# Presentation: 623304

## Chemical Risk Assessmentand Exposure Guidelines (and how AEGLs fit in)

-   Veronique  Hauschild, MPH
- Directorate of  Health Risk Management
- US Army Center for Health Promotion and Preventive Medicine
**Presentation to Arkansas Dept of Health - March 2003**

## AGENDA

- Background –CHPPM
- Introduction to Chemical Risk Assessment
- What are AEGLs
- What are the health effects associated with chemical warfare agent AEGLs?
- How are AEGLs used?

## Who is USACHPPM?

**Who is USACHPPM?**

**Notes:**
CHPPM traces its roots back to WWII when the Army’s Industrial Hygiene Laboratory was formed in response to the high level of occupational casualties in munitions plants.  In 1960, environmental health activities were added to form the Army Environmental Hygiene Agency.

## CSA

- Chief of Staff- Army

- MEDCOM / TSG
- Medical Command / The Surgeon General

- rest of Army

**Notes:**
CHPPM is a major subordinate command of the US Army Medical Command. The MEDCOM commander is dual hatted as the Army Surgeon General who ultimately reports to the chief of staff of the Army. 

## USACHPPM MISSION

- Preventive medicine, public health, occupational health and safety, and health promotion/wellness technical services
- Advise/assist Army OTSG in policy and guidance development
- Evaluate compliance and adequacy of programs and policies (report to OTSG)
- Support world-wide technical support (Army and DoD; other Federal and State entities; international efforts)

## Example USACHPPM CWA initiatives

_**Emergency Planning and Response**_** **
**Army/FEMA (CSEPP) AEGL policy** and supporting risk communication/ implementation guidance
- Coordination with National Advisory Committee on AEGLs (for CWA)
- Homeland defense planning support (Installations, States, other Federal)
- Development of safe soil /reentry levels (1999)
- Risk Communication support
_**Occupational and General Population and Environmental Health**_
- Re-evaluation and development of new AELs (1996-2000)
- Soil remediation goals and waste treatment goals (1999)
- Revision of DA Regs/Pams  (40-8/173; 50-6, 385-61)
- Coordination with CDC (supporting OEMD)
_**Military Exposures Guidelines**_** (MEGs) for air, water soil**
- USACHPPM TG 230 (Chemical Exposure Guidelines for Deployments)
- TB Med 577 (Field Surveillance of Drinking Water)

## Development & evaluation of  health criteria for different applications and populations

- Development & evaluation of  health criteria for different applications and populations

_**MILITARY**_
- -FHP
- -Operations
- -Army/DoD

**OCCUPATIONAL **_**HEALTH  **_
- Stockpile
- Homeland Defense
- - Research

**ENVIRONMENTAL & **_**PUBLIC HEALTH**_
- -US Stockpile
- -Non-Stockpile
- -Homeland Defense

## Chemical Risk Assessment and Standards Development:What is a ‘safe’ or ‘acceptable’ level of Chemical “X”?

_**Basics of the science:**_
- _What_ media (air, water, soil, surfaces?)
- _Who_ (what population?)
- _How long_ and/or _how frequent_ is the exposure?
- What health effects?
_**Additional Risk Management Considerations:**_
- What health effects?
- What are competing risks?  Are they ‘voluntary’?
- What are the the possible actions to be taken?
*Bottom line – every chemical has numerous safe/acceptable “numbers”*

##  Chemical Air Exposure Levels Continuum*

**mg/m****3**

**ug/m****3**

***Single  exposure***

***Lifetime  exposure***

- *not to scale for any specific chemical– general representation

- AEGL-1

- AEGL-2

- AEGL-3

- IDLH

- Daily 8-hr  worker TWA
- “WPL”

- Ambient air - general population lifetime
- “GPL”

- EC50

- LC50

- 15 min
- 4 x per day worker
- “STEL”

**Catastrophic release**

**     ****Work environments**

**Ambient air (emissions)**

## So what are Acute Exposure Guideline Levels (AEGLs)?

-      - Short-term, one-time, airborne exposure levels
-      - 3 levels of health severity and different exposure times
-      - For risk managers to appropriately balance risks and prioritize resources in
- 	Emergency planning/prevention
**  **Emergency response
**Concept started in the mid-80’s – result of Bhopal incident**

**Notes:**
Our primary goal has always been to protect civilians, site workers and deployed soldiers.

This goal has not changed.

