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1. ATSDR > Public Health Assessments & Consultations

HEALTH CONSULTATION

EASTERN MICHAUD FLATS CONTAMINATION
POCATELLO, BANNOCK AND POWER COUNTIES, IDAHO

V. CONCLUSIONS

Based on a review of available data and discussions with local, state, tribal, and federal environmental and health officials, ATSDR concludes the following:

• Transport of Emissions from FMC and Simplot. FMC and Simplot have released, and continue to release, large quantities of toxic chemicals to the air. According to monitoring and modeling studies, these chemicals have transported, and continue to transport, to virtually every location in the EMF study area, including locations in Chubbuck, Pocatello, and portions of the Fort Hall Indian Reservation. Ambient air concentrations of these toxic chemicals clearly vary from location to location within this region; the public health implications of the levels of contamination are reviewed below.



• Air Quality in Chubbuck and Pocatello from 1975 to the present. Levels of air pollution throughout Chubbuck and Pocatello have been and continue to be a public health hazard as a result of emissions from FMC, Simplot, and other sources. The unhealthy levels of air pollution in these cities occurs infrequently and is usually associated with a small number of days with particular meteorological conditions (inversions). ATSDR believes potentially unhealthy levels of air pollution in these cities will likely occur periodically in the future, unless emissions of particulate matter from FMC and Simplot and other sources are reduced. The components of air pollution causing the health hazard are PM (short-term and long-term) and sulfates (short-term only); insufficient monitoring data are available to comment on long-term exposures to sulfates. These components periodically reached levels that are associated with increased incidence of respiratory and cardiac conditions. Populations at greatest risk for suffering adverse health effects include individuals with pre-existing heart or lung disease, the elderly, children, and asthmatics.

Some population living near the phosphate plants may have also been exposed between 1977-1985 to levels of sulfur dioxide above levels of health concern. This population's exposures to PM, as well as sulfur dioxide, likely increased their risk for adverse respiratory health effects.

Between 1994 and 1998, long-term average ambient air concentrations of PM10 throughout Chubbuck and Pocatello were notably lower than in previous years, thus reducing health risks associated with chronic exposures. However, the recent severe inversions in the Portneuf Valley clearly show that potentially unhealthy acute exposures to PM can still occur and probably will occur in the future unless air emissions from FMC and Simplot and other major sources are reduced.

• Air Quality on the Fort Hall Indian Reservation. The highest concentrations of site-related contaminants in the entire EMF study area are consistently measured on the Fort Hall Indian Reservation, at a location between FMC and Interstate 86. These elevated levels of air pollution pose a public health hazard to individuals who are exposed to the air in this part of the reservation. Deed restrictions will prevent people from living in this area of concern, but access to this area is not restricted and potentially unhealthy exposures may still be occurring.



• Residents of the Fort Hall Indian Reservation who live immediately north of Interstate 86 might also have been exposed to potentially unhealthy levels of air pollution from 1975 to the present, but this cannot be confirmed since no ambient air monitoring has ever been conducted in this area. Thus, ATSDR cannot derive reliable estimates of past or present exposure for residents on most of the Fort Hall Indian Reservation, though some level of exposure to emissions from FMC and Simplot undoubtedly exists. Due to the data gaps, ATSDR considers current and past inhalation exposures among residents who live on the Fort Hall Indian Reservation at locations north of Interstate 86 to be an indeterminate public health hazard.

Air monitoring devices need to be installed on the Fort Hall Indian Reservation at locations north of Interstate 86 to characterize potential exposures and fill this important data gap.

• Review of Community Concerns. The health concerns expressed by community members in the EMF study area (i.e., increased incidence of asthma, upper respiratory illness, and heart disease) are reasonably consistent with adverse health outcomes reported in the epidemiological research for both acute and chronic exposures to elevated levels of PM2.5 and PM10. However, this consistency does not suggest that any given incident of these health outcomes is caused solely by inhalation exposures to PM2.5 or PM10. Rather, causality of any given disease is usually a result of multiple factors, such as smoking or exposure to indoor air contaminants.



