 µg/L xylene. No surfacewater samples were collected during the RI/FS from the storm sewer, catch basin, or stream.


Table IV*

Off-Site Groundwater (µg/L)

ContaminantConcentrationLocationComparison
Value

Lead41FI-A15 MCL
Manganese660FI-A50 RMEG

Benzo(a)pyrene

0.6

PW-38

0.005 CREG
Benzo(g,h,i)perylene0.22JPW-38none
Chrysene200PW-38nc

Benzene

38

FI-A

1 CREG

ND-Not detected
nc- noncarcinogen
None- none listed
J-compound detected, quantity estimated.
*From Remedial Investigation/Feasibility Studies. Fairfield Coal Gasification Site, Fairfield, Iowa, July 28, 1989. Prepared by B & W Waste Science andTechnology Corporation.

C. Toxic Chemical Release Inventory Information

To identify facilities that could contribute to the soil, surface water, and groundwater contaminationnear the site, IDPH searched the Toxic Chemical Release Inventory (TRI) Data Base for the period1988-1992. EPA developed TRI to provide information about chemical releases to air, water, or soilas provided by certain industries stipulated by Federal Regulations. TRI did not contain informationabout releases in the Fairfield and Jefferson County areas that could be influencing the site area.

D. Quality Assurance and Quality Control (QA/QC)

RI/FS data and the case narrative state that chemical analyses of the environmental samples werevalidated in accordance with the EPA Contract Laboratory Program and the consultant's qualityassurance guidelines. In preparing this public health assessment, IDPH relied on the informationprovided in the referenced documents and assumed that adequate QA/QC measures were followedwith regard to chain-of-custody, laboratory procedures, and data reporting. The validity of theanalyses and conclusions drawn for this public health assessment are determined by the availabilityand reliability of the referenced information.

E. Physical and Other Hazards

In December 1993, site access was completely restricted. Although excavation activities left openpits, no one, except remediation workers, can access the site.

PATHWAYS ANALYSES

A. Completed Exposure Pathways

The pathways analyses section is where health assessment personnel evaluate environmental andhuman components to determine whether people have been exposed to contaminants from the site inthe past, present, or will be in the future. A completed exposure pathway consists of the followingelements: a source of contamination, transportation of the contaminant through an environmentalmedium, a point of exposure, a route of human exposure, and an exposed population.

In a potential exposure pathway at least one element is missing, although risk from exposure may stillexist. Potential pathways indicate that exposure from a contaminant may have occurred in the past,may be occurring, or may occur in the future. An eliminated pathway means that data andinformation from the site indicate that human exposure to site-related contaminants will not occurbecause an exposure pathway element is missing and will likely never exist. The discussion thatfollows identifies the completed, potential, and eliminated pathways at this site. Past completedexposure pathways are summarized in

TABLE V.

Completed Exposure Pathways
PATHWAY
NAME
EXPOSURE PATHWAY ELEMENTS TIME/
STATUS
MEDIAPOINT OF
EXPOSURE
ROUTE OF
EXPOSURE
PEOPLE
EXPOSED

Site

Groundwater

Tap
Ingestion,
Inhalation,
Skin Contact
Private Well
Owners
Past/
Completed

Air

Air
On-site and
Immediate
Surrounding
Areas

Inhalation
Area
Residents
Past/
Completed

Groundwater

In the past, one downgradient off-site residential well (FI-A) used for domestic purposes, pumpedgroundwater from the glacial till aquifer and contained contaminants found at the site (Table IV). The well was found to be contaminated with benzene (38 µg/L), lead (41 µg/L), and manganese (660µg/L). Although this well is no longer in use, people who used the well, about 3-4 people, wereexposed to contaminants in the past through ingestion, inhalation of volatiles, and skin contact. Thehome is now connected to the municipal water supply system.

Air

People were exposed to contaminants released into the air during remedial activities conducted in1993. Exposure stopped or was substantially diminished when a containment structure was erectedover the excavation area. The total number of people exposed is not known, but we estimate thenumber exposed is less than 500 people.

