Metals Monitoring - Kokomo
The Indiana Department of Environmental Management (IDEM) and the United States Environmental Protection Agency (U.S. EPA) have partnered on a special project to examine the air quality risks posed by emissions of toxic metals from colored glass manufacturing. This project analyzed samples taken from an air monitor located near Kokomo Opalescent Glass (Kokomo, Indiana) to determine concentrations of toxic metals. The monitoring results were compared to public health benchmarks to determine any risk from acute (short-term) exposure. The statistical average of all the samples for each metal was used to determine if there are any chronic (long-term) risk. Monitoring for this project began on June 10, 2016. Samples were collected daily through the end of July, and then collected once every three days for the remainder of the project. Hexavalent chromium monitoring was added to the project starting February 15, 2017. Data collection for this project ended June 30, 2017.
For the period of June 10, 2016 through June 30, 2017, 155 valid samples were collected. These samples were analyzed for a suite of metals and seven metals of concern were compared against two sets of acute health benchmarks. When compared against the Occupational Safety and Health Administration (OSHA) 8-hour permissible exposure limit, no sample exceeded this limit for any of the seven metals of concern. When compared against a screening level for short-term health effects, eight of the 155 samples exceeded the screening level for cadmium and one exceeded the screening level for nickel. Two samples of hexavalent chromium exceeded the acute screening level. No samples of the other five metals exceeded the screening level for short-term health effects. No metals exceeded the chronic health effect levels generally considered to require action at this time.
Location: Corner of S. Market Street and E. State Street at the NE corner of Kokomo Opalescent Glass
Sampling time: 24 hours
Type: Particulate Monitor with Total Suspended Particulate (TSP) Inlet
Analysis: Inductively Coupled Plasma Mass Spectrometry (ICP-MS) – U.S. EPA Contract Lab
The initial analysis method for the samples was X-Ray Fluorescence (XRF). U.S. EPA reanalyzed all sample using the ICP-MS to achieve a lower method detection limit. The XRF analysis was discontinued on January 31, 2017.
IDEM does not have air quality standards for metals. Instead, IDEM uses the best available information about pollutant health effects to provide health-based comparison levels. Taking into account that the monitor is located on the property of the glass manufacturer and not at a location of public exposure, IDEM provides two types of health-based comparison levels; the OSHA 8-hour permissible exposure limit (PEL) for ensuring the protection of worker health and a screening leveI that IDEM uses as a conservative approach to evaluate short-term health effects. The health screening levels are used as a screening tool for additional investigation and do not necessarily mean health effects occur at that level. Additional information on sources of health benchmarks is provided at the end of this page.
|Table 1 - Kokomo Opalescent Glass Monitoring Acute Results June 10, 2016 through June 30, 2017 (155 Samples)|
|Maximum 24-hour Concentration (ug/m3)||OSHA 8-hour Permissible Exposure Limit (ug/m3)||# of Samples Above Permissible Exposure Limit||Short-term Screening Level (ug/m3) source)||# of Samples Above Short-term Screening Level||LaboratoryMethod Detection Level (MDL)(ug/m3)||Percentage of Samples Above MDL|
|Chromium (Cr)||0.043||500||0||0.5* (ONT)||0||0.0042||27%|
|Manganese (Mn)||0.060||5000||0||0.17 (REL)||0||0.000143||100%|
|Cobalt (Co)||0.048||100||0||0.071 (NH)||0||0.000097||88%|
|Nickel (Ni)||0.066||1000||0||0.06 (REL)||1||0.000204||100%|
|Selenium (Se)||0.464||200||0||0.71 (NH)||0||0.000054||100%|
|Cadmium (Cd)||0.237||5||0||0.03 (MRL)||8||0.000002||100%|
|Arsenic (As)||0.006||500||0||0.036 (NH)||0||0.000039||100%|
* The health benchmark provided for Chromium (Cr) represents Chromium III, not Chromium VI.
Laboratory Method Detection Level (MDL): Also known as the Method Detection Limit. The MDL is the minimum concentration of a substance that can be measured and reported with 99-percent confidence and is provided by the laboratory performing the sample analysis The percentage represents the number of samples that measure a concentration above the MDL.
Values Above Short-term Screening Level
The health screening levels are used as a screening tool for additional investigation and do not necessarily mean health effects occur at that level. The short-term screening level for cadmium is from the Agency for Toxics Substances and Disease Registry (ATSDR) and represents a Minimum Risk Level (MRL) derived for acute exposure: 1 to 14 days. The MRL is not intended to define a clean-up or action level. According to the Public Health Statement for cadmium, food and smoking are the two primary sources of exposure for the general public. Exposure levels may increase for people living near cadmium-emitting industries. Exposure to levels of cadmium above the MRL may increase the risk of damage to the lungs and kidneys.
Individual ICP-MS Data Points (Daily Readings):
Additional metals were analyzed; further information is available upon request.