What has changed is the science and the scenarios with which we find ourselves faced with dealing with the hazards associated with chemical agents.

As with EPA, CDC, and other health -oriented organizations,  we must constantly re-evaluate our guidance and procedures to ensure that they adequately meet the needs of the new scenarios and applications, and that we incorporate to scientific data or methods as they evolve.

## History of “Emergency” Exposure Limits

- _Regulatory_
- 1964- NRC EEGLs
- 1974- NIOSH IDLHs
- 1984- EPA National Air Toxics Strategy Separates Routine from Accidental Releases
- 1986- SARA Title III
- 1990- CAA 112r

- _Industry_
- 1964- AIHA EELs
- 1970s- Company Specific STELs
- 1984 – Bhopal Incident
- 1985- Company Specific EELs
- 1987- ORC ERPG Task Force
- 1988- AIHA ERPG Committee

**1993 – NAS Guidance for Developing AEGLs**
**1995-   Federal Advisory Committee Act (FACA)**
**1996 – National Advisory Committee on AEGLs**

**Notes:**
Our primary goal has always been to protect civilians, site workers and deployed soldiers.

This goal has not changed.

What has changed is the science and the scenarios with which we find ourselves faced with dealing with the hazards associated with chemical agents.

As with EPA, CDC, and other health -oriented organizations,  we must constantly re-evaluate our guidance and procedures to ensure that they adequately meet the needs of the new scenarios and applications, and that we incorporate to scientific data or methods as they evolve.

## Who Establishes AEGLs?A two-committee process (NRC ‘final say’ over NAC):  

**   ****National Advisory   Committee (NAC) for AEGLs**
*Co-chairs from EPA &  Industry*
- Public Sector:  Federal and State agencies
- Private Sector:   Industry, Academia,  Medical associations
- International regulatory reps: (unofficial members at present - Netherlands, France, Germany)
**	****	**

**National Research Council (NRC) Committee on Toxicology (COT)**
*Subcommittee on AEGLs*
- Under National Academy of Sciences –mandate to advise Federal government
- Private Sector:   Industry, Academia
- International technical reps: Canada, Netherlands, Germany

**Notes:**
Our primary goal has always been to protect civilians, site workers and deployed soldiers.

This goal has not changed.

What has changed is the science and the scenarios with which we find ourselves faced with dealing with the hazards associated with chemical agents.

As with EPA, CDC, and other health -oriented organizations,  we must constantly re-evaluate our guidance and procedures to ensure that they adequately meet the needs of the new scenarios and applications, and that we incorporate to scientific data or methods as they evolve.

## AEGL Development Process

- Based on _National Research Council (NRC)_ approved technical procedure (publicly available document)
- Several standardized review levels:
- _DRAFT_: Developed by National Advisory Committee (NAC-AEGLs);
- _PROPOSED_: Federal Register public comment period;
- _INTERIM_: NAC-AEGLs addresses public comments
- _FINAL_: _NRC Committee_ on Toxicology reviews/modifies and finalizes (publishes)

## Official NAC AEGL Level Definitions:

- _AEGL Level 1_:  level ***above which*** general population (including susceptible individuals) may have some notable discomfort ( non-disabling, transient and reversible)
- _AEGL Level 2_: level ***above which*** general population (including susceptible individuals) may experience serious long-lasting effects or impaired ability to escape
- _AEGL Level 3_: level ***above which*** general population (including susceptible individuals) could experience life threatening effects or death

***BUT:  These should not be interpreted too literally.... The final AEGL concentrations for chemicals (especially CWA) are designed to be VERY protective***

