PUBLIC HEALTH ASSESSMENT
CEDAR RAPIDS, LINN COUNTY, IOWA
Tables in this section list contaminants of concern at the Electro-Coatings site that were identifiedduring the RI/FS process. However, their listing does not imply that a health threat exists. Anevaluation of contaminants in subsequent sections determines whether exposure has occurred and ifsuch exposure has public health significance. IDPH and ATSDR select the contaminants of concernbased on the following factors: (1) concentrations of contaminants on and off the site, (2) field dataquality, laboratory data quality, and sample design, (3) comparison of site-related concentrationswith background concentrations, (4) comparison of site-related concentrations with healthassessment comparison values for noncarcinogenic and carcinogenic endpoints and other appropriatevalues, and (5) community health concerns. A contaminant that is listed does not imply that adversehealth effects will result from exposure, but indicates that a contaminant must be further evaluatedin the public health assessment.
Concentrations of contaminants in specific media are compared with health-based guidelines, andthe results are used to select contaminants for further evaluation. Comparison values includeEnvironmental Media Evaluation Guides (EMEGs), Reference Dose Media Evaluation Guides(RMEGs), and Cancer Risk Evaluation Guides (CREGs).
EMEGs are media specific values based on ATSDR's Minimal Risk Levels (MRLs). EMEGs donot evaluate carcinogenic effects. RMEGs are similar to EMEGs, but are based on EPA's ReferenceDoses (RfDs) rather than MRLs. Nor do they evaluate carcinogenic potential. CREGs areestimated contaminant concentrations based on a one excess cancer case in a million people exposedover a lifetime. CREGs are calculated from EPA's cancer slope factors. Other comparison valuesare used if EMEGs, RMEGs, or CREGs are not available. Such comparison values may includeEPA's Lifetime Health Advisory values, Maximum Contaminant Levels, or Action Levels.
Sampling activities were first conducted after the discovery of Cr VI in the cooling water atHawkeye Rubber, and again between February 18 and September 3, 1991. The activities includedenvironmental sampling of site subsurface soil, groundwater, and surface water and sediment inCedar Lake. Table 1 lists the contaminants of concern found in the groundwater at the site. Noother samples, other than groundwater, contained contaminants at levels of concern. However,surface water collected from Cedar Lake during earlier studies contained elevated levels ofchlordane. The chlordane is not site-related. A swimming and fishing advisory has been issued forthe lake, and signs are posted on the shoreline.
The groundwater plume of contamination in the sand aquifer is well defined for TCE (Figure 5) andCr VI (Figure 6). The PCE plume, however, is not well defined (Figure 7). TCE and Cr VI appearto be migrating in a southwesterly direction. This is also the direction of groundwater flow. Thehighest level of PCE contamination is at Hawkeye Rubber, located approximately 300 feetdowngradient of the Electro-Coatings facility. Investigators recorded in the RI document that PCEcontamination may have been the result of a one-time release into the environment (1). It is notclear where the release originated. The high concentrations of PCE near the Hawkeye Rubberfacility suggest that Hawkeye Rubber may be contributing to the PCE contamination. However, aslug of PCE could have been released from Electro-Coatings or from an unidentified sourcenorthwest of Electro-Coatings and has now reached the Hawkeye Rubber area. TCE contaminationis highest along the western edge of the Electro-Coatings facility. The largest concentration of Cr VIwas found near the former dip tank west of the Electro-Coatings facility.
Well water monitoring results suggest that Cedar Lake recharges groundwater in the area. Production wells that operate at Hawkeye Rubber may influence that condition. Groundwatersamples from the site indicate that the sand and bedrock aquifers are both contaminated with VOCs,cadmium, and Cr VI. MW-6D, MW-8D, MW-10D, PW-1, and PW-2 tap into the bedrock aquifer. All other monitoring wells tap into the sand aquifer. One groundwater sample at soil borehole B-11contained PCE at a maximum concentration of 15,400 micrograms per liter (µg/L).
Although the original source of the contaminants at the site was an underground storage tankcontaining Cr VI, the soil is no longer of concern since the contaminated soil was removed in 1992. The only contamination still on the site is contained within aquifers wherein the contaminants hadleached into. It should be noted that the contaminated aquifers are not part of the water supply andare not utilized by anyone for any purpose.
