PETITIONED PUBLIC HEALTH ASSESSMENT
BLUEFIELD, WEST VIRGINIA; BLUEFIELD, VIRGINIA; AND VICINITY
ATSDR must rely upon sampling data obtained by others, such as site owners and state and federal agencies, for evaluating the nature and extent of contamination at and surrounding the identified sites. Sampling information is available for several, but not all of the sites, and much of the data are relatively limited in quantity or focus. Sampling data that provide the framework for the evaluations in this assessment are summarized in tables in the Appendix.
Petitioners and other residents expressed concern about widespread presence of PCBs, PCDDs, PCDFs, TCE and numerous locations where they believe these compounds may be present. For Bull Tail Hollow, concern was also expressed about defoliant chemicals containing 2,4-D and 2,4,5-T. The maximum concentrations of contaminants observed in sample analytical data are summarized in Tables 1A and 1B, in the Appendix. Sample data are presented in greater detail in Tables 2 through 10, in the Appendix. To assist the community in understanding the prevalence of compounds, ATSDR has elected to present in those tables and to describe in this section a summary of all the sampling information received--including some concentration values that may be below levels of public health concern.
Tables 1A and 1B also include comparison values ATSDR used to make its evaluations. EMEGs are estimated comparison concentrations that are based on information determined by ATSDR from its Toxicological Profiles for specific chemicals. An RfDG comparison concentration is based on EPA's estimates of the daily exposure to a contaminant that is unlikely to cause adverse health effects. An MCL is a regulatory concentration that EPA deems protective of public health (considering the availability and economics of water treatment technology).
The term "on site" is used in this assessment when describing issues that apply within a specific site boundary. Contaminants might be present on site in source materials (for example, wastes)--and might be present in building materials or environmental media (soil, surface water, sediment, groundwater, air, or food-chain entities) as a result of contaminant releases. Where a remediation has occurred, residual contaminant levels typically are substantially reduced. On-site sample data are available for the following locations: Acken Sign Company, APCO Service Center, the Bernard Neal property, Joy Manufacturing, Lin-Electric, Mercer County Landfill, and the Sam Neal property. In addition, ATSDR has calculated concentration data for the water/chemical mixtures the power company reported spraying in the Bull Tail Hollow vicinity.
"Off site" typically refers to issues that apply beyond a site boundary. Off-site sampling data are only available for the property that adjoins the APCO Service Center and Joy Manufacturing sites.
In the contamination discussions that follow, ATSDR has noted where laboratory analytical data were not received for one or more of the predominant contaminants of concern (e.g., PCBs, TCE, PCDDs, PCDFs). The absence of those analyses might be because the evaluations conducted were not intended to be fully comprehensive or there was no reason to suspect the existence of a particular compound.
Where analytical results were available for dibenzodioxins and dibenzofurans, ATSDR reported the information (Tables/Appendix A) using the identical terminology provided in the data references. Thus, the tabular data are recorded using a variety of terms--equivalent TCDD, equivalent TCDF, PCDDs (total), PCDFs (total), and PCDDs. Also, the method for calculating equivalent TCDD and TCDF has changed over time. Some references provided concentration data in parts per million (ppm), and some used parts per billion (ppb); ATSDR used only ppm in its tables to facilitate comparison of information.
Acken Sign Service
Before remediation, sample data show that PCBs were present on site in building concrete at levels ranging up to 940 ppm and in dust collected from hard surfaces at levels ranging up to 150 ppm (10,11). Wood fragments, paint chips, and resinous material tested in the building showed lower concentrations of PCBs. Wipe samples taken from a variety of surfaces in the building showed PCBs to be present at a maximum value of 79 ug/100 cm2. Interior air sampling indicated that PCBs were less than 0.01 ug/liter. Limited testing conducted on site outside the building showed PCBs at 3 ppm in sludge from a water drainage system and showed PCBs to be less than 1 ppm in soils that underlie a graveled area.
Confirmatory wipe samples taken after facility remediation showed PCBs did not exceed 6.2 ug/100 cm2.
APCO Service Center
ATSDR did not receive sampling data for areas inside the building. Sampling data developed on the north and east edges of their outdoor storage area and also for swale areas close to the property are summarized in Table 3 of the Appendix (6,12,13).
Surface soil sampling near the east property line (by the Joy facility) and by the north property line (by the swale) show: 1) PCB concentrations up to 60 ppm close to the Joy facility, and 2) PCBs at 3 ppm at only one of the seven locations sampled to the west, along the north property line. A commenter indicated that the highest concentrations (60 and 51 ppm) were in a ditch below the discharge point of a pipe extending from an unknown location in the direction of the Joy facility. That information, together with observations that the eastern part of the Service Center property is downslope from the Joy facility, suggests that the PCBs encountered at the locations sampled on the Service Center property might result from off-site activities not associated with Service Center operations.
Available off-site sampling data (Table 3) show PCBs have been detected at levels of up to 62 ppm immediately downslope from the northeast corner of the Service Center property (where the highest concentrations were found within that site). For the reasons given above, the elevated PCBs encountered off site may result from activities not associated with Service Center operations. Farther west, sampling of swale soils close to the property showed PCBs to be less than 1 ppm. Those values are similar to concentrations recorded for the many other samples taken within the westerly part of the swale. Data were not available for PCDDs, PCDFs, or TCE. Remediation activities conducted in the eastern part the swale and associated follow-up test data are described later in this section under the "Joy Manufacturing" heading.
Sampling has been conducted for on-site soils at the Bernard Neal property; data are summarized in Table 4 of the Appendix (14,15,16). Analyses show that soils at the burn pit contained PCBs at concentrations as high as 1,600 ppm. Total PCDDs and PCDFs were reported at levels up to 0.004 ppm (as 2,3,7,8-tetrachlorodibenzodioxin equivalents) were also reported in the burn pit area. Beyond the burn pit, PCDDs were shown up to 0.002 ppm, and PCDFs were found at concentrations up to 0.0095 ppm. Sampling beyond the downslope edge of the burn pit showed PCBs at levels as high as 79 ppm. Elsewhere in the burnpit vicinity, PCB levels were only 1 ppm or less. Sampling in a runoff channel detected no PCBs. PCDDs and PCDFs were not analyzed for in the runoff channel. Data were not available for TCE.
Bluefield Area Streets and Alleys, City Park, Playgrounds, and High School Track
Data were not received for PCDDs, PCDFs, or TCE for streets, alleys, city park, or playgrounds. Six soil samples from unpaved streets were screened in the laboratory for evidence of chlorinated organic chemical compounds (17). The screening report showed that either unidentified chlorinated organic compounds or some type of oil was present in two samples. That information was qualitative, not quantitative. In 1993, an effort was made to duplicate the earlier sample and analyze for PCBs; none were detected (12).
Samples of soil taken in 1993 at four locations on the edge of the high school track were combined for analysis; PCBs were not detected (12).
Bull Tail Hollow
The power company sprayed power distribution lines in the Hollow twice, in 1969 and 1974/1975, using four different commercial herbicide formulations, mixed with water (18). A commenter reports the company has never used Agent Orange, but the active ingredients of Agent Orange, 2,4-D and 2,4,5-T were used in those two spray events. ATSDR reviewed mixture information and calculated concentrations for 2,4-D (48,000 ppm--4.8 percent) and 2,4,5-T (48,000 ppm--4.8 percent). Those application percentages are much lower than the 50% levels contained in Agent Orange. The power company reported that mixtures were sprayed at rates ranging from 15 to 24 gallons per acre. Using those application rates, ATSDR also calculated estimated quantities of herbicide applied per unit of ground area. The results of calculations--that is, estimated maximum concentrations and estimated maximum quantities per unit area--are presented in Table 5 of the Appendix. A commenter points out that most of the spray material, rather than reaching the ground, falls on vegetation and is absorbed into plant tissue. This absorbtion reduces the potential for exposure to man and the environment.
A commenter reports the company only uses herbicides that are registered for application in rights-of-way. Therefore, the use of 2,4,5-T was terminated in 1979 when licensing by EPA was discontinued (for this type of application) because the chemical frequently included low concentrations of TCDD. Although information received does not show whether the formulations sprayed in Bull Tail Hollow contained TCDD, ATSDR calculated potential levels of TCDD (Table 5), assuming the 2,4,5-T contained 1 ppm TCDD. The assumed TCDD content is 10 times greater that the 0.1 ppm limit manufacturers were required to achieve during the latter period 2,4,5-T was produced. The calculation results in Table 5 suggest that TCDD, if present, would likely have been at extremely low concentrations. One of the spray applications reportedly included two other herbicides (picloram and monosodium acid methanearsonate), which are not addressed further in the assessment because their limited use suggests they are less important than 2,4-D and 2,4,5-T with respect to potential health effects.
