Skip directly to search Skip directly to A to Z list Skip directly to site content




On May 22, 2000, the Agency for Toxic Substances and Disease Registry (ATSDR) was petitioned by Ohio Senator Mike DeWine to evaluate the health impacts from air pollution on residents of Marietta, Washington County, Ohio [1]. However, at that time, data were insufficient to address the petition.

In March 2002, ATSDR staff met with concerned residents about their health concerns and exposure to emissions from a nearby industrial complex. Located several miles outside the City of Marietta, Ohio, a former Union Carbide facility complex is currently occupied by four companies including: Eramet (metals refinery), Eveready Battery (battery manufacturer), Solvay (a solvent manufacturer), and Chevron Oil. AMP Ohio, originally built to provide power to Union Carbide, is located across the street from the complex. There is a residential area to the north of the facility. The predominant wind direction in the area is to the northeast. The City of Marietta is located 4 miles northeast of the facility, or "downwind" (see Appendix A). The residents are most concerned about Eramet because of the high volume of metals it refines annually, the facility being old enough to be exempt from many environmental pollution control regulations, and the perception of uncontrolled releases. Residents are also concerned that the other facilities are likely contributing to a "toxic soup" of contamination that impacts their community, but that Eramet is the greatest contributor of contamination in the area [2].

Area residents are concerned about the impact of the complex on their air quality and their health. They have reported a variety of symptoms, including: headaches, burning eyes, nausea, difficulty breathing, fatigue, muscle aches, tremors, sinus problems, bloody noses, a metallic taste in their mouths, a bitter metallic taste in their throats, an ammonia smell, and sore throats. Residents are also concerned about emissions of hexavalent chromium released through the chromium refining process, emissions from the electro-chromium process, and releases of chlorine and sulfuric acid used in the refining process [2]. No information regarding worker exposures or worker complaints from the Eramet facility have been made available to ATSDR.

ATSDR staff toured the Eramet facility in March 2002. This facility is located in an area that is primarily rural and the facility lies several miles outside the City of Marietta. The ferroalloy portion of the complex, which Eramet bought in 1999, occupies approximately 350 acres of land. The ferroalloy operation, which produces iron alloys for the steel, aluminum, and super-alloys industries, began in 1951. The ferroalloy operation includes several different refining processes. The facility is separated into a north and south side by a set of railroad tracks. To the north of the tracks are the electrolytic and briquetting operations that produce high-quality chromium metal, aluminum hardener briquettes and other specialty products. To the south of the railroad tracks are three submerged arc furnaces that produce a full range of ferromanganese and silicomanganese products for the steel industry. This area includes a "manganese oxygen refining" operation, which produces ferromanganese that contains limited amounts of carbon and silicon [3]. Eramet is the only producer of manganese ferroalloys in the United States, and is one of the largest manufacturers of these products in the world. In the year 2000, the Toxic Release Inventory (TRI) reported that Eramet released 431,600 pounds of manganese to ambient air. Although there are limited emission control systems in place for the ferromanganese operation (such as venturi scrubbers and baghouses), over half of the manganese emissions were released as "fugitive" or uncontrolled emissions [4].

In March 2003, ATSDR Region 5 staff requested that the ATSDR "Strike Team" (headquartered in Atlanta) assist in evaluating whether exposure to ambient air concentrations of metals reported in 2001 and 2002 are of health concern or warrant additional evaluation. Specifically, the Strike Team was asked: "Do levels of contaminants in air pose a health risk to area residents?"


The Ohio Environmental Protection Agency (Ohio EPA) has collected air samples from a Total Suspended Particulate (TSP) monitor since November 2000 [4]. The monitor is located approximately 4.5 miles to the north/northeast of the facility. Ohio EPA staff reported that the monitor was sited in its current location in response to a citizen complaint, and not specifically to address exposures to emissions to the Union Carbide complex [5]. However, an integrated air dispersion model has not been completed to determine if this location is the most highly impacted area of concern (i.e., the area with the maximum ambient air concentrations from facility emissions).

The attached Ohio EPA data package (Appendix B) includes data from the monitoring location for 2001-2002. The monitor filters were analyzed for the following metals: arsenic, beryllium, cadmium, chromium, lead, manganese, nickel, and zinc. Historic air data from 1990 through early 1992 (located in a farmer's field outside Marietta) at another location were also reviewed [6]. A comparison of air concentrations from 1990 to the present is limited by the fact that the 1990 monitor was in a different location than the current monitor (late 2000-present), and because it is not useful for assessing residential exposures (rural location).