B. Potential Exposure Pathways

Source Areas and Surrounding Soils

In the past, on-site workers, and perhaps area residents, may have ingested, inhaled, or contactedcontaminants found in soils. Prior to and at closure of the Fairfield Coal Gasification plant in 1950,coal-tar was disposed on site in the gas holder pit. The relief gas holder tank and former tar separatortank containing coal-tar were backfilled with fill material and crushed stone. Reportedly, excess coal-tar was disposed on site in the former drainage ditch south of the site. Also, contaminants migratedfrom the source areas into the surrounding soils. Site workers and residents in the immediate vicinitymay have been exposed to the contaminants through direct skin contact, incidental ingestion of dustand waste materials, and from inhaling contaminants in dust particles. The total number of peoplepossibly exposed is not known but is estimated to be less than 1,000. Removal of the source areamaterial and on-site soils has eliminated the possibility of future exposures, such as those thatoccurred during excavation activities.

Groundwater

Future exposures could occur if a new well is installed into a plume of goundwater contamination, orif a plume of contamination migrates into an existing well used for domestic purposes. Populations atrisk of future exposure to contaminants are residents living near the site that use well water for theirdrinking water or other purposes.


PUBLIC HEALTH IMPLICATIONS

In this section, health effects in people exposed to specific contaminants are discussed, state and localdatabases are evaluated, and specific community health concerns are addressed. Chemicals releasedinto the environment do not always result in human exposure. Human exposure to a chemicalcontaminant can only occur if people come in contact with the contaminant either by ingestion (eatingor drinking a substance containing the chemical), inhalation (breathing air containing the chemical), orby dermal absorption (skin contact with a substance containing the chemical).

To understand the type and severity of health effects that may be caused from exposure to a specificchemical contaminant, several factors related to the interaction of the chemical with the individualmust be considered. Such factors include the amount or chemical dose to which a person is exposed,the frequency and duration of exposure, the route the chemical enters the body (ingestion, inhalationor dermal absorption), and the multiplicity (combination of chemicals) of exposure.

Health effects are also related to such characteristics as age, sex, nutritional and health status, lifestyle, and family traits. All of these factors influence how a specific chemical is absorbed (taken up bythe body); metabolized (broken down by the body); and excreted (eliminated from the body).

In determining possible health effects produced by specific chemicals, ATSDR considers physical andbiological factors as well as a variety of other information, such as scientific literature, researchreports, and reports from other federal agencies.

To evaluate health effects, ATSDR has developed Minimal Risk Levels (MRLs) for contaminantscommonly found at hazardous waste sites. The MRL is an estimate of daily human exposure to acontaminant below which noncancerous, adverse health effects are unlikely to occur. MRLs aredeveloped for each exposure route and length of exposure: acute (less than 14 days), intermediate(15 to 364 days), and chronic (greater than 365 days). ATSDR discusses these MRLs in chemical-specific Toxicological Profiles. The chemical-specific profiles provide information on health effects,environmental transport, human exposure, and regulatory status. EPA has developed a ReferenceDose (RfD) that also estimates a daily exposure to a contaminant that may result in noncancerous,adverse health effects. The Toxicological Profiles and other references used in the preparation of thisPublic Health Assessment are listed in the Reference section of this document.

A. Toxicological Evaluation

In this subsection, potential health effects are presented that could occur in people exposed to sitecontaminants. A person must come into contact with contaminants in order for the chemicals tocause illness. Completed exposure pathways and potential exposure pathways have been identified. In the past, people were exposed to contaminants in their well water. In 1993, people were alsoexposed to contaminants released in the air during site remedial activities.

The public health implications of the completed exposure pathways regarding airborne contaminantsthrough inhalation and incidental ingestion during soil excavation at the site were evaluated in HealthConsultations provided by ATSDR on July 9, 1993, August 17, 1993, and October 26, 1993(Appendix B). These exposures were abated by the installation of the containment structure. Contaminated soils excavated at the site have also been transported to another off-site location fortreatment and further disposal. Public health implications regarding the completed exposure pathwayof contaminated groundwater are discussed below.