Four monitoring wells (MW-9, MW-11, MW-10, and MW-10D) have been designated as on-site wells. MW-10D taps into the bedrock aquifer, and all others tap into the sand aquifer. MW-9 contains the highest levels of VOCs, cadmium, Cr VI, and nickel found within the sand aquifer. Although VOCs and Cr VI were detected in the bedrock monitoring well, the levels of those contaminants did not exceed comparison values. Cadmium, found at 5 µg/L did exceed the 2 µg/L comparison value (EMEG) in the bedrock aquifer. Table 1 shows the maximum levels found for each contaminant of concern in the sand aquifer on site.
|Contaminant||Sand Aquifer||Comparison Value**|
|Volatile Organic Compounds|
* = RI/FS, April 1992
** = Comparison value at time of release for public comment.
*** = Lifetime Health Advisory
The other 10 monitoring wells and the two industrial wells at Hawkeye Rubber comprise the off-sitemonitoring well network. MW-6 contains the highest levels of PCE. Levels of all contaminantsexcept PCE decrease in the sand aquifer with distance from the site, however, higher concentrationsof contaminants are found in the off-site bedrock aquifer. A list of all contaminants of concernfound in off-site monitoring wells is shown in Table 2.
|Contaminant||Sand Aquifer||Bedrock Aquifer||Comparison Value**|
|Volatile Organic Compounds|
** = Comparison value at time of release for public comment.
*** = Lifetime Health Advisory
**** = Not Analyzed
Results of tests on sediment samples obtained by the Linn County Health Department from Cedar Lake between October 1990 and March 1991 indicate arsenic and chlordane are present insediments at levels above comparison values. This sampling was not part of the RI/FS. Sampleswere analyzed by the University of Iowa Hygienic Laboratory. Arsenic was found at 20 parts permillion (ppm) and chlordane was found at 0.6 ppm. The comparison values are 20 ppm (EMEG,chronic exposure for a child) for arsenic and 0.5 ppm (CREG) for chlordane. Polycyclic aromatichydrocarbons (PAHs) were also detected in lake sediments. However, none of the contaminantsdetected by UIHL have been associated with the site. Furthermore, although some contaminantswere present above comparison values, all were at levels typically found in nature.
In 1992, an investigation by IDNR found that chlordane was the only contaminant at levels ofhealth concern detected in sediment samples from Cedar Lake. Based on these findings, a CedarLake Health Advisory was issued by Iowa Electric Light and Power Company, IDNR, and the LinnCounty Health Department to inform the public not to swim in or eat fish from Cedar Lake (4). Health advisory warning signs are posted at the shoreline around the lake. The health advisoryinformation is being presented in this public health assessment because of the lake's proximity to thesite.
Quality Assurance/Quality Control information on the field and laboratory data was obtained forthis public health assessment. Field blanks, trip blanks, duplicate samples, and/or split samples wereanalyzed for samples.
In preparing this public health assessment, IDPH assumes that sampling analyses discussed in thereferenced documents followed correct chain of custody procedures, laboratory procedures, and datareporting procedures. Methylene chloride is a common laboratory contaminant, and some fieldblanks contained methylene chloride. The data presented for that contaminant may not reflect actuallevels found in the environment.
The validity of the analyses and conclusions reached in this public health assessment is determinedby the availability and reliability of referenced information.
No physical or other hazards were identified at the site.
IDPH searched the TRI database from 1988 through 1992 to identify facilities in proximity to theElectro-Coatings site that could contribute to contamination. Industries with 10 or more full-timeemployees are required by law to submit to the TRI estimated annual emission rates of toxicchemicals released to the environment (via air, water, land, or underground injection). PCE waslisted as a contaminant that is released by other industries in the Cedar Rapids area. PCE reportedlyhas never been used at Electro-Coatings (1).
The environmental and human components that lead to possible human exposure are evaluated inthis section of the public health assessment. An 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.
An exposure pathway can be complete, potential, or eliminated. In a completed exposure pathway,all elements exist and exposure to a contaminant has occurred, is occurring, or could occur in thefuture. In a potential exposure pathway, at least one element of the pathway has not been identifiedin the available information. However, exposure to contaminants is possible, either in the past,present, or future. An exposure pathway can be eliminated if at least one element of the pathway ismissing.
