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PUBLIC HEALTH ASSESSMENT

TRI-COUNTY PUBLIC AIRPORT
DELAVAN, MORRIS COUNTY, KANSAS


SUMMARY

The proposed Tri-County Public Airport (TCPA) National Priorities List site is a former World WarII Army Airfield. During its peak operating period the airfield consisted of more than 300 buildingsand housed approximately 2,000 personnel. The airfield had a waste water treatment plant, a200,000-gallon fuel storage tank, warehouse area, barracks, and a recreation area. The airfield wasofficially declared surplus in 1946 and deeded to the city of Herington, Kansas in 1948. Most of the300 buildings and structures previously at the airfield have been removed, but two hangars, a watertower, several water supply wells, and a few small buildings remain.

From 1948 to the present, the site has been leased to a number of companies for various purposes.Operations at the site have included, but are not limited to, aircraft restoration, aircraft storage, themanufacturing of farm implements, black powder manufacture, and the manufacture of roofingmaterials.

The nature and extent of environmental contamination at the TCPA site are still being determined.The Agency for Toxic Substances and Disease Registry (ATSDR) has reviewed the availableenvironmental data and found that people have been exposed in the past to drinking water fromwells contaminated with carbon tetrachloride, 1,2-dibromoethane (EDB) and trichloroethylene(TCE). Presently, no one is being exposed to site-related contaminants, via drinking water, at levelsabove the Maximum Contaminant Level (MCL) established by the Safe Drinking Water Act.Carbon filtration units have been installed on all residences with carbon tetrachloride, EDB, or TCElevels exceeding the MCL. These carbon filtration units are being monitored periodically to ensureproper operation. Former workers and trespassers on the site may have been exposed to soilscontaining TCE, vinyl chloride, cadmium, lead, and manganese. ATSDR saw no indication oftrespassing when visiting the site; however the TCPA site is not fenced and areas of contaminatedsoil are still present. Presently, on-site workers may be potentially exposed to contaminated on-sitesoils. For contaminants with an adequate amount of toxicological and epidemiological information,ATSDR believes adverse non-cancer health effects are unlikely for adults and children near theTCPA site due to past or present exposures. For those contaminants with known carcinogenicendpoints, ATSDR believes that there is no significant increased risk of developing cancer due topast or present exposures. However, the levels of some Volatile Organic Compounds (VOCs) indrinking water supply wells near the TCPA are similar to concentrations of VOCs found in drinkingwater studies that have shown possible increased risk of birth defects and higher incidence ofchildhood leukemia due to ingestion of VOC contaminated drinking water during the pregnancyperiod (12,13). Even though these studies suggest a possible association with VOC exposure and apossible increased risk of birth defects the results are not conclusive.

ATSDR has made recommendations to (1) provide a more permanent solution for drinking waterthat meets Safe Drinking Water Act regulations to residences with contaminated well water in thevicinity of the Tri-County Public Airport site, (2) continue periodic monitoring of the groundwaterplume to ensure that private drinking water wells currently outside the plume do not becomecontaminated by the migration of the plume, (3) take appropriate preventive measures to mitigateexposure if these well do become contaminated, and (4) inform trespassers and present workers on-site through signs or by other means that they should avoid unnecessary contact with site soils andsediment, especially near Hangar 1, Hangar 4, the former potential burial area, and the sump in thenorth motor pool.

ATSDR has no data for the TCPA site prior to 1997. Therefore, it is difficult to assess pastexposure. ATSDR believes exposure to site related contaminants via drinking water occurred in thepast, but has no way to determine the length of exposure. Exposure to carbon tetrachloride, EDB,and TCE above the MCL has been stopped through the installation of carbon filtration units atresidences with contaminated well water. ATSDR believes, on the basis of the review and analysisof available site related data, that there is presently no apparent public health hazard at the proposed TCPA National Priorities List site.


PURPOSE AND HEALTH ISSUES

The Tri-County Public Airport site was proposed to the National Priorities List (NPL) by the UnitedStates Environmental Protection Agency (EPA) in July 2000. The Agency for Toxic Substances andDisease Registry (ATSDR), located in Atlanta, Georgia, is a federal agency within the United StatesDepartment of Health and Human Services (DHHS). ATSDR, under the ComprehensiveEnvironmental Response, Compensation, and Liability Act of 1980 (CERCLA) conducts publichealth assessments for sites the EPA proposes to the NPL. Therefore, ATSDR has, under itsmandate, evaluated the public health significance of this site. The agency considered whetheradverse health effects are possible and has recommended actions to mitigate possible futureexposure.

The purpose of this public health assessment is to describe ATSDR's activities and to report theagency's conclusions, recommendations, and public health actions.

Community residents requested that ATSDR address the following issues in the public healthassessment:

  1. Could any of the chemicals found in drinking water wells near the proposed Tri-County Public Airport National Priorities List site have caused cancer in thecommunity?

  2. Could my child get ALS (Amyotrophic Lateral Sclerosis, a.k.a. Lou Gehrig'sDisease) from exposure to site related contaminants at the Tri-County PublicAirport?

  3. What is the relationship between Manganese exposure and Parkinson's Disease?

  4. Would the consumption by beef and dairy cattle of groundwater contaminated withcarbon tetrachloride and/or trichloroethylene result in adverse health impacts?

BACKGROUND

A. Introduction to the Site

The TCPA is located 7 miles east of Herington, Morris County, Kansas. The facility comprises approximately 3.5 square miles.

The TCPA was originally constructed as the Herington Army Airfield (HAA) in 1942. During peakoperations the airfield contained more than 300 buildings and housed approximately 2,000personnel. The airfield had a self-contained wastewater treatment plant , a 200,000-gallon fuelstorage tank, a warehousing area, and a barracks and recreation area.

HAA processed B-24 bombers between 1943 and the summer of 1944. The bombers arrived at thebase from the production line. Mechanics at HAA inspected, and sometimes overhauled electricalsystems, hydraulic systems, engines, and aircraft structures. Typically, an aircraft spent severalweeks at the base. Flight crews arrived at HAA after flight training and were matched up with theirparticular aircraft. After a short training program, the B-24 aircraft and crew would depart for theEuropean Theater of Operations.

In the summer of 1944, HAA's mission changed. It became the primary processing base for the newBoeing B-29 Super Fortress. Because HAA was located only a short distance from the Boeing plantin Witchita, it became the primary staging base for the B-29. Approximately 60 percent of the B-29's that flew to the Pacific Theater of Operations--about 74 aircraft per month--processed throughHerington. Maintenance operations at HAA occurred 24 hours per day, 7 days per week. Basemechanics performed all types of maintenance on the B-29, including: engine repair, cylinder repair,engine replacements, and other types of heavy maintenance. Changing and cleaning spark plugs wasan important function of the maintenance operation. The B-29 had 4 engines with 36 spark-plugseach, for a total of 144 spark-plugs. Army personnel used TCE and other solvents to clean spark-plugs and degrease aircraft parts during maintenance operations.

The HAA was officially declared surplus in 1946. The airfield property and buildings were deededto the city of Herington, Kansas in 1948.

