Interactive mechanism of working environments and construction behaviors with cognitive work analysis: an elevator installation case study

Unsafe behavior is a leading factor in accidents, and the working environment significantly affects behaviors. However, few studies have focused on detailed mechanisms for addressing unsafe behaviors resulting from environmental constraints. This study aims to delineate these mechanisms using cognitive work analysis (CWA) for an elevator installation case study. Elevator installation was selected for study because it involves operations at heights: falls from heights remain a major cause of construction worker mortality. This study adopts a mixed research approach based on three research methodology stages. This research deconstructs the details of the working environment, the workers’ decision-making processes, the strategies chosen given environmental conditions and the conceptual model for workers’ behaviors, which jointly depict environment–behavior mechanisms at length. By applying CWA to the construction industry, environmental constraints can easily be identified, and targeted engineering suggestions can be generated.     

Preventing fall-from-height injuries in construction: Effectiveness of a regulatory training standard

Introduction: A regulatory training standard for construction workers using fall protection equipment became mandatory in 2015 in the province of Ontario, Canada. By the end of the transition period in 2017, 418,000 workers had been trained to the new standard. Two primary research questions were posed: (1) To what extent does the WAH training affect practices at the worksite? and (2) Has there been a change in the incidence of fall-from-height injuries coincident with the introduction of the WAH Training Standard? Materials and methods: A longitudinal survey of 633 learners was conducted in 2017 at one-, four- and seven-week post-training. A quasi-experiment estimated the incidence of lost-time injuries attributed to falls from heights in 2017 compared to 2012–2014 for a census of construction workers insured for work disability in Ontario, Canada. Results: Learners self-reported substantial increases in knowledge of and improvements in safe work practices when working at heights. The incidence rate of lost-time claim injuries attributed to falls targeted by the training declined by 19.6% (95% CI: 10.7, −27.6), compared to corresponding declines of 2.1% (95% CI: −6.3, 9.9) for other fall injuries and 7.2% (95% CI: 1.8, 12.3) for non-fall traumatic injuries. The observed decline was largest among the smallest employers (<5 full-time equivalent employees). Conclusion: The evaluation findings provide consistent support for a conclusion that the mandatory training standard was effective in reducing the incidence of injuries targeted by the training. However, the effects were modest and did not eliminate the problem. Practical application: A mandatory training standard should be considered as one approach to preventing traumatic injuries. However, other approaches higher in the hierarchy of risk controls should also be considered.     

高处作业人员位置与生理信号相关性分析

为对高处作业人员位置状态进行识别,加强对高处施工人员作业状态的监控,采用VR技术模拟高处作业,同时利用人-机-环同步平台,采集平地处、一级高处作业(取4 m为例)以及二级高处作业(8 m为例)情景下的6种生理信号数据,运用SPSS软件对生理信号进行数据分析。结果显示,不同高处作业人员对皮电信号(EDA)的时域具有显著性影响,而与其他生理信号时域特征不具备明显的相关性;作业人员的EDA均值(IESA)与高度(H)呈现二次多项式相关性:IEDA=-0.0284H2+0.7377H+C(C为个体修正常数)。基于此,EDA可以作为高处作业人员位置的参考判定依据,并且安全管理人员可以对高处作业人员进行实时监控,减少高处作业事故。     

Occupational accidents with ladders in Spain: Risk factors

Introduction

Occupational accidents suffered by workers in Spain when using ladders were analyzed over a six year period from 2003-2008, during which the total of notified ladder-related accidents amounted to 21,725. Method: Different accident-related factors were identified for the purpose of developing a pattern of those factors that had the greatest influence on the seriousness and the fatality of such accidents. Thus, a series of variables were examined such as age and length of service of the injured worker, firm size, the work sector, the injury suffered, and the part of the body that was injured. Since falls is the most frequent and most serious of ladder related occupational accidents, a special analysis of falls was performed. Results: The findings showed that the seriousness of ladder-related accidents increased with the age of the injured worker. Likewise, accidents at places other than the usual workplace were more serious and registered higher fatalities than those that occurred at the usual place of work. Conclusions: The analysis of falls from ladders established that accidents in smaller-sized firms were of greater seriousness and involved more fatalities than those in larger-sized firms. The investigation also underlined the need for stricter compliance with preliminary safety assessments when working with ladders.     

