PETITIONED PUBLIC HEALTH ASSESSMENT
GREAT LAKES CHEMICAL CORPORATION
EL DORADO, UNION COUNTY, ARKANSAS
Figure 1. Site Map and Demographics
Exposure Pathway Table
| Pathway Name | Source | Medium | Route of Exposure | Exposure Elements | Exposure Activities | Chemicals of Concern | ||
|---|---|---|---|---|---|---|---|---|
| Point of Exposure | Receptor Population | Time | ||||||
| Private Well | Unknown | Groundwater | Ingestion, Inhalation, & Dermal Contact | Residential Water Taps Off-site | Users of private well | past | Drinking, Bathing, & Household Cleaning | PAHs (See Appendix C, Table 2) |
| Pathway Name | Source | Medium | Route of Exposure | Exposure Elements | Exposure Activities | Chemicals of Concern | ||
|---|---|---|---|---|---|---|---|---|
| Point of Exposure | Receptor Population | Time | ||||||
| Ambient Air | GLCC | Ambient Air | Inhalation | Off-site Residential Areas On-site | Residents and GLCC Workers | p,c,f | Outdoor Activities Working | Methyl Bromide |
| Surface Water | GLCC | Surface Water | Incidental Ingestion and Dermal Contact | Bayou de Loutre Little Cornie Bayou Off-site and On-site | Recreation Enthusiasts and GLCC Workers | p,c,f | Recreation Working | See Appendix C, Table 3 |
| Sediment | GLCC | Sediment | Dermal Contact | Creeks and Drainage Ditches Off-site and On-site | Residents and GLCC Workers | p,c,f | Outdoor Activities Working | Bromides and Chlorides |
| Key: GLCC = Great Lakes Chemical Corporation c = current; f = future; p = past | ||||||||
Environmental Sampling Data
| Chemical or Indicator | Number of Observations | Maximum Value |
|---|---|---|
| Barium | 281 | 36 ppm |
| Benzene | 5,606 | 55 ppm |
| Benzoic acid | 47 | ND |
| Bromides | 5,838 | 170,000 ppm |
| Bromoform | 5,559 | 36 ppm |
| Calcium | 281 | 37,000 ppm |
| Chlorides | 6,100 | 360,000 ppm |
| Dichloropropane | 21 | 1.89 ppm |
| Ethylene dibromide | 6,102 | 4,500 ppm |
| Ethylene dichloride | 6,086 | 700 ppm |
| Hexachloroethane | 47 | ND |
| Iron | 45 | 32 ppm |
| Manganese | 45 | 1.1 ppm |
| Methyl bromide | 47 | ND |
| Methylene chloride | 47 | 0.037 ppm |
| Phenol(s) | 92 | ND |
| Sodium | 326 | 65,000 ppm |
| Sulfates | 5,872 | 3,723 ppm |
| Toluene | 5,606 | 47 ppm |
| Tribromophenol | 6,102 | 5,300 ppm |
| Trichlorobenzene | 29 | ND |
Notes: As described in the text of this attachment, the data in this table should be viewed as an extensive accountof the groundwater sampling at the GLCC Main Plant, but not as a comprehensive account. A maximumconcentration of ND means the chemical was never detected.
