Dynamics of safety performance and culture: A group model building approach

The management of occupational health and safety (OHS) including safety culture interventions is comprised of complex problems that are often hard to scope and define. Due to the dynamic nature and complexity of OHS management, the concept of system dynamics (SD) is used to analyze accident prevention. In this paper, a system dynamics group model building (GMB) approach is used to create a causal loop diagram of the underlying factors influencing the OHS performance of a major drilling and mining contractor in Australia. While the organization has invested considerable resources into OHS their disabling injury frequency rate (DIFR) has not been decreasing. With this in mind, rich individualistic knowledge about the dynamics influencing the DIFR was acquired from experienced employees with operations, health and safety and training background using a GMB workshop. Findings derived from the workshop were used to develop a series of causal loop diagrams that includes a wide range of dynamics that can assist in better understanding the causal influences OHS performance. The causal loop diagram provides a tool for organizations to hypothesize the dynamics influencing effectiveness of OHS management, particularly the impact on DIFR. In addition the paper demonstrates that the SD GMB approach has significant potential in understanding and improving OHS management.     

Fatigue Subjective et Degradations de Performance en Environnement Hyperbare a Saturation

Au cours d'une plongée Active en atmosphere d'Helium-Oxygène (40 A.T.A. à saturation) trois sujets plongeura professionnels ont été souiius à une enquete quantifiée relative à leurs sensations de fatigue; paralleéement leur CFF (Critical flicker frequencyé a été déterminée.

Les inesuros ont été faitos en surface, pendant un confinement à I'Heliox, pendant la compression, le séjour au fond, la décompression, et après retour-surfaco (durée de l'exploration: 16 jours). L'analyse statistique des résultats a conduit aux conclusions suivants:

(1) Les signes subjectifs décelés ont consisté en baisse do vigilance et troubles physiques.

(2) Ces signes sont plus marqués pendant la compression et la saturation. lis sont réduits en décompression, sans effet conaécutif certain.

(3) Les signes de fatigue ne sont pas différents le matin et le soir.

(4) La fréquence critique do papillotoment (CFF) est négativement correlée avec la profondeur.

(5) Los modifications de CFF sont correlées avec le développement des signes subjectifs do fatigue.

(6) La fatigue hyperbare est un syndrome hétérogèno oú la baisse de vigilance et les troubles physiques paraissent tenir une place majeure.     

COSTA: A Computerized Support System for the Emergency Technical Advisory Body in Japan

If an accident resulting in an emergency occurs at a nuclear facility, the emergency technical advisory body (ETAB) is asked to make technical advice to the national government for emergency response. In order for the ETAB to carry out its role, a significant amount of materials containing information on nuclear power plants is prepared in the ETAB. These materials are all paper copies and very voluminous. Therefore it is required that they should be computerized for more effective use. Further, methods should be developed which aid the ETAB to understand the status of the affected facility and to predict potential radioactivity release to the environment.

To support the ETAB's activities in an emergency, the materials have been computerized as databases for more effective and quick use of them, and an expert system has been developed to quickly predict accident progression and environmental fission product release with the multivariate analysis method. The databases and the expert system have been unified to be a system of COSTA. The first phase of developing COSTA has been completed in FY1992. This paper describes the present status of development of COSTA.     

An exploratory study of the relationship between construction workforce physical strain and task level productivity

The monitoring of construction workforce physical strain can be a valuable management strategy in improving workforce productivity, safety, health, and quality of work. Nevertheless, clear relationships between workforce performance and physical strain have yet to be established. An exploratory investigation of the relationship between task level productivity and physical strain was conducted. Nine participants individually performed a four-hour simulated construction task while a wearable physiological status monitor continuously assessed their physiological condition. Heart rate, relative heart rate, and breathing rate were utilized as predictors of physical strain, and task level–single factor productivity was used as an index of productivity. Numerous regression models were generated using the collected data. This investigation initially unsuccessfully attempted to establish a relationship between physiological condition and productivity at the individual worker level. However, an analysis of the regression models showed that there is a relationship between productivity and either heart rate or relative heart rate at the group level, and that this relationship is parabolic. Breathing rate was proved to not be a significant predictor of productivity. Research results significantly improve understanding of the relationship between work physiology and task productivity. Researchers and practitioners may use the tested monitoring devices, analysis methods, and results to design further applied studies and to improve workforce productivity.     