Groundwater

Benzene

Benzene was detected in a private well at a maximum level of 38 µg/L. People who used the wellwater were exposed to benzene through ingestion, inhalation of volatilized benzene, and direct skincontact. Currently, the private well is no longer used for domestic purposes. The duration ofexposure is not known and the exposed individuals have not complained of any adverse health effects.

ATSDR has developed an acute MRL for exposure to benzene through inhalation.2 No MRLs havebeen developed to help evaluate benzene exposure through ingestion, nor are there any guidelines toevaluate exposure through skin contact.2 Based on the level of benzene detected in the well water,acute ill-effects are not expected to occur from exposures through ingestion, inhalation or dermalcontact. However, long-term exposure to the maximum levels of benzene found in private well watermay result in a slight increase of cancer risk when multiple routes of exposure (inhalation, ingestion,skin contact) are considered.2

Most data for long-term benzene exposure are from studies of workers employed by industries usingbenzene. Occupational exposures occur mainly through inhalation and dermal contact. Benzene,through its metabolites, affects the bone marrow. Antecedent lesions lead to leukocytopenia(reduction in the number of white blood cells) and thrombocytopenia (decrease in the number ofblood platelets). These conditions serve as diagnostic indicators for hematologic screening tests when benzene exposures are suspected.19

People who breathe benzene over a long period of time may experience harmful effects in tissues thatform blood cells, especially in the bone marrow. Anemia or excessive bleeding can result if damage issevere.2 Exposure to benzene can be harmful to the immune system, may cause damage toreproductive organs, and may affect the fetus of pregnant women. Leukemia is a type of blooddisorder associated with benzene exposure.2 However, adverse health effects that might occur inhumans following long-term exposure to low levels of benzene found in food or water are notknown.2

Several factors may predispose an individual's sensitivity to benzene. Individuals who havenutritionally poor diets, compromised immune systems, and genetic disorders are more sensitive toadverse health effects. Fetuses are at risk since benzene can cross the placenta. Also, drug andalcohol consumption contribute to an individual's sensitivity to benzene.2

Lead

Lead was detected in a private well at 41 µg/L. People who used the well water were exposed byingesting the lead in the groundwater. Inhalation and skin contact with lead in groundwater at thislevel are not considered significant routes of exposure.

ATSDR has no MRLs for lead, and EPA has no RfDs for lead at the present time. Recent leadexposure is measured through blood tests in units of micrograms of lead/deciliters of blood (µg/dL). No studies are available to indicate conclusively how much lead must be present in an environmentalmedium on exposure before increased lead levels in blood can be expected.10 The extent of pastexposures is difficult to assess because blood lead information is not available for people who wereexposed to lead in their well water. Extensive studies of various health end points resulting from leadexposures do not depend specifically on a water and blood lead relationship. Lead in drinking wateris probably absorbed more completely than lead in food. Adults absorb 5 to 15% of ingested lead andusually retain 5% of what is absorbed. On the average, the absorption rate for children may begreater than 41%, with 31.8% net retention in infants.19 Once absorbed into the body, excretion oflead is relatively less for children than adults. The net retention of lead is about 30 times greater inchildren than in adults.27 Hence, ingestion of lead in water may contribute to some increase in bloodlead levels.