| Chemical | Maximum Concentration (ppb ) | RBC-c (ppb) |
|---|---|---|
| Benzo[a]pyrene | 66 | 0.0092 |
| Benz[a]anthracene | 112 | 0.092 |
| Benzo[b]fluoranthene | 140 | 0.092 |
| Benzo[k]fluoranthene | 47 | 0.92 |
| Chrysene | 94 | 9.2 |
ppb parts per billion
RBC-c Risk-Based Concentration (carcinogenic effects)
| Chemical | Range of Detection Limits (ppm) | Comparison Value (ppm) | Reference (refer to cover letter for codes) | Number of Samples Analyzed for the Chemical | Number of Samples in Which Chemical Was Detected | Number of Samples in Which Concentration Exceeded the CV |
|---|---|---|---|---|---|---|
| 1,1,1-trichloroethane | 0.003--0.01 | 0.2 | MCL | 74 | 0 | 0 |
| 1,1,2,2-tetrachloroethane a | 0.005--0.01 | 0.0002 | CREG | 74 | 0 | 0 |
| 1,1,2-trichloroethane a | 0.005--0.01 | 0.0006 | CREG | 74 | 0 | 0 |
| 1,1-dichloroethane | 0.004--0.01 | NA | NA | 74 | 0 | 0 |
| 1,1-dichloroethylene a | 0.002--0.01 | 0.00006 | CREG | 74 | 0 | 0 |
| ethylene dibromide a | 0.005--0.01 | 0.0000004 | CREG | 16 | 7 | 7 |
| 1,2-dichlorobenzene | 0.005--0.01 | 0.6 | MCL | 60 | 0 | 0 |
| ethylene dichloride a | 0.002--0.01 | 0.0004 | CREG | 74 | 1 | 1 |
| 1,2-dichloropropane | 0.005--0.01 | 0.005 | MCL | 74 | 0 | 0 |
| 1,2-trans-dichloroethylene | 0.001--0.01 | 0.1 | MCL | 74 | 0 | 0 |
| 1,3-cis-dichloropropylene | 0.005--0.01 | 0.07 | MCL | 74 | 0 | 0 |
| 1,3-dichlorobenzene | 0.005--0.01 | 0.6 | LTHA | 60 | 0 | 0 |
| 1,3-trans-dichloropropylene a | 0.005--0.01 | 0.003 | RMEG (Child) | 74 | 0 | 0 |
| 1,4-dichlorobenzene | 0.005--0.01 | 0.075 | MCL | 60 | 0 | 0 |
| 2-chloroethylvinyl ether | 0.005--0.01 | NA | NA | 74 | 0 | 0 |
| acrolein a | 0.01--0.1 | 0.005 | c-EMEG (Child) | 27 | 0 | 0 |
| acrylonitrile a | 0.01--0.1 | 0.00006 | CREG | 27 | 0 | 0 |
| benzene a | 0.004--0.01 | 0.001 | CREG | 74 | 0 | 0 |
| benzyl chloride a | 0.005--0.1 | 0.0002 | CREG | 66 | 0 | 0 |
| bromoform | 0.004--0.01 | 0.004 | CREG | 74 | 3 | 3 |
| carbon tetrachloride a | 0.002--0.01 | 0.0003 | CREG | 74 | 0 | 0 |
| chlorobenzene | 0.005--0.006 | 100 | MCL | 37 | 0 | 0 |
| chlorodibromomethane a | 0.003--0.01 | 0.0004 | CREG | 74 | 0 | 0 |
| chloroethane | 0.01--0.02 | NA | NA | 74 | 0 | 0 |
| chloroform | 0.001--0.01 | 0.006 | CREG | 74 | 1 | 1 |
| dichlorobromomethane a | 0.002--0.01 | 0.0006 | CREG | 74 | 0 | 0 |
| dichlorodifluoromethane | 0.005--0.01 | 1.0 | LTHA | 18 | 0 | 0 |
| dichlorofluoromethane | 0.01--0.01 | NA | NA | 11 | 0 | 0 |
| epichlorohydrin | 0.005--0.1 | 0.07 | DWEL | 29 | 0 | 0 |
| ethylbenzene | 0.005--0.01 | 0.7 | MCL | 74 | 0 | 0 |
| methyl bromide | 0.01--0.02 | 0.01 | LTHA | 74 | 4 | 4 |
| methyl chloride a | 0.01--0.02 | 0.003 | LTHA | 74 | 2 | 2 |
| methylene chloride | 0.002--0.01 | 0.005 | CREG/MCL | 74 | 3 | 1 |
| tetrachloroethylene a | 0.004--0.01 | 0.0007 | CREG | 74 | 0 | 0 |
| toluene | 0.004--0.01 | 0.2 | i-EMEG (child) | 74 | 2 | 0 |
| trichloroethylene | 0.001--0.01 | 0.003 | CREG | 74 | 0 | 0 |
| trichlorofluoromethane | 0.005--0.01 | 2.0 | LTHA | 75 | 1 | 0 |
| vinyl chloride a | 0.005--0.02 | 0.0002 | c-EMEG (child) | 74 | 0 | 0 |
a Range of detection limits exceeds comparison value
| Maximum Depth of Soil Samples | Total Number of Samples | Distribution of Measured Concentrations | Maximum Concentration (ppm) | |||
|---|---|---|---|---|---|---|
| Non-Detects | 1 ppm | >1 ppm; 10 ppm | >10 ppm | |||
| Depth not indicated | 74 | 36 | 29 | 2 | 7 | 350 |
| Less than 3 feet | 57 | 28 | 22 | 2 | 5 | 5,800 |
| Greater than 3 feet but less than 10 feet | 178 | 67 | 55 | 17 | 39 | 8,100 |
| Greater than 10 feet | 325 | 116 | 111 | 42 | 56 | 6,800 |
| Overall | 634 | 247 | 217 | 63 | 107 | 8,100 |
Notes: (1) Shaded cells indicate samples where concentrations exceeded the CREG for ethylene dibromide (or 0.008 ppm).