Sampling information for Joy Manufacturing are summarized in Table 6 of the Appendix and include data developed by private, state, and federal organizations (5,6,12,13,19,20,21,22,23,24,25, 26,27,28,29,30,31).
Results of sampling that was performed in the mid 1980s before conducting a cleanup are provided on Page 1 of the table. Samples showed that PCBs were present in on-site soils outside the building at high levels (220,000 ppm) and also in building materials, such as paint chips (17,100 ppm). A few of the on-site soil samples were also analyzed for PCDDs and PCDFs (0.00259 ppm--expressed as total equivalent TCDD). Off-site sampling showed PCBs (58,000 ppm) in swale soils on the Galliat property to the north and northwest of the property and also in soils at the edge of Washington Street to the east. A few analyses also detected PCDD (0.0012 ppm--TCDD equivalent). Samples of soils from residential property showed low concentrations of PCBs (less than 1 ppm). ATSDR has not received TCE sampling data.
A site cleanup was conducted under EPA oversight. Extensive quantities of highly contaminated building materials and on-site soils were removed. Contaminated soils also were removed off-site in the eastern part of the swale (Galliat property). Sampling was conducted while the cleanup was in progress (page 2 of Table 6); five separate sampling evaluations were conducted after cleanup (pages 3, 4, 5, 6, and 7 of Table 6).
Data show that some relatively high levels of PCBs remained on site after cleanup--for example, in black material (13,000 ppm) exposed at the edge of a concrete slab, in wood chips (624 ppm) from a stairway, in soils (2,400 ppm) subsequently covered with concrete, in borehole concrete dust (1,400 ppm), in concrete (680 ppm) that was subsequently covered with concrete, and in paint chips (743 ppm). Low levels of PCDDs and PCDFs (less than 0.001 ppm--TCDD equivalent) were detected in asphalt and in the black material at the edge of a concrete slab.
Contaminated soils were removed along Washington Street, between the fence and street, and were replaced with clean soil. The depth and lateral extent of much of the soil removed beyond the building elsewhere, on and off site, was determined by analyzing multiple samples at grid points while the removal activity was in progress. Sample data indicate that excavation was conducted within each grid until low PCB concentrations (generally less than 1 ppm) were present in underlying soils--clean fill soils were then placed over each grid area. Some sampling conducted primarily on site after cleanup shows that relatively low PCB concentrations (less than 1 ppm to 28 ppm) remain in surface soils on the property--that sampling activity did not extend onto the Galliat property.
In late 1992, in response to a citizen's concern about the area that had been remediated, further PCB analyses (page 6, Table 6) were conducted for surface soils (19 samples), runoff water (3 samples), sediment (1 sample), and also air quality (3 samples). Surface soils were sampled from migration routes on the Joy property and on the eastern part of the Galliat property. PCBs were detected at low concentrations in about half of the soil samples obtained on site and off site. Most concentrations found were less than 1 ppm; maximum levels were 3.2 ppm (on site) and 1.8 ppm (off site) and occurred at drainage conduits. Runoff water samples were obtained on site and off site; PCBs were not detected. Air samples were taken around the buildings; PCBs were not detected. A sediment sample taken from the shallow depression on the Galliat property showed low PCBs (0.03 ppm).
Surface soils were sampled on nearby residential property (Page 4 of Table 6) after cleanup was completed at the Joy and Galliat properties. Analyses showed low levels of PCBs (less than 0.025 ppm) and low levels of PCDDs and PCDFs (less than 0.001 ppm--TCDD equivalent).
In 1993, more surface soil sampling was conducted at seven nearby residential and business properties (Page 7 of Table 6). PCBs were detected on two of those properties. At one, PCBs were present in four of six samples; at the other property, PCBS were present in three of six samples. The maximum concentration recorded was 1.3 ppm; others were less than 1 ppm. Surface soil samples from both the east and west parts of the swale also were analyzed for PCBs in 1993; 14 composite samples and 9 single samples were taken. PCBs were present in six samples--all from the western part of the swale; toward the high school--at levels less than 1 ppm (Page 7 of Table 6).
A commenter reports that two owners of property adjoining the Galliat tract brought legal action, claiming that their property was contaminated with PCBs. Both cases were dismissed because neither owner could produce evidence of contamination.
Sampling data obtained for a cleanup that was conducted at Lin-Electric in 1987 and 1988 are summarized in Table 7 of the Appendix (8). Information provided to ATSDR shows that some of the contaminants of concern were present at substantive concentrations on site before cleanup. For example, test results show that PCBs were present in residues on the floor (36 ppm), and TCE was contained in numerous materials (34,000 ppm). On-site sampling data are available for PCDDs or PCDFs, but off-site sampling apparently has not been performed. Information received by ATSDR, although extensive, does not clearly show what, if any, contaminant concentrations remained after cleanup.
Mercer County Landfill
The results of laboratory analyses conducted at the landfill are summarized in Table 8 of the Appendix (32). Analyses of several samples of leachate pond sediment and leachate-stained soils obtained on site showed some PCDDs and PCDFs were present at low concentrations (0.00075 ppm--TCDD equivalent). PCBs were not detected. Data are not available for TCE. Off-site sampling apparently has not been performed.
Sam Neal Property
The results of sampling conducted at this property are summarized in Table 9 of the Appendix (12,16,33,34). Analyses of soil samples obtained on site show PCBs at levels as high as 340 ppm, and show dioxin at levels up to 0.00339 ppm. Soils in the unoccupied residence basement showed PCBs up to 3.59 ppm and PCDD and PCDF of 0.0016 ppm (as 2,3,7,8-tetrachlorodibenzodioxin equivalents). Data are not available for TCE. Off-site sampling apparently has not been conducted.
Bluefield, WV, Public Water Supply System
The results of periodic sampling data for the Bluefield, WV, public water supply are summarized in Table 10 of the Appendix (13,35,36). The data show that PCBs, PCDDs, PCDFs and TCE were not detected.
Bluefield, VA, Public Water Supply System
The Bluefield, VA, public water supply has not routinely been analyzed for PCBs, PCDDs, PCDFs, and TCE. One sample was analyzed for PCBs in 1987, and another was analyzed in 1993 for all contaminants of concern; none were detected (13,37,38).
Green Valley-Glenwood Public Service District Water Supply--Bull Tail Hollow Reservoir
A GVGPSD executive reported to ATSDR that the water quality program for their water supply system does not include analyses for PCBs, PCDDs, PCDFs, and TCE. A reservoir water sample taken by an EPA contractor in 1993 was analyzed for the contaminants of concern; none were present (13). 2,4-D and 2,4,5-T were not detected in treated water from the reservoir (39). Analyses of treated water from the district's public well system showed similar results.
ATSDR has received little quality assurance information for site investigations, sampling, and laboratory analyses. EPA reported to ATSDR that all of the data provided by EPA and the contractor for Joy Manufacturing company have met EPA's standards (40). In preparing this assessment, ATSDR has presumed that all field and laboratory protocols and results are valid and has used the information in its evaluations. The completeness and reliability of information could affect the validity of ATSDR's conclusions.
None of the properties appear to pose a substantial physical
hazard to 1) those who might trespass onto accessible portions of
inactive sites or 2) informed workers at active facilities.
Because the Mercer County landfill and Bluefield, Virginia's
closed landfill contain municipal wastes, methane might be
emitted as a result of decomposing organic materials. Also,
volatiles from organic solvents or other chemicals might also be
released. Therefore, a potential for explosion exists 1) if
methane or combustible volatilized organic compounds accumulate
in an enclosure, such as beneath a landfill cap, or if compounds
migrate and accumulate in residences near the property, and 2) if
there is a source of ignition. ATSDR has not received any
sampling data for methane or other gases. Therefore, the
potential hazard cannot be evaluated further in this assessment.
Contaminants may migrate from their source locations along one or more environmental pathways to other areas on and off site. The manner of migration can be complex because it can be affected by the contaminants' physical and chemical characteristics, the presence of other chemicals, and the characteristics of individual environmental media--air, water, soil, sediment, and food-chain species. In an active workplace, contaminant migration can also be affected by production activities, worker clothing, vehicles, or construction. Confirming which pathways are of actual concern usually requires on- and off-site sampling and analytic data that identify specific chemicals and their concentrations. Little or no on-site sampling data are available for most of the sites; and, with the exception of the Galliat property and some of the public water supplies, no sampling information is available for off-site areas. Although specific contaminant pathways are generally not well defined for the sites, general pathway features can be described.
