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Baseline Personal DPM; Exposure Limits; Mine Ventilation Engineering Planning- A South African Journey Dr. B. K. Belle.

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Presentation on theme: "Baseline Personal DPM; Exposure Limits; Mine Ventilation Engineering Planning- A South African Journey Dr. B. K. Belle."— Presentation transcript:

1 Baseline Personal DPM; Exposure Limits; Mine Ventilation Engineering Planning- A South African Journey Dr. B. K. Belle

2 DPM Looks Like… Source: Health Effects Institute Source: Dr. Rogers, Australia

3 DPM Looks Like Diamond Platinum Gold Coal

4 What is DPM?

5 South Africa-Legal

6 DPM Hazard  ACGIH: 0.15 mg/m3, A2 (suspected human carcinogen) (1995); 0.05 mg/m3, A2 (1999); 0.05 mg/m3, A2 (2000); 0.02 mg/m3, (elemental carbon), A2 (2001); 0.02 mg/m3, A2 (2002); Withdrawn (2003); ACGIH- TLV for DPM –Under Notice of Intended Change (NIC)  January 19, 2001- MSHA (USA) Risk Assessment with respect to health effects, was: “Exposure to DPM can materially impair miner health or functional capacity. These material impairments include acute sensory irritations and respiratory symptoms (including allergenic responses); premature death from cardiovascular, cardiopulmonary, or respiratory cause; and lung cancer.” 66 Fed. Reg. 5853-5855 (Jan. 19, 2001).  MSHA-2001--Mean concentration of 0.64 mg/m3 TC for a period of 45 years of occupational exposure results in a relative risk of lung cancer of 2.0.  This established an interim concentration limit of 400 ug/m3 using total carbon (TC) as a surrogate for DPM, and a final limit of 160 ug/m3 TC, which was to take effect on January 6, 2006.  January 19, 2001-July 2005— 31 American Mines Study.  July 6, 2005- 400 ug/m3 TC; 308 ug/m3 EC (TC/EC Ratio of 1.3 for 90% of the valid samples~ 464)  January 20, 2007--the DPM limit was reduced to 350TC μg/m3 or 270EC μg/m3  May 20, 2008 –the final limit of 160TC μg/m3 and 123 ug/m3 EC

7 …Back in 1928

8 Diesel Engines in SA Mines Battery LocomotiveRusten Hornby Diesel Locomotive  1928- Van Dyk Consolidated Mines Ltd, Witwatersrand  Mining regulations-Proportion of CO and CO2 should not be more than 0.01% and 0.2% respectively  Dilution Factors varied from -0.013 m3/s/kw to 0.0325 m3/s/kW

9 Personal DPM Sampling Send DPM Filter Cassette For Analysis- NIOSH 5040 Analyzes Sample Filter For Total Carbon- OC-EC Control Filter Analyzed for the same

10 Engineering Sampling  Pressure Differential over a DPM selective filter (metering pump)  Robust  Tested in South Africa for Respirable Dust Measurement-Health 704  Calibration Issues Overcome  Production 6/08  Release (Nevada) 9/08 Diesel Detective (SKC / NIOSH)

11 DPM OEL History  Coal Mining– No personal Exposure standard yet; RAW Exhaust Standard -2.5 grams/hr-Maximum emission per engine  Australia—100 microgram/m3 (EC) or 200 microgram/m3 as TC (TC/EC Ratio-2)  Germany (non-coal)-0.3 mg/m3 elemental carbon  Canada  Majority of Provinces 1.5 mg/m3 (RCD)  Quebec0.6 mg/m3 (RCD)  Ontario0.4 - 0.6 mg/m3 (?)