From 1948 to the present, the site has been used by a number of companies for various purposes. Operations have included aircraft restoration and aircraft storage, as well as the manufacturing offarm implements, black powder, and roofing materials. From the 1950's to early 1960's, BeechAircraft leased all four hangars and several other buildings at the site. In 1980, the Raytheon AircraftCompany acquired Beech Aircraft. Operations conducted by Beech and Raytheon at the siteconsisted of a chromium conversion coat process, vapor degreasing, painting, paint stripping, wing-tank manufacturing, aircraft refurbishing, aluminum processing, aircraft starter generatormanufacturing, and steel wing-tank shipping container manufacturing. A wastewater treatmentsystem was used by Beech Aircraft for treating chromium process solutions and rinse waters. Paintstripping wastewater was transferred to a holding pond located north of Hangar 1, in or near an areathat is now considered a potential burial area. According to a former employee, both Hangar 1 andHangar 4 contained trichloroethylene (TCE) degreaser pits for cleaning aircraft parts. The vapordegreaser in Hangar 4 was approximately 12 feet deep, 20 feet long, and 6 feet wide. Both degreaserpits were filled in and paved over with concrete and are no longer visible.

Most of the 300 buildings and structures previously at the airfield have been removed, but twohangars, a water tower, several water supply wells, and a few small buildings remain. The main Tri-County Airport Authority office, pilots lounge, and buildings in the former barracks and recreationarea leased to a black powder manufacturer were constructed after the airfield was declared surplus.

Currently, the eastern portion of the site is occupied by Black Diamond Custom Feeders, Inc., a largemanufacturer of cattle feedlot equipment. The southwest corner of the site is fenced and occupied bythe Pyrodex Corporation, a black powder manufacturer that utilizes the southernmost Hangar(Hangar 4). The Pyrodex manufacturing process generates wastewater treatment sludges from themanufacture and processing of explosives. KDHE determined in 1994 that these sludges were non-reactive and allowed Pyrodex to be delisted as a Resource Conservation and Recovery Act (RCRA)hazardous waste generator. U.S. Stone, a custom limestone cutting operation, currently occupies thenorthernmost Hangar (Hangar 1). Prior to U.S. Stone, Insulfoam, and the Carlisle Syntec Company,a bonder of felt for roof underliners, operated in Hangar 1. The main north-south runway isoperational and is used by small commuter aircraft. The city of Herington maintains the pilots loungeand on-site maintenance building.

B. Site Investigations

EPA, KDHE, and the U.S. Army Corps of Engineers (USACE) have conducted numerousinvestigations on the site. USACE conducted an investigation at the TCPA from 1994 to 1997 andcompleted its final report in July 1998. The USACE concluded that ground water at the site,specifically that near the fuel storage area, had been impacted by BTEX (benzene, toluene, ethylbenzene and xylenes), 1,2-dibromoethane, total petroleum hydrocarbons, and lead. It also concludedthat soils on site had not been contaminated except in the wash rack area. Because the USACEconsidered the solvent contamination (TCE and cis-1,2-dichloroethylene) outside the scope ofDepartment of Defense responsibility, it deferred that contamination issue to EPA Region 7.

In May 1996, KDHE completed a preliminary assessment/screening site inspection of TCPA inresponse to the detection of TCE during the USACE investigation and concluded that thegroundwater beneath the TCPA site had been contaminated with TCE, 1,1-dichloroethene (DCE),and carbon tetrachloride, but there was no apparent contamination of the surface water or soilpathways at the site. KDHE recommended that an Expanded Site Inspection/Remedial Investigation(ESI/RI) be conducted at the site.

In October 1997, EPA and KDHE sampled private groundwater wells in the area around TCPA. Forty-three groundwater samples were collected from private wells within Latimer and the surrounding area. All TCE concentrations detected in wells within Latimer exceeded the TCE Maximum Contaminant Level (MCL) of 5 µg/L. Six of the eight wells in the surrounding area had TCE concentrations that exceeded the MCL. None of the DCE concentrations exceeded the MCL.

The EPA completed an ESI/RI at the site in June 1999.

The results of completed investigations indicate that ground water has been contaminated with TCE and DCE within 3 miles to the north and northwest of TCPA. TCE has been detected in groundwater samples collected from private wells within this distance at concentrations ranging from 3 micrograms per liter (µg/L) to 280 µg/L. TCE concentrations in 21 of the 23 private wells sampled exceeded the 5 µg/L MCL established by the EPA as the highest permissible level of TCE allowed in drinking water.

In March 2001, ATSDR visited the site to get an overview of site conditions and gather additionaldata. During the visit, ATSDR noted that access to most of the site is unrestricted.

The full extent and characterization of site contamination is on-going. Therefore, the release of thispublic health assessment deals with information available to ATSDR as of October 2002.Information obtained by ATSDR following the release of this document will be evaluated separately,as needed.

C. Site Geography

The primary surface water bodies in the TCPA site area are Clarks Creek, a tributary of the KansasRiver, and Level Creek, a tributary of the Neosho River. The TCPA site is on a topographicallyelevated area that serves as a surface water divide between the major drainage basins of Clarks Creekand the Neosha River. Clarks Creek is a perennial, north-northeast flowing creek that lies to the westand north of the site. The south flowing and north flowing reaches of the on-site drainage ditch flowinto tributaries of Clarks Creek. The general geology beneath the site consists of a succession of shaleaquitards and limestone aquifers. The shallowest aquifer is the Cresswell Limestone aquifer. TheStovall and Towanda aquifers lie below the Cresswell. According to ESI/RI data, a majority of private water wells in the vicinity of the site are completed into the Towanda aquifer.

D. Demographics

The community consists of approximately 19 residents living within a one-mile radius of the site. The nearest residence is approximately 2,500 feet north of the site boundary. There areapproximately 4 children six years old and younger living within a mile radius of the site. Homes near the site rely on groundwater sources for drinking water.


DISCUSSION

A. Nature and Extent of Environmental Contamination

Results of sampling activities are summarized as shown in Appendix B. The sampling data show thaton-site soil is contaminated with metals and volatile organic compounds (VOCs) and on-site and off-site groundwater is contaminated with VOCs. These data will be discussed in moredetail in the following sections of the document.

Six springs located to the north and northwest of TCPA were sampled for VOCs. These springs lie in the general direction of the groundwater plume. One spring had an elevated level of TCE (Appendix B, Table 1).

Data were analyzed by ATSDR for on-site and off-site drinking water supply wells that weresampled as part of the ESI/RI and the December 2000 and April 2001 quarterly sampling reports.On- and off-site drinking water supply wells were sampled for VOCs, 1,2-dibromoethane (EDB), anddibromo-3-chloropropane (DBCP) during each sampling event. Elevated levels of TCE, EDB, andcarbon tetrachloride were detected in some wells (Appendix B, Table 2).

Data also were analyzed by ATSDR for groundwater monitoring wells that were sampled during theESI/RI and the Quarterly Sampling Reports. The monitoring wells were sampled for VOCs andmetals. Several of the VOCs and metals exceeded ATSDR screening values (Appendix B, Table 3).

Samples of on-site soil and sediment were tested for VOCs and metals. Elevated levels of VOCs were found in subsurface soils adjacent to the former locations of the TCE degreasers at both Hangar4 and Hangar 1and near the former waste water treatment plant. Elevated levels of metals were foundnear Hangar 1 (north side) and at the former potential burial area and the north motor pool(Appendix B, Table 4).