Young children and fetuses are especially sensitive to the toxic properties of lead. Factors accountingfor this susceptibility include: the immaturity of the blood-brain barrier which allows the entry of leadinto the immature nervous system; enhanced gastrointestinal absorption of lead which is also affectedby the nutritional status of the child; low body weight; and the easy transfer of lead across theplacenta to the developing fetus.10

Exposure to women during pregnancy results in uptake by the fetus. For infants and young children,lead exposure can cause a decrease in intelligence quotient (IQ) scores, slow growth, and may causehearing problems. These effects can persist as children get older and can interfere with successfulperformance in school.10 A prospective study of newborns in Boston not only supports concern forblood lead levels in the 10 to 15 µg/dL range, but suggests that deficits in mental development mayoccur at even lower blood lead levels (6 to 7 µg/dL).18

Some people with lead poisoning may not be overly symptomatic. Because of the differences inindividual susceptibility, symptoms of lead intoxication and their onset may vary. With increasingexposure, the severity of symptoms can be expected to increase. Mild toxicity may result in musclepain and irritability. Moderate toxicity may result in bone pain, general fatigue, difficultyconcentrating, headache, diffuse abdominal pain, and weight loss. Severe lead toxicity may result inencephalopathy which may lead to seizures. A purplish line on the gums, known as a lead line, israrely seen today, but if present, usually indicates severe and prolonged lead poisoning.10

Manganese

Manganese has been detected in on-site and off-site subsurface soils at maximum levels of 1,500mg/kg and 910 mg/kg, respectively. However, since the levels of manganese are contained insubsurface soils, direct exposure is unlikely to occur, except during excavation activities at the site.

Manganese was also detected in one private well at 660 µg/L. This private well is no longer used fordomestic purposes. People who previously used this well were exposed to relatively low levels ofmanganese in the water through ingestion. Inhalation and skin contact at this level of manganese arenot considered significant routes of exposure.

Manganese is a natural element in the environment. It is found in most food and water. It is also anormal component of living things, including plants and animals. Ingestion of manganese in moderateexcess of the normal dietary level of 3 to 7 mg/day (3,000 to 7,000 µ;g/day) is not considered harmfulto humans.11 Because manganese is normally found in the human body, the body normally controlsthe amount that is taken up and kept. If large amounts are ingested, the body only absorbs what isneeded, and the excess is removed in the feces.11

The estimated dose for a person exposed to 660 µg/L of manganese is less than the level associatedwith adverse health effects. Animal data suggest that the potential for carcinogenic effects in humansupon exposure to manganese is relatively small.11

Noncarcinogenic PAHs

Total noncarcinogenic PAHs were found in two private wells at 0.81 µg/L. Those wells are used toirrigate vegetable gardens, but they are not used for drinking. The levels in the well water are farbelow any levels associated with adverse health effects.15

Carcinogenic PAHs

Total carcinogenic PAHs were found in two private wells at an estimated maximum of 0.22 µg/L. Those wells are used to irrigate vegetable gardens and are not used for drinking. Although studieshave indicated that fruits and vegetables may take up some PAHs, low levels are not expected toresult in any increased cancer risk from ingestion of these food items.5,15

B. Health Outcome Data Evaluation

Review of data from the Iowa Cancer Registry from 1973 through 1992 (on all cancer tissue sites)indicates no significant increases in any of the cancer tissue sites reviewed for residents of Fairfield(age groups 0 to 4 years and 85+), when compared to Jefferson County and the state. This reviewwas conducted prior to the start of this Public Health Assessment to determine the potential publichealth impact of site contaminants.

C. Community Health Concerns Evaluation

The following discussion is in response to public health concerns posed during the November 1993and December 1993 EPA/ATSDR/IDPH public meetings held in Fairfield, Iowa:

Question #1:

    Would health problems (nausea and vomiting) that adults and children experienced from odorsreleased during excavation activities at the site occur again next summer when remediation continues?

Answer:

    We do not expect any. The containment structure was installed to prevent odiferous compoundsfrom being released at the site during remedial activities.

Question #2:

    Could a health monitoring program be set up that would act as a surveillance or tracking system forhealth problems that may result from site remediation?

