PRELIMINARY PUBLIC HEALTH ASSESSMENT
MONARCH TILE, INC., FLORENCE DIVISION
LAUDERDALE COUNTY, ALABAMA
ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS
This section is a review of the environmental data collected at the site and an assessment of the quality of the data. This section also deals with on-site contaminants of concern and the frequency and concentration of these contaminants in various media. On-site contamination will be reviewed first, followed by off-site contamination. On-site, Monarch Tile, Inc. currently operates two plants on 26.8 acres used for the production of ceramic tile. Off-site is the surrounding community consisting of other businesses and residential districts.
A review of the sampling data reported in the Site Investigation found arsenic, barium, cadmium, chromium, lead, nickel, and zinc as on-site contaminants of concern (3,4).
These contaminants are evaluated in the subsequent sections of this health assessment to determine whether exposure to them has public health significance. We selected and discussed these contaminants based upon the following factors:
Listing a chemical as a contaminant of concern does not mean that adverse health effects will result from exposure. Instead, listing a chemical indicates that it will be evaluated further in this preliminary public health assessment.
The only off-site sampling conducted was of sediment samples taken from the ditches leading away from the site. The following contaminants of concern with values equal to or above the ATSDR comparison values, or for which no comparison values exist, were detected:
Arsenic
Barium
Cadmium
Chromium
Lead
Nickel
Zinc
These contaminants will be discussed in the section dealing with sediment. Contamination in other media are discussed in the sections that follow.
Toxic Chemical Release Inventory
A search of the Toxic Release Chemical Inventory 1991 (TRI91) for information on industries in the area surrounding the site showed point source releases of zinc compounds from one other industry in Florence. Although the industry released zinc compounds, the facility is located 1 1/2 miles southeast of the site near the Tennessee River, and cannot be associated with any contamination found in this preliminary public health assessment.
The tables presented in Appendix B list the contaminants of concern in various on-site and off-site
media. The contaminants of concern are evaluated in later sections to decide if exposure has
pubic health significance. The data tables include the following abbreviations:
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= Cancer Risk Evaluation Guides |
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= Environmental Media Evaluation Guides |
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= Reference Dose Media Evaluation Guides |
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= Maximum Contaminant Level |
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= Reference Dose |
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= parts per billion |
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= parts per million |
Comparison values used during the preparation of a public health assessment are contaminant concentrations in specific media used to select contaminants of concern for further evaluation. Those values include Cancer Risk Evaluation Guides (CREGs), Environmental Media Evaluation Guides (EMEGs), Reference Dose Media Evaluation Guides (RMEGs) and other relevant guidelines. CREGs are estimated contaminant concentrations based on one excess cancer in a million persons exposed over a lifetime. CREGs are calculated from EPA's cancer slope factors. An EMEG is the amount of a particular contaminant that can be present in a specific medium below which no known non-cancer effects are expected to result from exposure. An EMEG is derived from an ATSDR MRL. When EMEGs and CREGs are not available, RMEGs are used. An RMEG is the estimated intake of a media-specific contaminant below which no known non-cancerous health effects are likely to occur. An RMEG is derived from the EPA RfD. MCLs are currently enforced drinking water standards. An RfD is the maximum allowable daily dose or concentration of a contaminant that can be ingested without likelihood of causing health effects. Values derived for a pica child are based on an abnormal intake of soil by some infants which is approximately 5 g/day as compared to the average intake of 0.2 g/day.
On-site Groundwater
The Alabama Department of Environmental Management (ADEM) conducted a site-screening inspection (SSI) for the site. As a part of the investigation, groundwater sampling was conducted in two phases during 1989-1990. Figure 3 shows the location of the three on-site monitoring wells. The monitoring wells were drilled into the alluvial aquifer to depths of 55 feet to 100 feet. The well monitoring focused on areas adjacent to the three remaining settlement ponds. Lead was found in a well immediately adjacent to settlement pond number 3 and in the direction of the groundwater flow, but the concentration was below the MCL for drinking water. The on-site groundwater was again characterized by ENSR Consulting and Engineering in 1994 (5). The results of the groundwater sampling were similar to the previous investigations in that all contaminants were below levels of concern.
