1. © Gully Howard Technical Limited HHSEG Topic Talk 28 October 2015 Workplace exposure to airborne dust – health effects & risk quantification Gully Howard Technical, Portsmouth

2. © Gully Howard Technical Limited In the UK there are ~13,000 deaths per year due to exposure to airborne hazardous substances at work. Thousands of different chemical agents can potentially cause detrimental health effects in a wide range of different occupations. These airborne hazardous substances can be classified as either gases, vapours, fibres, mists, fumes or dust. Airborne hazardous substances

3. © Gully Howard Technical Limited Key Health Factors of Dusts Toxic effect What is the toxicology of the material and the respective target organ? Particle Size Where does it deposit? – upper respiratory tract or is it capable of reaching the alveoli in the deep lung? Inhalable dust (<100 microns) is the term given to all the dust capable of being inhaled through the nose and mouth. Respirable dust (<10 microns) is the dust small enough to reach the gas exchange region of the deep lung.

4. © Gully Howard Technical Limited Silica – worker exposure occurs in many industries affected e.g. mining, construction, ceramics RCS – Silicosis (fibrosis of lung) can lead to lung cancer Examples of hazardous dusts

5. © Gully Howard Technical Limited Wood dust exposure occurs in the construction industry particularly in woodworking workshops rhinitis, nose bleeds, asthma, nasal cancer Examples of hazardous dusts

6. © Gully Howard Technical Limited Diesel Particle Matter (DPM) some workers can potentially receive high exposures to DPM IARC designated human carcinogen, EC, OC, TC Examples of hazardous dusts

7. © Gully Howard Technical Limited The COSHH Regulations provides guideline exposure levels for ‘non-hazardous dusts’ of 10 mg.m -3 inhalable dust and 4 mg.m -3 respirable dust. These levels for ‘non Hazardous’ dusts are considered too high by many (e.g. IOM suggest controlling to 5 and 1 and TUC 2.5 and 1 mg.m -3.) ‘Non-hazardous’ dusts

8. © Gully Howard Technical Limited Breathing Zone Personal samples MUST be taken in the Breathing Zone 300mm Hemisphere around the nose and mouth Source :Airmet Scientific – reproduced with permission

9. © Gully Howard Technical Limited Sampling Pumps Small battery powered pumps that can be worn by a person on a waist belt. Most particulate sampling is carried out at flow rate of either 2.0 or 2.2 litre/min.

10. © Gully Howard Technical Limited IOM Sampling Head Gold standard sampling head for measuring inhalable dust fraction All collected dust measured (filter is weighed with the cassette) Easily handled 25 mm filter 2.0 litres/min (± 0.1) IOM sampler IOM cassette Transport clip Front Cassette Filter Support O ring Body cover front grid Source :Airmet Scientific-reproduced with permission

11. © Gully Howard Technical Limited Cyclone Sampling Head Respirable dust 25/37 mm filter 2.2 litres/min (± 0.1) Pump attached at top Inlet points down Source: HSE – reproduced with permission

12. © Gully Howard Technical Limited Filters Wide range of filter types including: Glass fibre filters Good particulate retention, collects at surface and within filter, best for gravimetric analysis Mixed cellulose ester (MCE) Weight easily affected by humidity changes Easily dissolved for analysis (metals) Particulates collected on surface only (transport)

13. © Gully Howard Technical Limited Sample Train for Inhalable Dust Pump Connecting tube IOM sampling head SAMPLER CONNECTINGTUBE PUMP Source :Airmet Scientific – reproduced with permission

14. © Gully Howard Technical Limited Sampler worn by a worker Source :University of Wollongong Pump usually placed on belt, in pocket or in suitable harness Sample head in breathing zone Calibrate flow rate at start - note start time Check flow rate during sampling Check flow rate at end - note stop time

15. © Gully Howard Technical Limited Calibration of sampling system Connect from pump to sampling head Connect from sampling head to calibrator Adjust flow to required flow rate Source :Airmet Scientific – reproduced with permission

16. © Gully Howard Technical Limited Dust direct reading Instruments Most dust monitors are based on light scattering techniques Beam of light shone through contaminated air. Light scattered by the dust is detected and is a measure of particulate concentration

17. © Gully Howard Technical Limited Deleading butt Vacuuming butt and target area Break period Vacuuming and mopping rest of range Cleaning surfaces in firing area with wipe cloth Determining pattern of exposure Results from a direct-reading dust instrument mounted on cleaner

18. © Gully Howard Technical Limited Observations and investigation ‘Art of occupational hygiene’ Determining exposure period - required for calculating time weighted average (TWA) Assessment of controls in place - this is not an optional extra – it is the law (Principles of good practice, Schedule 2A, COSHH Regs) General feel of the workplace (i.e. culture)

19. © Gully Howard Technical Limited Choosing a Lab Lab working to a Quality System (ISO 17025). Analytical methods are UKAS accredited. Take part in HSL’s Workplace Analysis Scheme for Proficiency (WASP) for metals, BTEX, RCS etc and can show for the last 3 rounds that they are consistently close to the ‘true value’.

20. © Gully Howard Technical Limited Occupational exposure limits Time weight exposure (over 8 hrs or 15 mins) and compare with long or short term OELs. Legal limits in UK WELs (EH40) Other European country’s OELs – IFA GESTIS website US ACGIH TLVs

21. © Gully Howard Technical Limited Reporting Makes a record (by law it has to be kept for 40 years) – procedures need to be in place to ensure such records are maintained. Report has to work for now i.e. be concise and clear and easily understood. But also be future proof – i.e. contain details on QA so it stands up in court in the future. Must provide appropriate control advice if exposures are high – i.e. what needs to done to protect the health of workers.

22. © Gully Howard Technical Limited Any questions? Paul Humphrey Chartered Occupational Hygienist Paul.Humphrey@ghtechnical.com Mob. 07944 629544 www.ghtechnical.com