Transformer dielectric fluids were reported to be typically 60 to 70% PCBs, and capacitor fluids and mine motor coolants were 100% PCBs. PCBs are a family of relatively stable compounds (41). The compounds are, in general, only slightly soluble in water and tend to bind strongly to particles of sediment and soil or to the surfaces of other materials such as wood and concrete. PCBs volatilize to the atmosphere to a very limited extent, and they tend to bioaccumulate in tissues of plants, animals, and humans. The specific gravity of the fluids is greater than that of water; thus, the fluids, if released to groundwater or to quiescent (non-flowing) surface water, tend to sink to the bottom of the water column. PCDDs and PCDFs can be generated by burning PCB fluids and sometimes are found to be impurities in such fluids and in 2,4,5-T. PCDDs and PCDFs, like PCBs, are relatively insoluble in water, tend to bind to sediment and soil, and tend to bioaccumulate in plant, animal, and human tissues. TCE, a strong organic solvent, is also only slightly soluble in water, but does not adsorb strongly to sediment, soil, or other materials. TCE is quite volatile and does not tend to bioaccumulate in biota. TCE also has a specific gravity greater than water and would tend to sink in the water column. 2,4-D and 2,4,5-T are relatively soluble in water and are relatively volatile in water mixtures. 2,4-D and 2,4,5-T do not bind strongly to soil or sediment and do not bioaccumulate in biota.
Chemicals can enter the environment as a result of planned (permitted) or accidental (not permitted) releases to the ground, to air, to surface water or sediment, to groundwater, and directly to plants and animals. Once in the environment, contaminants begin to disperse or migrate, depending on climatic factors, physical factors associated with the release setting, chemical factors associated with the contaminant, and factors associated with the environmental medium or media.
Chemicals that are placed onto or into the ground or that are deposited by air will contaminate the soil. The contaminants can in turn: remain bound to the soil; leach from the soil and enter groundwater; or migrate--if a liquid--directly to groundwater or surface water; or migrate with surface runoff in a dissolved form and in a particulate-sorbed form and enter surface water, or redeposit (particulate form) as sediment; or migrate by wind in a volatilized form; or migrate by wind in a particulate-sorbed form and redeposit elsewhere; or be taken up by plants and animals.
Chemicals dissolved in groundwater move with the groundwater, while movement of a mass of organic liquid tends to be independent of the groundwater flow. The rate at which dissolved contaminants are transported by water depends on the chemical properties of the contaminant and the medium through which it migrates. Most of the organic chemicals of concern tend to bind to aquifer materials, and, consequently their rate of movement tends to be slower than the groundwater. Groundwater and contaminants may remain underground for long distances or may discharge to nearby springs, creeks, or rivers--or to any water supply wells that may draw from the contaminated zone. Contamination may be limited to the shallowest groundwater zone, or it may enter deeper zones either by percolating through underlying materials or flowing along discontinuities or openings within the materials.
For dissolved contaminants in flowing surface water, the transport rate is typically much more rapid than in groundwater. Contaminated surface water may travel over land as precipitation runoff, it may flow in natural or man-made drainage channels, or it may enter the ground and recharge groundwater. Contaminants in surface water may be released by volatilization; be chemically degraded; be taken up by plants and animals (including aquatic life); or be sorbed to sediments. Sediment-sorbed contaminants may serve as a future source of surface water contamination, slowly releasing sorbed chemicals while dissolved concentrations are depressed. Precipitation rates, water flow rates, and physical characteristics of flow surfaces and channels will affect the amount of dilution of surface water contaminants and their transport rate. The same factors will affect the rate at which sediment-sorbed contaminants are transported.
Contaminants can be released into air in the form of gases, aerosols, or particulate-sorbed matter. Airborne contaminants can be transported large distances from the source or can be deposited locally depending on factors such as wind speed and direction, stability of the chemical, atmospheric pressure, humidity, temperature, precipitation, and particle or droplet size. Airborne contaminants, when deposited, may contaminate soil, groundwater, surface water, and food-chain entities.
Plants and animals (including aquatic life) growing or living on or in contaminated environmental media may contain contaminants in concentrations that far exceed the concentrations found in the surrounding, water, or air. Of particular concern are those chemicals that are highly fat soluble and may accumulate in the fatty tissues of animals. In the case of many plants, contaminants may not enter their tissues but may be sorbed onto the plant surface or to the small amounts of soil that adhere to the plant. Contaminants can be transported from a source as animals migrate or food crops are harvested.
Human exposures to contaminants can occur via three routes: ingestion, inhalation, and skin contact. This assessment considers past, current, or future exposures of persons at a contaminant source and, away from the source, of persons who are in the path of contaminant migration.
Acken Sign Services
A resident reported to ATSDR that, in earlier years, when the facility was used to repair mine motors and transformers, workers did not use protective equipment and came into extensive contact with oils and solvents. Based on that information, it is appropriate to consider that workers were likely to have been exposed to the contaminants of concern through inhalation, ingestion, and skin contact. Workers reportedly also transported contaminants home on their clothing--there, family members potentially were exposed. Bake ovens were likely to have discharged contaminants to ambient air. If so, air emissions might have resulted in periodic inhalation exposure to persons beyond the property limit. However, specific data are not available to confirm the concentrations of contaminants or exposures that may have existed at that time.
Following the cleanup in 1990, the current work force potentially experiences limited exposure to very low levels of residual contaminants on building surfaces--principally through incidental ingestion and skin contact. Based on the 1986 interior air data and the dust removal activities in 1990, it seems unlikely that current workers would experience measurable inhalation exposure. Sampling results suggest that contaminant levels are very low in soils and substantive exposure might not occur through the soil medium. However, because sampling data are incomplete, that cannot be confirmed.
A resident reported that, during mine motor repair, some waste oils were disposed of in building drains. A sample of soil/sludge taken from the steam-clean area storm drain in 1986, well after that repair activity terminated, contained a low level of PCBs. This information suggests that effluent from building drains probably has transported contaminants from the site. Three samples (pavement and surface soils) outside the building suggest that there might not be contaminants available there for transport by rain runoff. Effluent in storm drains flows toward the west and ultimately enters the Bluestone River at a point that is well downstream from the Bluefield, VA, public water intake. Thus, this public water supply should not be directly affected by drain effluent. Some of the drain effluent might enter the groundwater system at or downgradient from the site. Groundwater sampling data are not available to evaluate this issue. Water system officials report the site vicinity is serviced by the Bluefield, WV, public water system. Some private wells are in use in the area. Based on topography, groundwater is likely to flow toward the Bluestone River and should enter the river, or pass beneath it, well downstream from where Bluefield, VA, draws its water. Therefore, the Bluefield, VA, water supply is not likely to be adversely affected if contaminants were contained in groundwater. If any residences or businesses in the direction of groundwater flow obtain potable water from wells, and if that groundwater is contaminated, users could be exposed to contaminants of concern through ingestion, skin contact, and inhalation. ATSDR has no evidence that the exposures described have occurred.
If any contaminants reach the Bluestone River through the groundwater or surface runoff, some may bioaccumulate in the aquatic foodchain. If that occurs, persons who consume fish taken from the river potentially are exposed to the contaminants. ATSDR has no evidence that the exposure described has occurred.
APCO Service Center
A commenter reports that PCB handling procedures in place at the facility are now, and have always been, in accordance with or in excess of industry-wide practices and all regulations promulgated subsequent to the advent of concern for these materials. The company now handles an occasional devise containing small amounts of PCBs, and the company does clean up spills when such an event occurs. Work in the field of electrical distribution involves potential contact with some PCB material. Present workers whose job responsibilities may involve such contact are aware, and procedures are in place to keep this contact and the chance of exposure to an acceptable level.
Before the advent of special concern for PCBs, ATSDR considers some of the workers who serviced capacitors and transformers were likely to have been exposed by inhalation, ingestion, and skin contact to contaminants of concern. Prior to special concern for PCBs, some workers might also have transported contaminants home on clothing, potentially exposing family members. However, ATSDR has no evidence that the exposures described have occurred.
Current workers in the building or in the field might experience incidental exposure to contaminants of concern through incidental skin contact with dielectric fluids, incidental ingestion of fluids or residues, and, possibly, inhalation of volatilized fluids. Workers in storage areas outside the building might also experience incidental exposure to chemicals, if spilled, or exposed to contaminants in surface soils in a small part of the property nearest the Joy facility. The extent of any exposure should be minimal because of current awareness of chemical concerns and because of current company work practices. No evidence exists that company operations place any worker into an exposure situation that is uncommon in the industry. ATSDR has no evidence that the exposures described have occurred.
