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Please read this before using presentation. This presentation is based on content presented at the Exploration Safety Roadshow held in July 2013
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Please read this before using presentation • This presentation is based on content presented at the Exploration Safety Roadshow held in July 2013 • It is made available for non-commercial use (e.g. toolbox meetings, OHS discussions) subject to the condition that the PowerPoint file is not altered without permission from Resources Safety • Supporting resources, such as brochures and posters, are available from Resources Safety • For resources, information or clarification, please contact: RSDComms@dmp.wa.gov.au or visit www.dmp.wa.gov.au/ResourcesSafety
Managing fibrous minerals during exploration What should you look out for?
What does this presentation cover? Is there an increased encounter likelihood? What do asbestiform minerals look like? Where are they found? Why are asbestiform minerals hazardous? What are the health effects? Are there exposure controls?
What do the regulations require? • If you are likely to encounter asbestiformminerals. • You will need a fibrous minerals management plan • Getting started – use Appendix 3 of guideline
What does the guideline provide? Help the mining industry understand the hazards including potential health risks from fibre exposure Demonstrate a risk-based approach to fibre management Provide examples of dust control measures for various types of drilling as well as during blasting, earth moving and processing operations
Why mineral fibres? Rising demand for State’s minerals so some previously uneconomic orebodies containing fibrous minerals are now commercially viable Increased probability of encountering fibrous minerals as depths of exploration and mining increase All airborne fibrous minerals have some health implications
What types of mineral fibres are there? Asbestos “Asbestiform minerals” Erionite Winchite Brucite Rickterite Pyrolusite Many others
Asbestiform and non-asbestiform minerals Asbestiform riebeckite Non-asbestiform riebeckite
Asbestiform fibre types Crocidolite (Amphibole) Chrysotile (Serpentine)
How do we get asbestos? Parent rock is mafic or ultramafic (igneous) Disturbance in rock formation (e.g. faulting, slippage) Heat, pressure, water and minerals from parent rock lead to asbestos crystal formation Often occurs in “lenses” or bands (mm – cm) Mineral deposits with asbestos present include iron ore and nickel sulphides
Why are mineral fibres hazardous? Airborne and respirable size (low micron) Morphology (long and thin) Persistence in the lung (insolubility of fibres and macrophages) Interaction of fibres with lung tissue to induce free radical formation
What are the health effects? Least severity Greatest severity Exposure levels have decreased – and we want it to stay that way! • Asbestosis • Lung cancer • Mesothelioma • Pleural plaques The type of asbestos inhaled is an important factor in determining which lung disease may develop
Is everyone exposed to fibres? Typical non-occupational exposure is 0.0001 fibres/mL National exposure standard (TWA) is 0.1 fibres/mL (any form of asbestos) Humans breathe 10 to 20 m3 of air per day 10 m3 of air = 1,000 respirable fibres breathed in per day About 25,000,000 fibres inhaled in a lifetime
What is the respirable fibre definition? Fibre is defined by morphology (not mineralogy) Widely used definition < 3 µm diameter > 5 µm long > 3:1 aspect ratio Mining definition in WA [MSIR 9.33 (3)] Maximum width 1 µm Length > 5 µm > 5:1 aspect ratio
What’s dust management? Regulatory focus on fibre and dust management in mining Statutory obligation to manage dust emissions in drilling operations Obligation to monitor exposures to atmospheric contaminants Ensure exposures do not exceed occupational exposure standards (OES)
How do we control fibrous minerals? RC dry drilling Control dust = control fibre emission
What can we do? RC dust extraction system RC wet drilling Control dust = control fibre emission
Break-out discussion Do you encounter fibrous minerals during your exploration activities? Does your site have a fibrous minerals management plan? Does everyone potentially exposed to fibrous minerals on your sites know what is in the plan? What about you? Do you know what is in it?