(2) GLCC monitoring reports generally included a range of soil depths over which each sample was collected. The "maximum depth" in this table refersto the upper end of the depth range for a given soil sample. For example, ERG classified soils sampled over a depth range of 2 to 8 feet in the category of"maximum depth greater than 3 feet but less than 10 feet."
| Depth of soil sampling | Number of Samples | Distribution of Measured Concentrations | Maximum Concentration (ppm) | |||
|---|---|---|---|---|---|---|
| Non-Detects | 1 ppm | >1 ppm; 8 ppm | >8 ppm | |||
| Depth not indicated | 31 | 21 | 8 | 1 | 1 | 29 |
| Less than 3 feet | 24 | 19 | 5 | 0 | 0 | 0.5 |
| Greater than 3 feet but less than 10 feet | 70 | 43 | 18 | 7 | 2 | 43 |
| Greater than 10 feet | 132 | 56 | 30 | 25 | 21 | 140 |
| Overall | 257 | 139 | 61 | 33 | 24 | 140 |
Notes: (1) Shaded cells indicate samples where concentrations exceeded the CREG for ethylene dichloride (8 ppm).
(2) GLCC monitoring reports generally included a range of soil depths over which each sample was collected. The "maximum depth" in this table refersto the upper end of the depth range for a given soil sample. For example, ERG classified soils sampled over a depth range of 2 to 8 feet in the category of"maximum depth greater than 3 feet but less than 10 feet."
Evaluation of Environmental Contamination and Potential Exposure Pathways Methodology
Quality Assurance
In preparing this report, ATSDR relied on the information provided in the referenced documents andby contacts with the United States Environmental Protection Agency, Arkansas Department ofEnvironmental Quality, Arkansas Department of Health, Union County Department of Health, andcommunity members. ATSDR assumes that adequate quality assurance and control measures weretaken during chain-of-custody, laboratory procedures, and data reporting. The validity of theanalyses and conclusions drawn in this document are determined by the availability and reliability ofthe information.
Human Exposure Pathway Evaluation and the use of ATSDR Comparison Values
ATSDR assesses a site by evaluating the level of exposure in potential or completed exposurepathways. An exposure pathway is the way chemicals may enter a person's body to cause a healtheffect. It includes all the steps between the release of a chemical and the population exposed: (1) achemical release source, (2) chemical movement, (3) a place where people can come into contactwith the chemical, (4) a route of human exposure, and (5) a population that could be exposed. In thisassessment, ATSDR evaluates chemicals in environmental media that people living in nearbyresidences may come into contact with.
Data evaluators use comparison values (CVs), which are screening tools used to evaluateenvironmental data that is relevant to the exposure pathways. Comparison values are concentrationsof contaminants that are considered to be safe levels of exposure. Comparison values used in thisdocument include ATSDR's environmental media evaluation guide (EMEG) and cancer riskevaluation guide (CREG). Comparison values are derived from available health guidelines, such asATSDR's minimal risk levels and EPA's cancer slope factor.