Surface runoff is likely to transport nominal amounts of the soil contaminants found near the eastern property line into the swale. A commenter noted a pipe oriented from the direction of the Joy facility ends by the Center's eastern property line, and that area also is down slope from the Joy facility. Thus, the soil contamination found there, and any contamination that might migrate from there into the swale, may not result from APCO's operations. A resident reported there might be an underground pipe extending from the APCO building toward the embankment and discharging directly into a cavity. A commenter reported: 1) building drains are connected to the municipal sewer, and 2) there is a drain that transports a portion of the site storm water runoff to a sinkhole southwest of the property, not to the swale. Thus, there is no confirmation of building drain effluent being discharged to the environment or any associated exposure.
Additional discussion of the swale and groundwater are provided in the Joy Manufacturing section.
APCO Glen Lyn Plant
The plant is in an area that is generally rural and lightly populated. APCO reported their coal-burning systems include particulate emission controls and that they inject waste oils containing less than 50 ppm PCBs into the boiler only when it is at operating temperatures--flame, 3,000 degrees F and boiler, 2,400 degrees F. For these conditions, ATSDR believes combustion would be essentially complete and substantive PCB-, PCDD-, or PCDF-contaminated particulates are not likely to be released to ambient air. On this basis, there is little likelihood that area residents would receive substantive exposure to compounds via air migration through either skin contact, ingestion, or inhalation. ATSDR has no specific knowledge that releases or resident exposure have occurred.
Some of the plant workforce might experience incidental exposure to contaminants through skin contact or incidental ingestion if there are accidents or spills of dielectric fluids and if workers take inadequate precautions. ATSDR has no evidence accidents, spills, or worker exposure have occurred. No evidence exists that company operations place any worker into an exposure situation that is uncommon in the industry.
Spills, if they occurred and were inadequately contained or remediated, could result in releases to the immediate spill area; and releases, over a long period, conceivably could adversely affect groundwater, which is a source of public and private water in the area. Groundwater sampling data are not available for evaluating this potential exposure. However, since storage and handling of dielectric fluids is relatively recent and spills are subject to cleanup protocols, contaminants are not expected to have reached groundwater at levels that would adversely affect the quality of private and public water supplies. ATSDR has no evidence releases or exposure have occurred.
If contaminants were to reach the adjacent New River through discharge of groundwater or surface runoff, some chemicals may bioaccumulate in the aquatic foodchain. If that occurs, persons who consume fish taken from the river potentially would be exposed to the contaminants. ATSDR has no specific knowledge of releases or exposure.
Bernard Neal Property
The site, on Mintwood Road, is relatively remote because it is at the end of a long narrow valley and the shortest access requires a four-wheel drive vehicle. The property is undeveloped, but it appears to have contained some type of building in the past. The nearest house on the valley floor is vacant--others in the valley are much farther away. Several other homes are nearby, but higher on the valley slopes.
If a home was on the property when the wastes were deposited, the residents could have been exposed to contaminants through skin contact, incidental ingestion, and inhalation. Currently, an occasional trespasser might enter the property. If so, the trespasser could be exposed to contaminants in wastes or surface soils principally through skin contact, although ingestion and inhalation are possible. If a new home is ever constructed, future residents could experience exposure to contaminants via all routes. ATSDR has no evidence exposure has occurred. The absence of PCBs in soil samples taken in the intermittent drainage channel downstream of the burn area suggests substantive quantities of contaminated particles might not have migrated beyond the site.
Some contaminants may have leached from the wastes and entered the underlying groundwater system. Groundwater monitoring data are not available to evaluate this issue. The Bluefield, WV, public water system extends throughout the site vicinity. However, it is unknown whether any residents in the area still use private wells for potable or household water supply. Therefore, it is uncertain whether anyone would be exposed to contaminants that might have reached groundwater.
Site runoff either discharges into the Bluestone River some several miles away or migrates to groundwater along the drainage route. In the event that contaminants were transported to the river, topographic features suggest that the receiving point in the river should be downgradient from where Bluefield, VA, withdraws its water supply.
If contaminants from the site reach the Bluestone through groundwater or runoff discharge, some chemicals might bioaccumulate in the aquatic foodchain. If this occurs, persons who consume fish taken from the river potentially would be exposed to the contaminants. Sampling information are not available to ATSDR for evaluating whether contaminants of concern are present in groundwater, runoff, or fish.
If salvaged materials have included equipment that contained PCB-laden fluids, worker exposure to some contaminants of concern is possible. The principal exposure route for past and current workers is likely to be skin contact with liquid or with contaminated soils; although, incidental ingestion of contaminated material or inhalation of contaminated airborne dust are also possible. Substantial airborne migration of contaminants of concern to nearby businesses and residences is not likely to have occurred. Therefore, substantive exposure to the contaminants at adjacent properties appears unlikely. ATSDR has no specific knowledge of releases or exposure.
If contaminants of concern are present on site, some may have entered the underlying groundwater system. Monitoring data are not available to confirm whether groundwater is contaminated. The Bluefield, VA, public water distribution system extends throughout the site vicinity. However, it is not known whether any residents are still using private wells for their potable supply. Therefore, it is uncertain whether anyone would be exposed to contaminants that might have reached groundwater.
Groundwater or surface water runoff could discharge contaminants into the Bluestone River, which is adjacent to the property. However, any such discharge would not affect the Bluefield, VA public water supply because the site is downgradient from where water is withdrawn. If contaminants have been released to the river, some chemicals would tend to bioaccumulate in the aquatic foodchain. If that has occurred, persons who consume fish taken from the river are potentially exposed to contaminants. Sampling information are not available to ATSDR for evaluating whether contaminants of concern are present in runoff or fish.
The facility owner reported that he does not service motors containing PCBs and that only two or three oil-cooled motors have ever been repaired. If the oils contained PCBs, PCDDs, or PCDFs, past workers may have received limited exposure through ingestion, inhalation, or skin contact. A resident reported that oils from motor repair may have been disposed of on the ground in the area behind the building. If those oils contained PCBs, PCDDs, or PCDFs, past or current workers who enter this area might be exposed to contaminants in a soil matrix, principally through incidental ingestion. If TCE has been used or is being used as a solvent by Bluefield Armature, past or current workers potentially could be exposed through inhalation, skin contact, and incidental ingestion. ATSDR has no specific knowledge of releases or exposure. Sampling data are not available for evaluating these issues.
Bluefield Area Streets and Alleys, City Park, Playgrounds, and High School Track
At least some of the oils that were sprayed to reduce dust on unpaved roads, parks, playgrounds, and the high school track reportedly were obtained from facilities that handled PCB-laden fluids. Thus, spraying at some locations is likely to have deposited some of the contaminants of concern on the soils. Because most of the contaminants of concern are persistent in the environment, substantive concentrations might remain in surface soils--for example, on road surfaces that have not been paved or along the edge of those roads that have since been paved. Except for the high school track, substantive sampling information are not available to confirm whether the contaminants are present. At the track, four soil samples recently were combined for one analyses; PCBs were not detected.
Workers who sprayed the oil possibly were exposed to contaminants of concern--principally through skin contact and incidental ingestion. Skin contact and incidental ingestion also are possible routes for past and future exposure to contaminants in the sprayed soils, especially for children. Past and future resident exposure may also result from inhalation of contaminated soil particles suspended in air by vehicle traffic or by recreational activities. ATSDR has no evidence exposure occurred.
Some contaminants may have leached from the wastes and entered the underlying groundwater system. Monitoring data are not available to confirm whether groundwater is contaminated. The Bluefield, VA, and WV, public water systems extend throughout the area where spraying is most likely to have occurred. However, it is unknown whether some residents still are using private wells for potable or household water supply. Therefore, it is uncertain whether anyone would be exposed to contaminants that might have reached groundwater.
Although the specific network of sprayed roads and other areas has not been defined, at least some could be hydraulically upgradient from the reach of the Bluestone River where Bluefield, VA, draws its public water supply. Thus, contaminants could be transported by surface water or groundwater from sprayed areas and, after experiencing substantial dilution in the river, could enter the town's public water system. If so, residents might be exposed to contaminants of concern through potable, household, and industrial uses of water. The magnitude of such discharges to the river is likely to have diminished in the interval since spraying was terminated. Thus the levels of current or future exposure, if any, should be somewhat less than in the past. Analysis of the public water supply for PCBs in 1987 and for all of the contaminants of concern in 1993 did not detect any. That laboratory information appears too limited to use for exposure evaluation.
The raw water sources for the Bluefield, WV, public water system appear to be relatively remote from roads and playgrounds. Thus, that water supply might never have been affected by contaminants transported from sprayed surfaces. Periodic analyses of that system's water for the contaminants of concern have not detected any.
