PRELIMINARY PUBLIC HEALTH ASSESSMENT
MONARCH TILE, INC., FLORENCE DIVISION
LAUDERDALE COUNTY, ALABAMA
This section is a review of the environmental data collected at the site and an assessment of thequality of the data. This section also deals with on-site contaminants of concern and thefrequency and concentration of these contaminants in various media. On-site contamination willbe reviewed first, followed by off-site contamination. On-site, Monarch Tile, Inc. currentlyoperates two plants on 26.8 acres used for the production of ceramic tile. Off-site is thesurrounding community consisting of other businesses and residential districts.
These contaminants are evaluated in the subsequent sections of this health assessment todetermine whether exposure to them has public health significance. We selected and discussedthese contaminants based upon the following factors:
- Concentrations of contaminants on and off the site.
- Field data quality, laboratory data quality, and sample design.
- Comparison of on-site and off-site concentrations with health assessment comparison values for noncarcinogenic endpoints and carcinogenic endpoints.
- Community concerns when available.
Listing a chemical as a contaminant of concern does not mean that adverse health effects willresult from exposure. Instead, listing a chemical indicates that it will be evaluated further in thispreliminary public health assessment.
The only off-site sampling conducted was of sediment samples taken from the ditches leadingaway from the site. The following contaminants of concern with values equal to or above theATSDR comparison values, or for which no comparison values exist, were detected:
These contaminants will be discussed in the section dealing with sediment. Contamination inother 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 inthe area surrounding the site showed point source releases of zinc compounds from one otherindustry in Florence. Although the industry released zinc compounds, the facility is located 1 1/2miles southeast of the site near the Tennessee River, and cannot be associated with anycontamination found in this preliminary public health assessment.
The tables presented in Appendix B list the contaminants of concern in various on-site and off-sitemedia. The contaminants of concern are evaluated in later sections to decide if exposure haspubic health significance. The data tables include the following abbreviations:
|CREG||= Cancer Risk Evaluation Guides|
|EMEG||= Environmental Media Evaluation Guides|
|RMEG||= Reference Dose Media Evaluation Guides|
|MCL||= Maximum Contaminant Level|
|RfD||= Reference Dose|
|ppb||= parts per billion|
|ppm||= 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.
The Alabama Department of Environmental Management (ADEM) conducted a site-screeninginspection (SSI) for the site. As a part of the investigation, groundwater sampling was conductedin two phases during 1989-1990. Figure 3 shows the location of the three on-site monitoringwells. 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 wasfound in a well immediately adjacent to settlement pond number 3 and in the direction of thegroundwater flow, but the concentration was below the MCL for drinking water. The on-sitegroundwater was again characterized by ENSR Consulting and Engineering in 1994 (5). Theresults of the groundwater sampling were similar to the previous investigations in that allcontaminants were below levels of concern.
On-Site Surface Water
Surface water on-site consists of three settlement ponds. Monarch Tile, Inc. contracted withEcology 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 pondnumber 3. This analysis showed that arsenic, barium, chromium, lead and nickel exceededcomparison values. Figure 3 shows the location of the settlement pond while Table 1 presents thecontaminants of concern in the surface water. No sampling data exists for surface waters takenfrom pond 1 and 2 at Plant 2 or from the drainage ditches.
No on-site surface soil as defined by ATSDR (0-3 inches) were sampled in any of the siteinvestigations (ADEM's SSI, EE's site-characterization, and ENSR Consulting Engineering). Themost shallow soil was obtained by drilling borings to a depth of 10 feet. Therefore, the findingswere not used to determine the risk associated with contaminated surface soil. We will assess therisks attributable from contaminated soil should appropriate soil sampling be conducted in the future.
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, themiddle of the sludge trench at Plant 2, around scrap piles at the southwest corner of Plant 2outside the fence, near the south end of the sludge trench, and the old discharge point from theabandoned sump at Plant 1. The sediment samples were taken at a depth of 0 to 4 inches. Figure3 shows the locations of the on-site sampling. Table 2 shows the contaminants of concern thatwere found above the comparison levels. These samples were analyzed for various metals andonly arsenic was shown to be present above comparison values. Lead was found in the samplesand 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 ditchesdraining the plants to the north and south.
In 1990, ADEM completed Phase II of the Screening Site Investigation (4). Off-site sedimentsamples were taken at two locations south and four locations north of the plants within thedrainage ditches and analyzed for metals. Figure 4 shows the locations of the off-site sedimentsamples. The maximum concentrations of contaminants of concern in the sediment are presentedin 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 comparisonvalues. Lead is included in the list of contaminants of concern because it does not have acomparison 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 thesame 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 inthe northern drainage ditch (8). The areas where sediments were removed were resampled beforebackfilling with off-site material. No additional sampling has been conducted to establish theeffectiveness of the remediation.
No Quality Assurance/Quality Control (QA/QC) validation summary was available for thesampling. The conclusions in the report are based on the assumption that the soil, sediment, andwater samples are analytically valid. The conclusions of this study may be modified if data withproven validity through a Remedial Investigation/Feasibility Study show a significant variationfrom the present data.
No physical hazards were noted during the site visit.
An evaluation of Completed Exposure Pathways and Potential Exposure Pathways was made todetermine 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 acontaminant 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 asa potential exposure pathway. When one or more elements are missing and never has been andnever will be present, that pathway is eliminated from further consideration. Only the pathwaysthat are significant to the Monarch site are discussed in detail.
At this time, no completed exposure pathways can be identified from the limited amount ofenvironmental data available from the Monarch site. If additional information regardingenvironmental contamination becomes available, the data should be reevaluated to determinewhether a completed exposure pathway exists.
Potential exposure pathways are those for which a pathway element is missing. Table 4 containsthose pathways that are currently considered as potential pathways.