• Exposures to Acid Aerosols. The phosphate plants release several acids (e.g., sulfuric acid, phosphoric acid, and hydrofluoric acid) and chemicals that react in the air to form acids (e.g., phosphorous pentoxide, a signature constituent of the FMC emissions). Though these acids are respiratory irritants, the available data suggest that exposures to these individual acids in the EMF study area are not at levels of health concern. However, since the available data are limited, routine sampling of ionic species is needed to confirm this conclusion.



• Exposures to Metals and Other Inorganics. Neither short-term nor long-term exposures to the elemental forms of the metals and other inorganics detected in PM in the EMF study area are likely to result in adverse health effects. For non-carcinogenic adverse health effects, the concentrations of individual metals were well below levels in the scientific literature that showed adverse health effects in humans and animals. For adverse carcinogenic health effects, the concentration of metals is not likely to result in an appreciable increased risk of cancer in the exposed population. However, this conclusion is limited by the fact that data on annual average concentrations for metals are not available for time periods before 1994, when levels of PM, and hence heavy metals, were notably higher. For some metals, the paucity of toxicological data and the lack of data on the exact chemical species found in the ambient air prevents a complete assessment of the public health implications of exposure.



• Uncertainty in Acid and Metals Analyses. Although ATSDR's evaluation did not indicate a public health concern for individual metals and acids, there is some uncertainty with this analysis. Current science provides little evidence as to whether the mix of these air contaminants may increase or decrease their toxicological effects because of cumulative exposures. Some of the metals (e.g., cadmium) were detected at levels in the fine fraction that were similar or greater than levels found in highly urbanized areas of the United States. In addition, many of the metals detected in the EMF study area are transition metals. There is growing biological evidence that indicates that urban combustion particles (i.e., fine PM) can penetrate past the primary defense mechanisms of the lung, can elicit inflammatory changes in the lung and systematically (throughout the body), contain a constituent (soluble transition metals) that by itself can be demonstrated to produce lung damage, can produce electrocardiogram changes including arrhythmia (heart irregularities), and can kill animals with pre-existing heart and lung disease. The extent to which ATSDR's evaluation of exposures to metals in the EMF study area is able to capture these concerns is not known. However, the epidemiological evidence does indicate that PM, a measure of a mix of contaminants present in air, including most of the metals and acids detected in the EMF study area, is a good surrogate measure for estimating the short-term and long-term adverse cardiopulmonary health effects from exposure. From this standpoint, ATSDR evaluated and made definitive public health statements regarding the cumulative health effects of the exposure to the mix of metal and acid contaminants present in the EMF study area as measured by PM.



• Potential Exposures to phosphine and hydrogen cyanide. Though the monitoring data collected in the last 2 years suggest that off-site exposures hydrogen cyanide from FMC are not at levels of health concern for the non-worker population, no information is available to quantify exposures that might have occurred in earlier years. Moreover, phosphine may have reached levels of health concern at the FMC fenceline; however, these levels of health concerns were obtained using unreliable methods. ATSDR recommends that more monitoring be performed to confirm these data. Thus, the complete public health implications of off-site exposures to phosphine and hydrogen cyanide cannot be determined based on available data. ATSDR notes, however, that ongoing operation of FMC's Pond Management Plan should ensure that emissions do not reach levels of health concern in the future.



• Potential Future Exposures. Continued measures to reduce all major emissions sources of PM are needed to ensure that the decreasing airborne levels of PM in the EMF study area continue, and continued monitoring is needed to verify this trend. In general, future trends in inhalation exposure to PM and, consequently, the risks for PM-related illnesses will parallel the future trends in airborne levels of PM.