B. Pathways Analyses

ATSDR identifies human exposure pathways by examining environmental components and humanpractices that might lead to contact with contaminants of concern. A pathway analysis considers fiveprincipal 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. Completedexposure pathways are those for which the five elements are evident, and indicate that exposure to acontaminant has occurred in the past, is currently occurring, or will occur in the future. ATSDRregards people who come into contact with contamination as exposed. For example, people who residein an area with contaminants in the air, or who drink water known to be contaminated, or who work orplay in contaminated soil are considered to be exposed. Potential exposure pathways are those forwhich exposure seems possible, but one or more of the elements is not clearly defined. Potentialpathways indicate that exposure to a contaminant could have occurred in the past, could be occurringnow, or could occur in the future. Identification of an exposure pathway does not imply that healtheffects will occur. Exposures may or may not be substantive. Thus, exposures may or may not causeadverse health effects.

ATSDR staff reviewed site history; information on past, current, and planned activities; and mediasampling data. They identified various exposure pathways that warranted consideration. Those arediscussed in this subsection.

The ESI/RI determined that three main areas of TCE contaminated soil are present on the TCPA site,and that TCE has impacted the three uppermost aquifers both on and off the site. TCE contaminationwas originally verified in 15 nearby private drinking water wells to the north and northwest of the siteover an approximate 12 square-mile area. More recent data indicate that 22 private drinking waterwells have carbon tetrachloride, EDB, or TCE contamination exceeding the MCL. KDHE provided 6residences that had carbon tetrachloride, EDB, or TCE concentrations above the MCL in theirdrinking water with granulated activated carbon filtration units late in 1997. EPA also provided oneresidence with a carbon filtration unit and 15 residences with bottled water in 1997. Beginning in2000, a potentially responsible party (PRP) utilized a phased approach to install carbon filtration unitson all homes still using bottled water as the primary drinking water source. A PRP also replaced thecarbon filtration units originally installed by KDHE. Presently, all homes with carbon tetrachloride,EDB, or TCE contamination above the MCL have carbon filtration units. EPA determined that toevaluate the continuing health threat presented by the groundwater plume and possibleremedial/removal alternatives, quarterly sampling of selected water supply wells at the boundary ofthe plume and monitoring wells on and off the site was warranted. ATSDR reviewed analytical resultsfor sampling activities from the ESI/RI, the April 2000 quarterly monitoring and the quarterlysampling conducted from May 1999 to April 2000.

C. Completed Exposure Pathways

Elements of completed exposure pathways are provided in Appendix C, Table 2.

The groundwater in the vicinity of the TCPA is contaminated with metals and VOCs (Appendix B,Table 3). The full nature and extent of groundwater contamination is still being characterized. Thegroundwater plume flows north and north west of the site over an approximate 12 square-mile area.Current testing indicates that there is TCE contamination in 22 nearby drinking water wells. How longpeople were exposed to VOCs in private wells is not known. The HAA was closed in 1946 and turnedover to the city of Herington in 1948. If we assume that the groundwater contamination began duringthe airfield's operating days, it is possible for a resident of the area to have been exposed to site relatedcontaminants for approximately 50 years. Conversely, it is possible that contamination of thegroundwater occurred much later during the period when the HAA was leased to variouscompanies,which would make the exposure period for residents much shorter.

D. Potential Exposure Pathways

Elements of potential exposure pathways are provided in Appendix C, Table 1.

From observations made during ATSDR's site visit, it is possible for trespassers to access the TCPAsite. Most areas of the site are not fenced. The number of trespassers upon the site is not known, but isassumed to be less than 100 trespassers. It is possible that trespassers, as well as former and presentworkers, may have been intermittently exposed to contaminants present in soil. Surface-soil samplestaken from areas around the site (Appendix B, Table 4) have been shown to be contaminated withvarious VOCs and metals. The maximum concentration of TCE was 2,100 parts per million (ppm)and the maximum concentration of vinyl chloride was 12 ppm. Metals found in soil samples werecadmium at a maximum concentration of 48 ppm, lead at a maximum concentration of 1,700 ppm,and manganese at a maximum concentration of 4,400 ppm. The principal route of exposure would beby direct contact with and possible intermittent ingestion of contaminants in the soil. Inhalation ofcontaminants in fugitive dusts is also possible.

Monitoring of on-site water wells has not shown contamination of TCE to date; however, there ispotential for contamination to migrate into these wells in the future. A quarterly monitoring programis in place that should provide sufficient warning if site related contaminants do migrate into the on-site drinking water supply.

Three surface-water samples taken from eight springs and/or seeps to the north and north west of thesite have shown contamination with TCE at levels above the MCL (Appendix B, Table 1). Personswho trespass upon the property with these springs may be exposed intermittently to these contaminants via direct contact or incidental ingestion.


PUBLIC HEALTH IMPLICATIONS

A. Introduction

The contaminants of concern released into the environment at the proposed TCPA NPL site have thepotential to cause adverse health effects. However, for adverse health effects to occur, the pathway forexposure must be complete. A release does not always result in exposure. The health effects resultingfrom an interaction of an individual with a hazardous substance in the environment depend on severalfactors. One is the route of exposure; whether the chemical contacts the skin (dermal), is breathed in(inhaled), or consumed with food, soil, or water (ingestion). Another factor is the dose to which aperson is exposed, and the amount of the exposure dose that is actually absorbed. Mechanisms thatalter chemicals in the environment or inside the body, as well as combination (types) of chemicals arealso important. Once exposure occurs, characteristics such as age, sex, nutritional status, genetics, lifestyle, and health status of the exposed individual influence how the contaminants are absorbed,distributed, metabolized, and excreted. Together those factors and characteristics determine the healtheffects that may occur as a result of an exposure to a contaminant. Much variation in thesemechanisms exists among individuals. For example, all children mouth or ingest nonfood items tosome extent. This behavior is known as pica. The degree of pica behavior varies widely in thepopulation, and is influenced by nutritional status and the quality of care and supervision (3). Groupsthat are at increased risk for pica behavior include children 1 to 3 years old and children withneurological disorders (e.g., brain damage, epilepsy, and mental retardation).

To ensure that the health of children is protected, ATSDR has implemented an initiative to protectchildren from exposure to hazardous waste. ATSDR recognizes that the unique vulnerabilities ofinfants and children demand special emphasis in communities faced with contamination of their water,soil, air, or food. Infants and children are usually more susceptible to toxic substances than are adultsbecause of immature and developing organs. Children are more likely to be exposed to contaminantsbecause they play outdoors and often bring food into contaminated areas. These activities mayincrease their exposure to toxicants in dust, soil, and air. Some children exhibit excessive picabehavior, which may increase their intake of toxicants. Children are smaller, which results in higherdose concentrations in their bodies. Most importantly, children depend completely on adults for riskidentification, management decisions, housing decisions, and access to medical care. ATSDR'sevaluation described in this document considered children as a susceptible subpopulation.

The methods for calculating and evaluating exposure doses from ingestion are presented in Appendix D.

B. Exposure Scenarios

Exact information about the habits of trespassers upon the site is unknown. To evaluate possible exposures ATSDR made certain assumptions about the possible sources ofcontamination.

