Ken Cram Gary Mace

1. Australian Black Coal IndustryCoal Services Pty Limited Standing Dust CommitteeNSW Dust Sampling ResultsDust ManagementHygiene Issues Ken Cram Gary Mace

2. OVERVIEW 2006 Record Year for Australian Black Coal Industry Increased: • Production • Exports and $Value • Domestic Consumption • Number of Mineworkers Employed December 2006 – 118 Black Coal Mines • 74 Opencut Mines • 44 Underground Mines ( 29 Longwalls Faces)

11. Coal Services Pty Limited • 2001 NSW Coal Industry Act • Workers’ Compensation Insurance • Occupational Health & Rehabilitation • Occupational Hygiene (including coal dust monitoring) • Mines Rescue Emergency Response • Coal Industry Statistics • Ownership • NSW Minerals Council • CFMEU • Subsidiary Companies • Coal Mines Insurance Pty Ltd • Mines Rescue Pty Ltd

12. Respirable Dust Monitoring • Health Risk • Dust Sampling Program • Mineworker Medical Examination

13. Standing Dust Committee • Monitor Sampling Results • Evaluate Dust Hazards • Dust Control Methods • Information and Education

14. The Committee Meets Bi-MonthlyMainly at Mine Sites Since CSPL in January 2002 meetings at: • 25 Underground Coal Mines • 5 Open Cut Coal Mines • Southern Mines Rescue Station • Testsafe - Londonderry • Mine Safety Technology Centre - Thornton

15. Committee Initiatives • Introduction of Gravimetric Dust Sampling • Setting of Current Exposure Standards • CMHS Act Regulations 2006 recommendations: Respirable Dust Inhalable Dust Diesel Particulate • Research Projects Inhalable Coal Dust Exposure Limits Quartz Exposure Standard for AS 2985 Sampling Pump Flow Rate Change for AS 2985 Personal Dust Monitor (PDM) U /G Trials

16. Order 40Abatement of Dust on Longwalls • Initiated in 1990 • Dust Results of Previous Longwalls • Approval Conditions

17. NSW Coal MinesGravimetric Personal Dust Sampling From March 1984 to December 2004 The Specified Limits were: • 3 mg of Respirable DUST per m3 • 0.15 mg of Respirable QUARTZ per m3

18. Coal Mines Regulation Act 1982Coal Mines (Underground) Regulation 1999Coal Mine Health and Safety Act 2002Coal Mine Health and Safety Regulation 2006Specified Limits for Airborne Dust Since January 2005 • 2.5 mg of Respirable DUST per m3 • 0.12 mg of Respirable QUARTZ per m3

19. Coal Mines Regulation Act 1982 Coal Mines (Open Cut) Regulation 1999Coal Mine Health and Safety Act 2002Coal Mine Health and Safety Regulation 2006Specified Limits for Airborne Dust Since January 2005 • 2.5 mg of Respirable DUST per m3 • 0.1 mg of Respirable QUARTZ per m3 (includes surface parts of underground mines)

20. Dust Sampling 5 People • All Production Shifts:- • Continuous Miners – once per year • Longwalls – twice per year • All Others (once per year): • Other Underground • Surface Washeries and Plants • Open Cut Mines

21. Coal ServicesRespirable Dust Sampling March 1984 – December 2004 • Collected almost 53,000 personal dust samples • Sampled over 10,000 mining locations 62% other underground (mainly CM panels) 31% underground longwall faces 7% surface open cuts and coal prep plants

22. Respirable Dust Results (Including Re- Samples) 1984 - 2004 % Exceeding Limit Mining Method No. Personal Samples Number >3mg/m3 (including resamples) Longwall Faces Other Underground Open Cut/ Washeries 16 686 1 131 6.8 32 583 531 1.6 3 486 34 1.0

23. Mining Method No. Personal Samples Number >0.15mg/m3 3 486 66 16 686 687 32 583 517 Respirable Quartz Results (Including Re-Samples) 1984-2004 (including resamples) Opencut Washeries Longwall Faces Other Underground