• Exposures to Radionuclides. The findings of this health consultation (i.e., air pathway exposures and populations-at-risk) will be used by ATSDR in a future health consultation to address the concerns of the Shoshone-Bannock Tribe regarding potential exposures to airborne radionuclides.

VI. RECOMMENDATIONS

ATSDR recommends the following actions to ensure that residents of Chubbuck, Pocatello, and the Fort Hall Indian Reservation are not exposed to unhealthy levels of air pollution that may originate from FMC, Simplot, or other emissions sources in the EMF study area:

• Given the weight-of-evidence suggesting that levels of air pollution throughout the EMF study area have reached potentially unhealthy levels as recently as December 1999, ATSDR recommends that the existing IDEQ and at least the "primary" Shoshone-Bannock ambient air monitoring stations continue to operate to characterize air quality. More specifically, both PM2.5 and PM10 should continue to be monitored; sampling filters on days with high particulate levels should continue to be analyzed for levels of the same metals, other inorganics, and ionic species that are currently measured; and sampling filters from at least one station should be routinely analyzed for concentrations of these same constituents such that their annual average levels--an important parameter for evaluating health concerns--can be calculated.



• ATSDR recommends that IDEQ continue to issue warnings on days when levels of air pollution are expected to reach potentially unhealthy levels and to communicate these warnings to the local media. Residents in the EMF study area are encouraged to heed these warnings, which generally recommend residents, especially persons with respiratory conditions, to remain indoors and to avoid moderate levels of exercise as much as possible. By following these precautions, residents can best protect themselves from air pollution in the EMF study area as it occasionally reaches potentially unsafe levels.

Note: IDEQ currently characterizes air quality in Pocatello and Chubbuck on a daily basis using an Air Quality Index (AQI). The AQI ranges from zero (no pollution) to five hundred (large amounts of pollution). This index is updated on a daily basis and can be accessed through the hotline number at 208-236-6173 or on the Web at http://www.state.id.us/deq/ro_p/pro_air/aqi_report_pro.shtml. If further information is requested, residents should contact IDEQ at 208-236-6160.

• ATSDR recommends that at least one ambient air monitoring station be installed to measure ambient air concentrations of particulate matter on the Fort Hall Indian Reservation, north of Interstate 86, and near where people live. Such monitoring is needed to quantify the extent of inhalation exposures to site-related contaminants among residents of the reservation. To ensure that future monitoring efforts generate data useful for conducting public health evaluations, ATSDR will comment on relevant sampling plans or proposals, if requested.



• To minimize the amount of particulate matter released to the air in the EMF study area, ATSDR recommends that EPA, IDEQ, the Shoshone-Bannock Tribes, and the cities of Chubbuck and Pocatello continue to develop and implement air pollution control initiatives and enforce the existing ones. Additionally, to ensure that emissions of hydrogen cyanide and phosphine do not reach levels of health concern, ATSDR recommends that EPA carefully oversee, possibly by periodically collecting audit samples, the ongoing operation of FMC's Pond Management Plan. Moreover, ATSDR recommends that OSHA-approved methods be used to determine if phosphine has reached levels of health concern at the FMC fenceline.



• ATSDR recommends that a public health evaluation be performed to assess potential inhalation exposures to airborne radionuclides. ATSDR has already committed to complete such an evaluation.

Knowing that FMC and Simplot continue to emit toxic chemicals to the air, though in lower quantities than have been emitted in the past, ATSDR is committed to reviewing ambient air monitoring data, emissions monitoring data, and health outcome data as they become available for the EMF study area. The Public Health Action Plan (Section VII) provides additional information on future site-related activities.