Long term data is compared to the Unit Risk Factor (URF) to estimate the excess cancer risk and to the Reference Concentration (RfC) to estimate non-cancer risk. Both the URF and RfC are based on 70 years of constant exposure. The chronic results were analyzed using U.S. EPA recommended statistical methods. IDEM evaluated the data so that a 95% upper confidence limit of the mean (average) (UCL) could be determined. A 95% UCL represents a value which one can be 95% confident that the true mean (average) of the population is below that value
|Table 2 - Kokomo Opalescent Glass Monitoring Chronic Results June 10, 2016 through February 28, 2017 (114 Samples)|
|Compound||Average (95% UCL) of all Samples (ug/m3)||Cancer Unit Risk Factor (URF) (Source)||Excess Cancer Risk per million people||Non-cancer Reference Concentration (RfC) (Source)||Non-cancer Risk||Laboratory Method Detection Level (MDL) (ug/m3)||Percentage of Samples Above MDL|
|Chromium||0.0052||1.20E-02* (IRIS)||62.2*||0.1* (IRIS)||0.05*||0.0042||27%|
|Nickel||0.0031||2.60E-04 (CalEPA)||0.8||0.09 (ATSDR)||0.03||0.00020||100%|
|Cadmium||0.0120||1.80E-03 (IRIS)||21.6||0.01 (ATSDR)||1.2||0.000002||100%|
|Arsenic||0.0011||4.30E-03 (IRIS)||4.5||0.015 (ATSDR)||0.07||0.000039||100%|
* The health benchmark provided for Chromium (Cr) represents Chromium VI.
U.S. EPA uses a range between one in a million and one hundred in a million (1 to 100) when evaluating whether the estimated risk is at a level where action should be taken. Generally, U.S. EPA considers lifetime cancer risk estimates over one hundred in a million to be at levels where action or more investigation is required. Lifetime cancer risks that fall between the one in a million and 100 in a million range generate decisions and actions taking into account the assumptions used to determine the estimate. Lifetime cancer risk estimates below one in a million are usually considered not to require further action. The excess cancer risk from total chromium is compared to the health benchmark for the more toxic Chromium (VI).
Non-cancer hazard is a ratio that divides an exposure concentration by the reference concentration (RfC). A non-cancer hazard under 1.0 is commonly recognized to be below the health-protective level. Non-cancer hazards over 1.0 indicate that further investigation may be necessary and does not necessarily mean that health effects are expected. Given the many health-protective assumptions used in the evaluation, most non-cancer hazards over 1.0 are still unlikely to be associated with observable adverse health effects. The 95% UCL for cadmium was the only pollutant with a non-cancer hazard over 1. Chronic cadmium inhalation exposure may cause lung and kidney health effects.
The ICP-MS chromium monitoring is for all forms of chromium. On February 15, 2017 monitoring was started for a specific form of chromium known as hexavalent chromium or Chromium (VI). Chromium (VI) is a known cancer causing and inhalation irritant. The samples are collected on a coated filter and analyzed using Ion Chromatograph (IC). Data has been analyzed through June 30, 2017. Two of the 36 samples exceeded the acute screening level and none of the samples exceeded the chronic action level.
|Table 3 - Kokomo Opalescent Glass Monitoring Chromium (VI) February 15, 2017 through June 30, 2017 (19 Samples)|
|Compound||Maximum Acute 24-hour Concentration (ug/m3)||OSHA 8-hour Permissible Exposure Limit (ug/m3)||# of Samples Above Permissible Exposure Limit||Short-term Screening Level (ug/m3) (source)||# of Samples Above Short-term Screening Level||Laboratory Method Detection Level (MDL)(ug/m3)||Percentage of Samples Above MDL|
|Chromium (VI)||0.0009||5.0||0||0.0007 (ONT)||2||0.0000037||100%|
|Compound||95% UCL Average of all Samples (ug/m3)||Cancer Unit Risk Factor (URF) (source)||Excess Cancer Risk per million people||Non-cancer Reference Concentration (RfC) (source)||Non-cancer Risk||Laboratory Method Detection Level (MDL)(ug/m3)||Percentage of Samples Above MDL|
|Chromium (VI)||0.0002||1.20E-02 (IRIS)||2.7||0.1 (IRIS)||0.00||0.0000037||100%|
Individual IC Chromium (VI) Data Points (Daily Readings):
Monitoring results from the Kokomo Opalescent Glass Project indicate that cadmium is the primary pollutant of concern. Cadmium is used as a pigment for specific colors of glass produced at Kokomo Opalescent Glass. Wind direction analysis indicates the cadmium readings are highest when the wind blows from Kokomo Opalescent Glass toward the monitor. Cadmium acute and chronic health effects may adversely affect the lungs and kidneys. However, cadmium readings above the health benchmarks do not mean that adverse health effects may occur. The ambient air monitor was located on Kokomo Opalescent Glass property and there were no exceedances of the OSHA 8-hour permissible exceedance limit. The chronic cadmium statistical average is based on the health protective 95% UCL, an upper confidence level of the average. The statistical average value for cadmium is relatively comparable to other urban/industrialized locations. IDEM and the source will continue its cooperative relationship and may explore options for minimizing potential impacts from cadmium.
Sources of Health Information:
If available, the acute screening level benchmark for a specific metal is the MRL from the ATSDR. In cases where an MRL was not available for a metal of concern, IDEM selected the most conservative benchmark available from the remaining sources. In most cases, the short-term health benchmark represents a 24-hour exposure period. The Reference Exposure Levels (RELs) are 8-hour levels. The following sources were used to identify a peer reviewed short-term toxicity value:
- Agency for Toxic Substances and Disease Registry (ATSDR) Minimum Risk Levels (MRL)
- California Office of Environmental Health and Hazard Assessment Reference Exposure Level (REL)
- New Hampshire Regulated Toxic Air Pollutants (NH)
- Ontario Ministry of the Environment Ambient Air Quality Criteria (ONT)
- Occupational Safety and Health Administration (OSHA)
Health effect information is taken from Table 1 of the chronic inhalation exposure chart [XLS] available on the U.S. EPA Dose-Response Assessment for Assessing Health Risks Associated With Exposure to Hazardous Air Pollutants page.
The ATSDR Public Health Statement is available on the Centers for Disease Control (CDC) Agency for Toxic Substances & Diseases Registry website:
For questions about Kokomo metals monitoring, please contact the IDEM Office of Air Quality.