## Slide 15

## AMMONIA Air Criteria (mg/m3)

| Exposure duration ⃗ | 2-10 min | 10 min | 30  min | 1 hr | 4 hr | 8 hr | 8 hr/day 
lifetime | 24 hr/day 
lifetime |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
|  |  |  |  |  |  |  |  |  |
| LC50 | >5000 |  |  |  |  |  |  |  |
|  |  |  |  |  |  |  |  |  |
| AEGL 3* |  | 1880 | 1120 | 770 | 383 | 272 |  |  |
| AEGL 2* |  | 188 | 112 | 77 | 77 | 77 |  |  |
| AEGL 1* |  | 18 | 18 | 18 | 18 | 18 |  |  |
|  |  |  |  |  |  |  |  |  |
| AELs |  |  | 300
IDLH |  |  |  |  |  |
|  |  |  |  | 27
STEL |  |  |  |  |
|  |  |  |  |  |  |  | 18
TLV |  |
|  |  |  |  |  |  |  |  | 0.35 
(derived) |

- Lethality Concentration– 50 deaths – published data (animal and human) based human estimate
- AEGL- Acute Exposure Guideline Levels – *proposed levels
- Occ & Public Health standards developed by OSHA, NIOSH, and EPA

## Carbon Monoxide Air Criteria (mg/m3) 

| Exposure duration ⃗ | 2-10 min | 10 min | 30  min | 1 hr | 4 hr | 8 hr | 8 hr/day 
lifetime | 24 hr/day 
lifetime |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
|  |  |  |  |  |  |  |  |  |
| LC50 | >2500 |  |  |  |  |  |  |  |
|  |  |  |  |  |  |  |  |  |
| AEGL 3* |  | 1700 | 600 | 330 | 150 | 130 |  |  |
| AEGL 2* |  | 420 | 150 | 83 | 33 | 27 |  |  |
| AEGL 1* |  | NR | NR | NR | NR | NR |  |  |
|  |  |  |  |  |  |  |  |  |
| AELs |  |  | 1200
IDLH |  |  |  |  |  |
|  |  |  |  | 229
ceiling |  |  |  |  |
|  |  |  |  |  |  |  | 55
TLV |  |
|  |  |  |  |  |  |  |  | 3 
(derived) |

- Lethality Concentration– 50 deaths – published data (animal and human) based human estimate
- AEGL- Acute Exposure Guideline Levels – *proposed levels
- Occ & Public Health standards developed by OSHA, NIOSH, and EPA

## GB (SARIN)  Air Criteria (mg/m3) 

| Exposure duration ⃗ | 2-10 min | 10 min | 30  min | 1 hr | 4 hr | 8 hr | 8 hr/day 
lifetime | 24 hr/day 
lifetime |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
|  |  |  |  |  |  |  |  |  |
| LC50 | 3.5 |  |  |  |  |  |  |  |
|  |  |  |  |  |  |  |  |  |
| AEGL 3 |  | 0.38 | 0.19 | 0.13 | 0.07 | 0.051 |  |  |
| AEGL 2 |  | 0.087 | 0.050 | 0.035 | 0.017 | 0.013 |  |  |
| AEGL 1 |  | 0.0069 | 0.004 | 0.0028 | 0.0014 | 0.0010 |  |  |
|  |  |  |  |  |  |  |  |  |
| AELs |  |  | (2.0)*
IDLH |  |  |  |  |  |
|  |  |  |  | (0.003)*
STEL |  |  |  |  |
|  |  |  |  |  |  |  | 0.003*   (0.0004)
WPL |  |
|  |  |  |  |  |  |  |  | 0.0001*   (0.00002)
GPL |

- IDA - Institute for Defense Analysis ( endorsed by ASD)
- AEGL- Acute Exposure Guideline Levels (developed by NRC, referenced in TG230)
- AELs- Air Exposure Limits (endorsed by CDC, occupational and general population regulatory standards)