VII. PUBLIC HEALTH ACTION PLAN

The Public Health Action Plan (PHAP) for this health consultation describes the actions taken or planned for the EMF site. The purpose of the PHAP is to ensure that this health consultation not only identifies public health hazards, but provides a plan of action designed to mitigate and prevent adverse human health effects resulting from future exposure to hazardous substances in the environment. ATSDR is committed to following up on this plan to ensure that it is implemented. As needed, ATSDR will revise this PHAP by identifying the actions completed and those in progress. The public health actions taken or to be implemented are as follows:

Actions Completed

1. In 1990, ATSDR completed a public health assessment of the EMF site.



2. In 1995, ATSDR completed a health study of persons residing on the Fort Hall Indian Reservation by investigating concerns related to a number of respiratory and renal disorders.



3. In 1997, ATSDR completed a Site Review and Update for the EMF site.



4. From 1997 to 1999, the Idaho Division of Health, Bureau of Environmental Health and Safety (IDOH-BEHS) under a cooperative agreement with ATSDR, collaborated with the Southeastern District Health Department in Pocatello and the Shoshone-Bannock Tribal Health and Human Services in Fort Hall to complete several health education and outreach activities. The following actions were completed during this time frame:



• conducted environmental health needs assessments among residents of Fort Hall and Pocatello between August and October 1997.
• conducted an environmental health needs assessment among health care providers serving the Pocatello area between November 1997 and April 1998.
• conducted a needs assessment among educators in Pocatello School District 25 and the Fort Hall School District in April 1999.
• formed the Fort Hall/Pocatello Environmental Health Education Working Group to develop and implement an environmental health education strategy to address concerns and needs identified in the needs assessment.
• participated in several public availability sessions and meetings conducted by either ATSDR or EPA.
• developed an environmental health education/outreach strategy for implementation in Fort Hall and Pocatello. Activities implemented to date include 1) forming a technical advisory group; 2) publishing articles in the local newspapers discussing identified priority environmental health issues; 3) conducting continuing medical education seminars for health care providers; 4) conducting community environmental health presentations; and, 5) distributing educational materials at several local health fairs and community events



5. In 1998, ATSDR completed three health consultations that addressed the public health implications related to contamination of groundwater, surface water, and sediment.



6. In 2000, ATSDR, working with IDOH-BESH, developed a fact sheet to accompany the public release of this health consultation.

Action Planned

1. Using the results of this health consultation, ATSDR will evaluate of the public health implications of airborne radionuclides in the EMF study area.



2. ATSDR will evaluate the cancer incidence on the Fort Hall Indian Reservation and in the Pocatello area.



3. After completing the health evaluations for airborne radionuclides and cancer incidence, ATSDR will prepare a comprehensive public health assessment that aggregates the overall public health issues for the EMF site.



4. IDOH-BESH, under the cooperative agreement with ATSDR, will continue to conduct health education/outreach activities, as needed.



5. ATSDR's Division of Health Studies is considering the feasibility of conducting a health study that would examine the effect(s) of air pollution on the cardiopulmonary health of persons who resided in the vicinity of the site.



6. The Shoshone-Bannock Tribe is developing plans to site two new PM2.5 monitors on the Fort Hall Indian Reservation. These plans include the possibility of having them located at a different site than the current locations of the Primary, Background, and Sho-Ban monitors.

ATSDR will reevaluate and expand the Public Health Action Plan (PHAP) when needed. New environmental, toxicological, health outcome data, or the results of implementing the above proposed actions may warrant additional actions at this site.

VIII. SITE TEAM/AUTHORS

Gregory V. Ulirsch
Technical Project Officer/Environmental Health Scientist
Superfund Site Assessment Branch
Division of Health Assessment and Consultation, ATSDR

Debra Gable
Technical Project Officer
Superfund Site Assessment Branch
Division of Health Assessment and Consultation, ATSDR

Technical Consultation provided to ATSDR by:

John Wilhelmi
Eastern Research Group
Lexington, MA

VIII. REFERENCES

ARS, 1998. Ambient air monitoring data provided by Air Resource Specialists. December, 1998.

ATSDR, 1990. Preliminary Public Health Assessment for the Eastern Michaud Flats Contamination Site. Agency for Toxic Substances and Disease Registry. 1990.