On-Site Surface Water
Surface water on-site consists of three settlement ponds. Monarch Tile, Inc. contracted with Ecology and Environment, Inc. (EE) to conduct a site-characterization of the site in 1987 (6). The site-characterization included the analysis of one composite water sample from settling pond number 3. This analysis showed that arsenic, barium, chromium, lead and nickel exceeded comparison values. Figure 3 shows the location of the settlement pond while Table 1 presents the contaminants of concern in the surface water. No sampling data exists for surface waters taken from pond 1 and 2 at Plant 2 or from the drainage ditches.
Soil
No on-site surface soil as defined by ATSDR (0-3 inches) were sampled in any of the site investigations (ADEM's SSI, EE's site-characterization, and ENSR Consulting Engineering). The most shallow soil was obtained by drilling borings to a depth of 10 feet. Therefore, the findings were not used to determine the risk associated with contaminated surface soil. We will assess the risks attributable from contaminated soil should appropriate soil sampling be conducted in the future.
Sediment
During ADEM's SSI, four composite sediment samples were collected in 1989 and five in 1990 (3,4). The sampling locations were at the drainage ditches at the southwest corner of Plant 2, the middle of the sludge trench at Plant 2, around scrap piles at the southwest corner of Plant 2 outside the fence, near the south end of the sludge trench, and the old discharge point from the abandoned sump at Plant 1. The sediment samples were taken at a depth of 0 to 4 inches. Figure 3 shows the locations of the on-site sampling. Table 2 shows the contaminants of concern that were found above the comparison levels. These samples were analyzed for various metals and only arsenic was shown to be present above comparison values. Lead was found in the samples and has been added to the list because no comparison value has been established for this metal.
At this time, verifiable off-site contamination appears to be limited to sediments within the ditches draining the plants to the north and south.
Sediment
In 1990, ADEM completed Phase II of the Screening Site Investigation (4). Off-site sediment samples were taken at two locations south and four locations north of the plants within the drainage ditches and analyzed for metals. Figure 4 shows the locations of the off-site sediment samples. The maximum concentrations of contaminants of concern in the sediment are presented in Table 3. The contaminants of concern in the southern drainage ditch are limited to arsenic, barium, chromium and lead. Barium and chromium are present at levels above comparison values. Lead is included in the list of contaminants of concern because it does not have a comparison value. The contaminants of concern in the northern drainage ditch are arsenic, barium, cadmium, chromium, lead, nickel, and zinc. Arsenic, barium, cadmium, chromium, nickel, and zinc are above the comparison values. Background samples do show levels of arsenic in the same range as those taken from the drainage areas flowing away from the site (7).
Between May 11, 1993, and June 10, 1993, ENSR excavated some of the contaminated soils in the northern drainage ditch (8). The areas where sediments were removed were resampled before backfilling with off-site material. No additional sampling has been conducted to establish the effectiveness of the remediation.
C. Quality Assurance and Quality Control
No Quality Assurance/Quality Control (QA/QC) validation summary was available for the sampling. The conclusions in the report are based on the assumption that the soil, sediment, and water samples are analytically valid. The conclusions of this study may be modified if data with proven validity through a Remedial Investigation/Feasibility Study show a significant variation from the present data.
No physical hazards were noted during the site visit.
An evaluation of Completed Exposure Pathways and Potential Exposure Pathways was made to determine exposure to contaminants of concern by on-site workers and people living near the site. Exposure pathways are made up of five elements: source of contamination, environmental media, point of exposure, route of human exposure and receptor population.