Soil

  • People who trespassed upon the site were adults and school-aged children.
  • Intermittent exposure occurred at a maximum frequency of 3 days per week, 2-5 hours per visit, and not more than 30 weeks per year.
  • Children displaying pica behavior (children between 0 and 5 years old) were notpresent upon the site.
  • Exposures occurred at the maximum concentration detected.
  • Exposure via incidental ingestion occurred (though minimal).
  • The maximum period of time people could have been exposed was 30 years for non-carcinogenic compounds and 50 years for carcinogenic compounds.
  • The main route of exposure was most likely by direct contact.

Springs and Seeps

  • People who contacted spring or seep water on the site were adults and school children.
  • Intermittent ingestion occurred at a maximum frequency of 3 days per week and notmore than 30 weeks per year.
  • Children ingested an average of 0.5 liter of water per day; adults ingested an averageof 1 liter of water per visit.
  • Exposures occurred at the maximum concentration detected.
  • Exposure by direct contact and inhalation occurred (though minimal).
  • The maximum period of time people could have been exposed was 30 years for non-carcinogenic compounds and 50 years for carcinogenic compounds.
  • The main route of exposure was most likely by ingestion.

Drinking Water

  • People who drank contaminated water were adults and children.
  • Children ingested an average of 1 liter of water per day; adults ingested an average of 2 liters of water per day.
  • Exposure occurred at a maximum frequency of 365 days per year.
  • Exposures occurred at the maximum concentration detected.
  • Exposure by inhalation occurred (though minimal).
  • The maximum period of time people could have been exposed was 30 years for non-carcinogenic compounds and 50 years for carcinogenic compounds.
  • The main route of exposure was most likely ingestion of drinking water.

ATSDR has no methodology to determine amounts of chemicals absorbed through the skin.Therefore, an exposure dose for this route of exposure was not calculated. Contaminants which arecarcinogenic, at levels above health guidelines, and those for which there are no health guidelines available (Appendix E) will be discussed further.

C. Adult Population

Adults living in the vicinity of the TCPA were mainly exposed to VOCs by drinking water fromprivate wells, but also may have been exposed to VOCs by occasional contact with spring and seepwater and on-site soil and sediment. Laboratory animals have been exposed to these chemicals viacontaminated air, drinking water, and food. The results of these studies indicate that the nervoussystem and liver, and to a lesser degree, the kidney and heart are the organs of adults and animalsaffected by VOCs. In these studies, however, the amount of VOCs needed to cause adverse healtheffects occurred at levels 50 to 200 times higher than those levels received by people who drankcontaminated water or who were occasionally exposed to contaminated surface water, soil, andsediment (greater than 5 mg/kg/day vs. maximum of 0.086 mg/kg/day) at the TCPA site (6,7,10).

Trichloroethylene (TCE) was found in spring and seep water at a maximum concentration of 15 µg/L, in drinking water at a maximum concentration of 280 µg/L, and in on-site soil and sediment at a maximum concentration of 2100 ppm. TCE can enter the body by breathing air, by drinking water, or by skin contact. Health effects in people have been reported when exposed to levels of TCE at which its odor is noticeable. Animals exposed to moderate levels of TCE had enlarged livers, and high-level exposure caused liver and kidney damage. It is not known if these changes would occur in humans. The carcinogenicity of TCE has not been rated by EPA, but the International Agency for Cancer Research (IARC) considers it to be a probable human carcinogen.

ATSDR maintains a TCE exposure subregistry with approximately 4,300 participants. Informationfrom the subregistry indicates that participants reported that they had more health problems than whatis normally expected (10). The participants were exposed to TCE at levels of 2 to 19,380 ppbm indrinking water for up to 18 years. Only the rate for strokes was reported to increase with increasingconcentration of TCE in drinking water. Therefore, this study suggests that there may be a relationshipbetween exposure to TCE and an increased chance of having a stroke. However, these results do notprove a cause and effect relationship. This study did not confirm the health conditions (they were selfreported) and the study did not completely identify the exposure levels. In addition, the currentscientific literature does not document any known association of stroke and TCE exposure (10).

Besides strokes, the participants in the ATSDR TCE exposure subregistry reported other healthproblems (above the national averages, for various age and sex groups): hypertension, liver problems,anemia and other blood disorders, diabetes, kidney disease, urinary tract disorders, heart conditionsand skin rashes. These other health problems were not related to the concentration of TCE in theirdrinking water (the occurrence of health problems did not increase with higher exposure levels) (10).If the health problems had been associated with exposure to TCE, the number of people with a specifichealth problem should have increased with higher exposure levels. This is not what was reported toATSDR. Therefore, it is unlikely that the reported health problems (kidney disease, urinary tractdisorders, heart conditions, and skin rashes) are associated with exposure to TCE.

ATSDR calculated adult TCE exposure doses for spring and seep water, drinking water, and soilpathways, on the basis of the exposure scenarios previously outlined. The estimated exposure doseswere 100 to 1,000 times lower than the lowest observed adverse effect level (LOAEL) for animals (37mg/kg/day) (10).

Carbon tetrachloride (CCl4) was detected in private drinking water wells at a maximum of 19 micrograms per liter (µg/L). The MCL is 5 µg/L, but EPA has proposed a MCLG of zero. Experiments have not been performed on the effects of long-term exposure of humans to low levels of CCl4, so human health effects are not known. Studies have shown that the kidney and liver are sensitive to CCl4. Fortunately, if injuries to the kidney and liver are not too severe, these effects disappear after exposure stops. Many cases of CCl4 toxicity are associated with drinking alcohol. The frequent drinking of alcoholic beverages increases the danger from CCl4 exposure. Studies in animals have shown that CCl4 given by mouth can increase the frequency of liver tumors in some species (6). Studies have not been performed to determine if breathing CCl4 causes tumors in animals or humans, but it should be assumed that CCl4 could produce cancer. CCl4 is considered possibly carcinogenic to humans. Estimated exposure doses slightly exceeded the minimal risk levels (MRL) (0.007 mg/kg/day), but were well below the no-observed-adverse-effect-level (NOAEL) (11 mg/kg/day) and the cancer effect level (CEL) (47 mg/kg/day) (6).

1,2-dibromoethane (EDB) was found in drinking water wells at a maximum concentration of 0.712 µg/L. The MCL for EDB is 0.05 µg/L. EDB is rapidly absorbed into the bloodstream by any method of exposure. Most of it builds up in the liver or kidneys where it is rapidly broken down into different substances. These substances leave the body quickly in the urine with smaller amounts passed in liver bile into the stool. In animal studies, rats and mice that repeatedly breathed, swallowed or had skin contact with EDB for long periods had cancer in many organs. Based on these studies, the DHHS has determined that EDB may be reasonably anticipated to be a carcinogen. ATSDR calculated an exposure dose for EDB based on the maximum concentration found in drinking water (0.712 µg/L). The calculated exposure dose was well below the LOAEL (4 mg/kg/day) and the CEL (37 mg/kg/day).

Vinyl chloride was found in on-site soil and sediment at a maximum concentration of 12 ppm. Vinylchloride that enters the body through inhalation or ingestion enters the bloodstream rapidly. Studies inanimals show that extremely high levels of vinyl chloride can damage the liver, lungs, and kidneys.Results from several studies suggest that breathing air or drinking water containing low levels of vinylchloride may increase the risk of getting cancer; therefore, it is considered a human carcinogen.ATSDR calculated an exposure dose for vinyl chloride based on the maximum concentration found insoil. The estimated exposure dose was slightly above the MRL (0.00002 mg/kg/day), but more than250 times lower than the LOAEL in animals.