ATSDR, 1992a. Toxicological Profile for Barium. Agency for Toxic Substances and Disease Registry. July, 1992.

ATSDR, 1992b. Toxicological Profile for Vanadium. Agency for Toxic Substances and Disease Registry. July, 1992.

ATSDR, 1995. Fort Hall Air Emissions Study: Fort Hall Indian Reservation. Agency for Toxic Substances and Disease Registry. November, 1995.

ATSDR, 1996. Written correspondence from Barry Johnson (ATSDR) to Tony Galloway (Sho-Ban Tribes). August, 1996.

ATSDR, 1997a. Site Review and Up-Date for Eastern Michaud Flats Contamination, Pocatello, Bannock County, Idaho. Agency for Toxic Substances and Disease Registry. March 1997.

ATSDR, 1997b. Toxicological Profile for Cyanide. Agency for Toxic Substances and Disease Registry. September, 1997.

ATSDR, 1998a. Health Consultation: Groundwater Contamination at the Eastern Michaud Flats Contamination. Agency for Toxic Substances and Disease Registry. October, 1998.

ATSDR, 1998b. Health Consultation: Surface Soil Contamination at the Eastern Michaud Flats Contamination. Agency for Toxic Substances and Disease Registry. October, 1998.

ATSDR, 1998c. Health Consultation: Surface Water and Sediment Contamination at the Eastern Michaud Flats Contamination. Agency for Toxic Substances and Disease Registry. October, 1998.

ATSDR, 1998d. Toxicological Profile for Sulfur Dioxide.  Agency for Toxic Substances and Disease Registry. December, 1998.

ATSDR, 1999a. Toxicological Profile for Aluminum. Agency for Toxic Substances and Disease Registry. July, 1999.

ATSDR, 1999b. Toxicological Profile for Cadmium. Agency for Toxic Substances and Disease Registry. July, 1999.

ATSDR, 2000a. Toxicological Profile for Arsenic. Agency for Toxic Substances and Disease Registry. September, 2000.

ATSDR, 2000b. Toxicological Profile for Beryllium. Draft for Public Comment. Agency for Toxic Substances and Disease Registry. September, 2000.

ATSDR, 2000c. Toxicological Profile for Chromium. Agency for Toxic Substances and Disease Registry. September, 2000.

ATSDR, 2000d. Toxicological Profile for Manganese. Agency for Toxic Substances and Disease Registry. September, 2000.

Bechtel, 1993. Air Dispersion Modeling for Monitoring Site Locations. Bechtel Environmental, Inc. January, 1993.

Bechtel, 1995. Remedial Investigation Report for the Eastern Michaud Flats Site. Part III: Air Quality Characterization Air Monitoring Report, Volume I. Bechtel Environmental, Inc. September, 1995.

Bechtel, 1996. Remedial Investigation Report for the Eastern Michaud Flats Site. Part I: Executive Summary. Bechtel Environmental, Inc. August, 1996.

Bechtel, 1998. RCRA Pond Emission Study. Bechtel Environmental, Inc. October, 1998.

Dockery et al., 1993. Dockery DW, Pope CA, Xu X, Spengler JD, Ware JH, Fay ME, Ferris BG, Speizer FE. An Association Between Air Pollution and Mortality in Six U.S. Cities. The New England Journal of Medicine 329(24):1753-1759. December, 1993.

FMC, 1999a. OP-FTIR Air Monitoring System Quarterly Report: First Quarter 1999. FMC Phosphorous Chemicals Division. 1999.

FMC, 1999b. OP-FTIR Air Monitoring System Quarterly Report: Second Quarter 1999. FMC Phosphorous Chemicals Division. 1999.

FMC, 1999c. OP-FTIR Air Monitoring System Quarterly Report: Third Quarter 1999. FMC Phosphorous Chemicals Division. 1999.

