Health and Safety Executive research on wood dust exposure controls in British manufacturing

To generate new intelligence on occupational exposure to wood dust in woodworking manufacturing activities in Britain, the Health and Safety Executive (HSE) performed 22 occupational hygiene site visits to assess exposure and exposure controls between 2014 and 2017. The work aimed to characterise good practice and therefore sites with a poor health and safety record, as identified from HSE inspection records, were not invited to participate. Sites selected covered furniture production, joinery, saw milling, and boat building and repair. Twenty-three follow-up telephone interviews were also carried out across 15 of the companies with supervisors and managers to explore how they tried to promote good practice among the workforce, and if there are any potential challenges encountered. The aim of the interviews was to gain a better understanding of how to enable organisations to improve the management of wood dust exposure. This study found that 6.0% of all wood dust exposure measurements (15 out of 252) were above 5 mg/m³, and 17.6% of exposures to hardwood dust or mixtures of hardwood and softwood dust (38 out of 216) were above 3 mg/m³ (the then current and future workplace exposure limits). Sanding, cleaning, and maintenance activities were of particular concern. Improvements to exposure controls are required, in particular, improvements to local exhaust ventilation controls for hand-held power tools and hand sanding. The management, selection, and use of respiratory protective equipment were poor. All the managers and supervisors recognised that exposure to wood dust can pose serious health risks, and that controls were crucial to protecting workers' health. The findings from the telephone interviews suggest that supervision and provision of information about the health effects of exposure to wood dust were common approaches that organisations used to raise awareness and promote good practice, in relation to managing wood dust exposure. Worker attitudes towards controls, such as perceptions that they hinder task completion and habitual ways of working, were identified as factors influencing the use of controls. Risk communication approaches that focus on increasing workers' awareness of their susceptibility to ill-health using credible sources, such as peers, can help enhance the uptake of messages on the use of controls. Financial constraints were identified as a challenge to improving the control of wood dust, particularly for small companies.

Acute in vivo pulmonary toxicity assessment of occupationally relevant particulate matter from a cellulose nanofiber board

Cellulose nanofibers (CNFs) are an emerging engineered nanomaterial that are utilized in a variety of applications, including as a replacement for urea-formaldehyde, and other adhesives, as the binding agent in manufactured fiber and particle boards. To ensure the health and well-being of those producing, installing, or otherwise using cellulose nanofiber boards (CNFBs) it is imperative that the particulate matter (PM) produced during CNFB manipulation be evaluated for toxicity. We developed and internally verified a generation system to examine the PM produced by sanding CNFB using aluminum oxide sandpaper. With 80-grit sandpaper our system produced a low dispersity aerosol, as determined by a scanning mobility particle sizer and an optical particle counter, with a geometric mean of 28 nm (GSD = 1.60). ICP-MS evaluation showed little difference in metal concentrations between CNFB PM and nonsanded CNFB stock. We then used the system to simultaneously generate and expose both male and female C57BL/6J mice acutely for 4 hours at a concentration of 7.9 mg/m3. Sham-exposed controls were treated similarly but without sanding the CNFB. Analysis of bronchoalveolar lavage (BAL) fluid biomarkers showed no signs of inflammatory response at either 4- or 24-hours post exposure. Further, BAL cell viability, number of total cells, and pulmonary cellular recruitment were not significantly changed between the sham-exposed controls and CNFB-exposed mice. Histology further confirmed no pulmonary toxicity as a result of CNFB PM inhalation. We conclude that inhalation of a high concentration of the PM from manipulation of a CNFB did not produce acute toxic responses within 24 hours of exposure.

Health and working conditions in carpenter's workshops in Armenia (Colombia)

We conducted a study of the health and working conditions in 10 carpenter's workshops in the municipality of Armenia (Colombia). In these workshops, all the most exposed workers to wood dust were surveyed at the areas of sanding, brushing, immunization and painting (workers with the highest risk to get chronic respiratory disease). They were 177 workers. The use of hard and soft woods for furniture was detected. Besides, some pesticides, volatile organic solvents, synthetic epoxy resins glues and paintings, were used for finishes, which increases the risk of acquiring some neurological diseases and damage to the nervous system. Occurrence of cancer in nostrils mainly due to the use of hardwoods is an additional risk. With regard to the basic lighting conditions, it was found that half of workshops had deficiencies in special carving areas, because they were below the minimum allowable lighting limit level (500 lux). With relation to noise, all the workshops exceeded the permissible maximum limit value (85 dBA). With respect to the occurrence of occupational events, no data were found in the companies, or analysis of employee absenteeism due to the exposure to particulate matter.

Effectiveness of a worksite intervention to reduce an occupational exposure: the Minnesota wood dust study

OBJECTIVES

This study assessed the effectiveness of an intervention to reduce wood dust, a carcinogen, by approximately 26% in small woodworking businesses.

METHODS

We randomized 48 businesses to an intervention (written recommendations, technical assistance, and worker training) or comparison (written recommendations alone) condition. Changes from baseline in dust concentration, dust control methods, and worker behavior were compared between the groups 1 year later.

RESULTS

At follow-up, workers in intervention relative to comparison businesses reported greater awareness, increases in stage of readiness, and behavioral changes consistent with dust control. The median dust concentration change in the intervention group from baseline to follow-up was 10.4% (95% confidence interval = -28.8%, 12.7%) lower than the change in comparison businesses.

CONCLUSIONS

We attribute the smaller-than-expected reduction in wood dust to the challenge of conducting rigorous intervention effectiveness research in occupational settings.

Designing intervention effectiveness studies for occupational health and safety: The Minnesota Wood Dust Study

BACKGROUND

A planning model was used to guide the design of a randomized controlled study of the effectiveness of tailored interventions in lowering dust exposures in small woodworking shops.

METHODS

Guided by Green's PRECEDE-PROCEED model, we used a planning committee, focus groups and a pilot study to gain information on small woodworking shops, causes of and controls for high dust levels, and barriers and incentives surrounding availability and use of dust controls.

RESULTS

The planning committee identified key characteristics of small woodworking shop owners. Focus groups with owners and employees served to further elucidate why dust control was considered unimportant. The pilot study gave measures of dust exposures, tasks, and use of controls. Interventions focused on providing owners with technical and economic assistance to lower dust levels and an educational program for employees discussing health effects and effective methods of dust control.

CONCLUSIONS

The PRECEDE-PROCEED model proved a useful framework for designing an intervention in the occupational setting.