Aerial lift fall injuries: a surveillance and evaluation approach for targeting prevention activities

PROBLEM: Work on aerial lift platforms exposes workers to fall hazards. The objective of this study was to identify the most common injury scenarios and determine current research gaps for addressing fall incidents associated with aerial lifts. METHODS: Three databases were searched: Census of Fatal Occupational Injuries (CFOI), NIOSH Fatality Assessment and Control Evaluation (FACE) reports, and OSHA Incident Investigation Records. RESULTS: The majority of falls/collapses/tipovers were within the height-category of 10-29 feet. Tipovers comprised 44-46% of boom-lift falls and 56-59% of scissor-lift falls. Constructing and repairing activities were most commonly associated with fall/collapse/tipover incidents. DISCUSSION: CFOI and OSHA/FACE show convergent data, suggesting similar scenarios for aerial lift tipovers. IMPACT ON INDUSTRY: The analysis provides the aerial lift industry information to prioritize their efforts on aerial lift design.     

Deaths in construction related to personnel lifts, 1992-1999

Problem: This study examined deaths of construction workers due to personnel lifts (boom-supported and scissor lifts, suspended scaffolds, and crane platforms). Methods: Deaths of construction workers for 1992–1999 were examined using data from the Census of Fatal Occupational Injuries, a Bureau of Labor Statistics database. Results: The study identified 339 deaths: 42% from boom-supported lifts; 26% from suspended scaffolds; 19% from scissor lifts; 5% from crane platforms; and 7% from unapproved lifts (e.g., forklift platforms). The main causes of death were falls (36%), collapses/tipovers (29%), and electrocutions (21%). Discussion: Recommendations include: following OSHA regulations, wearing personal fall protection equipment, adequate maintenance, inspection before use, and training on the model of lift used. Precautions are also needed to prevent contact with overhead power lines. Impact on industry: The increasing popularity of boom-supported lifts and scissor lifts, both in construction and other industries, make their safety an important issue.     

How car and steel workers in different countries see their work

This study is concerned with how car and steel workers in different countries see their work and what features of their work they feel important. The material is drawn from two international projects, namely the car and steel industry studies, both coordinated by the Vienna Centre. The former study was carried out in 15 countries, comprising in all 126 production units from 38 plants and 3214 interviews of workers. The latter study was carried out in 10 countries, in 24 plants and 47 production units, 1576 workers were interviewed. Clear differences were found between countries in how critically the workers were oriented to the burdens and challenges of their work. This was interpreted to reflect country-specific work assessment standards. However, differences should be seen as differences in emphasis rather than as manifestations of work cultures, which substantially differ from each other. The order of importance among work characteristics was roughly the same from country to country: matters related to physical and economic security were widely considered the most important aspects of work.     

Changes in fall prevention training for apprentice carpenters based on a comprehensive needs assessment

Problem

Falls from heights in residential construction are common, especially among inexperienced workers.

Methods

We conducted a comprehensive needs assessment to determine gaps in the school-based apprentice carpenters' fall prevention training. A team of carpenter instructors and researchers revised the fall prevention training to fill these gaps. Apprentice evaluation and feedback guided ongoing curricular improvements.

Results

Most apprentice carpenters performed work tasks at heights prior to training and fall protection techniques were not commonly used at residential construction sites. Priorities of the revised school-based training included safe ladder habits, truss setting, scaffold use, guarding floor openings, and using personal fall arrest systems. New apprentices were targeted to ensure training prior to exposure at the workplace. We used adult learning principles to emphasize hands-on experiences. A framed portion of a residential construction site was fabricated to practice fall protection behaviors in a realistic setting. The revised curriculum has been delivered consistently and apprentice feedback has been very favorable.