12 SA DPM Journey

13 Calculations Where: DPM ST =sample DPM concentration measured in μg/m3 M=DPM mass (EC or OC) in μg/cm2 B=Controlled filter mass (EC or OC) in μg/cm2 FL=sample flow rate in liters per min ST=sampling time in min A=DPM filter deposition area, cm2  DPM Filter Deposition Areas  NIOSH 5040 method-8.55 cm2 for a 37-mm filter when using a three piece style cassette.  SKC impactor- between 8.11 and 8.21 cm2.  MSHA-8.04 cm2.  SA--??Like to Know

14 DPM Finger Prints

15 Finger Printing DPM





20 Calculation Errors  Statistically significant differences  More pronounced at stringent OELs Paired T-Test and CI: 8.04 cm2 Vs 8.40 cm2 Paired T N Mean StDev SE Mean 8.04 cm2 48 238.5 368.3 53.2 C11 48 249.2 384.8 55.5 Difference 48 -10.69 16.51 2.38 95% CI for mean difference: (-15.49, -5.90) T-Test of mean difference = 0 (vs not = 0): T-Value = -4.49 P-Value = 0.000

21 Adoption--Compliance Check  OEL x Error Factor = Enforceable Limit  Error factor for EC + OC = TC is 1.14;  Error factor for EC x 1.3 = TC is 1.12  Enforceable DPM limit for EC + OC = TC is: 160 TC µg/m3 x 1.14 = 182.4 TC µg/m3  Enforceable DPM limit for EC x 1.3 = TC is: 123EC µg/m3 x 1.12 = 138TC µg/m3  Citable—Both TC values exceed their respective enforceable limit EC + OC = TC EC x 1.3 = TC 123 EC µg/m3 x 1.3 = 160TC µg/m3 123EC µg/m3 x 2.5 = 308TC µg/m3


23 Ventilation Design Parameters 27.5 °C 308 EC  g/m 3 CH 4 1.4% CO 25ppm 5 mg/m 3 Regulatory Compliance Limits 27.5 °C 3 mg/m 3

24  Engineering control examples:  Low emission engines  Environmental cabs (filtered breathing air)  Ventilation upgrades (main or auxiliary)  Avoid Re-circulation  Alternate fuels, fuel additives  Remotely controlled equipment  DPM exhaust filters Engineering Controls p=total pressure across the fan Q=quantity through the fan P ow =power (also operating cost)

25 Engineering Control-Filter Systems Triple Filter System Single-Double – Triple Filter Systems

26 Practical Ventilation Controls

27 Ventilation DPM Audit tool  2.5 grams/hr tailpipe limit

28 Way Forward

29 Compliance Status??  January 6, 2003—19.3 % of mines non- compliance at 400 ug/m3 TC; Mean– 236 ug/m3 TC.  2007- USA--average exposure level was 181 µg/m3 TC and 21 % of the mines were cited for noncompliance. At the proposed limit of 160 µg/m3 TC, would they be out-of compliance-- ???!!  South Africa-- ??

30 Way Forward  Pro-actively carry out personal DPM exposure to understand the risk  The adoption of overseas TC/EC ratio/limits for compliance needs to be scientifically determined.  The ventilation planning and audit tool can be used effectively in all mines with regard to the number of diesel vehicles in use.  Consider diesel engine database for engineering control solutions where applicable when carrying out Personal DPM exposure levels.  DPM Measurement must be carried out in conjunction with the ventilation engineering parameters (m/s, m2, m3/s, WBT, DBT, humidity levels, Depth, BP)

31 Q & A  Should the ventilation engineering department to know the sulphur content of the Sulphur Levels??-Yes  Is “Tailpipe” Emissions Testing Required At Mine Site?-- No. This Is Engine Manufacturer’s Responsibility (MSHA, 2003).  Should the ventilation engineering department sensitise this hazard with relevant people for risk assessment??- Yes  Sharing of DPM information between the mines in order to arrive at an informed OEL for South Africa? --Yes

32 Way Forward  …an input to scientific approaches in developing appropriate conversion factors and OELs (Step down approach) for DPM and also in ensuring appropriate error factors for compliance determination in SA.

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