25. Dust Size Health Risks – CWP Silicosis Lowering health Risks Dust Exposures Reducing Dust Exposure Control Measures Ventilation as a Control Measure Water as a Control Measure Other Control Measures Dust Suppression Methods. Administrative Measures Surfactants PPE Dust Monitoring – Static v Personal Results & what they mean Inhalable Dust and DP Content

26. Dust Size • Pneumoconiosis can be prevented provided exposure to respirable coal dust is maintained below statutory levels – 2.5mg/m3, extensive monitoring programs, appropriate engineering and procedural controls. • AIRBORNE DUST YOU SEE - Generally inhalable - >50 micron • RESPIRABLE DUST - < 1 micron 100% penetration                                                     - < 5 microns 50% penetration                                                     -  > 6 microns don’t penetrate • Penetration depends on speed, mass/ surface area and composition • ie Aerodynamic settling velocity.

27. Health Risks • The health risk to mine workers has long been acknowledged as being related to prolonged exposure to high concentrations of respirable coal dust which can lead to pneumoconiosis and when mining high quartz content material silicosis. • Coal mining has historically been associated with the occurrence of disabling chest diseases. • ILO Classification system, the international standard, is the system used by Coal Services to grade pneumoconiosis on chest x rays of coal miners. • Under this system there are 4 major categories used to grade the severity of pneumoconiosis. • Category 0 is the normal state • 1 mild - unaware of presence, normal activities • 2 moderate - become symptomatic • 3 severe

28. Pneumoconiosis • Coal Workers pneumoconiosis results from the gradual accumulation of coal dust particles within the lung tissue, usually over a period of many years. • Most of the dust that is inhaled does not lodge in the lungs. • The larger particles are trapped in the nose and throat and the very smallest particles are exhaled in the same breath. • Only the particles in the 0.5 - 7 micron size range are deposited and the lungs have special clearance mechanisms to remove most of these particles in the course of the next few days or weeks. • The dust which is not cleared aggregates to form nodules which can be seen on X Ray or PM. Generally at least 20 -30 years of exposure is necessary to produce any significant degree of disease.

29. Silicosis • QUARTZ ( SILICA) Exposure = SILICOSIS IF EXPOSURES ARE SIGNIFICANT • A relationship between silica exposure and lung cancer. • In coal mines free silica in coal is low however mines with stone intrusions or where brushing of the floor is common may have a problem. • Exposures must be kept below - 0.12mg per cubic metre of air. • Silica is more irritating to lung tissue because of its chemical nature.

30. Silica and Coal • NOHSC and UWA have acknowledged that ‘coal dust is capable of inhibiting the fibrogenic effect of crystalline silica & therefore possibly its carcinogenicity’ (IARC 1997). • As a result they initially stated that the coal industry should have a separate study to establish a suitable exposure standard. • In the latest documentation from the NOHSC this important factor has been overlooked. • Overseas studies have linked excessively high silica exposure in coal mines to an increase in levels of silicosis. (Scottish coal mine –UK HS&E) • Silica is more prevalent an issue in the northern districts particularly in certain seams in the Singleton area. • Coal Services Health has been conducting far more silica analysis in recent years to ensure that workers health is not compromised.

31. Lowering Health Risks • When JCB established in 1948 pneumoconiosis was prevalent - • 16% all categories, 4.2% - 2 or worse. • Today prevalence so low that no new cases of pneumoconiosis have been detected in the last 10 years ( Standing Dust Committee 1997). • The incidence of pneumoconiosis in NSW is among the lowest in the world. In sharp contrast to the USA where unfunded black lung liabilities reach some $15 billion. • Why does NSW have such a good record? • Independent monitoring, improvements in engineering (ventilation), safe work practices, education, PPE.

32. Dust Exposures • Dust concentration depends on the method of mining, nature of the mineral being worked and dust suppression techniques in use. • Success in combating pneumoconiosis in NSW and QLD had largely been due to the fact that coal was almost exclusively won by using continuous miners and shuttle cars where all personnel work in intake air. • Longwall mining is potentially a more difficult environment to control. In longwall mining not only is the dust concentration higher due to the more rapid excavation rate but the pattern of movement of men make the system more difficult to analyse. • Dust below 5 microns is respirable - no significant weight or inertia and hence can remain suspended for longer periods in the atmosphere.