No completed exposure pathways have been identified at the site.
|Source||Environmental Medium||Point of Contact||Route of Exposure||Exposed |
|Site||Groundwater||Tap||Ingestion Skin Contact Inhalation||Future Private Well Owners|
Although contaminants are not associated with the site, Cedar Lake contains arsenic and chlordane. This public health assessment discusses that contamination in order to help people avoid exposure tothe contaminants. People who are not aware of the swimming advisory and use the lakerecreationally can come into contact with the contaminants through incidental ingestion or throughdirect skin contact with the contaminants in the water and sediments. Also, people who ignore or areunaware of the fishing advisory may ingest the contaminants that have accumulated in fish tissue ifthey eat fish taken from the lake. However, in the absence of actual fish tissue data and informationon how much fish is eaten, possible exposures cannot be further evaluated.
Groundwater is contaminated at the site, and the contamination has spread to off-site areas. Undernormal groundwater flow conditions, the groundwater flows to the southwest, with a westward flowcomponent, toward Cedar Lake and the Cedar River. Although most municipal wells are upgradientof the site, at least one municipal well is cross-gradient of the site. That well, and any other cross-gradient well, may intercept contaminants that flow westwardly from the site. Municipal water ismonitored routinely according to federal and state regulations. Any contamination would likely befound before the contaminated water could harm the people using the water. If wells becomecontaminated at levels of concern, people could be exposed to the contaminants through ingestion ofthe water, inhalation of the VOCs, and through direct skin contact with the contaminants in thewater.
No private wells, except the two Hawkeye Rubber Company wells, have been identifieddowngradient of the site. The industrial wells do contain site-related contaminants, but people donot come into contact with that water. Management at the facility is aware of the contamination. Ifa spill or leak occurs, people at the facility should avoid contact with the water. Because of thepossible westward groundwater flow component, contamination of new, private wells that may bedeveloped west of the site is possible. If wells are developed within the groundwater contaminantplume, people using the well water could be exposed to contaminants through ingestion or directskin contact with contaminants in the water. Because groundwater is contaminated, private welldevelopment should be discouraged.
In this section, discussions on the plausible health effects that could occur in people exposed to sitecontaminants are presented. However, a person must come into contact with the contaminants inorder for the chemicals to cause illness. No completed exposure pathways to contaminants havebeen identified at this site. Therefore, no illnesses are expected to occur as a result of the sitecontamination. Some potential exposure pathways, however, have been identified. Those exposurepathways involve the non-site related contamination in Cedar Lake, possible future use ofcontaminated groundwater, and possible emissions of contaminants to the air.
If people adhere to the fishing and swimming advisory for Cedar Lake, no exposure should occur. Ifpeople do swim or eat contaminated fish from the lake they could be exposed to contaminants. However, the public health implications of those exposures cannot be evaluated without informationon contaminant content in the lake water and sediments, and contaminant levels in the fish.
If the highest levels of the contamination found on-site and off-site migrate to municipal wells westof the site or to any new wells developed west of the site, the levels of PCE and Cr VI would be ofpublic health concern. However, the municipal water supply is monitored periodically, andcontamination entering the water supply system should be found before the water is distributed topeople at levels that could cause harm. As a preventive measure, the individual wells shouldcontinue to be monitored periodically. No new well development is known to be planned for areaswest of the site; however, if any wells are developed in that area, they should be tested forcontamination prior to use and periodically tested thereafter to avoid possible exposure.
Although it is a remote possibility, a potential exposure pathway for contaminants in groundwaterexists. In such a remote event, the only contaminants to be of concern would be Cr VI and PCE. This section provides a brief description of the potential health effects associated with exposure tothese contaminants at levels of public health concern.
Cr VI (5)
- Chromium (Cr) is a naturally occurring element found in rocks, soil, plants, animals, andvolcanic dust and gases. Cr has three main forms Cr 0, Cr III, and Cr VI. Cr III compoundsare stable and occur naturally, in the environment. Cr 0 does not occur naturally and Cr VIoccurs only rarely. Cr compounds have no taste or odor.
