Public health CBRN course
Public Health Risk Assessment
Bonnie Henry, MD, FRCPC
Doug Sider, MD, FRCPC
Case 1
 A tornado has just hit your community;
dozens of walking wounded are appearing at
the local hospital, as well as individuals
looking for loved ones
 Ambulance communications notifies the local
hospital to expect at least 30 patients of
varying severity in the next hour
 Municipal officials have called you to the EOC
and asked you to prepare some public safety
messages (re food, water, shelter)
Case 2
 An explosion has occurred at the Bloor
station in the Toronto subway system
 CBRN team is responding due to a phone call
to a local TV station from a terrorist group
chanting “Death to Canada” and claiming that
a radioactive substance has been released
Case 3
 A mysterious influenza-like illness
beginning in Southeast Asia has been
found to “jump” from birds to people
 Over 400 people of all ages have been
affected; mortality is 50%
 Recent reports indicate some human to
human transmission
Case 3
 The disease is making its way west;
cases are turning up in Europe
 The WHO announced that the world may
be entering Phase IV of the Pandemic
phases (human cases found with
subtype; established human spread)
Questions to ask:
1. Is my organization/community
prepared to respond to these events?
2. Does my organization/community
need to be prepared anyway?
3. What are our priorities?
Have you done your
risk assessment?
Goals of Session
 Describe the need for and context of
risk assessment in emergency health
planning
 Describe and prioritize the risks faced
by of your organization/community to
better prepare for public health
emergencies
Phases of an Emergency
(F/P/T National Framework)
1.
2.
3.
4.
5.
Risk assessment
Mitigation
Preparedness
Response
Recovery
Public Health Emergency Preparedness and Response

GOAL: To enable and ensure a consistent response to public
health emergencies and emergencies with public health impacts.
Hazard Identification and Assessment
Immediate Outcomes

Awareness of the hazards which are relevant to the catchment area of the
board of health.

Risk-based emergency planning and programming to guide ongoing
board of health preparedness efforts.
Requirement
1.
The board of health shall, in accordance with the Provincial Protocol on
Public Health Emergency Preparedness, 2007, identify and assess the
relevant hazards and risks to public health within the health unit area.
What’s your risk?
Naturally occurring events
Technological/infra-structure
events
Human related events
Natural events - examples
Hurricane
Tornado
Extreme heat/cold
Ice storm
Snow storm
Flood
Epidemic/pandemic
Epidemic/pandemic
Influenza
SARS
E Coli
Smallpox
Technological/
Infrastructure events
Electricity system failure
Transportation emergency
Water system emergency
Structural collapse
HAZMAT events
Fire
Nuclear power station events
Human Related Events
Terrorism – biological, chemical,
nuclear, radiological
Civil disturbance
Labour actions
Armed conflict
Large public gatherings
What is your risk for each?
Risk = Probability x Impact
www.ceep.ca
Risk = Probability x Impact
Components of Risk
Probability?
Impact?
A.
B.
C.
D.
4.
3.
2.
1.
Highly likely?
Likely?
Possible?
Unlikely?
Catastrophic
Critical
Serious
Marginal
Probability
Probability
Rating
Description
Detail
A
Highly Likely
nearly 100% probability in next year
B
Likely
between 10 and 100% probability in next year, or
at least one event in next 10 years
C
Possible
between 1 and 10% probability in next year, or
at least one event in next 100 years
D
Unlikely
less than 1% probability in next 100 years
Components of Impact
Impact
Impact
Human
Physical
infrastucture
Business
4.
3.
2.
1.
Catastrophic
Critical
Serious
Marginal
Impact - Human
4. high probability of death
3. high probability of injury or illness; low
probability of death
2. low probability of injury, illness or death
1. unlikely to cause injury, illness or death in
community members/providers
Impact – Physical Infrastructure
4. extensive physical infrastructure damage
with substantial service disruptions, high
costs and extended recovery time
3. moderate physical infrastructure damage
2. minor physical infrastructure damage
1. unlikely to cause physical infrastructure
damage causing service disruption with
resultant costs/recovery challenges
Impact - Business
4. numerous public/private sector entities
unable to provide services
3. significant/widespread or long term service
interruptions
2. minor or limited or short term service
interruptions
1. unlikely to cause public/private sector
service interruptions
Overall Impact Rating
11-12
Catastrophic
Community cannot assure core
public/private services without
extensive assistance from provincial
or federal resources
8-10
Critical
Community can only assure a normal
level of services with assistance from
outside the region or the community
is reduced to providing a minimal
level of service with normal resources
existing within the community
5-7
Serious
Community can assure a normal level of
services with assistance from within
region or reduced levels of service
with resources existing within the
community
3-4
Marginal
Normal level of functioning or increased
level of public/private services
required within the community
Risk Assessment - examples
Threat
Probability
Impact
(H+P+B)
Risk
Tornado
B
3+3+2
B8
Dirty Bomb
B/C/D
3+1+2
B/C/D6
Pandemic
influenza
B
4+1+4
B9
Risk Rating
A
Highly
Likely
B
Likely
C
Possible
D
Unlikely
11-12:Catastrophic
A11-A12
B11-B12
C11-C12
D11-D12
8 -10: Critical
A8-A10
B8-B10
C8-C10
D8-D10
5 - 7: Serious
A5-A7
B5-B7
C5-C7
D5-D7
3 - 4: Marginal
A3-A4
B3-B4
C3-C4
D3-D4
Impact/Probability
Priorities
1. Pandemic ‘flu’
2. Tornado
3. Dirty bomb
Priorities
Perform this exercise for all:
 Naturally occurring events
 Technological/infrastructure
events
 Human related events
Summary
Assessment of risks is first step in
planning
Helps focus efforts and ensures no
possibilities are missed
Helps prioritize efforts in preparedness
“The only thing more difficult than
preparing for an emergency is
having to explain why you didn’t”