In evaluating this site, ATSDR focused on the ability to assess health impacts based on the currently available air sampling data. ATSDR based its response on site conditions and information provided by Ohio EPA and the United States Environmental Protection Agency (USEPA). Two years and two months of recent data (Nov 2000 - Dec 2002) were reviewed for this evaluation. Approximately two years of historical data were also reviewed, but were not used to reach conclusions about current air conditions for the reasons mentioned in the previous section. In addition, volatile organic compound (VOC) data (1997, 2001-2002) and particulate matter data (1996-2000) of particles less than 10 microns (PM10) were also monitored. PM10 and VOC levels detected at the locations and during the years sampled were not detected at levels of health concern. Although the Union Carbide complex facilities emit other chemicals besides metals (e.g., ammonia, sulfuric acid, etc.) in large quantities (2,477,775 lbs., and 1,811,899 lbs. in 2000, respectively for Eramet alone [4]) no data for these other inorganic compounds are available for review at this time. Therefore, the focus of this document is the evaluation of ambient air concentrations of metals only.

To determine whether the level of contaminants could pose a health threat, ATSDR screens the concentrations of contaminants against health based guidelines, and researches scientific literature which may document health effects caused by exposure to contaminants. In this evaluation, the ambient air metals data was compared to ATSDR intermediate environmental media evaluation guides (IEMEG) and USEPA-Region 6 Risk-Based Human Health Screening Levels. IEMEGs are calculated from ATSDR minimal risk levels (MRLs) for intermediate exposures (those occurring for more than 14 days and less than 1 year). The USEPA non-cancer risk levels are derived using reference concentrations (RfCs), and cancer risk levels are derived using cancer slope factors (SFs). Both MRLs and RfCs are estimates of daily human exposure to a hazardous substance that is likely to be without appreciable risk over a specified duration of exposure (based on scientific evidence).

This comparison of data to screening levels revealed that levels of arsenic, cadmium, chromium (unspeciated), and manganese exceeded the ATSDR and USEPA screening levels during both the 1990-1992 and 2001-2002 sampling periods. Health-based screening levels are not available for lead or zinc in ambient air. However, there were no exceedances of the USEPA National Ambient Air Quality Standard for lead of an average of 1.5 µg/m3 per quarter [8]. It should be noted that chromium composition in the community's air is unknown (was not speciated during lab analysis), and as a protective measure, ATSDR compared levels in Marietta to hexavalent chromium guideline within the USEPA and ATSDR guidelines.

There are naturally occurring levels of metals in outdoor air (called "background levels"). Generally, arsenic levels in outdoor air are between 0.001-0.003 µg/m3 in rural areas and 0.02-0.1 µg/m3 in urban areas. Concentrations of cadmium in ambient air are very low, generally less than 5x10-9 µg/m3 (0.000000005 µg/m3); however, concentrations up to 5x 10-7 µg/m3 (0.0000005 µg/m3) have been detected in air near cadmium-emitting facilities. Chromium background levels range from 0.01-0.03 µg/m3. Average manganese concentrations are approximately 0.023 µg/m3 in the United States. Although these numbers represent "typical" background concentration across the United States, it should be noted that levels of metals are often higher in industrial areas [9-12].

The health-based screening levels used to evaluate these data address common human health inhalation exposure pathways. They do not consider all potential human health exposure pathways nor do they address ecological concerns. The comparison of preliminary investigation data against risk-based media concentrations provides for an initial evaluation for a set of environmental data. The values are not regulatory, but are derived using equations from USEPA and ATSDR guidance and commonly used defaults.

Arsenic and manganese consistently exceed health-based screening levels between 2001 and 2002. Chromium exceeded these criteria several times, up to levels over 30 times the screening level. Cadmium exceeded this level slightly during three months of the 26-month period. To better evaluate ambient contaminant concentrations in the future, additional metals should be included in future sampling.


It is difficult to infer the magnitude of the exposures or the potential health impacts from facility emissions on the surrounding community from available monitoring. Current data suggest that ambient concentrations of arsenic, cadmium, chromium, and manganese may at times exceed ATSDR and USEPA guidance values. However, it should be noted that guidance values are intended to be conservative, and are often orders of magnitude lower than observed health effects to allow a buffer of safety when screening data. Therefore, it is often necessary to review scientific studies to further evaluate measured concentrations of contaminants in air.

Levels of arsenic, cadmium, and chromium did not exceed levels of exposure that have been documented in scientific studies to cause adverse health effects in animals or humans [9-11]. At only one time (October 1991) during the four years of sampling was manganese present at levels that have been documented in the scientific literature to cause adverse health effects [12]. This concentration (in October 1991 of 1130 µg/m3) does not represent an average exposure. Under average conditions (<1.5 µg/m3), adverse health effects are unlikely.

Residents living closer to the facilities emitting these metals to air may have been exposed to air concentrations higher than those seen in the available air monitoring data. Therefore, a more thorough characterization of ambient air in the areas most greatly impacted by facility emissions is warranted. This may be accomplished by continued long-term sampling (1 year or more) in locations identified as areas most greatly impacted by the Union Carbide complex emissions.


