1 / 45

Silica. It’s Not Just Dust Rick Gleason, CIH, CSP October 8, 2009

Silica. It’s Not Just Dust Rick Gleason, CIH, CSP October 8, 2009. Rick Gleason, CIH, CSP rgleason@u.washington.edu (206) 856-6660. 1. History of Silica 2. L & I Regulations 3. UW Airborne Silica Sampling 4. Questions. Hawk’s Nest Tunnel West Virginia, 1932. In Nature Beach sand

boris-thornton
Télécharger la présentation

Silica. It’s Not Just Dust Rick Gleason, CIH, CSP October 8, 2009

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Silica. It’s Not Just Dust Rick Gleason, CIH, CSP October 8, 2009

  2. Rick Gleason, CIH, CSPrgleason@u.washington.edu(206) 856-6660

  3. 1. History of Silica2. L & I Regulations3. UW Airborne Silica Sampling4. Questions

  4. Hawk’s Nest Tunnel West Virginia, 1932

  5. In Nature Beach sand Granite Sandstone Clays Diatomaceous earth In Industry Mining Quarrying Stone cutting Sand blasting Concrete & mortar work Cutting, grinding, drilling, sanding Where is it found?

  6. Silica Exposure • Size of particles - can it be inhaled deep into the lung? • % silica in the dust • Concentration • How much time exposed each day? • How often exposed?

  7. What is Sililcosis • A Fibrotic disease of the lungs – it scars the lung tissue • Lung is less flexible and has less area for the exchange of oxygen • Makes it difficult to do hard work and breath • May be from short-term high exposure (acute) or long-term lower exposure (chronic)

  8. Silicosis • Incurable and irreversible • May progress even after exposure has stopped • This is completely preventable!

  9. Risk of Developing Silicosis* * Flinn et al, 1939

  10. Other Health Problems Related to Silica Exposure • Lung Cancer • More susceptible to tuberculosis • Maybe immune system disease • Kidney disease

  11. Silica Exposures Labor and Industries Rules

  12. Standard 10 (d) Sanitation and Cleanliness

  13. Labor and Industries Industrial Hygiene CodesWhat year???

  14. October 1, 1938

  15. Video: Stop Silicosis1938Available from the L & I DOSH Video Lending Library

  16. UW Research –ExposureWhat did we find? • 1,375 personal quartz samples • Geometric mean quartz concentration: • 0.13 mg/m3 • compare to Washington PEL of 0.1 mg/m3

  17. 9% 36% 55%

  18. Exposure by Tool Used

  19. Tool: abrasive blaster No.= 57 0.28 mg/m3 Range 0.01 – 832.71 mg/m3

  20. Tool: hand-held saw No.= 65 0.13 mg/m3 Range <0.01 – 14.15 mg/m3

  21. Tool: table saw No.= 51 0.07 mg/m3 Range 0.01 – 2.75 mg/m3

  22. Tool: walk-behind saw No.= 33 0.09 mg/m3 Range 0.02 – 1.64 mg/m3

  23. Tool: rock drill No.= 93 0.21 mg/m3 Range <0.01 – 16.00 mg/m3

  24. Tool: jackhammer/chipping gun No.= 178 0.15 mg/m3 Range <0.01 – 3.86 mg/m3

  25. Tool: broom/shovel No.= 49 0.03 mg/m3 Range <0.01 – 1.19 mg/m3

  26. Tool: surface grinder No.= 123 0.28 mg/m3 Range 0.01 – 18.20 mg/m3

  27. Tool: tuckpoint grinder No.= 102 0.61 mg/m3 Range 0.01 – 76.10 mg/m3

  28. Tool: concrete mixer No.= 32 0.04 mg/m3 Range 0.01 – 0.55 mg/m3

  29. Tool: backhoe/excavator/bulldozer/bobcat No.= 28 0.01 mg/m3 Range <0.01 – 0.12 mg/m3

  30. Tool: road mill No.= 48 0.11 mg/m3 Range 0.01 – 16.10 mg/m3

  31. Environment • No.Conc. • 0.08 Open Enclosed Confined 235 0.15 15 0.33

  32. Project Type Highway N= 294 0.13 mg/m3 17% Industrial/Commercial N = 465 0.09 mg/m3 12%

  33. Huge Variability in Exposure • Half of samples were below PEL (0.1 mg/m3) • 13% of samples were over 10 times the PEL! • These extremely high exposures represented 9 of 12 tools

  34. Prioritzing for Control • Abrasive blasting and grinding • Drilling, jackhammering, and chipping • Road demolition • Concrete cutting • Clean up and cement mixing • Heavy equipment demolition

  35. Exposure Summary • Control should focus on task and tool • Degree of enclosure and type of project are also important • There is a problem – we need to move on to controlling it!

  36. Vacuum on Tools • 90% exposure reduction is possible • LEV may reduce exposures below PEL

  37. Vac

  38. Flex Grinder and Shroud Metabo Grinder Sawtec Shroud

  39. Water Control • Typically very effective • High exposures can potentially result if: - Water application rate is low and/or - Work is enclosed • Common for cutting - some other applications • Problematic in some settings

  40. Water Control • Keep spray close to the • source • Keep spray continuous • during dusty operations • Keep water reservoir filled • Maintenance needed to avoid clogging

  41. * *Based on monitoring data > 6 hours *

  42. Summary • There is a problem – we need to move on to controls! • Respirators currently used aren’t always protective enough • We need to implement other controls or controls in combination with respirators

  43. More information:http://depts.washington.edu/silica/

More Related