1. Construction Safety Management
UP Copyrights 2009
Faculty of Applied Engineering and Urban Planning
Construction Safety Management
Civil Engineering Department
2nd Semester 2008/2009
CH 1: Injury Accidents and Their Causes
Lecture 3 - Week 2
Eng: Eyad Haddad

2. Injury Accidents and Their Causes Accidents don't just happen; they are caused. An Accident defined as : Un planned event which this event is undesirable ,unexpected ,and no controlled . Accident dose not necessarily result in an injury , Accident that can result in damage to equipment and Materials ليس بالضرورة ان يحدث إصابات بالأرواح نتيجة الحادث ولكن يمكن أن يحدث تلف بالآليات والمواد

3. that accidents do not just happen.
Final Comments :
There have been many attempts to explain the causes of worker accidents ?
Of the various theories that have been posited, there is general agreement
that accidents do not just happen.
The physical conditions in the workplace
The states of mind of the workers.
Managers and supervisors
The mental state of each worker.

4. why Do Accidents Occur? Effective accident prevention depends on an understanding of the reasons accidents occur. Why then do accidents occur? Some of the theories of accident causation will be discussed in this chapter Accident-proneness (Personal factors) 2- Goals-Freedom- Alertness (management should let a worker have a well defined goal and should give the worker the freedom to pursue that goal) Adjustment-Stress (safe performance is compromised by a climate that diverts the attention of workers) Chain-or-Events Distractions theories .

5. 1- The Accident-Proneness Theory
Perhaps the oldest and best - known theory of accident causation is the accident-proneness theory.
This theory is focused on personal factors related to accident causation.
It is based on the assumption that when several individuals are placed in similar
conditions, some will be more likely than others to sustain an injury.
Essentially the advocates of the theory contend that accidents are not randomly
distributed or that sustaining an injury is not simply a chance occurrence.
They assert that some persons have permanent characteristics that predispose them to
a greater probability of being involved in accidents.
Research Studies :
Vernon ( 1918 )
Farmer and Chambers (1929)
Shaw and Sichel ( 1971)
Schulzinger ( 956 )
De Reamer ( 1958 )
Denning ( 1983 )

6. The Accident-Proneness Theory
Vernon :
One of the first researchers on this topic stated that accident proneness could be traced to personality traits .
Farmer and Chambers (1929) :
Defined accident proneness as "a personal idiosyncrasy الصفات الشخصيةpredisposing the individual who possesses it in a marked degree to a relatively high accident rate."
Shaw and Sichel 1971
This theory has the underlying assumption that even when exposed to the same conditions, some people are more likely to be involved in accidents because of "their innate propensity الميل بالفطرة for accidents .
Several researchers have concluded from such studies that injuries are not randomly distributed and that some individuals sustain more injuries than would be predicted by chance a1one

7. 2. The Goal –Freedom- Alertness Theory
Was first suggested by Kerr (1950, 1957) :The theory states that
“safe work performance is the result of a psychologically rewarding work environment”
كلما كانت البيئة النفسية للعمل جيدة ينتج عن ذلك مستويات أعلي لإنجاز العمل والعكس صحيح
He believed that
"great freedom to set reasonable attainable goals is accompanied typically by high quality work performance.“
وضع الأهداف المعقولة والقابلة للتطبيق تؤدي بالضرورة لحدوث انجاز للعمل ضمن معايير الجودة
The essence of the theory is that management should let a worker have a well- defined goal and should give the worker the freedom to pursue that goal.
لذلك يتوجب على الادارة ان تحدد لكل عامل هدف واضح وإعطاءه مساحه من الحرية لانجاز ومتابعة هذا الهدف( العمل).

8. The Goals – Freedom - Alertness Theory (cont.)
According to the goals-freedom-alertness theory, managers and
supervisors should be trained to make the work more
rewarding for workers.
They might do so through various managerial techniques, including
participative management,
clear work assignments,
positive reinforcement,
and goal setting.

9. 3- Adjustment - Stress Theory
Kerr explain accident causation : The adjustment-stress theory states that safe performance is compromised by a climate that diverts the attention of workers .
The goals-freedom-alertness theory states that workers will be safe in a fulfilling or positive work environment, the adjustment-stress theory sets forth the conditions under which a worker will not be safe.
It contends that "unusual, negative, distracting stress" الضغط النفسي الداخلي placed on workers increases their "liability to accident or other low quality behavior"
This theory emphasizes the nature of the work climate as a major factor in accident occurrence.

10. Adjustment-Stress Theory cont.
Kerr referred to the theory as a climate theory.
The climate or environment conditions can be assumed to be either:
Internal
(fatigue إعياء, alcohol consumption إدمان الكحول, loss of sleep قلة النوم, drugs, disease الامراض, or such psychological stresses as worry, personal problems مشاكل شخصية, or anxiety القلق) .
external.
(noiseالضجة , illumination الإضاءة القوية, temperatureالحرارة, or excessive physical strain إجهاد غير محتمل)
If the worker cannot adjust to the stress, the chance of injury is increased.
In other words, stress diverts a worker’s attention during work hours and that diversion increases the susceptibility to injury.

11. Adjustment-Stress Theory cont.
For example :
read a road map while driving a car (not safe )
a driving when there is time Spare ( very safe )
Many of the sources of stress are:
attributable to management
job security
A stressful situation can arise between a worker and a supervisor
Family
Personal sources of stress include substance abuse, bodily pain, fatigue, and lack of sleep
Supervisors should be sensitive to their workers and should be able to tell
when a worker appears to be particularly distraught.

12. Kerr's Estimates of Relative Merites of Different Accident Theories in Explaining Accident Occurrence
Figure 1.1

13. Typical project Organizational Structure of a General Contractor

14. Organizational Chart on a Construction Project

15. ** Final Comments :
There have been many attempts to explain the causes of worker accidents ?
Of the various theories that have been posited, there is general agreement that accidents do not just happen.
The physical conditions in the workplace
The states of mind of the workers are invariably the primary factors
under consideration.
Managers and supervisors certainly have the ability to influence the
physical conditions.
The mental state of each worker.
- Managers and especially supervisors should try to identify such situations and respond accordingly.
- It is also incumbent on managers and supervisors to recognize that their actions can exert an unfavorable influence on the mental states of workers , Workers of not want to be injured, so a cooperative spirit should exist with regard to safety.

16. Review Question :
1. Defend and criticize the past research that has attempted to test the validity of the accident-proneness theory.
2. Explain how the distractions theory can be used to point out management's role in accident prevention.
3. Describe the different theories of accident causation.
4. which theory of accident causation gives the most consideration to the physical conditions at the place of work?
5. Compare the adjustment-stress theory with the distractions theory.
6. Does the chain-of-events theory place the blame for accident on management?
7. How are the goals-freedom-alertness and adjustment-stress theories related?
8. Describe conditions under which the distractions theory would suggest that safety and productivity are in conflict. Conversely, describe conditions under which the distractions theory would suggest that safety and productivity are not in conflict but are simultaneously achievable.
9. why is the chain of events considered a conceptualization of accident causation rather than a theory?
10. How does management playa role in the chain of events of accident causation? Give examples.