ATSDR recognizes that in communities faced with contamination of their air, water, soil, or food, the unique vulnerabilities of infants and children demand special emphasis. ATSDR is committed to evaluating the health impact of environmental contamination on children, and uses health guidelines in its investigations that are protective of children. Further characterization of ambient levels of metals is needed to evaluate the impact of facility emissions on children's health in this community.


No physical hazards were identified in this evaluation.


The ATSDR Strike Team was tasked with answering the question, "Do levels of metals in air pose a health risk to area residents?"

  • Available data suggest that metals in air, particularly arsenic and manganese (and to a lesser degree, chromium and cadmium) could potentially pose a threat to residents close to the facilities of concern because they exceeded health-based screenings values. However, at this time, the exposure is an indeterminate hazard (i.e., not enough information) because the locations for the air sampling data may not reflect the most highly exposed populations, and that data analysis has included a limited number of metals. As a result, the magnitude of exposures and the threat to public health is uncertain.
  • Levels of particulates and volatile organic compounds are not present at concentrations of health concern at the current monitoring locations. However, no data are available to assess levels of these contaminants in areas closer to the industrial complex.
  • Some contaminants that are likely to be present, given facility processes, have not been sampled for (such as ammonia and sulfuric acid).


To better define the health threats, specific recommendations for collecting additional air sampling data are provided below.

  1. ATSDR or USEPA should model emissions from Eramet, Eveready, Solvay, Chevron, and AMP Ohio to determine what contaminants could be present in ambient air, and the locations where they are likely to most significantly impact human health. This information will aid in determining the most appropriate locations for additional air sampling.

  2. After modeling is completed, ATSDR, Ohio EPA, and USEPA should determine what additional ambient air data is necessary to adequately investigate the impact of facility emissions on the health of residents.

  3. When contaminants of concern have been identified, additional, long-term sampling should be performed (for 1 year or more).

  4. ATSDR should evaluate the data collected from additional air monitoring and air modeling (e.g., wind roses) to establish an exposure pathway, and determine whether air emissions could negatively impact the health of Marietta residents.


Michelle A. Colledge
Environmental Health Scientist
Office of Regional Operations
Region 5

Jennifer A. Freed
Environmental Health Scientist
Exposure Investigations and Consultations Branch
Division of Health Assessment and Consultation

Reviewed by

Gregory M. Zarus
Strike Team Leader/Atmospheric Scientist
Exposure Investigations and Consultations Branch
Division of Health Assessment and Consultation

John Abraham
Exposure Investigations and Consultations Branch
Division of Health Assessment and Consultation

Tina Forrester
Deputy Director
Office of Regional Operations

Mark Johnson
Senior Environmental Health Scientist
Office of Regional Operations
Region 5


  1. Agency for Toxic Substances and Disease Registry. Letter from petitioner to Agency for Toxic Substances and Disease Registry. May 22, 2000.

  2. Agency for Toxic Substances and Disease Registry. Notes from meeting with concerned community. Marietta, Ohio; March 24, 2002.

  3. Eramet. Profile of Facility in Marietta, Ohio. November, 2000.

  4. United Stated Environmental Protection Agency. Toxic Release Inventory Database. Exiting ATSDR Website, accessed May 2003.

  5. Ohio Environmental Protection Agency. Raw data package for metals in air: 1990, 1991, 2001, 2002. Columbus, Ohio. Received March 26, 2003.

  6. Paul Koval, Supervisor, Air Toxics Unit, Ohio Environmental Protection Agency; communicated during March 26, 2003 conference call with OEPA, USEPA- Region 5, Ohio Department of Health, and ATSDR.

  7. Paul Koval, Supervisor, Air Toxics Unit, Ohio Environmental Protection Agency; personal communication with Mark Johnson, ATSDR. March 2003.

  8. Ohio Environmental Protection Agency. Air standard for lead. Ohio Administrative Code, Chapter 3745-71. Exiting ATSDR Website. Division of Air Pollution Control. Accessed May 9, 2003.

  9. Agency for Toxic Substances and Disease Registry. 2000. Arsenic, Toxicological Profile. Department of Health and Human Services.

  10. Agency for Toxic Substances and Disease Registry. 2000. Cadmium, Toxicological Profile. Department of Health and Human Services.

  11. Agency for Toxic Substances and Disease Registry. 2000. Chromium, Toxicological Profile. Department of Health and Human Services.

  12. Agency for Toxic Substances and Disease Registry. 2000. Manganese, Toxicological Profile. Department of Health and Human Services.


