Video Exposure Monitoring – Reducing Peak Exposures
Video Exposure Monitoring – Reducing Peak Exposures Mark WagstaffeCentre for Public Health Research
Acknowledgements• Purdue University – Professor Jim McGlothlin and Mark Sharpe – From “Wow” to “What’s Next? The Future of Video Exposure Monitoring - http://www.aihasynergist- digital.org/aihasynergist/201001?pg=30#pg30• Centre for Public Health Research, Massey University – Professor Jeroen Douwes – Professor Bill Glass – Kerry Cheung – Brad Prezant – Samuel Keer• Safe Work Australia• HRC, DoL and ACC
Exposure Surveillance• NOHSAC noted in 2006 that (outcome) surveillance is, to some extent, “the ambulance at the bottom of the cliff ”.• What is really required are actions to prevent occupational disease and injury happening, by preventing the workplace exposures that cause them.• The surveillance of “exposures and hazards and controls” is just as important as, and should ideally be integrated with, the surveillance of disease and injury.
Workplace Exposures• Disorders that have a relatively long latency between exposure and occurrence are appropriate candidates for an exposure surveillance system, because the outcome monitoring reflects exposures years beforehand rather than current or recent exposures.• Using outcome information to plan prevention measures in long-latency conditions means that prevention initiatives are based on historical exposures that may not reflect current occupational exposures. In such situations, monitoring current exposures seems more logical and more likely to lead to faster improvements in OH&S.
Workplace Exposures• Workplace exposures can be consistent over a work shift or quite variable. The variability in exposure patterns is generally not measured, although it has been suggested that peak exposures may be associated with more severe health effects.• For example, if two workers have identical average exposures, the one who occasionally experiences peak exposures may be at greater risk than the one whose exposure remains relatively constant.
Multi Channel Video Exposure Monitoring• Video exposure monitoring (VEM) synchronises real time (or near real time) chemical, biological, radiological and/or physical exposure data, wirelessly with a video recording of workers and/or environmental activities.• Over exposure to chemical, physical or radiological agents usually occurs during 20 per cent or less of the overall work cycle, that is, approximately 80 per cent of a worker’s exposure occurs during one-fifth of the time needed to complete a task.
Peak Exposures• A small reduction in peak exposures however can have a large effect on reducing the time-weighted average exposure. The effectiveness of the intervention in reducing overall exposure and preventing disease can be much greater using VEM technology.• Multi-channel VEM technology can now be used to add additional monitoring capability by providing monitoring of multiple exposures simultaneously, such as dust, UV radiation, solvents and noise, into a single “job exposure” record• VEM permits a detailed permanent record of the work tasks performed and associated levels and has been able to identify exposure patterns previously unrecognized, allowing better and more cost-effective control of workplace hazards.
Effective control measures need to be based on a thorough understanding of (peak) exposures • Educational intervention measures alone result in only a modest reduction in exposure (~10-15% in wood workers and bakery workers) • 8-hour TWA exposures provide little insight into peak exposures and therefore have limited usability in identifying optimal control strategies • Specific task-based interventions targeting peak exposures can lead to reductions of more than 50% (example bakery workers; Meijsters et al., 2008)
Exposure survey of airborne dust and formaldehyde inthe New Zealand joinery and furniture making industry • A significant proportion of joinery and furniture workers (19% and 8% respectively) are exposed to dust levels in excess of the current occupational exposure limit of 5 mg/m3. • The majority of joinery and furniture workers (87% and 63% respectively) are exposed to inhalable dust levels in excess of current international standards of 1 mg/m3.
Average inhalable dust concentrations (mg/m3) of joineries and furniture makers.
Hand Electric Sander This video is available at http://youtu.be/MdaOtfkfL0g
Fumigants in shipping containers • Measuring real time exposure to Methyl Bromide and other fumigants as workers unload shipping containers. • Use of VEM to characterize peak exposures to fumigants (VOC’s) • Remote grab samples of air for observed peaks
Fumigants in shipping containers • 8 hours sample for off gassing after unloading. • Evaluation of current controls e.g. 5 ppm when container closed after being fumigated • Health questionnaire and observed work practices for unloading shipping containers.
Year in the Life of a Farmer• Measuring real time worker exposure to noise (vibration), dust, heat and UV using multi channel VEM. – Measuring of health parameters such as heart rate, internal temperature at the same time and questionnaire. – Sampling for pesticides, (skin, urine and carpet samples) – Peak activity periods not just a single event • Single exposure record for a task or occupation. • Observed work practices and suggested improvements proven by data.