PUBLIC HEALTH ASSESSMENT
AMERICAN BEMBERG PLANT
ELIZABETHTON, CARTER COUNTY, TENNESSEE
Samples have been taken on-site of several media: surface soils, subsurface soils; land fill wastes, groundwater, and surface water. Off site, sampling data are available for river sediment and water and for fish. Ambient air quality data pertinent to Bemberg's operations are not available, and, thus, cannot be evaluated. Review of the sampling data and other site-related information indicates that contaminants associated with rayon production remain in the BIC building basement and the closed lagoon and landfill. Contaminants have been released to on-site soils, groundwater, and the river. Review of data for the soil samples taken towards the site property line suggests that substantive contamination has not migrated to the site boundary or to off-site soils. Contaminants released to the river periodically affected water quality in the past; sediment and biota also may have been affected at that time.
ATSDR identified contaminants to consider for public health impact evaluation. Identification of those contaminants here does not does not imply that human exposure has occurred or that exposure would actually result in adverse health effects. Exposure and health effects are described in subsequent sections of this assessment. Contaminant selection considered the following factors:
- Concentrations of contaminants in wastes and environmental media
- Sampling plan design and data quality
- Relationship of concentrations to ATSDR's public health evaluation comparison values (information about comparison values is provided in Table 1, in Appendix A)
- Exposure potential
- Community health concerns
ATSDR reviewed EPA's Toxic Chemical Release Inventory (TRI) (5), which provides information about annual releases of toxic chemicals for many industrial facilities. The data base did not include toxic release information for any facilities in the site vicinity.
Surface Soils and Other Surficial Materials
Two investigations initiated in the early 1990s evaluated surface soil and other surface materials at many locations on the property. Surface samples were taken at the closed lagoon and landfill vicinity and former ball fields in Area D, around some of the former Bemberg buildings and in the BIC building basement in Area B, and at several locations toward the site boundary in Areas A, C, and D (2,6). The samples were principally soils. However, in the BIC building and at the lagoon and landfill, some samples may have been soil-like materials (e.g., process waste, debris, sediment). Several metals (arsenic, barium, cadmium, copper, lead, manganese, mercury), polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) were present at one or more locations at concentrations that warrant evaluation for public health impact. Data for background samples and those taken on-site near the site boundary show that on-site soils are not substantively contaminated toward the site perimeter and substantive contamination should not be present in off-site soils. Soils data are summarized in Table 2 (2,6).
As part of an investigation at the landfill in 1980, prior to its closure, one shallow soil sample (1- to 2- foot depth) and several deeper samples were analyzed for copper. The shallow sample contained 26,000 parts per million (ppm) copper (7).
Several on-site monitoring wells have been installed and sampled. The data show low levels of tetrachloroethene (maximum, 0.011 parts per million [ppm]) and toluene (maximum 0.005 ppm). A few metals, especially manganese, exceed regulatory Maximum Contaminant Levels (MCLs) by as much as two orders of magnitude (8,6). Because contaminated site groundwater is not used for any purpose, there are no potential health consequences associated with it, and no further assessment is made in this document.
River Water and Sediment
The river watershed is very large and contains many potential industrial and nonindustrial sources of contaminants. During Bemberg's early operations, ammonia in the river water rose to levels that required the Johnson City Water Department to temporarily close their intake. Correlating the quality of the treated (potable) water and river ammonia levels from so long ago is not feasible; thus, the past ammonia releases cannot be addressed in this assessment. In 1993, several river water and sediment samples were obtained upstream and downstream from the site. Water samples showed a few metals present, and sediment samples showed many metals and a few organic chemicals present (2). The concentrations identified are below levels that would warrant evaluation for public health impact; these media are not discussed further in this document.
There are no fish advisories for the Watuaga River (9). Fish tissue sampling in 1983 in the river about 15 miles
downstream of the site showed arsenic and cadmium (up to 0.3 ppm) were present in stripped bass. Cadmium was
present in catfish (up to 0.2 ppm). Copper (up to 1.0 ppm) was found in carp. PCBs were present in carp (up to 2.0
ppm) and in catfish (up to 0.5 ppm) (10). The source of those contaminants cannot be identified. At the low
concentrations reported, the fish contaminants do not warrant evaluation for public health impact.
