Quartz and respirable dust in the Dutch construction industry : A baseline exposure assessment as part of a multidimensional intervention approach

Quartz exposure can cause several respiratory health effects. Although quartz exposure has been described in several observational workplace studies, well-designed intervention studies that investigate the effect of control strategies are lacking. Tis article describes a baseline exposure study that is part of a multidimensional intervention program aiming to reduce quartz exposure among construction workers. In this study, personal respirable dust and quartz exposure was assessed among 116 construction workers (bricklayers, carpenters, concrete drillers, demolishers, and tuck pointers). Possible determinants of exposure, like job, tasks, and work practices, use of control measures, and organizational and psychosocial factors, were explored using exposure models for respirable dust and quartz separately. Stratified analyses by job title were performed to evaluate the effect of control measures on exposure and to explore the association between control measures and psychosocial factors. Overall, 62% of all measurements exceeded the Dutch occupational exposure limit for quartz and 11% for respirable dust. Concrete drillers and tuck pointers had the highest exposures for quartz and respirable dust (0.20 and 3.43 mg m-3, respectively). Significant predictors of elevated quartz exposure were abrasive tasks and type of material worked on. Surprisingly, in a univariate model, an increased knowledge level was associated with an increase in exposure. Although control measures were used infrequently, if used they resulted in approximately 40% reduction in quartz exposure among concrete drillers and tuck pointers. Only among concrete drillers, the use of control measures was associated with a higher score for social influence (factor 1.6); knowledge showed an inverse association with use of control measures for concrete drillers, demolishers, and tuck pointers. In conclusion, the detailed information on determinants of exposure, use of control measures, and constraints to use these control measures can be used for the determination and systematic prioritization of intervention measures used to design and implement our intervention strategy. Tis study underlines the need for multidisciplinary workplace exposure control strategies although larger study populations are necessary to determine a possible causal association between organizational and psychosocial factors and psychosocial factors and control measures

'Relieved working' study: systematic development and design of an intervention to decrease occupational quartz exposure at construction worksites

Occupational quartz exposure continues to be a serious hazard in the construction industry. Until now, evidence-based interventions aimed at reducing quartz exposure are scarce. The aim of this study was to systematically develop an intervention and to describe the study to evaluate its effectiveness. Methods/Design. The intervention was developed according to the principles of the Intervention Mapping protocol, meaning that evidence from the literature was combined with information collected from stakeholders (e.g., construction workers, managers and researchers). The intervention aimed to integrate technical, behavioural and organizational factors. The intervention consists of two plenary meetings for all employers within the company, and individual visits at construction worksites, including specific intervention materials. Additionally, a demonstration session regarding control measures was organized for all managers. The effectiveness of the intervention will be evaluated in a cluster randomized controlled trial among eight construction companies, with measurements at baseline and follow-up. Outcome measures are personal respirable dust and quartz exposure by means of exposure assessment, and behavioural and organizational determinants which will be assessed by means of questionnaires. Additionally, a process evaluation will shed light on whether the intervention (does not) works, and, if so, the reasons for this. Discussion. Applying Intervention Mapping in the development of an intervention to reduce occupational quartz exposure was useful, as different stakeholders provided input for the intervention as well as the implementation strategy. Therefore, the feasibility of the intervention has been enhanced, as it appeals to construction workers and managers and will not unduly interfere with the ongoing construction work. Trial registration number. NTR4586 (May 7th 2014)

Process evaluation of an intervention program to reduce occupational quartz exposure among Dutch construction workers

OBJECTIVES: Evaluate the process of an intervention in the construction industry to reduce quartz exposure. METHODS: In a cluster randomized controlled trial, data on seven process aspects (ie, recruitment, reach, dose delivered, dose received, fidelity, satisfaction, and context) were quantitatively collected on manager and worker levels. RESULTS: Dose delivered was 95% for the plenary sessions and 20% for the worksite visit. Although the protocol was mostly implemented as intended, dose received was lower than expected. Both managers and workers appreciated the intervention and recommended the intervention for future implementation. Workers attending all intervention sessions were most satisfied about the intervention. CONCLUSIONS: High rates for dose delivered and fidelity for the plenary sessions and relatively high satisfaction rates were achieved. Furthermore, continuous monitoring of contextual factors beforehand and alongside the implementation of interventions is recommended

Effectiveness of a Multidimensional Randomized Control Intervention to Reduce Quartz Exposure Among Construction Workers