FMC, 1999d. OP-FTIR Air Monitoring System Quarterly Report: Fourth Quarter 1999. FMC Phosphorous Chemicals Division. 1999.

FMC, 2000. OP-FTIR Air Monitoring System Quarterly Report: First Quarter 2000. FMC Phosphorous Chemicals Division. 1999.

FR, 1999. Federal Rulemaking for the FMC Facility in the Fort Hall PM-10 Nonattainment Area; Proposed Rule. Federal Register, Vol. 64, No. 29. February, 1999.

Godleski, et al., 2000. Mechanisms of Morbidity and Mortality from Exposure to Ambient Air Particles. Health Effects Institute. February, 2000.

Hartman, 1999. Written correspondence from Rob Hartman (FMC) to John Wilhelmi (Eastern Research Group, Inc.). March, 1999.

IDEQ, 1991. Power/Bannock Counties PM-10 Receptor Modeling: Background and Preliminary Work. Idaho Division of Environmental Quality. January. 1991.

IDEQ, 1998a. Idaho Environment 1998. Idaho Division of Environmental Quality. 1998.

IDEQ, 1998b. CMB Receptor Modeling for the Special Winter Study in Pocatello, Idaho. Idaho Division of Environmental Quality. September. 1998.

IDEQ, 1999a. Portneuf Valley Particulate Matter (PM10) Air Quality Improvement Plan. Idaho Division of Environmental Quality. March, 1999.

IDEQ, 1999b. Database of results from chemical analyses of particulate filters. Provided by Diane Riley, Idaho Division of Environmental Quality. May, 1999.

IDEQ, 1999c. Written correspondence from Tom Edwards (IDEQ) to John Wilhelmi (Eastern Research Group). February, 1999.

IDEQ, 1999d. Written correspondence from Tom Edwards (IDEQ) to Greg Ulirsch (ATSDR). December, 1999.

IDEQ, 2000a. Release of preliminary ambient air monitoring data. Personal communication between Tom Edwards (IDEQ) and John Wilhelmi (Eastern Research Group). January, 2000.

IDEQ, 2000b. CMB Analysis for PM10 Scenario for 1999, Pocatello, Idaho. 2000.

IDH, 1975. Implementation Plan for the Control of Air Pollution in the State of Idaho. Idaho Department of Health/Idaho Air Pollution Control Commission. February, 1975.

IDHW, 1988. Air Quality Annual Report - 1987. Idaho Department of Health and Welfare. July, 1988.

IDHW, 1991. Power/Bannock Counties PM-10 Receptor Modeling:  Background and Preliminary Work. Idaho Department of Health and Welfare. January, 1991.

Jones et al., 1964. Environmental and Clinical Aspects of Bulk Wheat Fumigation with Aluminum Phosphide. American Industrial Hygiene Association Journal. 25: 375-379. 1964.

Krewski, et al., 2000. Particle Epidemiology Reanalysis Project. Health Effects Institute. July, 2000.

Neill, 1980. Airborne Particulate Size Analysis in the Pocatello Area. D.T. Neill, Idaho State University Energy Experiment Station. May, 1980.

NIOSH, 1994. NIOSH Pocket Guide to Chemical Hazards. National Institute for Occupational Safety and Health. June, 1994.

OMNI, 1991a. Dispersion Modeling Protocol for the Pocatello Nonattainment Area. OMNI Environmental Services, Inc. September, 1991.

OMNI, 1991b. Source Apportionment Analysis of the Pocatello Nonattainment Area. OMNI Environmental Services, Inc. October, 1991.

Pope et al., 1995. Pope CA, Thun MJ. Namboodiri MM, Dockery DW, Evans JS, Speizer FE, Heath CW. Particulate Air Pollution as a Predictor of Mortality in a Prospective Study of U.S. Adults. American Journal of Respiratory and Critical Care Medicine. 151:669-674.

