Presentation to BOHS / OHSI Exposure Control and Containment Conference in Liverpool October 2016. Explores the challenges of designing and implementing local exhaust ventilation systems to control worker exposure to dust in developing economies

1. Challenges of Using LEV in
Developing Economies
Mike Slater
Diamond Environmental Ltd.
Chair of WHWB-UK
YEARS OF
OCCUPATIONAL
HYGIENE

2. 2
Workplace Health Without Borders

3. There are 3 billion
workers in the world…
3
Source:
World Health Organization (WHO)

4. There are 3 billion
workers in the world…
Nearly 2 billion of them
work in unhealthy and
unsafe conditions
4
Source:
World Health Organization (WHO)

5. 2.34
1.6
1.24
0.742
0 0.5 1 1.5 2 2.5
Occupational injuries
and disease
HIV/AIDS
Road traffic
Armed Conflict and
Violence
Millions of Deaths per Year Worldwide

6. 6
accidents
14%
diseases
86%

7. About 150,000 workers
die from respiratory
disease every year

8. Exposure to dust is a major cause of respiratory disease
including in Europe – this photo was taken in the UK
Local exhaust ventilation (LEV) is a common solution to
this type of problem

9. Unfortunately we don’t always get it right
Even in Europe LEV systems are poorly designed

10. 10
Silica = 1.9 mg/m3
Dust exposures can be a real problem in the developing world
Controls are often non-existent

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Challenges of designing
and implementing LEV
systems in developing
countries

12. 12
Lack of funding

13. 13
Lack of expertise

14. 14
Lack of resource

15. 15
Availability of
supplies and
equipment

16. 16

17. 17
Maintenance
difficulties

18. 18

19. 19
Workplace Health Without Borders

20. Workplace Health Without
Borders (WHWB)
A non-profit international
organization
Registered as a charity in
Canada
Branches recently established
in the USA and UK
20

21. Workplace Health Without
Borders (WHWB)
Engages volunteers to address
workplace health issues around
the world
21

22. A world where workers do not get sick
because of their work
22
Vision

23. 23
Some WHWB
Projects

24. 24
Brick plant project - addressing silica and other
hazards in brick plants in Nepal, Pakistan and
Tanzania

25. 25
Provided technical assistance on sampling for
silica in Pakistan brick plants

26. Agate Polishing in Gujarat

27. ▪ Produces Semi Precious stones used for jewelry and
ornaments
These are agate “pebbles”

28. ▪ Produces Semi Precious stones used for jewelry and
ornaments
After polishing

29. 29
Used to make jewellry

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31. Silica – Agate Jewelry
Industry
▪ Estimated 1 million exposed in this industry
▪ Prevalence of silicosis is 20-30% (workers)
and 11% in family members
▪ Elevated levels of accelerated silicosis,
Tuberculosis

32. Resp. Dust: 0.61 mg/m3
Quartz = 0.54 mg/m3

33. Resp. Dust: 0.61 mg/m3 Quartz = 0.54 mg/m3

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Silica = 1.9 mg/m3

35. Project Goal
• Use inexpensive, locally available
materials
• Low power demand

36. 36
Pilot system
In the lab

37. Grinder
4” x 10” Hood
20 Litre Pail
with Lid, which
supports fan
200 CFM Fan
@ 3/8”WG
Exhaust
Exhaust duct terminates
ca 6” inside pail vertically

38. Dustrak (resp) <0.05
mg/m3
Dustrak (resp)>20 mg/m3
(exhaust)

39. Trial Intervention: Horizontal Wet Wheel
39
Receptor / captor hood

40. 40
Simple wet
system to
capture some of
extracted dust
using waste
drum

41. 41
Pre-hood With LEV
Respirable dust
(mg/m3)
0.8 <0.33
Quartz
(mg/m3)
0.53 0.09

42. Revised
Design

44. Horizontal wet wheel #2
44

45. Horizontal wet wheel #2
45
Pre-intervention: quartz 3.0 mg/m3
Post-intervention: quartz 0.05 mg/m3

46. 46
Vertical
grinder

47. 47
Before After
Resp. dust
(mg/m3)
1.7 0.64
Quartz
(mg/m3)
1.2 0.10

48. Dry horizontal grinder
Before After
Resp. dust (mg/m3) 1.9 0.4

49. Dry Ball Mill
Respirable Dust: 36 mg/m3 , Quartz = 17 mg/m3
49

50. Dry Ball Mill
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Respirable Dust: 0.51 mg/m3 , Quartz = <0.03 mg/m3

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Lack of funding
Lack of expertise
Lack of resource
Availability of supplies
Maintenance difficulties

52. 52
Thanks to Paul Bozek,
University of Toronto

53. Learn more and get in touch!
Join WHWB: www.whwb.org
53
Workplace Health Without Borders