33. LW Dust Exposures • Studies have shown that high dust exposures on longwall mining operations are mainly due to: • Inadequate air volume and velocity; • Insufficient water quantity and pressure; • Poorly designed external water spray systems; • Lack of dust control at the stageloader and crusher; • Dust generated during support movement; • Cutting sequences that position face workers downwind of the cutting machine.

34. Control Measures • Ventilation • Volume • Goaf Curtains • Air Splitters (Barriers, Batwings) • Water • Optimised delivery • Sprays – types and location • Administrative Measures • Interrogate process and tasks of high exposure • Cutting sequences • Operator location

35. Ventilation as a Control Measure • Ventilation has probably been the most significant factor in reducing excessive exposure to dust. • It can be used simply to keep people in clean air while moving dust away from the work area. • Careful observation of the work area and simple ventilation design can help ensure that available air can be used to effectively isolate the person from the exposure. • In more difficult situations mechanical sources may be required ie ventilation fans.

36. Ventilation • Ventilation should be considered the PRIMARY method of controlling dust. • Adequate quantities of air must be available to dilute and carry or direct the airborne dust away from the operators work area. • In addition to the quantity of air, other engineering controls including brattice curtains, flexible (eg rubber belt) air splitting devices can be used to effectively direct the air.

38. Air Splitting Screens

39. Water as a Control Measure • Airflow – direction and velocity • Droplet size – Spray type • Dust Particle size – primarily respirable or inhalable • Electrostatic charge • Proximity to breakage – location of sprays • Water quality • Water volume • Maintenance – no. of sprays operational • Drainage

40. Water as a Control Measure • Optimising water delivery may require • Increasing pump capacity for increased flow and pressure • Increasing line sizes to decrease pressure and maintenance downtime • Improving water quality by using filtering devices to reduce maintenance. • Reviewing the type of sprays, their location and effectiveness.

41. Spray Locations

42. Types of Sprays • Hollow cone sprays can be used for external shearer sprays, shearer clearer, crusher & transfer points. • Atomising sprays are the best for dust scrubbing, however are susceptible to damage and fouling

43. Types of Sprays • Venturi sprays are may be either hollow cone or atomising enclosed in a shroud where air is drawn through to increase pressure a lower droplet size. • Full cone produce a circular coverage at higher velocity and larger droplet size – best for wetting coal pre transfer points.

44. Types of Sprays • Flat spray nozzles produce a rectangular spray pattern of large droplets at high velocity – best for transfer points and under conveyor wiper systems • Solid stream – essentially a flat spray with a circular spray pattern – best for direct wetting eg pick and drum sprays

45. Other Control Measures • Roadway Dust Control • Wetting agents (surfactants) • Water Infusion • Foam Application • Scrubber Systems • Production constraint • Pick Wear • PPE

46. Dust Suppression Methods BSL • Curtains in the throat of the BSL & improved jointing to minimise dust make Dust Scrubber • (Extracts dust from the crusher & the discharge point

47. Dust Suppression Methods Dust Scrubber Photos

48. Administrative Measures • Interrogating the process • Review of work procedures across all shifts • Review monitoring results (Is there a difference and if so – why?) • Interrogation of operator positioning using Hund survey to highlight potential exposures and reduction of the same. • Utilise both on-site engineering operational and external resources to optimise what’s already in place.

49. Surfactants • The effectiveness of water to reduce dust can be enhanced by the use of a surfactant or softener. • This chemical compound alters the surface tension of the water to allow it to trap more dust. • Atomising the water provides a greater surface area to make contact with the dust. • All factors that apply to effective water usage apply to water sprays used in conjunction with a surfactant. • The concentration of the surfactant should be adequately controlled.

50. PPE • Dust respirators should only be used as the last line of defence and must not take the place of prevention of dust suppression techniques. • All respirators must be capable of filtering the dust to provide relatively clean air to the user with low resistance to breathing. Fitting must be adjusted to exclude contaminated air during inhalation. Facial hair or beards may adversely affect the efficiency of the seal on respirators. • It should NOT BE ASSUMED that dust respirators can be used when there is a deficiency in O2 or where the contaminant is highly toxic.