Adults in the vicinity of the TCPA site also may have been exposed to some metals through occasionalcontact with on-site soil and sediment. The metals detected in on-site soil above ATSDR comparisonvalues were cadmium, lead, and manganese.

Cadmium was detected in on-site soil and sediment at a maximum concentration of 48 ppm. Cadmium has the ability to cause dermal irritation. Some eczema patients patch-tested with 2%cadmium chloride showed some reaction. Cadmium is classified by EPA as a probable humancarcinogen based upon epidemiological studies of humans. The epidemiological studies indicate thatcadmium may be a carcinogen via the inhalation route of exposure with the resulting condition beinglung cancer. These conditions occurred in occupational settings at concentrations much higher thanthose found in on-site soil and sediment samples (5). On considering the locations where the sampleswere taken, ATSDR believes that the inhalation route of exposure is not of significance in thispathway. ATSDR calculated an exposure dose for cadmium based on the exposure scenariospreviously outlined in the PHA. The estimated exposure doses did not exceed ATSDR's MRL.

Lead was detected in on-site soil and sediment at a maximum concentration of 1,700 ppm in subsurface soil and a maximum concentration of 270 ppm in surface soil. Ingestion of lead at veryhigh levels in soil may, over time, result in neurological impairment such as learning disabilities--especially in children. Dermal exposures are not considered to be significant in humans because thedermal absorption rate for inorganic compounds of lead is low. Lead has been shown to cause cancerin animals. ATSDR has no MRL and EPA has no RfD for lead. ATSDR calculated exposure doses forlead. The estimated exposure doses were below the LOAEL for neurological effects in monkeys (0.05mg/kg/day). The estimated exposure doses are approximately 20,000 times lower than the CEL inanimals.

People who trespassed on the site and came into contact with on-site surface soils could have beenexposed to manganese at a maximum concentration of 4,400 ppm. Dermal exposure is usually not aconcern because manganese has not been found to enter the body through undamaged skin. No studieswere found that reported cancer in humans associated with manganese. Few animal studies on thissubject are available. Gastrointestinal absorption of manganese is approximately 3%-5%. Theestimated exposure dose was below the EPA's reference dose (RfD) of 0.005 mg/kg/day.

On the basis of information reviewed, ATSDR believes that adults would have very infrequentexposure to areas at the TCPA site with elevated levels of soil contamination. The main route ofexposure to the contaminants in the soil or surface water would be by direct contact or incidentalingestion. ATSDR calculated exposure doses in soil, sediment, and surface water for adults on thebasis of the exposure scenarios previously presented in the PHA. ATSDR believes that these veryinfrequent exposures to metals or VOCs in soil, sediment, or surface water would not causeadverse non-cancer or cancer health effects.

The main exposure pathway for adults would be through ingestion of contaminated drinking waterfrom private drinking water wells in the vicinity of the TCPA site. ATSDR calculated exposure dosesfor the ingestion of VOC contaminated drinking water, based on the exposure scenarios previouslyoutlined in the PHA. From this analysis, ATSDR believes that exposure to VOCs in drinking waterwould not cause adverse non-cancer or cancer health effects to adults.

D. Child Population

Children, particularly the fetus, are susceptible to the toxic effects of chemicals if the chemicals crossthe placental barrier. Before birth, the fetus is forming the body organs that need to last a lifetime. Thisis the time when chemical injury might have the greatest effect. Laboratory animal andepidemiological studies indicate that VOC exposures to the fetus may result in adverse health effects.However, the amount of VOCs given to pregnant laboratory animals was higher than what peoplewere actually exposed to by drinking water or through occasional exposure to surface water and on-site soil and sediment at the TCPA site. This indicates that VOC exposures to people near the TCPAsite may not have been at levels that could affect children.

On the other hand, recent epidemiologic studies suggest that the exposures that occurred couldpossibly result in adverse health effects to children exposed as a fetus. The New Jersey Department ofHealth evaluated effects of VOCs in drinking water on birth outcomes in an area of northern NewJersey (13). Information on birth outcomes status and maternal risk factors was obtained from vitalrecords and the New Jersey Birth Defects Registry. This study found that exposure to TCE duringpregnancy increased the risk of the fetus developing central nervous system defects, neural tubedefects (NTD), and oral cleft defects. The authors concluded that their study by itself cannot resolvewhether the drinking water contaminants caused the reported adverse birth outcomes.

Two other studies have shown possible increased risk of birth defects [small for gestational age (SGA)and NTD] and higher incidence of childhood leukemia due to ingestion of drinking watercontaminated with TCE and tetrachloroethylene (PCE) during the pregnancy period. In Woburn,Massachusetts, a 1979 drinking water sampling of two contaminated wells detected TCE at 267 ppband PCE at 21 ppb. A cluster of childhood leukemia was linked to these drinking water contaminants(18). A study of birth outcomes parallel to the childhood cancer study found increased risks for severalbirth defects including NTD and an increased risk of SGA. It is unclear whether the increased riskswere due to the TCE, PCE, or the mixture. Because TCE was the predominant contaminant, the focushas been on TCE (18). A study at Camp Lejeune, North Carolina, found a potential association withreduced birth weight and SGA in male infants from long-term exposure to TCE during pregnancy(12). However, the sample size was small and considerably weakens the evidence for a causalassociation.

Health effects seen in children from exposure to toxic levels of carbon tetrachloride could be expectedto be similar to the effects seen in adults. No studies were located regarding reproductive effects ordevelopmental effects in humans after oral or inhalation exposure to carbon tetrachloride (6).

1,2 dibromoethane (EDB) is not known to cause birth defects in people. No studies were locatedregarding developmental effects in humans after inhalation or oral exposure to EDB. No studies werelocated regarding reproductive effects in humans from oral exposure to EDB, but one showed apossible reduction in sperm count for male workers occupationally exposed by inhalation to EDB.

There is limited information available on the toxicity of vinyl chloride in children. Two studies of communities located near vinyl chloride polymerization facilities suggested there might beincreased developmental toxicity or increased fetal loss when one of the parents had beenoccupationally exposed to vinyl chloride. However, both studies failed to demonstrate a statisticallysignificant correlation (11).

In addition to VOC exposure at the TCPA site, there also was possible intermittent exposure ofchildren to some metals. The metals found at the TCPA site that were above ATSDR comparisonvalues were cadmium, manganese, and lead.

Health effects seen in children from exposure to toxic levels of cadmium are expected to be similar tothe effects seen in adults. Children are most likely to be exposed to cadmium in food or water. Mostingested cadmium moves through the gastrointestinal (GI) tract without being absorbed. Cadmium hasthe potential to cause adverse neurological effects; however, only a few studies have reported anassociation between environmental cadmium exposure and neuro-psychological functioning.Endpoints that were affected included verbal IQ, acting-out, and distractibility. The placenta may actas a partial barrier to fetal exposure to cadmium. Long-term exposures of infants and children tocadmium may result in the accumulation of cadmium in the bone (5).