The derivation of a comparison value uses conservative exposure assumptions, resulting in valuesthat are much lower than exposure concentrations observed to cause adverse health effects; thus,insuring the comparison values are protective of public health in essentially all exposure situations.That is, if the concentrations in the exposure medium are less than the CV, the exposures are not ofhealth concern and no further analysis of the pathway is required. However, while concentrationsbelow the comparison value are not expected to lead to any observable health effect, it should not beinferred that a concentration greater than the comparison value will necessarily lead to adverseeffects. Depending on site-specific environmental exposure factors (for example, duration ofexposure) and activities of people that result in exposure (time spent in area of contamination),exposure to levels above the comparison value may or may not lead to a health effect. Therefore,ATSDR's comparison values are not used to predict the occurrence of adverse health effects.
The comparison values used in this evaluation are defined as follows: The CREG is a concentrationat which excess cancer risk is not likely to exceed one case of cancer in a million persons exposedover a lifetime. The CREG is a very conservative CV that is used to estimate cancer risk. Exposureto a concentration equal to or less than the CREG is defined as an insignificant risk and is anacceptable level of exposure over a lifetime. The risk from exposure is not considered as asignificant risk unless the exposure concentration is approximately 10 times the CREG and exposureoccurs over several years. The EMEG is a concentration at which daily exposure for a lifetime isunlikely to result in adverse noncancerous effects.
Selecting Contaminants of Concern
Contaminants of concern (COCs) are the site-specific chemical substances that the health assessorselects for further evaluation of potential health effects. Identifying contaminants of concern is aprocess that requires the assessor to examine contaminant concentrations at the site, the quality ofenvironmental sampling data, and the potential for human exposure. A thorough review of each ofthese issues is required to accurately select COCs in the site-specific human exposure pathway. Thefollowing text describes the selection process.
In the first step of the COC selection process, the maximum contaminant concentrations arecompared directly to health comparison values. ATSDR considers site-specific exposure factors toensure selection of appropriate health comparison values. If the maximum concentration reported fora chemical was less than the health comparison value, ATSDR concluded that exposure to thatchemical was not of public health concern; therefore, no further data review was required for thatchemical. However, if the maximum concentration was greater than the health comparison value,the chemical was selected for additional data review. In addition, any chemicals detected that did nothave relevant health comparison values were also selected for additional data review.
Comparison values have not been developed for some contaminants, and, based on new scientificinformation other comparison values may be determined to be inappropriate for the specific type ofexposure. In those cases, the contaminants are included as contaminants of concern if currentscientific information indicates exposure to those contaminants may be of public health concern.
The next step of the process requires a more in-depth review of data for each of the contaminantsselected. Factors used in the selection of the COCs included the number of samples with detectionsabove the minimum detection limit, the number of samples with detections above an acute orchronic health comparison value, and the potential for exposure at the monitoring location.
Public Comments and ATSDR's Response
This appendix contains the comments received during the public comment period for GLCCand ATSDR's response to those comments. The comments have been numbered and are initalic with the response directly below each comment.
- A citizen wrote to ATSDR that they disagreed with the findings and are no longerinterested in this public health assessment.
These comments have been noted and included in ATSDR's official site file.
- The official plant name and location are incorrect. The correct title is "Great Lakes Chemical Corporation El Dorado Plant".
This change has been implemented in ATSDR's database and in the public health assessment.
- On page 5, insert the following sentence: The Arkansas Department of EnvironmentalQuality (ADEQ) monitored the GLCC property line and Parkers Chapel (a nearbyresidential community) weekly for methyl bromide from June 2, 1995 to May 27, 1996.Most analytical results were below the EPA risk-based concentration for ambient air".
The ambient air sampling event referred to in this comment has been evaluated and included in the public health assessment.
- Page 6; page 7;- 16,000 ppm looks high by 10x.
ATSDR re-evaluated the sampling summary and 16,000 ppm is correct.