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 assessthe risks attributable from contaminated soil should appropriate soil sampling be conducted in the future.
Sediments in the southern and northern drainage ditches are a potential exposure pathway forMonarch Tile, Inc. workers on-site and for residents off-site. We have classified the sedimentexposure pathway as potential rather than completed. During our inspection of the ditches andsubsequent 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 byplant workers; therefore, worker exposure is expected to be minimal.
Samples from the drainage ditches showed contaminants above ATSDR's comparison values forpica children, but below levels for normal ingestion rates of children and adults. These drainageditches do pass within 500 feet of residential areas where children may be playing; however, wedo not know if or how often the children play in these areas. The ditches closest to the plant areovergrown and are not easily accessible to small children. It is unlikely that young children haveaccess to these areas.
No data are available on ambient air quality. It is possible that exposures may have occurred inthe past. However, owing to a lack of data, it is impossible to assess the possibility of airexposures either on-site or off-site. According to ADEM, the glazed tiles are free from hazardousconstituents and the kilns are fired by natural gas so that current exposures do not exist. Wenoted during the site visit that some areas of the site are sparsely vegetated and littered withbroken tile. No surface soil samples were taken; therefore, we cannot rule out the possibility ofexposure to fugitive dusts.
Public Water Supply Pathway
The public water supply for the area comes from three surface water intakes; one at theconfluence of Cox Creek and Cypress Creek, the intake in the Pickwick reservoir, and an intake inthe Wheeler Reservoir. We eliminated the public water supply as an exposure pathway becausethe surface water intakes are three or more miles from the site so that significant dilution wouldoccur from other water sources before any contaminants reach the intake. Furthermore, thesesupplies are monitored for contaminants on a routine basis and would be removed from use ifcontaminated.
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, itis highly unlikely that sediments at the site would migrate in sufficient quantity to bioaccumulatein edible species and thus pose a health risk. The same is true for the southern drainage ditchwhere heavy metal concentrations in the sediments appear lower than the levels in the northernditch. Therefore, the concentrations of sediments also are unlikely to pose any health threat. TheTennessee Valley Authority (TVA) has conducted fish tissue monitoring in the area (9). TheTVA monitoring data do not indicate that the fish taken from Cypress Creek have significantlevels of the heavy metals found at the site.
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 tothe 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 materialinto the adjacent groundwater. Clay soils are characteristic of the area and extend at least 50 feetbelow the surface, impeding the dispersion of contaminants through this medium.
This section discusses the health effects due to exposure to specific contaminants and addressesspecific community health concerns. However, completed exposure pathways have not beenidentified with the site. At this time, the only potential exposure pathway for which data exists issediments. Rather than speculate on the possible effects on an assumed population, we will notassess the health effects of the metals. More reliable estimates of health effects can be made onlywhen more data are generated. When this data becomes available, the site will be reevaluated todetermine completed exposure pathways and toxicologic implications.
ATSDR evaluates health effects based on Minimal Risk Levels (MRL) for contaminantscommonly found at hazardous waste sites. The MRL is an estimate of daily human exposure to acontaminant below which non-cancer adverse health effects are not expected to occur. ATSDRhas developed MRLs for each route of exposure, such as ingestion or inhalation, and for length ofexposure, such as acute (up to 14 days), intermediate (15 to 365 days) and chronic (greater than365 days). The information on MRLs is given in ATSDR's Toxicological Profiles. These profilesare chemical-specific, providing information on health effects, environmental transport, humanexposure, and regulatory status. The EPA develops reference doses (RfD), which are levels ofexposure below which no adverse health effects are expected to occur. EPA's reference dosesmay 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 exceedATSDR's comparison values, or for which no guidelines have been developed.
We reviewed cancer mortality data for Lauderdale County on the National Cancer InstituteMAPS program. This program was originally designed to target areas for early cancer detectionand prevention efforts for populations with the greatest need. Lauderdale County residents hadoverall 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 databy zip code obtained from the Center for Health Statistics, ADPH. This overall cancer death ratewas 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 directlyadjacent to the site.
Infant and perinatal related mortality in Lauderdale County is similar to the state averages. Sincelead was a contaminant of concern, we examined the state database containing elevated bloodlead levels. Two adults and six children were located in Florence having blood lead levels overthe 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.
We have addressed each of the community concerns about health as follows:
- Are there any exposures to environmental contaminants that are responsible for thehigh cancer rate in the area?
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 Institutedata also show the county and national cancer mortality rates to be similar. Presently, the environmental data available cannot establish that exposure tocontaminants on- or off-site causes excess cancer in the community.
- Are respiratory problems (allergies and asthma) caused by the substances present at the site?
There is no evidence to substantiate the existence of airborne contaminants at thesite. According to ADEM, the emission of the kiln would not allow a significantamount 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.
- Is there any danger to children from contamination (e.g., lead) at the site?
The ditches draining the site in the northerly and southerly directions contain smallamounts of heavy metals in the sediments. The exposure to the metals is ofconcern only if children were actually playing in the ditches and consuming largequantities of the sediments. We do not know of a population of children with suchexposures around the site. An examination of the ADPH's elevated blood leaddatabase indicates that from 1991 through 1993, two adults and six children hadelevated blood lead levels. These individuals did not live around the site and aresuspected of acquiring the blood lead through lead based paint or occupationalexposure.
- Can neurologic problems, such as dizziness, headaches, forgetfulness, depression,seizures, or swelling of the eyes be caused by the substances at the site?
Although cadmium and lead are associated with some neurological health effects,it is unlikely that people have been exposed to levels that may cause neurologicalproblems.
- Can any of the contaminants trigger arthritis?
There is no indication that any of the chemicals on-site increase the incidence orseverity of arthritis.