If contaminants have been transported by runoff or groundwater to the Bluestone or East Rivers from the areas that were sprayed, some chemicals would tend to bioaccumulate in the aquatic foodchain. If that occurs, persons who consume fish taken from the river are potentially exposed to the contaminants. Sampling information was not available to ATSDR for evaluating whether contaminants of concern are present in groundwater, runoff, or fish.
Bull Tail Hollow
Sampling data are not available to determine whether contaminants of concern are present in the Hollow. Residents may have been exposed to contaminants contained in oils sprayed on unpaved portions of the road or to contaminants contained in herbicides. Children as well as adults may have been exposed principally through inhalation of volatiles or through ingestion and inhalation of contaminated soil particles from the road or from sprayed areas. Skin contact with these chemicals may also have occurred along the road and along the distribution lines. The more persistent contaminants contained in the oils may still be present at reduced levels and result in continued potential for exposure. However, TCE and the principal herbicide contaminants are not persistent when exposed to the atmosphere and most likely became an unimportant source for such exposure within months of each application. Herbicide nonpersistance and their limited frequency of application suggest that herbicides are not likely to have been an important source of exposure. ATSDR has no evidence that exposure has occurred.
If any rainwater runoff from affected areas has drained into the water supply reservoir, oil contaminants would principally have combined with sediments or some may have accumulated in fish tissue. TCE and herbicide contaminants would likely have remained in the water column and degraded over a period of months. Therefore, public water supply users and swimmers might have received some exposure to contaminants in reservoir water, principally through ingestion and inhalation. Also, those who have consumed fish from the reservoir may have been exposed to contaminants accumulated in the tissues. ATSDR has no specific information about releases. Sampling conducted in 1993 showed none of the contaminants of concern were present in reservoir water. That sampling information appears too limited to evaluate exposure.
TCE and herbicide contaminants also are relatively more mobile in soil than the other contaminants of concern and might have migrated to groundwater. Therefore, the one private water well user might have been exposed to contaminants through ingestion and other domestic water uses. ATSDR has no specific knowledge about water quality for that well or about exposure.
Workers who prepared, loaded, or sprayed herbicides might have experienced incidental exposure to chemicals through ingestion, inhalation, or skin contact. ATSDR has no specific knowledge of exposure.
Available information suggests that at least some former workers were likely to have been exposed to contaminants of concern through skin contact, inhalation, and incidental ingestion while the facility operated. Workers may also have transported these contaminants to their homes on clothing, potentially exposing family members. During operation, oven vents are likely to have released some contaminants to ambient air, resulting in periodic inhalation exposure to nearby residents. Limited sampling of soils taken from nearby residential and business properties did not detect elevated levels of contaminants. Thus, soils on nearby properties possibly have not been a source of substantive exposure to contaminants of concern.
If the site remains fenced, inactive, and intact, substantive exposure to the contaminants that remain on the property is not likely to occur now or in the foreseeable future. However, if a business reactivates the property or the property is developed for residences without additional cleanup, substantial exposure to contaminants of concern is likely to occur through skin contact, ingestion, or inhalation.
Persons are not likely to enter the off-site swale area unless some type of development is initiated. Any such development is more likely to be industrial than residential and probably would require placing fill soils over the existing swale surface. Before Joy's cleanup, anyone who entered the eastern swale area potentially was exposed to substantive concentrations of contaminants in soils or wastes through skin contact, incidental ingestion, and possibly inhalation. Surface soil data obtained in the eastern swale following cleanup of that area suggest that persons entering the area now and in the future might not be exposed to substantive levels of chemicals. Analytical results from many samples taken in the western swale also suggest that persons who enter that area now or in the future might not be exposed to substantive concentrations of contaminants. ATSDR has no evidence exposure has occurred within the swale.
Four borings to depths as much as 70 feet did not provide groundwater for sampling. Thus, no analyses have been conducted to determine whether groundwater resources have been contaminated in the vicinity. ATSDR's evaluations suggest that some of the contaminants transported to the swale might reach the groundwater system relatively rapidly, but sampling data and site-specific geologic data are not sufficient to confirm either migration mechanisms or groundwater contamination. The presence of a sinkhole reported southwest of the APCO depot and other information suggest that the swale may be within a geologic system in which solution channels can develop in bedrock. A shallow depression observed in the east part of the swale appears to pond some of the runoff from Joy and the northeast part of the Service Center property--that feature might be the surface expression of a sinkhole. In addition, an outlet pipe has not been provided at the embankment to discharge swale runoff. ATSDR's observations of vegetation at the embankment suggest that water ponds there for only a short period. Thus, some runoff probably migrates to groundwater relatively rapidly there or farther upgradient in the swale. ATSDR has no evidence releases have occurred.
Water system officials report the site vicinity, and the rest of Bluefield, WV, is serviced by public water supplies obtained principally from reservoirs in watersheds that are a few miles to the east and northeast. Those reservoirs are not topographically downgradient from the swale area. Groundwater flow from the site is likely to be toward the west. One plausible--but unlikely--scenario is that groundwater from the site might flow to one or more of the several springs that provide a small part of the Bluefield, WV, raw water. The springs are to the east, south, and west of the site, on the flank of East River Mountain. ATSDR observed that most of the springs are at higher elevations than the swale--and the three springs that are at lower elevations are over a mile west of the property. If groundwater from the site is contaminated and does discharge at a spring, the original contaminant concentrations should be substantially reduced by dilution in the groundwater regime prior to reaching the spring and further reduced in the reservoir system into which spring water is discharged before it is treated and distributed to the public. Water from the Bluefield, WV, system has been tested periodically for all the contaminants of concern; but none have been detected. Therefore, it is unlikely that the public has experienced substantive exposure to contaminants of concern through that public water system.
Bluefield, VA, draws its water supply from the Bluestone River, which is several miles west of the site. From a topographic perspective, groundwater from the site conceivably might discharge into a reach of the river upgradient from the city's withdrawal point. Although contaminant exposure could result if this flow scenario occurs, the concentrations in drinking water supplies are likely to be low because of dilution that would occur in the groundwater regime and in the river. The water system does not routinely test for the contaminants of concern, but one sample in 1993 showed none were present. ATSDR has no evidence exposure has occurred.
If groundwater has been contaminated in the site vicinity and if any residents downgradient are still using private wells, the residents might be exposed to contaminants of concern through ingestion, inhalation and skin contact. ATSDR has no evidence exposure has occurred.
If contaminants reach the Bluestone River through groundwater or surface runoff, some may bioaccumulate in the aquatic foodchain. If that occurs, persons who consume fish taken from the river are potentially exposed to the contaminants. ATSDR has no evidence exposure has occurred.
Available sampling data developed as a part of cleanup at the property suggest that some who worked at the plant before Lin-Electric's ownership were likely to have been exposed to substantive levels of some of the contaminants of concern through skin contact, inhalation, and incidental ingestion. Workers might also have transported contaminants home on clothing and potentially exposed family members to the chemicals. While in operation, ovens are likely to have discharged contaminants to ambient air. If so, air emissions might have resulted in periodic inhalation exposure to persons beyond the property limit. ATSDR has no evidence exposure has occurred.
When Lin-Electric took over the property, the owner reported that the company established a policy prohibiting use of all the contaminants of concern. Therefore, current and future workers are not likely to be exposed to chemicals from new sources. However, information available to ATSDR is not sufficient to confirm whether any substantive concentrations of chemicals remain from previous work activities. Cleanup included flushing drains and removing concrete, building materials, process equipment, wastes, and some on-site soils. Remediation was approved by state personnel who had evaluated the activities and the supporting documentation while cleanup was in progress. The supporting documents ATSDR received do not describe cleanup criteria and do not clearly define the areas sampled or remediated--nor do the documents fully characterize contaminant concentrations that remained afterwards. In the absence of more comprehensive documentation, ATSDR assumes that current and future workforces might be exposed to some residual contaminants of concern on the property, principally through skin contact or incidental ingestion. However, ATSDR has no evidence exposure has occurred.
Investigations showed that TCE was released into the ground from a storage tank that was removed during remediation. Some of the contaminated soils were also removed, but groundwater was not sampled or remediated. If groundwater contains substantive concentrations of TCE--or any of the other contaminants of concern--and if anyone downgradient uses private wells as a water supply, ingestion, inhalation, and skin contact exposures could occur through potable and household use. ATSDR has no evidence exposure has occurred. Groundwater flow from the site should be toward the Bluestone River, to a reach that is well downstream from where Bluefield, VA, draws its water.
The principal work activities have taken place inside the building, and most of the surrounding area is paved. Therefore, contaminants probably have not been deposited on soils at adjacent properties at levels at which exposure would be a concern. However, sampling data are not available to confirm this.