Changing the speed of shift rotation: a field study

Abstract

A group of 33 controllers of an emergency service were studied before and after a change in shift roster. The original roster was the traditional weekly rotating type of three shifts, morning, afternoon and night in that direction, in which controllers worked seven consecutive shifts of the same type. This was changed to a rapidly rotating roster of shifts with no more than three consecutive night shifts. The direction of shift change remained the same. Sleep and meal diaries were kept by all controllers for 2 weeks before the roster change. Self-report measures were taken of health, social drug consumption and work variables, an anxiety inventory, the State-Train Anxiety Inventory and the Work Environment Scale were administered both before and 5 months after the roster change. Significant improvements were found after the shift roster change on almost all measures with the exception of self-reported nervousness and loss of appetite and a number of items in the Work Environment Scale. This finding provides some evidence from the field for the argument that rapidly rotating shifts may be the optimal form of shift system.     

Some factors affecting motorcyclists' conspicuity

Three experiments examined some of the factors that might affect motorcyclists' conspicuity to other road users. In each case, subjects saw a sequence of slides showing traffic, some of which contained a motorcyclist. A record was taken of their reaction times to decide whether or not a motorcyclist was present in each slide. Experiments 1 and 2 examined the effects on conspicuity of headlight use, type of clothing, distance of motorcyclist from viewer, and driving situation (urban or semi-rural). Experiment 3 looked more closely at environmental influences on motorcyclist conspicuity, systematically varying the level of background ‘clutter’ behind the motorcyclist. All three experiments indicate that the effectiveness of the conspicuity aids used, especially clothing, may depend on the situation in which the motorcyclist was located: bright clothing and headlight use may not be infallible aids to conspicuity. Brightness contrast between the motorcyclist and the surroundings may be more important as a determinant of conspicuity than the motorcyclist's brightness per se. Motorcyclists' conspicuity is a more complex issue than has hitherto been acknowledged.     

Effect of Delays in Afterheat Removal on Consequences of Massive Air Ingress Accidents in High-Temperature Gas Cooled Reactors

Massive ingress of air into the core of a high-temperature gas cooled reactor is among the accidents with a low occurrence frequency, but there are still gaps in understanding with respect to its consequences. In the present paper, massive air ingress combined with a delayed start of the afterheat removal system is investigated and compared to air ingress, accidents with normal operation of the afterheat removal procedure. A computer programme REACT/THERMIX used for these accident analyses is described. For a high-temperature gas cooled reactor with a pebble bed core, it is shown that massive air ingress has no real safety endangering consequences even if the operation of the afterheat removal system is delayed by 6 h.     

建筑施工企业安全管理问题与对策研究

本文对建筑施工企业安全管理问题进行了研究，并制定了相应的对策来解决这些问题，希望能为广大的建筑施工企业管理者提供一些参考。     

Occupational slip,trip, and fall-related injuries can the contribution of slipperiness be isolated?

To determine if the contribution of slipperiness to occupational slip, trip and fall (STF)-related injuries could be isolated from injury surveillance systems in the USA, the UK and Sweden, six governmental systems and one industrial system were consulted. The systems varied in their capture approaches and the degree of documentation of exposure to slipping. The burden of STF-related occupational injury ranged from 20 to 40% of disabling occupational injuries in the developed countries studied. The annual direct cost of fall-related occupational injuries in the USA alone was estimated to be approximately US$6 billion. Slipperiness or slipping were found to contribute to between 40 and 50% of fall-related injuries. Slipperiness was more often a factor in same level falls than in falls to lower levels. The evaluation of the burden of slipperiness was hampered by design limitations in many of the data systems utilized. The resolution of large-scale injury registries should be improved by collecting more detailed incident sequence information to better define the full scope and contribution of slipperiness to occupational STF-related injuries. Such improvements would facilitate the allocation of prevention resources towards reduction of first-event risk factors such as slipping.     

Occupational slips and falls: more than a trivial problem

Abstract

The significance of occupational falls is established through analysis of workers' compensation data of a major insurance company. The data covered 11%of the American privately insured workforce and exposure estimates were based on Bureau of Labor Statistics demographics. The number of incidents and the relative cost of falls were examined by age, gender, industry, climate and geographic region and empirical data are presented. These data establish the enormous cost of falls measured in terms of individual pain and suffering and in losses to industrial organizations.