Answer:

    ATSDR and IDPH feel that your personal health care provider is the person best qualified to evaluateyour health concerns. That person has a record of your health prior to, and possibly following, yourexposure. In order to help your health care provider understand more about environmental exposuressuch as the ones you experienced, ATSDR and IDPH provided information to the health careproviders in your area. The information provided included fact sheets about exposure tocontaminants commonly found at sites like this one. For people exposed to contaminants through usethe of contaminated well water, the Toxicological Evaluation section of this document providesrelevant information. ATSDR and IDPH will continue to provide information to you and your healthcare providers as requested.

Question #3:

    Could the monitoring program be long-term, and could physicians be provided with consultativeservices for community members?

Answer:

    If your personal health care provider feels that a problem has developed or may develop at a level thatwarrants long-term monitoring, that person may recommend that you return periodically for furtherevaluation and follow-up. Neither IDPH nor ATSDR have physicians that could provide long-termmonitoring. We can provide you with a list of clinics that have doctors who specialize inoccupational and environmental exposures; however, none of those clinics are available in yourimmediate area. We feel that your personal health care provider can offer you the best assessment ofany conditions you may be experiencing at this time.

Question #4:

    Could contaminants released at the site cause respiratory problems in residents, especially those withan asthmatic condition? Could the contaminants at the site cause a chronic cough that started in earlyJune 1993?

Answer:

    Individuals with a genetic predisposition to develop immediate hypersensitivity reactions againstcommon environmental antigens (such as people with asthma), are often affected. People withasthma, are more sensitive to elevated levels of dust or soil particles released into the air, regardlessof what chemical compounds may be present in the airborne particles.23 It would be difficult todetermine whether your chronic cough is a result of exposure to site contaminants. Your personalphysician is the person best qualified to evaluate your condition.

Question #5:

    Is food, such as apples grown adjacent to the site, safe to eat? Were plants that died near the siteaffected by site-related contamination?

Answer:

    The levels of contaminants in the vicinity of the site that are known to bioaccumulate in edibleportions of plants or fruit trees are very low. For that reason, we consider the apples safe to eat. Ifpesticides have been used, we recommend that the apples be washed before eating. The localagricultural extension office was contacted by EPA to determine why trees near the site have died. At the time this document was prepared for release, we had not received an answer.

Question #6:

    Could the community establish a direct communication line with EPA, IE, and medical personnel toevaluate health complaints/concerns in relation to site remedial activities? Could EPA inform thecommunity directly and in advance of impending site activities?

Answer:

    EPA, ATSDR and IDPH will be available to answer any questions you may have. EPA has indicatedthey will provide information to you concerning remedial activities. ATSDR and IDPH will provideinformation on any health concerns you may have. ATSDR and IDPH, as previously stated, haveprovided information on possible exposures to local health care providers.

Question #7:

    Could toxicological information be provided for each contaminant listed in the public healthassessment.

Answer:

    Yes. You may obtain fact sheets from IDPH or ask ATSDR for information through the Division ofToxicology. Please keep in mind that not all contaminants selected for further evaluation may harmyou. You must come into contact with the contaminant at high enough levels for it to make you sick. Information has been provided in this document on those contaminants to which we feel some of you were exposed.

The address for ATSDR's Division of Toxicology is:

    Agency for Toxic Substances and Disease Registry
    Division of Toxicology
    1600 Clifton Road     Mail Stop E-29
    Atlanta, Georgia     30333

Question #8:

    Could remediation plans be modified to include total site encapsulation and source clean-up (down to40 feet)?

Answer:

    A containment structure has been installed around the areas where soil removal has taken place. People living near the site should not be exposed to contaminants if the volatiles and entrained dustparticles are held within the protective structure. This means that people living near the site shouldno longer be affected by potential airborne contaminants.

    EPA will decide what modifications need to be made in light of the community concerns expressedduring excavation at the site in 1993. ATSDR and IDPH are available to review any modificationsEPA may consider to determine if those plans are protective of public health.

Question #9:

    Could warning signs and a full-time security guard be provided to further protect the public fromcontamination at the site?

Answer:

    EPA placed large warning signs on the site perimeter fence on January 10, 1994. Night-time and after-hour security was in place prior to that date.


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