- * under evaluation (new proposed)

## Slide 19

## Slide 20

## Slide 21

## Slide 22

## Summary of CWA AEGL Status/Issues

- HD and Nerve Agent AEGLs  are ‘FINAL’:
- NRC pre-publication (March, 2003)
- ‘Street version’ publicly purchasable book by May ($58 from the National Academies Press at 800-624-6242)
- Or – will be viewable online:  www.nap.edu
- “Final” values currently cited in USACHPPM Fact Sheets
- Overall data considered good quality (exception VX);
- Data- based values are down-adjusted  with “uncertainty factors” (providing a margin of safety) to account for unknowns:
-  Animal- to human extrapolation
-  Human variability
-  Data quality

## Sulfur Mustard Health Effects and AEGLs

**Sulfur Mustard Health Effects and AEGLs**

**Significant adverse effects**

**No significant adverse effects**

**Severe adverse effects**

**No adverse effects**

- Above AEGL 3, increasingly severe *delayed* effects and incapacitation, to include (delayed) blistering and lung effects;  eventually potential fatalities
**AEGL-3**

**AEGL-2            AEGL-3**
- Above AEGL 2, increasing chance of significant eye irritation with possible *delayed* impairment of vision; possible breathing difficulties approaching the AEGL 3;  effects will be *delayed*, but not permanent

**AEGL-1**
- Below AEGL 1, no observed adverse effects

**AEGL-1            AEGL-2**
- Above AEGL 1, may begin to see minor eye discomfort, irritation, redness; effects will be *delayed* but not permanent

****** ****AEGL1**

****** ****AEGL 2   **

****** ****AEGL 3**

**few     ********    many**

**few     ********    many**

**few     ********    many**

****** ****Margin of safety addresses uncertainties that may not be completely explained by available data**

## Nerve Agent Health Effects and AEGLs

**Nerve Agent Health Effects and AEGLs**

**Significant adverse effects**

**No significant adverse effects**

**Severe adverse effects**

**No adverse effects**

- Above AEGL 3, increasing cases nausea, vomiting,  then seizures and increasing possibility of  fatalities
**AEGL-3**

**AEGL-2            AEGL-3**
- Above AEGL 2, increasing degree of miosis (constriction or shrinking  of the pupil) with possible impairment of vision after dark or in dim light; runny nose; sweating; possible breathing difficulties, but  no permanent effects

**AEGL-1**
- Below AEGL 1, no observed adverse effects

**AEGL-1            AEGL-2**
- Above AEGL 1, may begin to cause minor miosis (constriction or shrinking  of the pupil); possible runny nose; no permanent effects

****** ****AEGL1**

****** ****AEGL 2   **

****** ****AEGL 3**

**few     ********    many**

**few     ********    many**

**few     ********    many**

****** ****Margin of safety addresses uncertainties that may not be completely explained by available data**

## AEGL APPLICATIONS: EPA Guidance for Toxic Industrial Chemicals

- US EPA Chemical Emergency Preparedness Office (CEPP)  to replace use of “ERPGs” with AEGLs (*Federal Register 1996*)
- Current CEPP guidance requires use of ERPG Level 2 in Risk Management Plans (RMPs) to model potential for reaching civilian population
-  ABOVE LEVEL 2 requires facilities to develop preventive measures
- Initially Level 3 was considered, as well as IDLH, but determined not enough safety margin

## AEGL APPLICATIONS: Toxic Industrial Chemicals, cont’d

*Per representative of USEPA CEPP office: *
- Level 1 not used in prevention aspects (planning) because
- ‘represents level of exposure  that doesn’t cause significant, much less permanent effects, and which citizens are potentially exposed to in daily lives (pumping gas, cleaning, hobbies)’
-  ‘there are more important things to worry about during an incident’
- No known use of Level 1 (ERPGs or AEGLs) in response implementation
- HAZMAT teams typically use the distances identified in the Emergency Response Guidebook which presents _Isolation Zones_ and _Protective Action Distances_
- The toxicological exposure values used to determine these boundaries  included ERPG 2-3, IDLH, and LC50’s based on animal studies

