HEALTH CONSULTATION
SURFACE SOIL CONTAMINATION
EASTERN MICHAUD FLATS CONTAMINATION
POCATELLO, BANNOCK COUNTY, IDAHO
Based upon the data and information reviewed, the Agency for Toxic Substances and DiseaseRegistry has drawn the following conclusions:
- It is unlikely that the general public, including children, has been, is currently, or will be exposed to significant levels of site-related surface soil contamination. Therefore, it is unlikely that any adverse human health effects have or will occur because of site-related surface soil contamination. The nearest residence to the FMC and Simplot facilities is over one mile away. Analytical results of surface soil samples indicate that there is not any site-related surface soil contamination at levels of health concern within the nearest residential areas. In addition, very few people trespass onto the facilities. The deed restriction on the land near and on the facilities should prevent any of the contaminated land from being used for residential areas.
- Workers at the FMC facility may be exposed (ingestion and inhalation) to cadmium contaminated surface soil. The highest concentrations of cadmium in surface soil was found at the FMC facility. These exposures may increase the potential for the workers to develop proteinuria (proteins found in the urine because of damage to the kidneys), particularly workers that smoke. Good occupational practices (e.g., the use of respirators, where appropriate, and frequent hand washing, particularly before eating) can significantly reduce the worker's potential to be exposed to cadmium.
- Slag and gypsum pile workers may be exposed to elevated levels of alpha, beta, and gamma radiation. These exposures may increase the risk of a worker to develop cancer. However these exposures can and are significantly reduced by good occupational practices (e.g., shielding provided by vehicles and dust control), thereby significantly reducing the workers' risk of developing cancer.
- Given the potential for worker exposures to site-related contaminants in surface soil andthe potential for adverse health effects to occur in exposed workers, ATSDR has classifiedthe Eastern Michaud Flats Contamination NPL site as a Public Health Hazard in regards to surface soil.
ATSDR makes the following recommendations:
- Appropriate remedial actions and worker protection activities should be instituted or continued to prevent worker exposures to site-related contaminants.
- Appropriate remedial actions should be taken to prevent the surface soil contaminants from migrating into the local groundwater and surface water.
- The land deed restrictions instituted and planned for the property presently owned byFMC and Simplot should remain in effect so that those lands will not be developed into residential or agricultural areas.
Sven E. Rodenbeck, Sc.D., P.E.
Environmental Engineer Consultant
Section A, Superfund Site Assessment Branch
Division of Health Assessment and Consultation
Agency for Toxic Substances and Disease Registry
- Agency for Toxic Substances and Disease Registry (ATSDR). Site Review and Up-Datefor Eastern Michaud Flats Contamination, Pocatello, Bannock County, Idaho. Atlanta,Georgia: U.S. Department of Health and Human Services, Public Health Service; March11, 1997.
- Bechtel Environmental, Inc. Remedial Investigation Report for the Eastern Michaud FlatsSite. San Francisco: Bechtel Environmental, Inc.; August 1996.
- ATSDR. Preliminary Public Health Assessment for Eastern Michaud Flats Contamination,Pocatello, Bannock County, Idaho. Atlanta, Georgia: U.S. Department of Health andHuman Services, Public Health Service; August 24, 1990.
- ATSDR. Toxicological Profile for Arsenic. Atlanta, Georgia: U.S. Department of Healthand Human Services, Public Health Service; April 1993.
- ATSDR. Toxicological Profile for Beryllium. Atlanta, Georgia: U.S. Department ofHealth and Human Services, Public Health Service; April 1993.
- ATSDR. Toxicological Profile for Lead. Atlanta, Georgia: U.S. Department of Healthand Human Services, Public Health Service; April 1993.
- Ecology and Environment, Inc. Baseline Human Health Risk Assessment, EasternMichaud Flats, Pocatello, Idaho. Lancaster, New York: Ecology and Environmental, Inc.;July 1995.
- ATSDR. Toxicological Profile for Fluorides, Hydrogen Fluoride, and Fluorine. Atlanta,Georgia: U.S. Department of Health and Human Services, Public Health Service; April 1993.