Conclusions

Integration of needs assessment results was invaluable in revising the school-based carpenters apprentice fall prevention curriculum. Working closely with the instructors to tailor learning experiences has provided preliminary positive results.

Impact on Industry

The fall safety of the residential construction industry continues to lag behind commercial construction and industrial settings. The National Occupational Research Agenda includes a Strategic Goal to strengthen and extend the reach of quality training and education in the construction industry via mechanisms such as construction safety and health training needs assessments. This study demonstrates how a structured process can be used to identify and remedy gaps and improve training effectiveness. We encourage others to take steps to assess and increase the impact of training efforts directed at all residential construction professionals; including both union and non-union workers. The implications are even greater in the non-union sector where most U.S. residential work is done.     

Assessment of energy balance against the nutritional status of women carriers in the brickfields of West Bengal

The Indian brick industry is an unorganized sector in which large numbers of migrant women workers are employed. A survey was conducted on 62 women workers working in different brickfields of West Bengal to assess their physiological workload, nutritional profile, total energy expenditure and energy balance. Energy intake was calculated using physiological fuel values of carbohydrate, fat and protein. From the results it is seen that 13% of the sample population falls under severe (grade III) chronic energy deficiency. The average daily consumption of the workers was comparatively lower than their daily energy expenditure, considering the nature of the job which falls under heavy to extremely heavy categories. This negative energy balance is effectively observed in the nutritional anthropometry data. Thus, an immediate ergonomics intervention with better nutrition should be implemented to improve the health status of the workers so they can safely continue to work for a longer period.     

Development and validation of a method for evaluating temporary wooden guardrails built and installed on construction sites

Wooden guardrails are usually built and installed on construction sites to protect workers against falls. In this context, it is extremely difficult to verify whether they are safe and comply with existing regulations. The present study describes the development and validation of an evaluation method and a test protocol for verifying whether these wooden guardrails are safe and meet the requirements of the Québec Safety Code for the construction industry (S-2.1, r.6) in order to ensure that workers have adequate fall protection. This study shows that some wooden guardrails do not comply with S-2.1, r.6. The evaluation method and test protocol are reproducible and easily applicable on construction sites and can easily be adapted to international regulations.     

Improving an algorithm for classifying error types of front-line workers: Insights from a case study in the construction industry

The objective of this study was to propose improvements in an algorithm for classifying error types of front-line workers. The improvements involved: (a) making recommendations on organizing the data needed to apply the algorithm (e.g. identify actions and decisions that may serve as a reference for analysing the types of errors) and (b) drawing up guidelines for interpreting the questions that are part of the algorithm (e.g. how to define what counts as a procedure). The improvements were identified on the basis of testing the algorithm on construction sites, an environment in which it had not yet been implemented. Thus, 19 occupational accidents which had occurred in a small-sized construction company were investigated and the error types of both workers who had been injured and crew members were classified. The accidents investigated were used as a basis both to illustrate how the improvements proposed should be put in practice and to illustrate how practical insights for safety management might be derived from the algorithm.     

Factors in offshore planning that affect the risk for major accidents

The purpose of this paper is to systematically analyse a typical planning process in the offshore industry from the perspective of causes of major accidents, with the ultimate aim of identifying factors that affect the risk for major accidents occurring. We first study and describe a typical planning process for offshore oil and gas operations in Norway. Then we analyse a number of theories of major accidents, to see how the different theories and their explanations of causes and contributing factors can be of relevance for future plans and planning processes. Finally, we review accident investigations to search for evidence of how weaknesses in planning processes can contribute to major accidents through the above identified factors. Also, we try to identify any additional factors that have not been recognised through the theoretical review. This provides empirical support for the theoretical basis. Thirteen factors which directly or indirectly can influence the planning process causing a major accident potential are identified. These are exemplified through a review of investigation reports. The paper suggests that planning process should focus more on increasing quality in the plans at an early phase, with examples from incidents, and illustrate the relation between planning quality and potential for major accidents.     