Effluent from building drains and surface runoff from around the building discharge to the city storm drain system, which in turn discharges to an open ditch leading to the Bluestone River at a location that is downgradient from where Bluefield, VA, draws its public water supply. If the contaminants reach the river by way of runoff or groundwater, some would tend to bioaccumulate in the aquatic foodchain. If that has occurred, persons who consume fish taken from the river are potentially exposed to contaminants. Sampling information is not available to ATSDR for evaluating whether contaminants of concern are present in runoff, groundwater, or fish.
Mercer County Landfill
While waste fluids from mine motor repair were reportedly being disposed of in the 1970s, workers at the landfill could have been directly exposed to contaminants of concern through skin contact and possibly incidental ingestion or inhalation. ATSDR has no specific evidence exposure occurred. The area where wastes were once discharged continued to receive fill, so it appears the wastes are now covered with newer waste materials. Thus, direct exposure of current or future workers to those early wastes is not likely.
Limited sampling data suggest that leachate and leachate-stained soils on the landfill lower slope, and sediments--and possibly water--in runoff collection ponds contain some contaminants of concern. In earlier years, pond water was pumped and sprayed onto the active fill area. This activity may have resulted in workers being exposed to contaminants through inhalation, skin contact, and incidental ingestion. However, ATSDR has no evidence that exposure occurred. Now, human exposure to contaminants in leachate flow paths or in the ponds is not likely because landfill operations have changed substantively and because topography and contaminant locations discourage access. If pond sediments are ever removed to augment water storage capacity, workers might be exposed to contaminants, principally through skin contact and incidental ingestion.
Wind or vehicle traffic probably has deposited some contaminated dust or waste particles on site or on adjacent residential or business properties. However, sampling data are not available to determine whether either workers or persons off site are likely to experience substantive contaminant exposure through ingestion, inhalation, or skin contact.
Observations suggest that the collection ponds might overflow periodically and transport some contaminants into an off-site channel and stream system that connects with Brush Creek at a point that is downstream from reservoirs that water system officials report provide water to the city of Princeton, WV, and other communities. Brush Creek ultimately discharges to the Bluestone River at a point far downstream from where Bluefield, VA, draws its water. Thus, any pond overflow should not affect public water supplies. However, some contaminants transported by pond overflow could bioaccumulate in the aquatic foodchain, and humans might be exposed to the chemicals through fish consumption. ATSDR has no evidence exposure has occurred.
If contaminants of concern have been transported by groundwater beyond the landfill, any persons downgradient who use private wells for their water supply may be exposed to the chemicals through ingestion, inhalation, and skin contact. Information provided to ATSDR does not include groundwater sampling data or specific details about well water use. Residences and businesses closest to the ponds and the area where mine motor liquids had been deposited are reported to be connected to the GVGPSD system--which, for that area, obtains its water from sources that supply the town of Princeton. However, several residences located 1,000 to 2,000 feet away, in a topographically downgradient direction are not connected and, hence, might obtain their water supply from private wells. Some residents farther away, along the rural road by the east property line, may also use private wells for water supplies. ATSDR has no evidence exposure has occurred.
Old Bluefield, VA, Landfill
While the landfill was active, workers may have been exposed to contaminants in waste oils that were reportedly deposited there. Sampling information is not available to confirm whether waste residues are present at the existing ground surface or are buried within the fill. The site is unlikely to be developed or have substantial human traffic in the foreseeable future because of its steep topography, remote location, and prior history. However, some trespassers could enter the property. If so, trespassers potentially would be exposed to contaminants of concern principally through inadvertent skin contact or ingestion. ATSDR has no evidence exposure has occurred.
If runoff has transported substantive contaminants off site, some chemicals might be present in sediments within the drainage channel that passes through the small community of Hales Bottom. Residents there, especially children, might be exposed intermittently to contaminants in the channel, principally through inadvertent skin contact or ingestion. Sampling data are not available to confirm whether sediment contamination has occurred. ATSDR has no evidence exposure has occurred.
Some contaminants of concern might also have leached from the wastes to groundwater and migrated downgradient to private wells believed to provide potable water for residents of Hales Bottom. Groundwater from the site is likely to discharge to the Bluestone River near Hales Bottom, a location that is far downstream from where Bluefield, VA, draws its water supply. Sampling data are not available to confirm whether Hales Bottom residents are being exposed to substantive contaminants through potable and household uses of groundwater.
Sam Neal Property
Workers who previously burned motors and transformers and reclaimed copper are likely to have been exposed to contaminants of concern through inhalation, skin contact, and incidental ingestion. ATSDR has no evidence those exposures occurred.
The property has two residences. The western home is occupied, and ATSDR observed small children at play. Residents, especially children, are likely to be exposed to contaminants in surficial soils, or in ash residues, through ingestion and skin contact, especially in areas where burning previously occurred. Inhalation of contaminated dust particles is also possible. In the second residence, which is not currently occupied, the basement area (dirt floor) reportedly had been used for some reclamation activities. Soils there--and possibly other components of the home--are shown to be contaminated and could be a source of exposure to inhabitants. A small shed-like structure at which outdoor reclamation activities were also conducted is still present and is used for storage purposes. Thus, items presently stored in the shed may have become contaminated and may provide sources for contaminant exposure to anyone who comes in contact with them. ATSDR has no evidence exposures have occurred.
Available data do not clearly show that the lateral extent of soil contamination on the property has been defined. A home on an adjacent property to the east is near the area on site where outdoor reclamation activities took place. If soil contamination extends onto the adjacent property, those residents could be exposed to the chemicals, principally through skin contact and ingestion.
Some contaminants may have leached from the wastes and entered the underlying groundwater system. The Bluefield, WV, public water system extends throughout the site vicinity. However, it is not known whether some residents still use private wells for potable or household water supply. Therefore, it is uncertain whether anyone would be exposed to contaminants that might have reached groundwater.
Site runoff either discharges into the Bluestone River several miles away or to groundwater along the drainage route. Although some contaminants may be transported to the river, topographic considerations suggest that the receiving point in the river should be downgradient from where Bluefield, VA, draws its water supply.
Should contaminants reach the Bluestone through groundwater or
runoff discharge, some chemicals would tend to bioaccumulate in
the aquatic foodchain. If that occurs, persons who consume fish
taken from the river potentially are exposed to the contaminants.
Sampling information is not available to ATSDR for evaluating
whether contaminants of concern are present in groundwater,
runoff, or fish.
As discussed in the preceding section, children and adults at the Sam Neal Property may being exposed to PCBs and dioxin at levels of possible health concern. There were likely exposures of workers to PCBs in the past at Acken Sign, APCO Service Center, Joy Manufacturing, and Linn Electric. There were no relevant sampling data for the APCO Glen Lyn Plant, Blacor Steel, Bluefield Armature, the streets of Bluefield, Bull Tail Hollow, and the Old Bluefield Landfill in Virginia.
The Toxicological Evaluation discussion in this section will explain possible health hazards from the two chemicals, PCBs and dioxin, for which there is evidence of exposure. Community health concerns will be addressed in the Evaluation of Community Health Concerns section. Cancer mortality data from a Centers for Disease Control and Prevention (CDC) mortality database will be used to help address some of the concerns. As discussed in the Health Outcome Data segment of the Background section, no appropriate health outcome data were identified. The process that ATSDR uses to identify biologically plausible health outcomes will be briefly discussed in the Evaluation of Health Outcome Data.
In a public health assessment, the toxicological evaluation can be done by contaminant, route of human exposure, or by target organ toxicity. The evaluation will be made for PCBs and dioxin.
Typically, the toxicological evaluation in a public health assessment involves comparison of the exposed dose for persons in an exposure pathway to ATSDR's Minimum Risk Levels (MRLs). The MRL is an estimate of daily human exposure to a contaminant below which noncarcinogenic adverse health effects are unlikely to occur. MRLs have been developed for inhalation and ingestion routes of exposure, and for duration of exposure, such as acute (less than 14 days), intermediate (14 to 364 days), and chronic (over 365 days). The exposure dose, based on contaminant concentrations and exposure duration for the area where exposure has, is, or could occur, is compared to the MRL appropriate for the route and duration of exposure.
As previously described, ATSDR's MRLs are estimates of daily human exposure to a contaminant below which noncarcinogenic adverse health effects are unlikely to occur. This means that any exposure dose that is below the appropriate MRL does not represent a noncarcinogenic hazard to human health. An exposure dose above the appropriate MRL indicates that evaluation of the toxicological literature needs to be done to determine whether the specific exposure situation represents a health hazard.
The risk of carcinogenic health effects is also evaluated in this section. EPA's Cancer Slope Factor for a contaminant is used to calculate the maximum risk from 70 years of exposure. The actual risk of cancer is probably lower than the calculated number.