Exposure pathways are classified as completed or potential if the exposure cannot be eliminated. Completed pathways are those for which all five elements are present and human exposure to a contaminant of concern has occurred in the past or present, or is expected to occur in the future. When one or more of the elements are absent but could exist, then the pathway is characterized as a potential exposure pathway. When one or more elements are missing and never has been and never will be present, that pathway is eliminated from further consideration. Only the pathways that are significant to the Monarch site are discussed in detail.
A. Completed Exposure Pathways
At this time, no completed exposure pathways can be identified from the limited amount of environmental data available from the Monarch site. If additional information regarding environmental contamination becomes available, the data should be reevaluated to determine whether a completed exposure pathway exists.
B. Potential Exposure Pathways
Potential exposure pathways are those for which a pathway element is missing. Table 4 contains those pathways that are currently considered as potential pathways.
Soil
No surface soil as defined by ATSDR (0-3 inches) were reported in any of the site investigations (ADEM's SSE, EE's site characterization, and ENSR Consulting Engineer's reports). Therefore, it is impossible to assess the possibility of soil exposures either on-site or off-site. We will assess the risks attributable from contaminated soil should appropriate soil sampling be conducted in the future.
Sediment Pathway
Sediments in the southern and northern drainage ditches are a potential exposure pathway for Monarch Tile, Inc. workers on-site and for residents off-site. We have classified the sediment exposure pathway as potential rather than completed. During our inspection of the ditches and subsequent investigations, we have no evidence that actual exposure is occurring or has occurred. Contaminated sediments in the ditches and sludge trench are not in areas commonly trafficked by plant workers; therefore, worker exposure is expected to be minimal.
Samples from the drainage ditches showed contaminants above ATSDR's comparison values for pica children, but below levels for normal ingestion rates of children and adults. These drainage ditches do pass within 500 feet of residential areas where children may be playing; however, we do not know if or how often the children play in these areas. The ditches closest to the plant are overgrown and are not easily accessible to small children. It is unlikely that young children have access to these areas.
Ambient Air
No data are available on ambient air quality. It is possible that exposures may have occurred in the past. However, owing to a lack of data, it is impossible to assess the possibility of air exposures either on-site or off-site. According to ADEM, the glazed tiles are free from hazardous constituents and the kilns are fired by natural gas so that current exposures do not exist. We noted during the site visit that some areas of the site are sparsely vegetated and littered with broken tile. No surface soil samples were taken; therefore, we cannot rule out the possibility of exposure to fugitive dusts.
Public Water Supply Pathway
The public water supply for the area comes from three surface water intakes; one at the confluence of Cox Creek and Cypress Creek, the intake in the Pickwick reservoir, and an intake in the Wheeler Reservoir. We eliminated the public water supply as an exposure pathway because the surface water intakes are three or more miles from the site so that significant dilution would occur from other water sources before any contaminants reach the intake. Furthermore, these supplies are monitored for contaminants on a routine basis and would be removed from use if contaminated.
Biota Pathway
The only on-site surface water bodies are settlement ponds that would not support aquatic life. Cox Creek, approximately 1 1/2 miles to the north of the site, is not a significant fishery. Also, it is highly unlikely that sediments at the site would migrate in sufficient quantity to bioaccumulate in edible species and thus pose a health risk. The same is true for the southern drainage ditch where heavy metal concentrations in the sediments appear lower than the levels in the northern ditch. Therefore, the concentrations of sediments also are unlikely to pose any health threat. The Tennessee Valley Authority (TVA) has conducted fish tissue monitoring in the area (9). The TVA monitoring data do not indicate that the fish taken from Cypress Creek have significant levels of the heavy metals found at the site.
Groundwater Pathway
ADEM's SSI report (4) documents five wells in existence within a three mile radius of the site (3). A recent communication with Florence Water personnel indicates that all residents have access to the public water system and that private wells are not used as a potable water source.