Although low levels of manganese are necessary for human health, chronic exposure (exposuresoccurring over a period of one year or longer) to high manganese levels may be harmful. Children--especially neonates less than one month old--may be unusually susceptible to the effects ofmanganese. There is some limited evidence that prenatal or neonatal exposure of animals to elevatedlevels of manganese can lead to neurological changes in the newborn. A number of studies indicatethat neonates retain a much higher percentage of ingested or injected manganese than adults, both inanimals and in humans. The result of high retention is increased levels of manganese in tissues ofexposed neonatal animals, especially in the brain. Dermal exposure is not a concern since manganesehas not been found to enter the body through undamaged skin (9).

Exposure to lead is particularly dangerous for unborn children and young children (0-5 years old)because of their greater sensitivity during development. Studies have shown that lead contamination inexterior dusts and soil at concentrations of 500 to 1000 mg/kg can begin to influence blood leadconcentrations in children residing in lead contaminated areas (8). Blood lead levels may be raisedabove background. Lead exposure is hazardous for unborn children and young children because theyare more sensitive to lead during development. Unborn children can be exposed to lead through theplacenta. Such exposures could cause premature births, smaller babies, and a decrease in mentalability.

Children are more likely to experience lead-induced adverse health effects because they absorb leadthrough the GI tract more readily than do adults. They also have immature detoxification enzymesystems which lead to an increase in body burden of ingested lead. Children also have lower thresholdsfor neurological and hematological adverse effects from lead exposure (8).

On the basis of reviewed information, ATSDR believes that children, especially those between oneand five years old, would infrequently, if at all, play near the areas with elevated levels of soilcontamination or near the off-site springs and seeps. If exposure occurs, the main route of exposure tothe contaminants in soil or surface water would be by direct contact or incidental ingestion. ATSDRcalculated exposure doses in soil, sediment, and surface water for children, according to the exposurescenarios previously presented. On the basis of this analysis, ATSDR believes that these veryinfrequent exposures to metals or VOCs in soil, sediment or surface water would not cause adversehealth effects.

The main exposure pathway for children or an unborn fetus (via the mother) would be throughingestion of contaminated drinking water from private wells in the vicinity of the TCPA site. ATSDRcalculated exposure doses for the ingestion of VOC contaminated drinking water, according toexposure scenarios previously outlined. On the basis of this analysis, ATSDR believes that exposureto VOCs in drinking water would not cause adverse health effects to children. However, as wassuggested from cited studies, ATSDR does not know whether the levels of VOCs found in drinkingwater near the TCPA site might adversely affect an unborn child.

E. Toxicologic Summary

Increased risk of cancer is not expected to occur from intermittent exposures to cadmium and vinylchloride in on-site surface soil and sediment, or from exposure to carbon tetrachloride, 1,2-dibromoethane, or trichloroethylene. It is not known if exposure to lead and manganese causescancer in humans. Many of the adverse health effects described for lead exposure are the result ofexposure to lead at high concentrations. Due to the rural nature of the site, it is not likely that children,especially 5 years old or younger, would play at the site. In addition, exposure to on-site contaminantsby trespassers or former and present workers would have been minimal. Therefore, adverse healtheffects, although possible, are unlikely to have occurred.

Considering the data reviewed, exposure to contaminated on-site media would cause minimaleffects, if any. However, direct contact with surface soils should be avoided, especially near thehangars where the higher levels of contamination were found. ATSDR recommends, to be safe,children should avoid contact with site contaminants, especially cadmium, lead, and TCE.

On the basis of reviewed data, exposure to contaminants in drinking water wells does not appear tohave been at sufficient levels to have caused adverse non-cancer or cancer health effects.Although, as discussed in the child population section, some studies (Woburn, MA, and CampLejeune, NC) do suggest an association between long-term in utero exposure to VOCs (i.e., TCE) andpossible fetal health effects. The level of TCE found in drinking water wells in the Woburn study wasin the same range as that found in drinking water wells at the TCPA site. The TCE levels found in theCamp Lejeune study were 3 to 4 times higher than what was found at TCPA. Therefore, even thoughadverse fetal health effects may have been possible, they are not likely to have occurred.

ATSDR has no data for the TCPA site prior to 1997. Therefore, it is difficult to assess past exposureat the site. ATSDR based its analyses in this report on the highest levels of contaminants found in aparticular medium (surface water, drinking water, soil, and sediment). Past contaminant levels mayhave been higher or lower. For some contaminants (i.e., TCE) much higher levels were found inground water monitoring wells; however, ATSDR believes exposure at these higher levels to beunlikely.

F. Uncertainty Analysis

Uncertainty exists in ATSDR's evaluation of VOC exposure and the possibility of harmful effects toresidents. First, estimating exposure is uncertain. These uncertainties are listed here:

  • ATSDR based its evaluation of estimated exposure on the maximum level detected and assumed that some people were exposed to these levels for up to 30 or 50 years. In fact, people are likely to have been exposed to lower levels and higher levels over the course of many years.

  • The length of time people may have been exposed to TCE contaminated drinking water is unknown. To be conservative, ATSDR estimated the length of exposure to be approximately 50 years. This covers the time period beginning when HAA was deeded to the city of Herington (1948) to around 1997, when the first residences received carbon filtration units and bottled water. The actual period of exposure may have been much shorter if contamination occurred during the years the property was leased to various companies. For this Public Health Assessment ATSDR used the values of 30 years and 50 years for its estimations of the exposure dose.

  • Many factors affect the air concentration of VOCs during and after showers and a change in these factors could increase or decrease the amount of exposure to VOCs that would have occurred because of volatilization from showers. In addition, dermal absorption may be overestimated or under estimated. To account for effects from inhalation and dermal absorption, ATSDR used the very conservative approach of tripling the VOCs ingestion exposure doses to account for these exposure pathways.

Second, uncertainties exist in comparing the estimated doses to animal and human studies and deciding whether or not harmful effects might occur. These uncertainties are described in more detail here:

  • The route of exposure can at times affect the toxicity of a chemical in two ways: a chemicalmay cause a harmful effect by one route of exposure such as inhalation, but not by anotherroute such as ingestion. In addition, the chemical amount that causes a harmful effect might bedifferent according to the route of exposure. A chemical might be more toxic by inhalationthan by ingestion, or vice versa.

  • When several routes of exposure occur at the same time, evaluating each route of exposuremay or may not be appropriate. As is the case for the TCPA, people with contaminated wellwater are exposed through inhalation and through dermal contact when they take a shower.The total amount of exposure is probably just as important as the individual route of exposure.However, a decision needs to be made as to which toxicity studies should be used forcomparison. Should inhalation studies be used or should dermal absorption studies be used. Inthe case of dermal absorption studies, such studies are frequently not available. Because theuncertainty about the most appropriate route of exposure exists, ATSDR combined the doseused in both inhalation and ingestion studies to decide whether harmful effects might occur.

  • Totaling all the chlorinated VOCs to decide if harmful effects might occur may or may not beappropriate. Very few controlled studies have been conducted looking at exposure to a mixtureof chlorinated VOCs. Some occupational studies exist where exposure was to a mixture ofVOCs, but it is unclear which chemicals might be responsible for the effects found in those studies.

G. Review of Health Statistical Data

Due to the small number of people living in proximity to the proposed TCPA NPL site, an evaluationof health statistical data and a comparison with local population health data would not provide usefulor meaningful information. Therefore, no health outcome data evaluation was conducted.