There is little evidence with respect to the effectiveness of intervention programs that focus on the reduction of occupational quartz exposure in the construction industry. This article evaluates the effectiveness of a multidimensional intervention which was aimed at reducing occupational quartz exposure among construction workers by increasing the use of technical control measures. Eight companies participating in the cluster randomized controlled trial were randomly allocated to the intervention (four companies) or control condition (four companies). The multidimensional intervention included engineering, organizational, and behavioural elements at both organizational and individual level. Full-shift personal quartz exposure measurements and detailed observations were conducted before and after the intervention among bricklayers, carpenters, concrete drillers, demolishers, and tuck pointers (n = 282). About 59% of these workers measured at baseline were reassessed during follow-up. Bayesian hierarchical models were used to evaluate the intervention effect on exposure levels. Concrete drillers in the intervention group used technical control measures, particularly water suppression, for a significantly greater proportion of the time spent on abrasive tasks during follow-up compared to baseline (93 versus 62%; P < 0.05). A similar effect, although not statistically significant, was observed among demolishers. A substantial overall reduction in quartz exposure (73 versus 40% in the intervention and control group respectively; P < 0.001) was observed for concrete drillers, demolishers, and tuck pointers. The decrease in exposure in the intervention group compared to controls was significantly larger for demolishers and tuck pointers, but not for concrete drillers. The observed effect could at least partly be explained by the introduced interventions; the statistically significant increased use of control measures among concrete drillers explains the observed effect to some extent in this job category only. Sensitivity analyses indicated that the observed decrease in exposure may also partly be attributable to changes in work location and abrasiveness of the tasks performed. Despite the difficulties in assessing the exact magnitude of the intervention, this study showed that the structured intervention approach at least partly contributed to a substantial reduction in quartz exposure among high exposed construction workers

Revisiting the effect of room size and general ventilation on the relationship between near- and far-field air concentrations

This paper explores tacit knowledge sharing. This case demonstrates the significance of knowledge sharing to organizational performance, by exploring the contribution of tacit knowledge sharing to the success of projects in the Australian Film Industry (AFI). The differences between knowledge sharing, collaboration and communication, and their interrelations are addressed. We also explore the concepts of knowledge, information, and data. In the interchanges reported here the knowledge shared is almost entirely tacit, and the “raw” data and information do not exist without the context that makes them knowledge. The paper includes the identification of many factors affecting knowledge sharing, not all of which have been identified by previous researchers. This research contributes to a better understanding of tacit knowledge and how that knowledge is shared. This in turn contributes to a better understanding of how knowledge management can be supported in a modern organization, where often the technology is used in ways not well understood by system managers and software developers. A better understanding can lead to better ICT design and support of knowledge sharing both within and across organizations

Revisiting the effect of room size and general ventilation on the relationship between near- and far-field air concentrations

Objectives: In 1999, Cherrie carried out a series of mathematical simulations to investigate dispersion of pollutants through two indoor zones: the near-field (NF) and the far-field (FF). The results of these simulations were used to derive modifying factors for use in exposure modeling. However, in the original simulations, no account was taken of deposition on surfaces, either from sedimentation of aerosols or other mechanisms or the potential effects of intermittent or short duration sources. These factors may affect pollutant dispersion, particularly the relationship between NF and FF levels. The Advanced REACH Tool (ART) is based on a two-zone dispersion paradigm. Further simulations have been carried out to help ensure that the ART realistically reflects pollutant dispersion.Methods: Pollutant dispersion has been simulated using a two-compartment well-mixed box model to represent the NF and the FF. Simulations were repeated for a range of room sizes and ventilation conditions. Intermittent sources (e.g. batch processes) were simulated by having the source active for 1 h followed by a 1-h gap, while short duration work emissions were set to last for 10 min, 30 min, 1 h, or 4 h, within the working day. Deposition was modeled by adding an equivalent air exchange rate based on published research data. Simulations were undertaken for non-volatile, monodisperse aerosols of aerodynamic diameter: 0.3, 1, 3, 10, 30, and 100 µm and the results were then interpreted in terms of typical polydisperse industrial aerosols.Results: Room size and general ventilation strongly influenced dispersion from the NF to the FF as Cherrie had originally found. When varying the duration of the simulation, the biggest difference from continuous work was seen in small poorly ventilated rooms, with the ratio of the NF to FF concentration for 1-h work in the smallest room and lowest air exchange rate being a fifth of that calculated for continuous work. For large rooms and high general ventilation rates, the duration of the activity made little difference to dispersion. The results suggest that for the purposes of dispersion intermittent batch work is equivalent to continuous work. For typical simulated poly-disperse aerosols, the main effect of aerosol deposition was to reduce the predicted high concentrations compared to vapours when working in confined spaces.Conclusions: Both short duration of source emissions and deposition of aerosols have an important effect on dispersion, and the results from this study have been reflected in the ART model. © The Author 2011