Identification of specific human exposure pathways in this section does not imply that adverse health effects are associated with them; health issues are discussed in the Public Health Implications section. ATSDR identifies human exposure pathways by examining environmental and human components that might lead to contact with contaminants. A pathway analysis considers five elements: a source of contamination, contaminant presence or transport in an environmental medium, a point of human exposure, a route of human exposure, and an exposed population. Completed exposure pathways are those for which the five elements are evident, indicating that exposure to a contaminant either has occurred in the past, is currently occurring, or will occur in the future. ATSDR regards people who come in contact with contamination to be exposed: for example, people who work or play in contaminated soil, or who drink contaminated water, or who reside in an area with contaminated air are considered exposed. Potential exposure pathways are those for which one or more of the elements is not clearly defined, but exposure is plausible. Potential pathways indicate that exposure to a contaminant could have occurred in the past, could be occurring now, or could occur in the future.
ATSDR staff reviewed site history; past, current, and future activities on and off the site; and media sampling data and identified several completed exposure pathways (past, current, or future). Those pathways are associated principally with exposures to wastes, soils, air, sediment, and aquatic biota and are summarized in Table 3, along with clarifying comments about their evaluation. ATSDR also identified potential exposure pathways associated with the reuse of Area B buildings and with river water withdrawn downstream by Johnson City for community potable water supply while the plant operated. A state employee expressed concern about a potential future groundwater source for public water supplies located within 1 mile of the site. Potential exposure pathway elements are summarized in Table 4; evaluation comments also are provided in the table..
ATSDR examined each of the exposure pathways in Tables 3 and 4 in terms of frequency, duration, and likely contaminant concentrations, and identified a few pathways that warranted further evaluation and discussion of potential public health impact. Those pathways include:
Past Completed Exposure
- Former Workers --Former Bemberg plant workers are likely to have been exposed to Bemberg's
contaminants in wastes or soils or air via incidental ingestion, dermal contact, or inhalation.
Former Users of Ball Fields -- Players are likely to have been exposed to Bemberg's contaminants in surface soils via incidental ingestion, dermal contact, and inhalation.
Current Potential Exposure
- Grounds Workers -- Some workers, such as grounds and maintenance staff, possibly may be exposed at
present to Bemberg's contaminants in soil or other materials via incidental ingestion, dermal contact, and inhalation.
Future Potential Exposure
- BIC Building Basement Reuse -- If the basement area is reused without cleanup, future workers are
likely to be exposed to contaminants that are present in materials there (e.g., exposed soil, wastes, debris).
Construction Workers -- In the future, construction workers for new development on site might be exposed to Bemberg's contaminants in soil or other materials via incidental ingestion, dermal contact, and inhalation.
This section addresses the possible effects that Bemberg's contaminants might have had on public health.
This section contains information on the contaminants to which certain people have been, are, or may become exposed and that may cause adverse health effects. Although the relative toxicity of a chemical is important, the response of the human body to chemical exposure is actually determined by several additional factors, including the magnitude of exposure (how much), the duration of exposure (how long), and the route of exposure (i.e., breathing, eating, drinking, or skin contact). Lifestyle factors (i.e., occupation and personal habits) have a major impact on the likelihood, magnitude, and duration of exposure. In addition, individual characteristics such as age, sex, nutritional status, overall health, and genetic constitution affect how a contaminant is absorbed, distributed, metabolized, and eliminated from the body. Accordingly, the probability that exposure-related adverse outcomes will actually occur does not depend solely on concentrations in environmental media.
From evaluations of contaminants (Table 2) and exposure pathways (Tables 3 and 4), ATSDR determined that exposures to several categories of on-site workers and the former ballfield users warranted more detailed toxicological evaluation and discussion in this section. As reported earlier -- air quality data pertinent to Bemberg's operations are not available, so inhalation exposure could not be evaluated; also, sampling data indicate that substantive soil contaminants and associated potential exposures do not extend beyond the site onto adjacent properties.