## Why Are AEGL Level 1 Values Derived? 

- Demonstrates that full spectrum of health effects have been considered
- Level 1 and Level 3 bracket potential low end and high end effects around this action level with
- * It COULD be used as a ‘notification level’ to acknowledge that exposed person may NOTICE something (but not at a critical action level)
- There is not a Level 1 AEGL for all  chemicals if the first effect is more appropriate as a Level 2
**BUT –the NAC-AEGL does not provide any specific implementation guidance or recommendations as to applications (they develop AEGL values only)**

## Think of a Tornado Emergency ..... 

**Tornado sighted in area**

**Conditions right for a tornado**

**Tornado hits**

**Normal weather**

**Think of a Tornado Emergency ..... **

- Assistance required

- Personal action required

- Personal awareness advised

**Tornado WARNING**

**Tornado WATCH**

## CHPPM Suggested Applications of CWA AEGLs

**Significant adverse effects**

**No significant adverse effects**

**Severe adverse effects**

**No adverse effects**

**CHPPM Suggested Applications of CWA AEGLs**

- (increasing chance of fatalities)
**AEGL-3**

**AEGL-2            AEGL-3**
- (increasing chance of severe irritation/impact ability to escape)

**AEGL-1**

**AEGL-1            AEGL-2**
- (increasing chance of discomfort/ annoyance)

**  ****Primary concern > AEGL-3 –be prepared to TREAT and ASSIST (rescue)**
** ****Minimize exposures between  AEGL 2-3**
-  EX: Recommend shelter-in place (SIP) >AEGL 2
-  **Prevent unnecessary  response related hazards:**
-  ‘alert’ when > AEGL1 <2
-  Prevent additional entry at > AEGL 1
-  Allow unrestricted reentry if < AEGL 1

**AEGL-1***

**AEGL-2***

**AEGL-3***

**few     ********    ****many**

**few     ********    ****many**

**few     ********    ****many**

## Example AEGL Application – CEPP and  Homeland Defense

**>AEGL-3**

- AEGL-2

- AEGL-3

- AEGL-1

**<AEGL-3 >AEGL-2**

**<AEGL-2 >AEGL-1**

**<AEGL-1**

**Example AEGL Application – ****CEPP and  Homeland Defense**

- Possible fatalities; severe effects ; medical attention

- Moderate effects; possible medical attention -***prevent these exposures***

- Non-permanent, mild effects– **warning range (take action at AEGL-2)**

- No adverse health impact (possible odor, annoyance ***starting at*** AEGL-1)

## EXAMPLE: Installation Threat Assessment

**“****plume” based boundaries based on AEGL-2**

**Notes:**
The risk management approach, as described in FM 100-14 and FM 3-100.4, is a process for identifying, assessing, and controlling risks as well as evaluating the effectiveness of risk control measures.  The OEH/ED identifies hazards that pose health threats to individuals critical to mission accomplishment.  These can ultimately be expressed as medical threats to the force and the mission.  The components of the risk management process have been translated into operational principles for assessing medical and health threats arising from OEH/ED hazards.  The Army OEH/ED surveillance and risk assessment system is designed to identify, assess, and recommend control measures for health and medical threats to CONUS U.S. forces from OEH/ED hazards.  The goal of the surveillance and risk assessment mission is to provide information to commanders so that informed ORM decisions can be made that consider OEH/ED hazards. 