H. Community Health Concerns

  1. Could any of the chemicals found in drinking water wells near the proposed TCPA NPL site have caused cancer in the community?
  2. Response:
    According to cancer statistics from the Center for Health and Environmental Statistics at the KDHE, Morris County had 93 cancer deaths for the years 1994 through 1998. The age-adjusted death rate from cancer for Morris County was nearly equal (120.2 vs. 119.6) to the age-adjusted death rate for cancer for the state of Kansas. Morris County's age-adjusted death rate for cancer was below the age-adjusted rate for the U.S. population for the years 1994 through 1998. ATSDR contacted KDHE to request a breakdown by cancer type (specifically liver, kidney, and leukemia) for cancer deaths that occurred in Morris County. KDHE reported that for the years 1996 through 1999 there were no liver cancers, four kidney cancers, and 3 leukemia's in Morris County.

    Based on information received from KDHE and the local residents to this point, there is no evidence of any unusual cancer incidence patterns among persons living in the area of groundwater contamination from the TCPA site. The numbers and types of cancer identified are what we would expect given the age and sex distribution of the population in the area. We have not observed any "clustering" of specific types of cancers (especially cancer types theorized to be associated with contaminants found at this site, such as liver, kidney, or leukemia) that would suggest a potential association to the TCPA site.

  3. Could my child get ALS (Amyotrophic Lateral Sclerosis, a.k.a. Lou Gehrig's Disease) from exposure to site related contaminants at the TCPA?
  4. [Good Housekeeping, The Mystery at Kelley Air Force Base, July 2001]

    Response:
    ALS is a disorder involving loss of the use and control of muscles. The nerves controlling these muscles shrink and disappear, which results in loss of muscle tissue due to the lack of nervous stimulation. The cause of ALS is unknown and there is no known treatment or cure for the disease.

    As is stated in the Good House Keeping article about Kelly Air Force Base, ATSDR is working in conjunction with other federal and state agencies to investigate cases of ALS reported in the vicinity of the base. ATSDR is presently conducting an extensive review of the scientific literature concerning ALS and exposure to environmental chemicals. Special attention will be given to what is known or suspected regarding environmental exposures at Kelly Air Force Base. Results of the literature review will be shared with the public when it becomes available.

    ATSDR does not know whether exposure to chemicals from the TCPA site or other sites may contribute to ALS. Research and studies in this area are currently being conducted that will hopefully give us a better understanding of ALS and its possible cause in the future.

  5. What is the relationship between Manganese exposure and Parkinson's Disease?
  6. Response:
    There is evidence from studies in humans that inhalation exposure to high levels of manganese compounds can lead to a disabling syndrome of neurological effects which resembles Parkinsonism and is referred to as manganism or manganese induced Parkinsonism. The first signs of the disorder are usually subjective, often involving generalized feelings of weakness, heaviness or stiffness of the legs, anorexia, muscle pain, nervousness, irritability, and headache. Typically, neurological effects from manganese exposure do not become apparent until exposure has occurred for several years, but some sensitive individuals may show signs after as little as 1-3 months of exposure. Manganism has been documented in occupational type exposures for example, in welders who have been exposed to high levels of manganese dust or fumes in mines or foundries. There is only limited evidence that oral exposure to manganese leads to neurological effects in humans (9).

    The levels of manganese found at the TCPA site are much lower than exposures in an occupational setting. The highest level of manganese found in on-site soil and sediment was 4,400 ppm. ATSDR calculated an exposure dose for manganese in soil and sediment. The estimated exposure dose was well below the EPA RfD. Lifetime exposures to levels below the RfD are not likely to cause harmful effects in people.

  7. Would the consumption of groundwater contaminated with TCE and/or carbon tetrachloride by beef and dairy cattle result in adverse health impacts?
  8. Response:
    ATSDR completed a health consultation in October 1997 addressing this question. ATSDR reviewed data from wells that provided water to homes and/or cattle and found that they contained a maximum of 391 ppb TCE and a maximum of 21 ppb carbon tetrachloride. It was assumed that the water samples were collected either from the tap or from the actual well. Because, both TCE and carbon tetrachloride are quite volatile some of the contaminants would be expected to volatilize during the process of filling containers for cattle. Therefore, the levels of TCE and carbon tetrachloride consumed by cattle were most likely lower than the actual tap or well samples. In animals, TCE that is ingested is absorbed and metabolized rapidly. Bioaccumulation studies of TCE have been conducted in aquatic organisms and indicate a low tendency to bioaccumulate. No studies regarding bioaccumulation in cattle were found, but more than likely cattle would also have a low tendency for bioaccumulation. Like TCE, carbon tetrachloride has little tendency to bioaccumulate in animals.

    ATSDR reviewed additional data collected by EPA from wells used for watering livestock for this public health assessment. Data values for TCE ranged from none detected to 190 ppb and data values for carbon tetrachloride were all less than 1 ppb. On the basis of the levels found, bioaccumulation of compounds in beef or dairy products is not expected to be of health concern for consumers.

    In addition, ATSDR conducted a literature search for information regarding health effects of TCE on cattle. ATSDR found no information specific to TCE and bovine health. One journal article was found which discusses research conducted with goats and milk-fed kids (14). The object of this particular study was to examine tissue distribution, secretion into milk and expiration to expired air after ruminal or gastrointestinal absorption of methyl chloroform (MCF), trichloroethylene (TCE), and tetrachloroethylene (PCE) which were intra-ruminally or orally distributed to lactating goats and milk-fed kids. The study results indicated that MCF is readily exhaled through alveolar breath; TCE is adaptatively metabolized to metabolites in the body; and PCE is the most significantly tissue-partitioning, as well as the most secreted substance in milk. The levels of TCE and PCE administered to goats in this study were much higher than those found in drinking water near the Tri-County Airport site. ATSDR does not expect that beef or dairy cattle consuming TCE or CCL4 at the concentrations measured in the water (391 ppb and 21 ppb, respectively) would result in adverse health effects to cattle.


CONCLUSIONS

  1. ATSDR has identified one completed exposure pathway. Persons who were exposed to waterfrom contaminated drinking water wells off-site by ingestion, inhalation, and/or absorption.ATSDR has provided a toxicologic evaluation of contaminants reported to be present indrinking water wells. On the basis of that evaluation, ATSDR believes that adverse non-cancer and cancer health effects are unlikely for adults and children near the TCPA site.However, as is discussed in more detail in the Child Population section, the maximum sampledconcentration of TCE in a drinking water supply well near the TCPA site is similar toconcentrations of VOCs (i.e., TCE) found in drinking water studies that have shown possibleincreased risk of birth defects (SGA, NTD) and higher incidence of childhood leukemia due toingestion of VOC contaminated drinking water during the pregnancy period (12,13). Eventhough these studies suggest a possible association with VOC exposure and a possibleincreased risk of birth defects the results are not conclusive.

  2. Three potential exposure pathways were identified; off-site surface water and springs, on-sitedrinking water wells, and on-site surface soil and sediment. ATSDR has provided toxicologicevaluations of the contaminants reported to be in surface water and springs and soil andsediment. ATSDR believes that adverse non-cancer and cancer health effects are unlikely.

  3. The population surrounding the site is relatively small. Adverse health effects due to exposuresto site related contaminants are not expected to have occurred. Therefore, health outcome data were not evaluated.

  4. ATSDR has reviewed and provided a response to community concerns expressed duringATSDR visits to the site and the surrounding area.