- Cr III is an essential nutrient in our diet, but we need only a very small amount. Other forms of Cr are not needed by our bodies.
- Cr is used for making steel and other alloys, bricks in furnaces, dyes and pigments, and forchrome plating, leather tanning, and wood preserving.
- All forms of Cr can be toxic at high levels, but Cr VI is the most toxic.
- Ingesting very large amounts of chromium (several times greater than the levels found at thissite) can cause stomach upsets and ulcers, convulsions, kidney and liver damage, and death.
- It is not known if Cr harms the fetus or the ability to reproduce. Mice that ingested largeamounts of Cr had reproductive problems and offspring with birth defects. The levels ofexposure at the site are far below the levels used in this study.
- Some people, who are sensitive to Cr, may have allergic reactions including severe rednessand swelling from dermal exposure. However we have received no reports of thesesymptoms from the community at this site.
- The U.S. Department of Health and Human Services (DHHS) has determined that Cr VI is aknown carcinogen. This is based on increased lung cancer in some workers who wereexposed to chromium via inhalation. However, the occupational exposures in the study weremuch higher than the exposures at this site. Furthermore, inhalation is not a major route ofconcern at this site. Animal studies also indicate Cr VI is a carcinogen. We do not haveenough data to determine if Cr 0 or Cr III are carcinogenic.
- Other names for PCE include perchloroethylene, tetrachloroethylene, and tetrachloroethene. It is a nonflammable liquid at room temperature. It evaporates easily into the air and has asharp, sweet odor. Most people can smell PCE when it is present in the air at a level of 1part PCE per million parts of air (1 ppm) or more, although some people can smell it at even lower levels.
- PCE is a manufactured chemical that is widely used for dry cleaning of fabrics and formetal-degreasing. It is also used to make other chemicals and is used in some consumerproducts.
- Much of the PCE that gets into the water or soil evaporates into the air. Microorganisms canbreak down some of the PCE in soil or underground water. In the air, it is broken down bysunlight into other chemicals or brought back to the soil and water by rain. It does notappear to collect in fish or other animals that live in water.
- Concentrations of PCE above the odor threshold (particularly in closed, poorly ventilatedareas) can cause effects such as dizziness, headache, sleepiness, confusion and nausea.
- Irritation may result from repeated or extended skin contact with PCE. These symptomsoccur almost entirely in work (or hobby) environments when people have been accidentallyexposed to high concentrations or have intentionally used PCE to get a "high."
- In industry, most workers are exposed to levels lower than those causing obvious nervoussystem effects. The health effects of breathing in air or drinking water with low levels of PCE are not known.
- Results of animal studies, conducted with amounts of PCE hundreds of times higher thanthose found at this site, show that PCE can cause liver and kidney damage. Exposure tothese very high levels of PCE can be toxic to the unborn pups of pregnant rats and mice. Changes in behavior were observed in the offspring of rats whose mothers breathed highlevels of the chemical while they were pregnant.
- DHHS has determined that PCE may reasonably be anticipated to be a carcinogen. PCE hasbeen shown to cause liver tumors in mice and kidney tumors in male rats.
No completed exposure pathways have been identified. Therefore, no adverse health outcomeswould be expected. Moreover, area residents have not mentioned any specific health concernsrelated to the site. For those reasons, no health outcome data have been evaluated for this site.
- Why has there been such a long time lag between identification of the problem and finally deciding what to do about it?
- Do we expect the current drinking water standard for Cr (i.e., 100 parts per billion,ppb) to be permanent? Other EPA standards have not been permanent, usuallybecoming smaller.
- Cr is a trace element.
- The drinking standard for Cr has already been increased from 50 ppb to 100 ppb.
- Very low drinking water standards are typically associated with carcinogeniccompounds and, while Cr VI is a suspected carcinogen by inhalation, it is not acarcinogen by ingestion.
- How much Cr initially leaked?
- Was Cr found in water and sediment samples from Cedar Lake?
- What is going to happen to Hawkeye Rubber?