Does company size matter? Validation of an integrative model of safety behavior across small and large construction companies

Introduction: Previous safety climate studies primarily focused on either large construction companies or the construction industry as a whole, while little is known about whether company size has significant effects on workers' understanding of safety climate measures and relationships between safety climate factors and safety behavior. Thus, this study aims to: (a) test the measurement equivalence (ME) of a safety climate measure across workers from small and large companies; (b) investigate if company size alters the causal structure of the integrative model developed by Guo, Yiu, and González (2016). Method: Data were collected from 253 construction workers in New Zealand using a safety climate measure. This study used multi-group confirmatory factor analyses (MCFA) to test the measurement equivalence of the safety climate measure and structure invariance of the integrative model. Results: Results indicate that workers from small and large companies understood the safety climate measure in a similar manner. In addition, it was suggested that company size does not change the causal structure and mediational processes of the integrative model. Conclusions: Both measurement equivalence of the safety climate measure and structural invariance of the integrative model were supported by this study. Practical applications: Findings of this study provided strong support for a meaningful use of the safety climate measure across construction companies in different sizes. Safety behavior promotion strategies designed based on the integrative model may be well suited for both large and small companies.     

The effect of age on safety and work practices among domestic trash collectors in Québec

Aging is associated with physiological modifications which may affect work activities. Trash collectors' work at the back of garbage trucks is both solitary and strenuous, and it therefore appeared relevant to investigate the effects of aging in these workers. The working hypotheses were that older trash collectors work at different speeds and adopt different work practices than do younger ones, and that these differences affect the frequency and nature of accidents and mishaps in the two age groups. A multidisciplinary approach, incorporating statistics, ergonomics, and social sciences, was adopted. Workers at least 35 years old were compared to younger workers, using data from three sources: accident data (176 cases), observation of 17 trash collectors during 36 collection trips (more than 150 hours of observation), and semi-directed interviews of 11 trash collectors. Analysis indicated that older trash collectors: (1) adopt a slower work rhythm; (2) are helped more often by teammates; (3) are involved less frequently in mishaps; (4) declare themselves less fatigued and to have suffered fewer accidents; and (5) are proportionally more likely to be victims of slips, falls, and back injuries resulting from movements under load. There was no observed difference, however, between the work practices adopted by the two groups of workers or the length of work absences following accidents.     

Using a psychological contract of safety to predict safety climate on construction sites

Introduction: The fact that safety climate impacts safety behavior and delivers better safety outcomes is well established in construction. However, the way workers safety perception is inclined and developed is still unclear. Method: In this research, the influence of supervisors' developing safety climate and its impact on workers' safety behavior and their conceptualization of safety is explored through the lens of the ‘Psychological Contract’ (PC). More specifically, it is argued that ‘Psychological Contract of Safety’ (PCS) is a vital factor in explaining how workers attach meaning to a supervisor behavior. Extant research suggests: (a) safety climate is based on the perception of workers regarding safety; and (b) PCS is based on perceived mutual obligations between workers and supervisors. As a result, this research argues that if PCS or mutual obligations between workers and supervisors are fulfilled, then safety climate of the workers will be positively influenced. A model is presented depicting PCS as an alternative intervention in understanding how safety climate could be influenced and predicted by the level of fulfillment of mutual safety obligations. Using Structural Equation Modeling (SEM) the model of the PCS is validated with data collected from a mega-construction project in Australia. Results: The results suggest that to have a positive and strong safety climate, top-level managers must ensure that mutual safety obligations between supervisor and workers are fulfilled. This enables the PCS to be introduced as a new ‘predictor’ of safety climate. Practical applications: The novel outcome of the research could be considered as a management intervention to modify supervisors' behavior to produce better safety outcomes.     