  5. ATSDR believes exposure to site related contaminants via drinking water occurred in the past,but has no way to determine the length of exposure. Exposure to TCE in drinking water hasbeen stopped by installing carbon filtration units at residences where carbon tetrachloride,EDB, or TCE exposure exceeds the MCL. One residence with a private drinking water wellhas detected levels of TCE less than the MCL. This well is being monitored quarterly.Therefore, ATSDR presently considers the site to be a no apparent public health hazard.

RECOMMENDATIONS

  1. Currently 23 homes in the vicinity of the TCPA site have carbon filtration systems installed ontheir drinking water wells to filter-out or reduce exposure to site related contaminants(specifically, carbon tetrachloride, EDB, and TCE). These carbon filtration systems must beperiodically monitored to ensure their effectiveness, because the sorbent media can becomesaturated allowing break through of contaminants. Because of the time, effort, and cost ofproperly maintaining these carbon filtration units, ATSDR recommends that a morepermanent solution be implemented to provide residents with drinking water that meets orexceeds the regulations of the Safe Drinking Water Act.

  2. One home in the vicinity of the TCPA site has had two detected levels of TCE less than theMCL (0.6 ppb and 1.5 ppb). The drinking water well at this residence should be periodicallymonitored. If carbon tetrachloride, EDB, or TCE levels exceed the MCL in the future, acarbon filtration unit should be installed for this residence.

  3. There are several residences down gradient of the currently defined TCPA groundwaterplume. There is potential for contaminants from the TCPA plume to migrate into thesedrinking water wells. These drinking water wells should be periodically monitored for siterelated contaminants. If site related contaminants migrate into these down gradient wells in the future appropriate action should be taken to prevent exposure.

  4. Trespassers and on-site workers should avoid unnecessary contact with site soils and sediment,especially near Hangar 1, Hangar 4, the former potential burial area, and the sump in the north motor pool.

PUBLIC HEALTH ACTION PLAN

The purpose of the public health action plan (PHAP) is to ensure that this public health assessmentgoes beyond presenting ATSDR's conclusions and recommendations about public health issues at theproposed TCPA NPL site. The PHAP describes the actions that are designed to stop or preventharmful effects resulting from exposure to hazardous substances at the site.

A. Actions Undertaken

  1. At the request of EPA, ATSDR completed a consultation to determine whether adversehealth impacts could occur if TCE and carbon tetrachloride were consumed by dairyand beef cattle (October 1997).

  2. ATSDR completed a second consultation at the request of EPA to address thefollowing questions: Is it ATSDR's recommendation to provide bottled water at levelsabove the MCL? At what level do we consider inhalation as a hazard and providewhole-house (October 1997)?

  3. ATSDR completed a record of activity recommending that homes using bottled waterhave a filtering system furnished to reduce contamination (January 2000).

  4. ATSDR visited the TCPA site to verify site conditions and gather pertinentinformation and data for the site (March 2001).

  5. ATSDR met with local citizens to determine their health-related concerns regardingthe TCPA site (June 2001).

B. Actions Planned

  1. ATSDR will continue to collaborate with the appropriate federal, state, and localagencies to pursue the implementation of recommendations outlined in this publichealth assessment.

  2. ATSDR will continue to review new environmental and health outcome dataassociated with the TCPA site as necessary and provide updates when appropriate.

AUTHOR OF REPORT

Robert B. Knowles, M.S., REHS, Division of Health Assessment and Consultation


ATSDR Team Members
for the Tri-County Public Airport Public Health Assessment

Shawn Blackshear, ATSDR Regional Representative, EPA Region VII
Dawn O'Connor, Division of Health Assessment and Consultation


REFERENCES

  1. Agency for Toxic Substances and Disease Registry. Agency for Toxic Substances and DiseaseRegistry Record of Activity. Tri-County Public Airport, Herington, Kansas. October 10,1997.

  2. Agency for Toxic Substances and Disease Registry. Agency for Toxic Substances and DiseaseRegistry Record of Activity. Tri-County Public Airport, Herington, Kansas. October 17,1997.

  3. Agency for Toxic Substances and Disease Registry. Public health assessment guidancemanual. Atlanta: US Department of Health and Human Services, 1992.

  4. Agency for Toxic Substances and Disease Registry. Toxicological profile for arsenic. (update) Atlanta: US Department of Health and Human Services; 1998 Aug.

  5. Agency for Toxic Substances and Disease Registry. Toxicological profile for cadmium. (update) Atlanta: US Department of Health and Human Services; 1999 Jul.

  6. Agency for Toxic Substances and Disease Registry. Toxicological profile for carbontetrachloride. (update) Atlanta: US Department of Health and Human Services; 1994 May.

  7. Agency for Toxic Substances and Disease Registry. Toxicological profile for 1,2dibromoethane. Atlanta: US Department of Health and Human Services; 1992 Jul.

  8. Agency for Toxic Substances and Disease Registry. Toxicological profile for lead. (update)Atlanta: US Department of Health and Human Services; 1999 Jul.

  9. Agency for Toxic Substances and Disease Registry. Toxicological profile for manganese. (update) Atlanta: US Department of Health and Human Services; 1997 Sept.

  10. Agency for Toxic Substances and Disease Registry. Toxicological profile fortrichloroethylene. (update) Atlanta: US Department of Health and Human Services; 1996Feb.

  11. Agency for Toxic Substances and Disease Registry. Toxicological profile for vinyl chloride. (update) Atlanta: US Department of Health and Human Services; 1996 Feb.

  12. Agency for Toxic Substances and Disease Registry. Volatile organic compounds in drinkingwater and adverse pregnancy outcomes. Interim report. United States Marine Corps Base,Camp Lejeune, North Carolina. Atlanta: US Department of Health and Human Services; 1997Jan.

  13. Bove FJ, Fulcomer MC, Klotz JB, Esmart J, Dufficey EM, Saurin JE. Public drinking watercontamination and birth outcomes. A J Epidemiol 1995;141:850-62.

  14. Hamada T. Transfer of methyl chloroform, trichloroethylene and tetrachloroethylene to milk,tissues, and expired air following intra-ruminal and oral administration in lactating goats andmilk-fed kids. Environ Pollut 1995;87(3):313-8.

  15. IT Corporation. Quarterly progress report, area water well and whole-house water treatmentsystem sampling, January through March 2001, Tri-County Public Airport Site, MorrisCounty, Kansas. March 30, 2001.

  16. IT Corporation. Sampling and analysis plan for the removal action work plan, Tri-County Public Airport Site, Morris County, Kansas. July 21, 2000.

  17. Kondakis XG, Makris N, Leotsinidis M, et al. Possible health effects of high manganeseconcentration in drinking water. In: Toxicological profile for manganese. Atlanta: USDepartment of Health and Human Services; 1997 Sep.

  18. Lagakos SW, Wessen, BJ, Zelen, ME. 1986. An analysis of contaminated well water andhealth effects in Woburn, MA wells. J Am Statistical Assoc 1986; 81:583-96.

  19. U.S. Environmental Protection Agency. Expanded site inspection/ remedial investigation, Tri-County Public Airport site, Herington, Kansas. June 1999.

  20. U.S. Environmental Protection Agency. Summary report for quarterly sampling, Tri-County Public Airport site, Herington, Kansas. December 2000.


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