Assessing Hazards and Managing Risk associated with Naturally Occurring Asbestos (NOA): The Geologist, The Laboratory, and The Occupational Hygienist

Transcription

1 The Chartered Society for Worker Health Protection OH2017 April 24-27, Harrogate, UK Assessing Hazards and Managing Risk associated with Naturally Occurring Asbestos (NOA): The Geologist, The Laboratory, and The Occupational Hygienist Session 7a - Asbestos Wednesday, April 26, 2017 Fred W Boelter, CIH, PE, BCEE, FAIHA Jacob Persky, MPH, CIH RHP Risk Management Inc. 1

2 Definitions Asbestos A term for 6 fibrous minerals harvested for their commercial value and use as a product ingredient. The 6 minerals are chrysotile, and the amphiboles cummingtonite-grunerite (amosite), riebeckite (crocidolite), actinolite, anthophyllite, and tremolite. NOA - "Naturally Occurring Asbestos " is asbestos from natural geologic deposits. (Not harvested for the purpose of becoming an ingredient). EMP - thoracic-size elongate mineral particles (EMPs) that grow either in an asbestiform habit (e.g., asbestos fibers) or in a nonasbestiform habit (e.g., as needle-like [acicular] or prismatic crystals), as well as EMPs that result from the crushing or fracturing of non-fibrous minerals (e.g., cleavage fragments). 2

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5 NIOSH Asbestos Roadmap EMPs are not asbestos Reduce exposures to the lowest feasible concentration REL airborne asbestos fibers and related EMPs is 0.1 countable/cc by PCM averaged over 100 minutes Determinants of Particle Toxicity and Health Effects (Deposition, Clearance/Retention, Biopersistence, Particle Characteristics, Toxicity Studies, Thresholds) Chrysotile is different Framework for additional study DHHS (NIOSH) Publication No

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7 Where are NOA/EMP 7

8 How are EMP formed 8

9 Metamorphic Minerals 9

10 Temperature and Pressure 10

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13 Pacific Coast 13

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15 The CDRP Moving 7MM Cubic Yards 15

16 Blueschist (Franciscan Complex) Brecciated Serpentinite (37% chrysotile) 16

17 A Risk Definition India - just another routine day of production RISK = f ( Bad Effects) Exposure 17

18 Risky vs. safe What does free of risk mean? Do we mean safe? How do we achieve? How do we confirm? Can we agree? Maybe we need to frame the discussion 18

19 The Challenge In 1924, asbestosis was first diagnosed in the UK, however, UK has no asbestos mines. Malignant asbestos disease in the UK relates to amosite and crocidolite from South Africa. Non-commercial amphiboles or naturally occurring asbestos (NOA) and elongate mineral particles (EMPs) are being questioned regarding disease risk. Non-regulated NOA/EMP include olivine in Scourie Scotland, erionite in Cappadocia Turkey, winchite in Libby Montana, and iron glaucophane in Calaveras California. 19

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22 Lab Methods Potential Hazard: Not Risk - Lab methods were developed to simulate some condition of disturbance and create a measurable airborne concentration. Some methods alter the mineral to enhance fiber releasability. How do airborne breathing zone concentrations compared with respective lab methods? 22

23 Rotating Drum 23

24 Continuous Drop 24 24

25 Vertical Elutriator 25

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29 Is this of interest? Why? 29

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31 NIOSH REL Is This Correlation Compelling? BZ f/cc Bulk f/gram 31

32 Results - %, f/g, s/g A lab method may report hundreds of thousands of f/gram in a bulk sample yet minimal airborne fibers are quantifiable in the breathing zone. Having tools to focus exposure assessments is valuable but a laboratory value can be misleading. Step back and reflect on what question we are trying to answer. Ann. Occup. Hyg., Vol. 52, No. 8, pp ,

33 1,037,793,103,448,276 s in my backyard aka 1x10 15 But, I don t want any 33

34 Isn t this zero? 34

35 Conclusion Hazard and risk are not the same and lab results do not assess exposure. NOA and EMP assessment tools are not well understood and unnecessarily costly if misapplied. Irrational fear can result when confusing hazard values (i.e. f/gram) with dose values (i.e. f/cc-years). NOA/EMP analysis is not an asbestos bulk analysis. Risk management needs appropriate and validated tools to differentiate significant from insignificant. The Geologist, Laboratory, and Occupational Hygienist have respective roles to meaningfully characterize risk and make management decisions. 35

36 The Anthropocene Epoch Has Arrived 36