IDNR and EPA have responsibility for the oversight and timing of activities at this site. From ahealth perspective, we would note that the problem was identified in March 1976, almost 25 yearsago. Measures were initially taken by Electro-Coatings to cease further releases. They alsoinstalled monitoring wells at the direction of the state which they sampled frequently for a couple ofyears along with the Hawkeye Rubber Company industrial wells. Little activity occurred fromabout 1979 to 1983. In 1983, interest in the site was renewed when samples of the HawkeyeRubber PW-1 were collected by the municipal wastewater treatment plant which indicated thatpersistent levels of Cr contamination remained. In response, Electro-Coatings installed another welland resumed sampling of monitoring wells for a few months. IDNR identified the site forpreremedial Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA;aka, superfund) consideration. Again little activity occurred until 1986 when IDNR conducted asite inspection which subsequently led to the site being proposed for the National Priorities List(NPL) in June 1988. Listing of the site on the NPL became final in October 1989. IDNR issued anadministrative order to Electro-Coatings in September 1989 to conduct a remedial investigation andfeasibility study (RI/FS) of the site. The company was in bankruptcy at the time and was not able toproceed. In September 1990, IDNR initiated remedial investigation activities. In October 1990,Electro-Coatings entered into a consent order with IDNR in which they agreed to conduct the RI/FS. They conducted three phases of investigation in 1991 and submitted an RI/FS report to IDNR inApril 1992. The April 1992 RI/FS suggested that the Hawkeye Rubber Company was the primarysource of VOC contamination. In response to this uncertainty, IDNR conducted a supplementalremedial investigation in June 1992 and completed a report of this investigation in October 1992. In January 1993, Electro-Coatings was asked to revise the RI/FS. They responded with anAddendum to the RI/FS in April 1993. From that time until the Proposed Plan was approved byEPA in July 1994, IDNR and EPA prepared supplemental RI and FS documents and went through aseries of reviews and modifications of these documents and the Proposed Plan between the twoagencies.
It should be noted that throughout the history of this site, never has a worsening condition beenidentified. That is, an expansion of the contaminant plume or increase in contaminant levels has notbeen found which would suggest the need for immediate action. It has been apparent for some timethat Hawkeye Rubber well PW-1 has done a good job of containing most contamination emanatingfrom the Electro-Coatings site.
It is certainly possible that the drinking water standard for Cr could change. However, it is notlikely that the standard for Cr would be substantially reduced for the following reasons:
It is estimated that the initial leak consisted of about 200 gallons of solution containing 32 ounces of chromic acid flakes per gallon.
Cr was found in two samples of water from Cedar Lake at concentrations below the MCL. However, Cr was not detected in split samples collected and analyzed by IDNR. Cr was also notdetected in a subsequent water sample from Cedar Lake. Only low levels (i.e., typical ofbackground soils) of Cr were detected in sediment samples from Cedar Lake. It should be noted thatsamples were collected near former discharge points.
Shortly after Hawkeye Rubber Company was confirmed as the source of PCE contamination, theytook action to replace their equipment that had been cleaned with PCE with equipment that could becleaned with soap and water. They have also conducted a groundwater investigation. Containmentof contaminated groundwater has been and continues to be provided by the nearby industrial well(PW-1) operated by Hawkeye Rubber Company.
ATSDR's Child Health Initiative recognizes that the unique vulnerabilities of infants and childrendemand special emphasis in communities faced with contamination of their water, soil, air, or food. Children are at greater risk than adults from certain kinds of hazardous substances emitted fromwaste sites and emergency events. They are more likely to be exposed because they play outdoorsand they often bring food into contaminated areas. They are shorter than adults, which means theybreathe dust, soil, and heavy vapors close to the ground. Children are also smaller, resulting inlarger doses of chemical exposure per body weight. The developing body systems of children cansustain permanent damage if toxic exposures occur during critical growth stages. Most importantly,children depend completely upon adults for risk identification and management decisions, housingdecisions, and access to medical care.
The available information does not indicate that children are or have been exposed to site-relatedcontaminants at levels which would cause illness or disease. Furthermore, it is unlikely that childrenwill be exposed in the future since contaminants are contained by PW-1. Although no health follow-up actions are indicated at this time, should additional data become available, ATSDR and IDPHwill evaluate that data for any follow-up health actions that may be indicated.