In this public health assessment, the range of concentrations of PCBs found in the Bluefield area will be compared to ATSDR's MRL and EPA's Cancer Potency Factor for PCBs. The concentrations of dioxin found will be compared to ATSDR's MRL for dioxin. Any exposure doses determined to be above the appropriate MRL will then be evaluated further.
Exposure Doses for Polychlorinated Biphenyls
The range of PCB concentrations at the one location where exposure may be currently occurring vary widely. At the Sam Neal Property (Table 9), the maximum concentration of PCBs in October 1987 was 33 ppm, in June 1993, 55 ppm, in March 1987, 250 ppm, and in February 1986, 340 ppm.
When compared to the intermediate MRL for ingestion of PCBs of 0.0001 mg/kg/day, exposures of children and adults to the maximum levels on the Sam Neal Property in February 1986 (340 ppm), and in March 1987 (250 ppm) exceed the MRL (42). Exposure of children, (not adults) to the maximum PCB concentrations detected in October 1987 (33 ppm) and June 1993 (55 ppm) also exceeds the MRL.
Exposure doses for adults at the Sam Neal Property were calculated in the following manner. The four different concentrations of PCBs, 33, 55, 250, and 340 ppm or milligrams/kilogram (mg/kg), were multiplied by the soil ingestion rate for adults, 0.0001 kg/day. Those figures were divided by the average weight for an adult, 70 kg (154 pounds). The results in mg/kg/day were more than 10 times lower than the MRL of 0.0001 mg/kg/day for 33 and 55 ppm, but were greater than for 250 and 340 ppm. The calculation assumes that there was daily exposure to soil contaminated at maximum concentrations.
The exposure doses for children at the Sam Neal Property were calculated in a manner similar to that for adults, except that a soil ingestion rate of 0.0002 kg/day and a 10 kg body weight were used. Exposure doses for children for all four maximum concentrations exceeded the MRL of 0.0001 mg/kg/day.
Exposure doses for PCBs for adults and children at the Sam Neal Property will be discussed further in this section.
Exposure of persons at the Sam Neal Property to the maximum levels of PCBs may represent a slight increase of a person's lifetime risk of cancer. Using EPA's Cancer Potency Factor for PCBs of 7.7 (mg/kg/day)-1, exposure of residents of the Sam Neal Property to the range of PCB levels, 33 to 340 ppm, may represent a slight increase of a person's lifetime risk of cancer (43).
That risk was calculated in the following manner. The four known maximum concentrations of PCBs, 33, 55, 250, and 340 ppm, were multiplied by the soil ingestion rate for adults of 0.0001 kg/day. Those figures were divided by the average adult body weight of 70 kg. Those products were then multiplied by the Cancer Potency Factor of 7.7 (mg/kg/day)-1. The results represent the maximum risk for cancer after 70 years of exposure to a range of 33 to 340 ppm. These results will be evaluated later in this section.
Exposure Doses for Dioxin
When compared to the intermediate MRL for ingestion of TCDD (dioxin) of 0.000000001 mg/kg/day, exposures of adults and children to the maximum concentrations on the Sam Neal Property, 0.0039 and 0.094 mg/kg, exceed the MRL (42). The exposure doses for adults and children on the Sam Neal Property were calculated in a manner identical to that described for PCBs at the Sam Neal Property. The exposure doses for dioxin for adults and children at the Sam Neal Property will be further discussed later in this section.
The maximum level of dioxin of 0.094 mg/kg or ppm at the Sam Neal Property is above the concentration for carcinogenic effects of 0.001 ppm established by the CDC (59). This will be further discussed later in this section.
Possible Health Consequences of the Exposure Doses for PCBs
The four sets of environmental sampling data for the Sam Neal Property represent different health hazards. It is unclear from the data available to ATSDR, which, if any, of the four sets is most representative of exposure concentrations for PCBs at the Sam Neal Property. The children exposure doses for all four concentrations and the adult exposure doses for the two highest maximum concentrations, 250 and 340 ppm, exceed the MRL of 0.0001 mg/kg/day. However, as will be discussed, a review of the toxicological literature on PCBs indicates that the exposures probably do not represent a health hazard.
Studies of exposed workers clearly indicate that PCBs can affect the liver, skin, and eyes, especially after long-term exposures (44). There is some evidence that associates PCB exposure in workers with respiratory, gastrointestinal, hematological, muscular and skeletal, developmental, and neurological effects. However, the data are not strong enough to establish a cause-effect relationship. Exposure in the studies mentioned above were inhalation and/or dermal exposures rather than ingestion. In addition, exposure levels were all much higher than those at the Sam Neal Property.
Several human studies suggest that prenatal exposure to PCBs may be associated with developmental effects (44-49). A series of investigations of Michigan children identified small, but statistically significant, deficits in birth size (45), gestational age (45), and visual recognition memory (46). Some of the effects were still detectable at four years of age (46,47). A study of North Carolina newborns identified some mild, but measurable behavioral effects (49).
However, the effects observed in the Michigan and North Carolina children cannot be firmly linked to PCB exposure (44). The mothers of the North Carolina newborns had been exposed to dichlorodiphenyl dichloroethene (DDE), which also appears to be linked to the same behavioral effects as PCBs (49). Causation by other chemical agents could not be precluded for the Michigan studies (47). The deficits in birth size and gestational age observed in the Michigan children (45), were not seen in the North Carolina study (49). In addition, the studies did not identify a clear dose-response relationship, which does not permit their use in evaluating whether health effects might occur in residents at the Sam Neal Property.
Information from animal studies is of sufficient quality to permit such an evaluation. In the long term (i.e., a year or longer), developmental effects from PCBs occur at levels at least ten times lower than other effects (44). Developmental effects, therefore, will be used in this evaluation.
Noncarcinogenic health effects from exposure to PCBs at the Sam Neal Property are unlikely to occur based on a comparison of the exposure doses to the available data from animal studies. Three studies of developmental effects of 12-18 months duration were used for this evaluation (50,51,52). Monkeys and humans are very similar in their responses to toxic chemicals (53), which allows comparisons without adjustment for inter-species differences. The no-observed-effects levels for the three developmental studies are at least 10 times greater than the exposure doses for adults at the Sam Neal Property (50,51,52,53). The first observed effects in the three studies occur at concentrations at least 100 times greater than the exposure doses.
Exposures of residents at the Sam Neal Property to the maximum levels of PCBs represent a low to moderate increase of a person's lifetime risk of cancer. These increased risks represent the maximum risk for cancer after 70 years of exposure. Because there are only two households (if, or when, both residences are occupied) and perhaps 7-10 residents, the actual chance of any of the residents contracting cancer is very small. Also, actual exposure duration is probably considerably less than 70 years. In addition, the method used to calculate EPA's Cancer Potency Factor assumes that high dose animal data can be used to estimate the risk for low dose exposures in humans (54). The method also assumes that there is no safe level of exposure (55). There is little experimental evidence to confirm or refute those two assumptions. Lastly, the method computes the 95% upper bound for the risk, rather than the average risk, which results in a 95% chance that the risk is actually lower, perhaps by several orders of magnitude (56).
Possible Health Consequences of the Exposure Doses for Dioxin
The exposure dose of adults and children to the maximum level of dioxin of 0.094 ppm, exceeds the MRL of 0.000000001 mg/kg/day. However, as will be discussed, a review of recent studies on human exposure to dioxin-contaminated soils indicates that these exposures probably do not represent a health hazard.
Two recent studies of long-term human exposure to soils contaminated with up to 2.2 ppm of dioxin did not identify any health effects (57,58). A broad battery of physical, clinical and immunological exams were administered to persons who had lived in areas contaminated with dioxin.
The maximum level of dioxin at the Sam Neal Property does not represent a significant additional lifetime risk of cancer considering plausible exposure circumstances. The 0.001 ppm level set by CDC assumes an exposure of 70 years (59). The Sam Neal Property is occupied by renters and thus it is unlikely that anyone's exposure would exceed 10 years. Another factor is that CDC's level used soil ingestion rates of 0.001 to 0.01 kg for children (59), which greatly exceed the rates cited in a recent evaluation (60). That evaluation identified maximum daily soil ingestion rates of 0.00025 to 0.0005 kg and average rates of 0.00005 to 0.0001 kg.
Plausible Health Outcomes
The main criteria for identifying a plausible outcome is the existence of a completed exposure pathway for a chemical that is suspected to be a carcinogen and/or to cause other adverse health effects such as birth defects, learning disabilities, etc. Noncarcinogenic health outcomes are identified through a review of the toxicological literature.