- ATSDR. Toxicological Profile for Cadmium. Atlanta, Georgia: U.S. Department ofHealth and Human Services, Public Health Service; April 1993.
- National Research Council. Health Risks of Radon and other Internally deposited Alpha-Emitters BEIR IV. Washington, D.C.: National Academy Press; 1988.
- National Research Council. Health Effects of Exposure to low levels of IonizingRadiation BEIR V. Washington, D.C.: National Academy Press; 1990.
| - | |||||
| Contaminant and Units | Maximum Concentration at FMC | Maximum Concentration at Simplot Gypsum | Background Levels According to EPA | ATSDR Comparison Value for Ingestion and Source* | |
|---|---|---|---|---|---|
| Ore | Slag | ||||
| Arsenic mg/kg | 14.6 | 0.6 | 0.9 | 7.5 | 0.5 CREG |
| Beryllium mg/kg | 1.9 | 2 | 2.8 | 1 | 0.2 CREG |
| Cadmium mg/kg | 77.8 | 103 | 37 | 1.9 | 500 Adult EMEG |
| Fluoride mg/kg | 13,200 | 7,800 | 7,650 | 600 | 35,000 Adult EMEG |
| Gross Alpha pCi/g | ~200 | 240 | ~200 | 25** | 15 |
| Gross Beta pCi/g | 400 | 1,100 | 46 | 31** | 50 |
| Gross Gamma µrem/h | 50 | 52 | 30 | 15** | None |
| * - A description of the various comparison values is presented in Appendix B. Unless indicated otherwise, the comparison values listed are for chronic exposures (greater than 365 days). ** - EPA did not select a background level for gross alpha, gross beta, and gross gamma. The background levels report for these three contaminants were developed by the consultant for the companies. EPA is the U.S. Environmental Protection Agency mg/kg is milligrams of contaminant per kilogram of soil. pCi/g picocurie per gram of soil. µrem/h is microrems per hour. | |||||
| Contaminantand Units | Maximum Concentration at FMC | Maximum Concentration at Simplot | Background Levels According to EPA | Comparison Value and Source* |
|---|---|---|---|---|
| Arsenic mg/kg | 27.1 | 55 | 7.5 | 0.5 CREG |
| Beryllium mg/kg | 2.9 | 5.2 | 1 | 0.2 CREG |
| Cadmium mg/kg | 5,110 | 131 | 1.9 | 500 AdultEMEG |
| Fluoride mg/kg | 221,000 | 123,000 | 600 | 35,000 AdultEMEG |
| Lead mg/kg | <500 | 2,370 | 29.1 | 400 EPA Screen |
| Gross Alpha pCi/g | 216 | 406 | 25** | 15 |
| Gross Beta pCi/g | 133 | 13.8 | 31** | 50 |
| Gross Gamma µrem/h | 45 | 25 | 15** | None |
| * - A description of the various comparison values is presented in Appendix B. Unless indicated otherwise, the comparison values listed are for chronic exposures (greater than 365 days). ** - EPA did not select a background level for gross alpha, gross beta, and gross gamma. The background levels report for these three contaminants were developed by the consultant for the companies. EPA is the U.S. Environmental Protection Agency mg/kg is milligrams of contaminant per kilogram of soil. pCi/g picocurie per gram of soil. µrem/h is microrems per hour. | ||||
| Contaminantand Units | MaximumConcentrationDetected | Maximum Mean Concentration Detected within a Sector | Background Levels According to EPA | ComparisonValue andSource* |
|---|---|---|---|---|
| Arsenic mg/kg | 18.4 | 8.28 | 7.7 | 0.5 CREG |
| Cadmium mg/kg | 189 | 62.2 | 1.9 | 500 Adult EMEG |
| Fluoride mg/kg | 27,200 | 7,532 | 600 | 35,000 Adult EMEG |
| * - A description of the various comparison values is presented in Appendix B. Unless indicated otherwise, the comparison values listed are for chronic exposures (greater than 365 days). EPA is the U.S. Environmental Protection Agency mg/kg is milligrams of contaminant per kilogram of soil. pCi/g picocurie per gram of soil. mrem/h is millirems per hour. | ||||