Pope, C.A., 2000. Epidemiology of Fine Particle Air Pollution and Human Health: Biological Mechanisms and Who's at Risk? Environmental Health Perspectives. 108 (Supplement 4): 713-723.

Samet, et al., 2000. The National Morbidity, Mortality, and Air Pollution Study Part II: Morbidity, Mortality, and Air Pollution in the United States. Health Effects Institute. June, 2000.

Schwartz, J., 1999. Air Pollution and Hospital Admissions for Heart Disease in Eight U.S. Counties. Epidemiology. 10(1): 17-22.

Severson, 1999. Personal communication between Jim Severson (FMC) and Debra Gable (ATSDR). March, 1999.

Sho-ban, 1989. Air Quality Monitoring Plan and Particulate Exposure Assessment. Shoshone-Bannock Tribes Air Quality Program. April, 1989.

Sho-Ban, 1996. Written correspondence from the Shoshone-Bannock Tribes to Barry Johnson (ATSDR). August, 1996.

TRC, 1993. Power-Bannock Counties PM10 SIP Dispersion Modeling Study. TRC Environmental Corporation. March, 1993.

USEPA, 1992. Pocatello PM10 Saturation Study. U.S. Environmental Protection Agency, Environmental Services Division. April, 1992.

USEPA, 1996. Air Quality Criteria for Particulate Matter. U.S. Environmental Protection Agency, National Center for Environmental Assessment. EPA/600/P-95/001aF. April, 1996.

USEPA, 1997. Fact Sheet: EPA's Revised Particulate Matter Standards. U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards. July, 1997.

USEPA, 1998. Air quality monitoring data downloaded from the Aerometric Information Retrieval System (AIRS). U.S. Environmental Protection Agency. December, 1998.

USEPA, 1999a. Technical Support Document; Federal Implementation Plan for the FMC Facility in the Fort Hall PM-10 Nonattainment Area. U.S. Environmental Protection Agency, Region 10. January, 1999.

USEPA, 1999b. Integrated Risk Information System (IRIS): On-Line Database. U.S. Environmental Protection Agency, National Center for Environmental Assessment. June, 1999.

USEPA, 1999c. Toxic Release Inventory (TRI) State Files Documentation for RY 1997. Prepared for the U.S. Environmental Protection Agency. March 22, 1999.

USEPA, 1999d. Fort Hall Source Apportionment Study: Final Report. Prepared for the U.S. Environmental Protection Agency. EPA 600/R-99/103. September, 1999.

Willis, Ellenson, and Conner, 2000. Monitoring and source apportionment of particulate matter near a large phosphorus production facility. Journal of the Air and Waste Management Association, submitted. 2000.

FIGURES

Figure 1. General Study Area for EMF Health Consultation

Figure 2. Windrose Prepared from Meteorological Data Collected at the Pocatello Municipal Airport between 1985 and 1989

Figure 3. Monitoring Locations

Figure 4. Area of Impact of PM10 and 2.5 Exposures in EMF Study Area (1975-1993)

Figure 5. The Fort Hall PM10 Nonattainment Area and the Portneuf Valley PM10 Nonattainment Area

TABLES

Table 1. 1997 and 1998 TRI Air Emissions Data for FMC and Simplot

Facility	Pollutant	Pounds Released to the Air, by Reporting Year
		1997	1998
Emissions Data Reported by FMC	Antimony compounds	130	130
	Arsenic compounds	27	30
	Barium compounds	1,656	1,000
	Cadmium compounds	3,631	2,520
	Chromium compounds	2,505	2,350
	Copper compounds	84	80
	Cyanide compounds	13,152	232,136
	Hydrogen fluoride	5,311	Not reported
	Manganese compounds	14	10
	Nickel compounds	284	270
	Phosphine	16,992	35,170
	Phosphorous (yellow or white)	0	0
	Selenium compounds	1,975	1,940
	Zinc compounds	1,657	1,130
Emissions Data Reported by Simplot	Ammonia	121,000	425,000
	Hydrogen fluoride	33,000	36,000
	Methanol	Not reported	15,000
	Nitrate compounds	0	0
	Nitric acid	0	0
	Phosphoric acid	0	0
	Sulfuric acid aerosols	39,830	67,850