Designating a chemical as a carcinogen (for purposes of health
outcome data evaluation) is based on the following:
|(a)||classification by the National Toxicology
Program (NTP)(1) in its Annual Report on
Carcinogens as a "known human carcinogen" or
"reasonably anticipated to be a carcinogen"; or
|(b)||classification by the International Agency for Research
on Cancer (IARC)(2)
as a 1, 2A, or 2B carcinogen; or
|(c)||classification by the United States Environmental Protection Agency (EPA)(3) as an A, B1, or B2 carcinogen.|
A latency period of at least 10 years between exposure and diagnosis has been observed in most studies of human cancer. If exposure began less than 10 years before the latest data available, analysis of health outcome data for cancer incidence or mortality is not likely to be useful, particularly if the exposure level is low (61).
The Virginia State Tumor Registry has data from 1970-90 on cancer in Virginia residents. However, the registry became population-based in 1990. Population-based data are necessary to identify cancer rates for an area. An evaluation of cancer data for the Bluefield area in Virginia cannot be conducted because there are only population-based data from 1990. Usually, at least five years of data are necessary.
This lack of at least five years of data is also the reason why West Virginia's Tumor and Birth Defects Registries were not accessed.
Health Outcomes Identified as Community Health Concerns
In response to community concerns about cancer and diabetes, ATSDR reviewed mortality data for cancer and diabetes for Tazewell County, Virginia and Mercer County, West Virginia, and other adjoining counties in both states. This database is maintained by the Office of Analysis and Epidemiology of the National Center for Health Statistics of CDC.
Available data on the extent of contamination by PCBs, dioxin, dibenzofuran, and TCE have been reviewed and are discussed in the Environmental Contamination and Other Hazards and Pathways Analyses section. Therefore, this section will focus on the available information on cancer and diabetes in the Bluefield area.
As discussed previously, information specific to the Bluefield area is not available. Mortality data for Tazewell, Mercer, and adjacent counties were accessed for 1979-1988, the only years available. The age-adjusted rates for Tazewell and Mercer Counties will be compared to the rates for Virginia, West Virginia, and the United States. They will also be compared to the rates for the counties adjoining Tazewell and Mercer Counties along the Virginia-West Virginia border. Because the Bluefield area is over 95% white, the comparisons listed below will be for whites. The comparison of rates for African-Americans produced results similar to those described in the following paragraphs.
The age-adjusted mortality rate for diabetes in Tazewell County, Virginia was 12.9 per 100,000, while for Mercer County, West Virginia it was 15.2 per 100,000 population. The rates for Virginia, West Virginia, and the United States were 10.5, 16, and 13.5 per 100,000, respectively. While the rate in Tazewell County is higher than Virginia as a whole, the rate is similar to the adjoining counties in Virginia and West Virginia. The rates in the four counties adjoining Tazewell and Mercer along the West Virginia-Virginia border are similar. For Buchanan and Bland Counties, Virginia, the rates for diabetes mortality were 13.6 and 12.5 per 100,000. For McDowell and Wyoming Counties in West Virginia, the rates were 27.1 and 22.5 per 100,000.
Diabetes is the 7th leading cause of death in the United States (62). There are two types of diabetes commonly found here (63). Those are insulin dependent diabetes mellitus (IDDM) and non-insulin dependent diabetes mellitus (NIDDM). The major difference between these two types is that very little or no insulin is produced by people with IDDM, while in NIDDM the insulin produced is not properly used by the body. IDDM frequently has its onset in people under 19. NIDDM occurs most frequently in those over 40 (62). In the U.S., about 80% of diabetes cases are NIDDM (62).
IDDM appears to be related to a complex interaction of genetic and environmental factors (63). It tends to run in families (i.e., is inherited), especially those from northern Europe. Its onset may be triggered by environmental agents such as congenital rubella, Coxsackie B, and mumps. Besides these viruses, a rodenticide (N-3-pyridylmethyl,N-p-nitrophenyl) also appears to trigger the onset of IDDM.
The occurrence of NIDDM is associated with genetic and behavioral factors (63). NIDDM runs in families, but, unlike IDDM, it is much more common in Hispanics, Native Americans, Polynesians, and other groups, rather than in northern Europeans. Other important factors are diet, obesity, age, social economic status.
Based on the data reviewed about the rate of mortality from diabetes in Tazewell and Mercer Counties, there is no excess of diabetes. The validity of this conclusion is somewhat limited by the lack of data specific to the Bluefield area.
All types of cancer
The rates for all types of cancer in Tazewell and Mercer Counties were not in excess for 1979-1988. The rate for Tazewell County was 184.2 per 100,000, while the Virginia rate was 187.5 per 100,000. The rates for Mercer County and West Virginia were 171.5 and 190.1 per 100,000 respectively.
Lung and stomach cancer
As discussed previously, there are no health outcome data specific to the Bull Tail Hollow area. Because this area lies entirely within Tazewell County, Virginia, lung and stomach cancer data for that county will be described. The age-adjusted rate for stomach cancer for 1979-1988 in Tazewell County was 5.2 per 100,000. This is greater that the rate for Virginia (4.4) but not the rate for the United States (5.3). The significance of these results needs further evaluation.
Stomach cancer has been linked with diet, a number of occupations, socioeconomic status, and asbestos (64). The link with diet focuses on consumption of smoked and salted foods, and foods contaminated with aflatoxin. Increased rates of stomach cancer have been associated with a number of occupations including coal mining, farming, nickel refining, rubber processing, and timber mill workers. It is unclear whether the increased rates of stomach cancer are a result of a specific agent or are a reflection of socioeconomic status. In this country and Europe, the rate of stomach cancer increases as socioeconomic status decreases. The increased rates observed in asbestos workers appear to be related to asbestos fibers.
The age-adjusted rate for lung cancer for 1979-1988 in Tazewell County was 55.0 per 100,000. This is greater than the rates for Virginia (52.9) and the United States (48.0). The significance of these results needs further evaluation.
Lung cancer can be caused by several environmental agents (65). The evidence for a cause-effect relationship between lung cancer and tobacco smoke is very strong. There is good evidence for asbestos, radon, chromium, and arsenic as causes of lung cancer.
The concerns described in the Community Health Concerns section were addressed as follows.
1. Cleanup of Joy Manufacturing was insufficient
The post-cleanup sampling data indicate that PCBs are still present at Joy Manufacturing, and significant exposure to PCBs could occur, based on the media sampled. Disturbance of the concrete covers over PCB-contaminated soil could result in exposure that might result in a health hazard. The possible disturbance of these covers will have to be a factor in future uses of the Joy Manufacturing property.
2. Contamination of municipal water supply
Residents expressed concern that contaminants released at the Joy and APCO Service Center sites may have entered solution cavities in the underlying bedrock and reached springs that help supply the municipal water system.
The Bluefield, WV, system acquires most of its water from reservoirs in other watersheds. Several springs also supply a relatively small part of the demand. Three of those springs are topographically downgradient from the Joy and APCO sites, but are more than one mile away. Bluefield, VA, draws its water supply from the Bluestone River, which is several miles downgradient from the west of the Joy and APCO Service Center sites. Some of the other sites may also have released contaminants to groundwater. It is likely that any contaminant released to groundwater would be substantively reduced in concentration during transport either underground or in the source river, storage impoundments, or the treatment and distribution systems. Periodic sampling of the Bluefield, WV, water supply (the latest in 1993) has not detected any of the contaminants of concern.
Water from the Bluefield, WV, system was tested for PCBs in 1987 and for all of the contaminants of concern in 1993, and none have been detected. Therefore, it is unlikely that the public has experienced substantive exposure to contaminants of concern through the municipal system. The Bluefield, VA, system does not routinely analyze for contaminants of concern. However, should any site-related contaminants of concern reach the Bluestone River and be entrained in this system, they are likely to be at low concentrations. Periodic sampling is needed to better evaluate this issue.
3. Total cancer and diabetes
These concerns are evaluated in the Health Outcome Data Evaluation section. The rates of age-adjusted mortality for diabetes and excess cancer for Tazewell and Mercer Counties were as expected for this area of West Virginia and Virginia.
4. Workplace exposure to toxic chemicals
There is insufficient information to evaluate worker concerns.
5. Lung and stomach cancer in Bull Tail Hollow area
These concerns are evaluated in the Health Outcome Data Evaluation section. The age-adjusted mortality rate of stomach cancer for Tazewell County (there were no data for just Bull Tail Hollow) was greater than the rate for Virginia but was less than the rate for the United States. The age-adjusted mortality rate of lung cancer for Tazwell County was greater than the rates for Virginia and the United States. The significance of this needs further evaluation.
6. Mental health and environmental contamination
No clear association between exposure to chemicals in the environment and mental health impacts has been established to date. ATSDR is funding research to examine this issue.