The monitoring wells around the sediment ponds indicate very little if any leaching of the material
into the adjacent groundwater. Clay soils are characteristic of the area and extend at least 50 feet
below the surface, impeding the dispersion of contaminants through this medium.
Introduction
This section discusses the health effects due to exposure to specific contaminants and addresses specific community health concerns. However, completed exposure pathways have not been identified with the site. At this time, the only potential exposure pathway for which data exists is sediments. Rather than speculate on the possible effects on an assumed population, we will not assess the health effects of the metals. More reliable estimates of health effects can be made only when more data are generated. When this data becomes available, the site will be reevaluated to determine completed exposure pathways and toxicologic implications.
ATSDR evaluates health effects based on Minimal Risk Levels (MRL) for contaminants commonly found at hazardous waste sites. The MRL is an estimate of daily human exposure to a contaminant below which non-cancer adverse health effects are not expected to occur. ATSDR has developed MRLs for each route of exposure, such as ingestion or inhalation, and for length of exposure, such as acute (up to 14 days), intermediate (15 to 365 days) and chronic (greater than 365 days). The information on MRLs is given in ATSDR's Toxicological Profiles. These profiles are chemical-specific, providing information on health effects, environmental transport, human exposure, and regulatory status. The EPA develops reference doses (RfD), which are levels of exposure below which no adverse health effects are expected to occur. EPA's reference doses may be used when ATSDR minimal risk levels are not derived for a particular compound. Appendix B contains the compounds and the media where the levels of contaminants exceed ATSDR's comparison values, or for which no guidelines have been developed.
B. Health Outcome Data Evaluation
We reviewed cancer mortality data for Lauderdale County on the National Cancer Institute MAPS program. This program was originally designed to target areas for early cancer detection and prevention efforts for populations with the greatest need. Lauderdale County residents had overall and cause-specific cancer mortality rates similar to Alabama and U.S. residents. Additionally, the overall cancer death rate from 1988-1993 was calculated using cancer death data by zip code obtained from the Center for Health Statistics, ADPH. This overall cancer death rate was similar to comparable areas in Alabama. The cancer death rates by county or zip code, however, may still not truly evaluate the rate of cancer in smaller regions such as areas directly adjacent to the site.
Infant and perinatal related mortality in Lauderdale County is similar to the state averages. Since lead was a contaminant of concern, we examined the state database containing elevated blood lead levels. Two adults and six children were located in Florence having blood lead levels over the Centers for Disease Control and Prevention level of concern of 10 micrograms per deciliter.
The reported cases were either from occupational exposure or exposure to lead-based paint. These cases were not in the vicinity of the site and were unassociated with the site.
C. Community Health Concerns Evaluation
We have addressed each of the community concerns about health as follows:
The records obtained from the Center for Health Statistics, ADPH, do not indicate an unusually high cancer mortality rate for the area. The National Cancer Institute data also show the county and national cancer mortality rates to be similar. Presently, the environmental data available cannot establish that exposure to contaminants on- or off-site causes excess cancer in the community.
There is no evidence to substantiate the existence of airborne contaminants at the site. According to ADEM, the emission of the kiln would not allow a significant amount of particulate or other hazardous material to be released in the air. Considering the nature of the material currently used for the tile and colorants, respiratory problems are an unlikely result from contaminants at the site.
The ditches draining the site in the northerly and southerly directions contain small amounts of heavy metals in the sediments. The exposure to the metals is of concern only if children were actually playing in the ditches and consuming large quantities of the sediments. We do not know of a population of children with such exposures around the site. An examination of the ADPH's elevated blood lead database indicates that from 1991 through 1993, two adults and six children had elevated blood lead levels. These individuals did not live around the site and are suspected of acquiring the blood lead through lead based paint or occupational exposure.
Although cadmium and lead are associated with some neurological health effects, it is unlikely that people have been exposed to levels that may cause neurological problems.
There is no indication that any of the chemicals on-site increase the incidence or severity of arthritis.
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