Disaster Exposure: The Four R’s
Daniel A. Vallero, Ph.D.
National Exposure Research Laboratory
U.S. Environmental Protection Agency
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Risk Assessment:
Risk assessment* is a process where information is
analyzed to determine if an environmental hazard
might cause harm to exposed persons and
ecosystems.
Many decisions are made based on risk at various stages of a
disaster: rescue, recovery, re-entry and re-habitation.
* “Risk Assessment in the Federal Government” (National Research
Council, 1983)
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In exposure, time is of the essence…
Short-term
exposures
can be
accompanied
by chronic
effects….
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2
Time & Quality of Information to Protect Public and
First Responders Vary by Stage:
Re-entry
Rescue
Exposure
Recovery
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Re-habitation
3
Rescue
Lesson learned: ORD part of overall team to protect public health
• Portable, state of the art equipment and expertise provided to first
responders
• “Research” focus needs immediacy….
– Same tools often applied, but at higher levels of detection and more immediate
reporting
• Crime scene, forensics and rescue efforts have primacy
• Responder protection is also crucial
• Proper respirators and personal protection
– EPA takes respirator use very seriously….
• Protocols
• Very different from “environmental exposures”
– e.g. levels of dioxins and benzene to protect firefighters with PPE much
higher than a person without protection exposed for 30 years
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Recovery
– Somewhat more time to consider potential public exposures…
• … but still working under first responder teams
• Logging data and retrospectively conducting analyses
• Different quality assurance needs, but still not the “typical” research design
– Crime scene forensics still ongoing (defer to law enforcement), but more
deliberate
• In WTC, evidence moved to Staten Island
– Adaptation to FEMA and other management actions
• Coordination among EPA, Army Corps of Engineers, FEMA and
response agencies.
• Examples:
– Water & wastewater treatment plant assessment
– Separation of hazardous wastes
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Re-Entry
–Even more time (longer exposures)
• Closer to typical research protocol, but must support local/state
agencies
–Benchmarks are crucial
• Understandable
• Allows for risk comparisons
• Helps distinguish reported concentrations from reasonable exposures
–EPA has protocols, but need to be tailored to each
emergency
•
•
•
•
•
Start with applicable and relevant standards
Go to risk-based approach
Last resort: Occupational scenarios (e.g. OSHA PAL)
Then adapt
Characterize background….
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Re-habitation
–Longest potential exposures
• Closest to typical metrics (e.g. lifetime average daily dose)
–Conservative approaches are challenged
• People and businesses want to get back to normal
• Need solid reasons for denying this…
–Benchmarks
• Rely on State and Local to start the process
• Technical approach
– Background
– Detection limits
– Technical practicality, etc…..
• Remediate to health standard or best estimate of what
background was prior to accident, or….?
– E.g. by proxy (may not know what it was, but use general urban
background)
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Some Key Milestones
EPA has learned numerous lessons and has been improving emergency
response, by:
– Assessing and remediating indoor contamination caused by building
collapse or other environmental disaster.
• National Homeland Security Research Center developing subchronic
health-based exposure advisory levels for the general public called
Provisional Advisory Levels (PALs).
– PALs address exposure durations of one day, 30 days, and two years for
chemical contaminants detected in air or drinking water.
– EPA has developed PALs for over 20 chemicals
– Equates to over 360 separate values : three exposure durations, for three
levels of severity and for two environmental media .
• Continuing effort with the National Research Council's Committee on
Toxicology to develop Acute Exposure Guidance Levels (AEGLs).
– Emergency response standards applicable to the general public.
– 3 levels of severity and for the durations of 10 minute, 30 minute, one hour, 4
hour and 8 hour exposures.
• PALs being developed for benchmarks to bridge the gap between acute
exposure durations covered by the AEGLs & the chronic lifetime
exposures covered by inhalation RfCs & oral RfDs.
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Some Key Milestones (Cont’d)
– Developed a method to assess risk from exposures to contaminated
building surfaces.
• Will be incorporated into upcoming revision of the Risk Assessment Guidance
for Superfund, Part E, Dermal Risk Assessment
– Continually developing & refining scenario-driven disaster response plans
on national & regional level.
• Inter-agency working groups, sponsored by EPA and DHS, have developed
restoration plans for large transportation infrastructures.
• Produced universal templates to support generic disaster preparedness plans
for various scenarios.
• Supporting several inter-agency working groups developing uniform validated
sampling plans, analytical methods and quality assurance protocols to support
timely cleanup and restoration of infrastructures after disaster events.
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Bottom Line
Exposure is critical to each phase of emergency
response….
Re-entry
Rescue
Exposure
Recovery
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National Exposure Research Laboratory
Re-habitation
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Contact me:
[email protected]
Photo image area measures 2” H x 6.93” W and can be masked by a
collage strip of one, two or three images.
The photo image area is located 3.19” from left and 3.81” from top of page.
Each image used in collage should be reduced or cropped to a maximum of
2” high, stroked with a 1.5 pt white frame and positioned edge-to-edge with
accompanying images.
Office of Research and Development
National Exposure Research Laboratory