Notes: The table only lists emissions to the air. As required by TRI, the facilities also reported releases of the listed compounds to other media (e.g., surface water and soils).
TRI data are self-reported, and the accuracy of the TRI data for these two facilities is not known.
The TRI regulations require facilities to disclose releases of a wide range of hazardous air pollutants, but not for all toxic contaminants. Therefore, the data in this table should not be viewed as a comprehensive emissions inventory.
Source of information: USEPA 1999c.

Table 2. PM10 Emissions Data for the Fort Hall Nonattainment Area and the Portneuf Valley Nonattainment Area

Sources in the Fort Hall PM10 Nonattainment Area (USEPA 1999a)
Source Name	Estimated PM10 Emissions (tons per year)
FMC	727
Paved Roads	571
Agricultural Windblown Dust	310
All Other Sources	198
Sources in the Portneuf Valley Nonattainment area (IDEQ 1999a)
Source Name	Estimated PM10 Emissions (tons per year)
Unpaved Roads	1,230
Windblown Dust (Agricultural)	894
Windblown Dust (non-Agricultural)	492
Paved Roads	419
Agricultural Tilling	376
Fires	363
Residential Heating	237
Residential and Commercial Construction	175
Road Construction	142
Simplot	135
All Other Sources	362

Notes: The Fort Hall Nonattainment Area is located in the southernmost portion of the Fort Hall Indian Reservation and does not include the town of Fort Hall. Approximately 500 people live within the Fort Hall Nonattainment Area (USEPA 1999a).
The Portneuf Valley Nonattainment Area spans approximately 100 square miles and includes the cities of Chubbuck and Pocatello (IDEQ 1999a). Roughly 75,000 people live within this nonattainment area (USEPA 1999a).
The emissions data in this table are estimates and might understate or overstate actual emissions levels.

Table 3. Overview of Monitoring Studies of Metals and Other Inorganics

Elements with at least one ambient air concentration higher than corresponding health-based comparison values (further evaluation of these elements is presented in the "Public Health Implications" section of this report):
Aluminum Arsenic Barium	Beryllium Cadmium Chromium	Manganese Vanadium
Elements with all measured concentrations lower than corresponding health-based comparison values (these elements are not evaluated further in the report):
Antimony Chlorine Cobalt Copper Iron Lead	Mercury Molybdenum Nickel Selenium Silver	Strontium Thallium Tin Titanium Zinc
Elements detected in the EMF study area, but for which ATSDR and EPA have not developed health-based comparison values (a brief evaluation of these elements is presented in the "Public Health Implications" section of this report):
Bromine Calcium Carbon Cesium Gallium Germanium* Gold* Indium*	Iodine Lanthanum Magnesium Palladium* Phosphorous Potassium Rhodium Rubidium	Scandium Silicon Sodium Sulfur Tellurium Tungsten Uranium Yttrium Zirconium

Notes: Elements in this table refer to those that were measured by x-ray fluorescence, which includes some elements (like bromine) that are typically not categorized as metals.
Refer to Appendices A.2, A.3, and A.9 for a detailed review of the ambient air monitoring data that led to the above classifications.
Many of the elements listed above are potentially radionuclides. As explained earlier, this health consultation does not evaluate public health hazards for exposures to radionuclides. A future ATSDR health consultation will address this topic.
* denotes elements that were reported as detected by air monitoring studies, but the measurement uncertainty exceeded the actual concentration. As a result, it is not certain whether these elements are present in the air in the vicinity of the EMF site. Therefore, these elements are not discussed further in the "Public Health Implications" section of this health consultation.

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