How much wood is in that dust?

Transcription

1 Health and Safety Executive How much wood is in that dust? Peter Stacey, Andrew Simpson and Christopher Keen

2 Why Wood Dust? Soft wood Asthma Work aggravated asthma One of the most frequently reported suspected agents (actual cases) for workrelated asthma SWORD ( ) Hard wood Associated with nasal cancer

3 Why focus on construction? 1.2 m people exposed in construction industry in Europe (33 % ) carpenters Construction = highest exposures to wood dust 21% are greater than 5 mg.m -3 Kauppinen T, et al Occupational Exposure to Inhalable Wood Dust in the Member States of the European Union Ann Occup Hyg. 50 (6):

4 Wood dust Typical work task

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6 HSL: HSE s Health and Safety Laboratory Crown Copyright, HSE 2016

7 How do we measure wood dust? Gravimetric analysis assumes all the sample is wood

8 New Build Homes

9 Activities potentially disturbing other dust

10 Contribution to inhalable dust Plaster Concrete Mortar Sand Brick dust Insulation block dust White paint - rutile HSL: HSE s Health and Safety Laboratory Crown Copyright, HSE 2016

11 A MORE SELECTIVE MEASUREMENT OF INHALABLE WOOD DUST HSL: HSE s Health and Safety Laboratory Crown Copyright, HSE 2016

12 Sampler selection IOM Wall losses Not all sample on the filter Flow rate 2 l min -1 More prone to projectiles Button Minimised wall losses Most sample on the filter Flow rate 4 l min -1 More sensitivity Deposit is more uniform HSL: HSE s Health and Safety Laboratory Crown Copyright, HSE 2016

13 Button sampler performance with IOM Wood dust (Calm air conditions) Button sampler filter analysis is more precise less variability than IOM

14 Button sampler performance with IOM Plaster dust (Calm air conditions) The majority of dust has smaller particle sizes than the wood dust

15 Blank filter Wood

16 Analytical Procedure X-Ray Diffraction (XRD) Rietveld Analysis Thermal Gravimetric Analysis (Furnace 510 C) Quantification Quartz Gypsum Calcite Cement phases Rutile (TiO 2 )

17 Direct on-filter Analysis using X-ray Diffraction with Rietveld No calibrations needed Quantifies crystalline and amorphous material Using internal standard in the filter matrix

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19 Furnace at 510 C

20 RESULTS HSL: HSE s Health and Safety Laboratory Crown Copyright, HSE 2016

21 Personal TWA concentrations Inhalable vs Wood Dust Inhalable Dust Personal TWA mg m -3 Wood Dust Personal TWA mg m -3 Percent Difference (%) % % % % % % % %

22 What else is in these samples?

23 Messages Gravimetric analysis alone over estimates wood dust exposure for construction carpenters Capability to get a more complete picture of worker exposure from one filter sample e.g. TiO 2, quartz, gypsum XRD and Rietveld analysis was successfully used for on filter measurement

24 HSL is the commercial arm of the Health and Safety Executive, HSE. Our commercial work delivers high quality science to meet the needs of industry and government in the UK and overseas. Our commercial customers can commission services and research using our state-of-theart scientific laboratory in Buxton, as well as analytical expertise from other parts of HSE s science base.