Theories of Accident Causation
CII OSHA Recordable Performance -
1993-2000
1
Lost Time
10.4
Recordables
297
First Aid
Near Misses?? At Risk Behaviors??
A DISPROPORTIONATE NUMBER OF ACCIDENTS OCCUR IN CONSTRUCTION
Nearly 6.6% of the industrial workforce is in construction. But, over 20% of the fatalities occur in construction (1,154 fatalities in 2000) And, over 12% of the disabling injuries occur in construction (over 500,000 injuries in 2000) Do these statistics have anything to do with firms serious about safety?
What Is An Accident?
Unplanned event Generally associated with negative consequences – Fatalities – Injuries – Near misses – Damaged materials – Shattered nerves
Do accidents just happen or are they caused?
Theories of Accident Causation
Understanding the causes of accidents may lead to an effective means of their prevention. No worker wants to be injured, but it still happens thousands of times every working day. Why??
1: Accident Proneness Theory
Accident-Proneness Theory
Old View
“Injuries happen to people who have a genetic predisposition to being injured”
The theory states that there are inherent characteristics of some individuals that predispose them to a greater probability of being involved in accidents.
Accident-Proneness Theory
A very controversial theory Many research studies have been conducted which lend support for the theory (Studies show injuries are not randomly distributed, but do studies recognize differences in hazard exposure?) Other studies have shown that there is no basis for the theory
Accident-Proneness Theory
New View
Recent researchers view accident proneness as being associated with the propensity of individuals to take risks or to take chances. This presents a more positive view for safety, as behavior can be altered even if the propensity to take risks cannot.
2: GOALS-FREEDOMALERTNESS THEORY
Goals-Freedom-Alertness Theory
This is a fundamental concept that accidents are the result of low quality (unsafe) behavior resulting from an unrewarding psychological climate that does not contribute to mental alertness.
Goals-Freedom-Alertness Theory
Workers should have the ability to set attainable goals. Workers should have the freedom to pursue their goals. This will result in a “rich” work climate with alertness and fewer accidents (Workers stay focused)
Goals-Freedom-Alertness Theory
A
positive work environment is good for safety.
3: ADJUSTMENT STRESS THEORY
Adjustment Stress Theory
A negative work environment contributes to accident causation. A negative work environment is often caused by stress. Excessive stress prevents the individual from focusing on the work.
Adjustment Stress Theory
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•
• •
•
• •
Stress comes from many sources. On the Job Poor relationship with the supervisor Poor relationship with crew members Harsh deadlines Poor coordination Excessive rework Cost overruns Long overtime commitments Crowded work areas Jobsite hazards
Adjustment Stress Theory
Stress comes from many Sources. Off the Job P •oor relationship with the spouse • sick child • mortgage due date
Table 1.1 Social Readjustment Rating Scale of Holmes and Rahe Value Life Event
Death of spouse Divorce Marital separation Jail term Death of close family member Personal injury or illness Marriage Fired at work Marital reconciliation Retirement Change in health of family member Pregnancy Sex difficulties Gain of new family member Business readjustment Change in financial state Death of close friend Change to different line of work Change in number of arguments with spouse Mortgage over $10,000 Foreclosure of mortgage or loan 100 73 65 63 63 53 50 47 45 45 44 40 39 39 39 38 37 36 35 31 30
Change in responsibilities at work Son or daughter leaving home Trouble with in-laws Outstanding personal achievement Wife begins or stops work Begin or end school Change in living conditions Revision of personal habits Trouble with boss Change in work hours or conditions Change in residence Change in schools Change in recreation Change in church activities Change in social activities Mortgage or loan less than $10,000 Change in sleeping habits Change in number of family get-togethers Change in eating habits Vacation Christmas Minor violations of the law
29 29 29 28 26 26 25 24 23 20 20 20 19 19 18 17 16 15 15 13 12 11
4: Chain of Events
Chain of Events
This is not truly a theory of accident causation, but is often referred to as one. It is really a conceptual portrayal of how accidents occur. The chain of events states that there is not a single cause of an accident but there are many causes an accident.
Chain of Events
In general, every accident is preceded by a series of events or activities. If any one event or activity had been done differently, the accident would not have occurred (“break the chain to avoid the accident”). Different people may be associated with the different links in the chain.
Chain of Events
This has implications for many parties on the construction site (the worker who was injured, the worker’s crew, the foreman, the superintendent, other crews, the project manager, the subcontractors, the safety rep., etc.). There are many links in the chain and only one link needs to be broken. Also called the Domino Theory
If I had done this, that would not have happened
Contributing Factors
Only one party is required to break the chain!!
5: Distraction’s Theory
Distraction’s Theory
This theory states that accidents are caused when workers are distracted when they are performing their work tasks. There are two types of distractions.
Distraction’s Theory
Jobsite Hazards can be a source of distraction
– Workers will try to avoid being injured so they naturally focus on the hazard, but this occurs as they are trying to do work. Trying to get the task done may cause the worker to be distracted and to ignore the hazard, resulting in an injury.
The Dilemma:
Focus on the Hazards
or
Focus on Getting Tasks Done
high
Distraction: Working near a powerline
low focus on distraction
Probability of Injury Occurrence low
high focus on distraction
Safe Safe low Zone Zone
Work Task Achievement
high
high
Probability of Injury Occurrence
Distraction: Minor Hazard
low focus on distraction
low
low
high focus on distraction
high
Work Task Achievement
I n j u r y
Low Focus on Hazard
O c c u r r e n c e
High Focus on Hazard
Low
Task Achievement
High
I n j u r y
Don’t work in this zone!!!
Low Focus on Hazard
High Focus on Hazard Low Task Achievement High
O c c u r r e n c e
Distraction’s Theory
Mental worries can be a source of distraction.
– Workers will try to focus on the work to be done, but may be distracted by worries caused by personal or job-related concerns. Failure to be able to focus on the work increases the likelihood of being injured. – Remember the Holmes and Rahe Scale
high
high focus on distraction
Probability of Injury Occurrence
Major Mental Distraction
low
low
low focus on distraction
Work Task Achievement
high
Can distracted workers be identified?
Each of the Accident Theories Help Our Understanding of Accident Causation
Remember, no worker wants to be injured. Worker tasks should be structured so they are least likely to be injured.
How to Achieve Safety:
Don’t permit unsafe behavior Provide a rewarding work environment Make everyone responsible for safety Provide a safe work environment.
Thank you!!!