## Update CSEPP AEGL Policy Paper 20 (AEGLs) and Enclosure (Risk Communication Package)

## USACHPPM Health Risk Communication Workshops

- For more information or to register on line, go to:
- _[http://](http://chppm-www.apgea.army.mil/risk)__[chppm](http://chppm-www.apgea.army.mil/risk)__[-www.](http://chppm-www.apgea.army.mil/risk)__[apgea](http://chppm-www.apgea.army.mil/risk)__[.army.mil/risk](http://chppm-www.apgea.army.mil/risk)_
- or call Ms. Suaquita Perry at 410-436-3515

- April 	     --  Las Vegas, NV
- June 	     --  Providence, RI
- August    --  Seattle, WA

## 
USACHPPM Chemical Agent Health Standards WEBSITE
http://chppm-www.apgea.army.mil/HRA/Caw/index.html

Veronique Hauschild, MPH
Deployment Environmental Surveillance Program (DESP)
410-436-5213/DSN 548-5213   FAX – 2407
Veronique.Hauschild@apg.amedd.army.mil

Coleen Weese, MD
PM, Occupational and Environmental Medicine Program
410-436-2578/DSN 584-2578   FAX  -4117
Coleen.Weese@apg.amedd.army.mil

Stephen Graham, CIH
PM, Industrial Hygiene Field Services
410-436-5244/DSN 548-3118   FAX – 9988
Stephen.Graham@apg.amedd.army.mil

Glenn Leach, PhD
Director of Toxicology  (US Army official member of NAC-AEGL)
410-436-5244/DSN 548-5244   FAX – 2407
Glenn.Leach@apg.amedd.army.mil

***USACHPPM Chemical Agent Health Standards WEBSITE***
_***http://chppm-www.apgea.army.mil/HRA/Caw/index.html***_
**Veronique Hauschild, MPH**
**Deployment Environmental Surveillance Program (DESP)**
**410-436-5213/DSN 548-5213   FAX – 2407**
- _[Veronique.Hauschild@](mailto:Veronique.Hauschild@apg.amedd.army.mil)__[apg](mailto:Veronique.Hauschild@apg.amedd.army.mil)__[.](mailto:Veronique.Hauschild@apg.amedd.army.mil)__[amedd](mailto:Veronique.Hauschild@apg.amedd.army.mil)__[.army.mil](mailto:Veronique.Hauschild@apg.amedd.army.mil)_
**Coleen Weese, MD**
**PM, Occupational and Environmental Medicine Program**
**410-436-2578/DSN 584-2578   FAX  -4117**
- _[Coleen](mailto:Coleen.Weese@apg.amedd.army.mil)__[.](mailto:Coleen.Weese@apg.amedd.army.mil)__[Weese](mailto:Coleen.Weese@apg.amedd.army.mil)__[@](mailto:Coleen.Weese@apg.amedd.army.mil)__[apg](mailto:Coleen.Weese@apg.amedd.army.mil)__[.](mailto:Coleen.Weese@apg.amedd.army.mil)__[amedd](mailto:Coleen.Weese@apg.amedd.army.mil)__[.army.mil](mailto:Coleen.Weese@apg.amedd.army.mil)_
*** ***
**Stephen Graham, CIH**
**PM, Industrial Hygiene Field Services**
**410-436-5244/DSN 548-3118   FAX – 9988**
- _[Stephen.Graham@](mailto:Stephen.Graham@apg.amedd.army.mil)__[apg](mailto:Stephen.Graham@apg.amedd.army.mil)__[.](mailto:Stephen.Graham@apg.amedd.army.mil)__[amedd](mailto:Stephen.Graham@apg.amedd.army.mil)__[.army.mil](mailto:Stephen.Graham@apg.amedd.army.mil)_
**Glenn Leach, PhD**
**Director of Toxicology  (US Army official member of NAC-AEGL)**
**410-436-5244/DSN 548-5244   FAX – 2407**
- _[Glenn.Leach@](mailto:Glenn.Leach@apg.amedd.army.mil)__[apg](mailto:Glenn.Leach@apg.amedd.army.mil)__[.](mailto:Glenn.Leach@apg.amedd.army.mil)__[amedd](mailto:Glenn.Leach@apg.amedd.army.mil)__[.army.mil](mailto:Glenn.Leach@apg.amedd.army.mil)_

**USACHPPM POCs:**