Facility Map


Data Summary of Detected Ambient Metal Concentrations: 1990-91, 2001-02 (µg/m3)
Metal Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Health-Based Guideline

No data collected

0.00149 0.00086 0.00066 0.002 0.00161 ATSDR: 0.0002µg/m3 (Ca)
USEPA: 0.00045µg/m3 (Ca)
Beryllium 0.00006 0.00010 0.00010 0.00017 0.00003 ATSDR: 0.0004µg/m3 (Ca)
USEPA: 0.0008µg/m3 (N)
Cadmium 0.00074 0.00051 0.00038 0.0006 0.00031 ATSDR: 0.0006 µg/m3 (Ca)
USEPA: 0.0011µg/m3 (N)
Chromium 0.00505 0.00343 ND ND ND ATSDR: 0.00008 µg/m3 (Ca)
USEPA: 0.000023 µg/m3 (N)
Lead ND ND ND ND ND OEPA: 1.5µg/m3 (N)
Nickel ND ND ND ND ND ATSDR: 0.2 µg/m3 (N)
Zinc 0.044 0.0366 0.0308 0.0357 0.0286 No screening level
Arsenic 0.00121 0.00119 0.0014 0.002 0.00578 0.00119 0.00757 0.0104 0.00812 0.00372 0.00172 0.00519 See above
Cadmium 0.00029 0.00045 0.00102 0.00097 0.00131 0.00038 0.00569 0.00227 0.00103 0.00816 0.00067 0.00129 See above
Chromium ND ND ND 0.00487 0.00613 0.00465 ND 0.00615 0.00933 0.0128 0.00721 ND See above
Manganese NA NA NA NA 0.824 0.173 0.173 0.546 0.916 1130.0 0.37 0.43 ATSDR: 0.04 µg/m3 (N)
USEPA: 0.051 µg/m3 (N)
Nickel ND ND ND ND 0.00557 ND ND ND ND ND ND ND See above
Zinc 0.0273 0.0356 0.0288 0.0857 0.0538 0.0482 0.0637 0.22 0.16 0.329 0.202 0.191 No screening level
Arsenic 0.0014 0.00084 0.0011 0.0016 0.0012 0.0025 0.0018 0.0019 0.0013 0.0018 0.0024 0.0019 See above
Beryllium 0.00014 ND ND ND 0.00006 0.00005 ND ND 0.00004 ND ND ND See above
Cadmium 0.00055 0.00039 0.00023 0.00038 0.0026 0.00063 0.00026 0.00037 0.00028 0.00087 0.00071 0.0048 See above
Chromium 0.0048 ND ND ND ND ND ND ND ND ND 0.0057 ND See above
Lead 0.056 0.0066 ND 0.005 0.005 0.0099 0.0082 ND 0.0096 0.009 0.011 0.011 See above
Manganese 0.096 0.13 0.16 0.19 0.12 0.33 0.1 0.094 0.027 0.73 1.4 0.42 See above
Zinc 0.11 0.025 0.022 0.026 0.033 0.044 0.024 0.043 0.033 0.054 0.062 0.04 No standard
Arsenic 0.0008 0.0022 0.00077 0.00027 0.001 0.0018 0.0014 0.0062 0.0007 0.0007 0.0009 0.001 See above
Cadmium 0.00077 0.00031 0.00016 0.00003 0.00024 0.0011 0.00064 0.00018 0.0002 0.0003 0.0003 0.001 See above
Chromium 0.0051 ND ND ND ND ND ND ND ND ND ND ND See above
Lead 0.0098 ND ND 0.0004 ND ND 0.0086 ND 0.001 0.005 0.009 ND See above
Manganese 1.2 0.1 0.1 0.007 0.02 0.089 0.11 0.083 0.01 0.01 0.07 0.01 See above
Zinc 0.068 0.033 0.031 0.0025 0.026 0.033 0.027 0.016 0.02 0.02 0.02 0.02 No standard

µg/m3= micrograms of metal per cubic meter of air
Highlighted, bolded cells are concentrations which exceeded the ATSDR and USEPA health-based screening levels
NOTE: ATSDR and USEPA health based screening levels are based on hypothetical risk analysis.
(Ca) notates cancer endpoints, and (N) notates non-cancer endpoints.

Table of Contents The U.S. Government's Official Web PortalDepartment of Health and Human Services
Agency for Toxic Substances and Disease Registry, 4770 Buford Hwy NE, Atlanta, GA 30341
Contact CDC: 800-232-4636 / TTY: 888-232-6348

A-Z Index

  1. A
  2. B
  3. C
  4. D
  5. E
  6. F
  7. G
  8. H
  9. I
  10. J
  11. K
  12. L
  13. M
  14. N
  15. O
  16. P
  17. Q
  18. R
  19. S
  20. T
  21. U
  22. V
  23. W
  24. X
  25. Y
  26. Z
  27. #