There were two main exposure scenarios for the former workers at the site who might have accidentally ingested small amounts of contaminated materials (soils, wastes, etc). Workers are assumed to have been on site five days a week, 50 weeks per year, for 30 years, and to have ingested 100 milligrams of soil a day.
One exposure scenario involves plant workers who were likely to have been accidentally exposed occasionally to arsenic, barium, cadmium, copper, lead, manganese, mercury, PCBs, and PAHs through ingestion of, and skin contact with, contaminated materials (wastes, soils, etc.) in the BIC building basement and any associated processing areas (Table 2). This exposure would have been added to that from process air emissions, which cannot be evaluated because relevant data are not available. The amounts of arsenic, barium, cadmium, copper, manganese, mercury, PCBs and PAHs this group of workers were exposed to are below levels that are known to cause adverse health effects in experimental animals or in human epidemiological studies (11,12,13,14,15,16,17,18,19). The amount of lead is five times higher than the 2,000 ppm soil lead guidance for a child's exposure recently proposed by the EPA. However, in the nonfasting human adult, only about 6% of the total amount of lead taken in gets into the blood. Although there is no record of blood lead levels for this group of former workers, it is unlikely that under typical workplace conditions they accidentally ingested enough lead to cause adverse health effects.
The second exposure scenario is associated with former Bemberg grounds and maintenance workers who were likely exposed to one or more of arsenic, copper, lead, manganese and low levels of PAHs in materials at the closed lagoon and landfill areas, and in some of the on-site surface soils (Table 2). The amounts of arsenic (11), copper (14), lead (15), manganese (16) and PAHs (19) in the contaminated materials are below levels known to cause adverse health effects.
Former Users of the Ball Field
Adults and children who played at the former ball fields on the property were likely exposed to arsenic and manganese in soil (Table 2). The amounts of arsenic and manganese adults and children might have been exposed to are not likely to cause adverse health effects (11,16).
Grounds and maintenance workers currently may be exposed to low levels of arsenic, cadmium, copper, lead, manganese and PAHs in contaminated materials principally at the former lagoon area and around the existing buildings (Table 2). The amounts of contaminants are below levels that are known to cause adverse health effects (11,13,14,15,16,19).
If the basement of the BIC building is reused but not cleaned, future workers there likely would be exposed to the contaminants that now exist in materials there. As further industrial-type development occurs elsewhere on the property, the construction workers and some of the industrial workers are likely to be exposed to site-related contaminants (Table 2). Based on present knowledge of conditions, our evaluations suggest that those exposures are not likely to be at levels of health concern.
Child Health Issues
Evaluations have not identified any child health issues associated with this site. However, in the unlikely event that the planned land use for the industrial park changes, and the site is developed for residential or other municipal use, child health issues should be re-evaluated.
The state does not compile health outcome data for the specific groups of potentially affected populations being evaluated in this assessment (e.g., people on and near the site). Hence, site-specific health outcomes cannot be evaluated from the available data.
- Did the contaminants in soil at the site, and eating fish from the Watauga river
cause scoliosis (problems of the spine), cancers and other health problems in area
The abnormal spine problems, cancer or other unspecified health problems reportedly being experienced by area residents are not likely related to site contaminants. A toxicological evaluation indicates that workers at the former site, and people who played at the ball field for about three years were not exposed to contaminants at levels that could cause adverse health effects. The amounts of contaminants in fish taken from the Watauga river 15 miles downstream in 1983 were low, and are not likely to cause adverse health problems for people. We cannot be sure that the concentrations in fish 15 miles downstream are representative of the fish being caught near the plant during it's early years of operation. Thus, we cannot use those data to say, with confidence, that fishermen near the site were not being adversely affected by fish consumption during early years of operation. We do know that Bemberg's installation of waste handling and effluent treatment facilities began in the 1960s and, thereafter, would have substantively reduced contaminant releases to the river. We also know that river water and sediment samples taken by the plant in 1991 do not show elevated contamination. Although we are unable to assess early exposure, we believe that in more recent years, there is very little likelihood that fish being caught might contain any significant site contaminants.
Cancer registry information and the vital records are not specific for workers or the population near the site. In addition, there is no evidence that contaminated soil from the site has impacted any residential areas.