“Safety is everyone's job:” The key to safety on a large university construction site

Problem

Construction risk management is challenging.

Method

We combined data on injuries, costs, and hours worked, obtained through a Rolling Owner-Controlled Insurance Program (ROCIP), with data from focus groups, interviews, and field observations, to prospectively study injuries and hazard control on a large university construction project.

Results

Lost-time injury rates (1.0/200,000 hours worked) were considerably lower than reported for the industry, and there were no serious falls from height. Safety was considered in the awarding of contracts and project timeline development; hazard management was iterative. A top-down management commitment to safety was clearly communicated to, and embraced by, workers throughout the site.

Discussion and Impact

A better understanding of how contracting relationships, workers' compensation, and liability insurance arrangements influence safety could shift risk management efforts from worker behaviors to a broader focus on how these programs and relationships affect incentives and disincentives for workplace safety and health.     

地铁施工工人不安全行为关联规则研究

当前工人不安全行为研究多侧重从理论和方法的角度出发,而通过数据挖掘探究规律性方面的研究存在不足,因此,提出了地铁施工工人不安全行为关联规则研究。首先,构建关联规则挖掘数据库,以大量反映现场不安全行为的照片为数据来源。然后,利用Apriori算法,通过SPSS Modeler软件建模,以地铁车站施工机械操作人员为例介绍关联规则挖掘过程和结果。结果表明:机械操作人员存在有效强关联项为“开挖降水→挖土机作业时周围区域内有其余工人作业活动”。说明针对不同工种岗位的工人,在不同施工阶段存在易出现的不安全行为,可以有针对性地进行控制与管理,从而降低事故率。     

Multilevel learning from accidents – Case studies in transport

Substantial efforts have been devoted to accident investigations, but do we gain a reasonable benefit from these efforts? The current study explores multilevel (individual, company, sector/trade, authorities) learning from major accidents and serious incidents. Specifically, this involves identifying a set of learning criteria, i.e. factors or indicators that potentially support and contribute to multilevel learning processes. Identifying such criteria is based on: (i) the accident investigation process, (ii) the follow-up efforts, and (iii) contextual aspects. Three Norwegian accident investigations in transportation (aviation, marine, rail) represent the empirical foundation for the study. Learning criteria were derived by both document analyses from the accidents (e.g. investigation reports) and literature reviews on organizational learning. These were the basis for a workshop regarding learning from accidents, with participants from the aviation, marine, and rail sector. Key results from this workshop are presented and discussed. The study concludes by presenting a set of criteria for learning from accidents.     

Study of factors associated with risk of work-related stairway falls

This report describes a study of stairway risk factors based on video tape recordings of workers using 31 flights of stairs selected from among the industries with the highest frequency and severity rates for stair-related injuries. The video tapes were reviewed to identify all incidents, i.e., falls, trips, slips, missteps, and moments of temporary instability. The characteristics of the 98 stair users who were involved in an incident were compared to the characteristics of a matched group of stair users who did not have incidents. The factors that best discriminated between the incident group and the nonincident group were: (a) The incident group tended to be those whose movement was impeded by others and who were older; and (b) The nonincident group tended to be those who were wearing glasses and those who were very large or heavy individuals. The influence of stairway physical features on the risk of injury was examined using correlation analysis. The measure of risk was the incidence rate (observed incidents per number of observed uses) for each flight as well as for each tread. Among the several variables significantly correlated with higher incidence rate are: (a) higher effective riser height and less effective tread depth; the safest stairs have an effective riser height not greater than 7 in. (18 cm) and an effective tread depth no less than 11 in. (27 cm); and (b) for descent only (92% of the injuries), the size of the nosing projection; it appears that nosing projections that exceed $\text{11}\text{16}$ in. (1.8 cm) are associated with higher incidence rates.