Asbestos concerns in the 21st century: The Libby, Montana issue - PowerPoint PPT Presentation

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Asbestos concerns in the 21st century: The Libby, Montana issue

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  1. Asbestos concerns in the 21st century: The Libby, Montana issue Mickey Gunter University of Idaho Moscow, Idaho plus, other thoughts

  2. Talk overview • Libby overview • Critical thought(s) • Basic (?) knowledge • Teaching idea, approach & information • Good mineral, bad mineral • What’s the “real” environmental concern(s)

  3. Libby overview Am Min (1959)

  4. Seattle Post Libby mining details • 1923: Start of operations • 1950’s: 1,200,000 tons / year, ~30% vermiculite & 5% “tremolite” with 1/2 of that being asbestos • 1964: WR Grace buys mine • 1980’s: Medical studies • 1990: Mine closes • 1999: PI & EPA, ATSDR, etc….

  5. Death statistics (U.S.A./year) • 2,100,000: deaths • - 600,000: heart diseases • - 500,000: cancer • 150,000: lung cancer “The dose makes the poison” (Paracelsus, 1567). 290,000,000 • -435,000: smoking cigs • 400,000: (too much) food • 85,000: (too much) booze • 43,000: auto accidents

  6. Death statistics (asbestos and…) • asbestosis ~ 300 • silicosis ~ 100 • mesothelioma ~ 300 • airlines & lightning ~ 150 • - mad cow disease ~ 0 • snake bites ~ 0 • - SARs & countless others < 10

  7. Risk of death vs Fear of death - self imposed fear of death - by ignorance risk of death

  8. Teaching idea

  9. Teaching approach • overview of “problem” • define material, properties & analytical stuff • describe diseases & exposures • discuss case studies • discuss risk & societal impact(s) in context • What’s the “real problem”?

  10. Obtaining (accurate) information

  11. Now what? • Refereed literature • Common sense • 35,000,000 homes with Zonolite in USA • Non-biased sources • Whose side are you on? • Where does funding come from, for either side? • “Correct” government sources • Vital statistics of the USA • Agencies working in “their” area of specialty

  12. Silicosis & asbestosis deaths in the U.S.A. Gunter 1999

  13. Lung cancer deaths in the U.S.A.

  14. Libby diseases & on-going issues • Libby miner studies (1986 & 2003), SMR’s • ~ 250 for asbestosis, mesothelioma & lung cancer • Local lawsuits • Mr. Crayon, EPA, ATSDR & residents • 11 asbestosis deaths, no mesothelioma • no elevated lung cancer rate • MEG lung cancer SMR = 137 (10) & 133 (5) • Tremolite at Libby? • Zonolite in 35,000,000 homes nationwide

  15. Zonolite insulation & respirable asbestos bag weight = 6,000 grams < 177 mm = 65 grams

  16. Background levels of dust In air: - 0.0004 to 0.01 fibers / cc -> breathe 4,000 to 100,000 fibers / day (Mossman et al. 1990, Klein 1993) - 10mg / m3 (of 5mm sized particles) -> breathe 2,500,000 particles / day (Norton & Gunter 1999) In lungs: - 80,000,000 “fibers” with 50% asbestos general population Vancouver, BC (Chrug 1983) - white-asbestos = 50,000,000 and tremolite-asbestos = 6,000,000 general population San Francisco (Chrug & Warnock 1980)

  17. Good mineral, bad mineral? “Since the benefits of the natural environment in providing essential elements and nutrients are well known, the focus in this book has been on the harmful side of the relationship.” From Geology and Health, Skinner & Berger 25% of world population at risk

  18. Asbestos: good mineral, bad mineral?

  19. Overview of real “superfund” site(s)

  20. Final thoughts • As scientists, we must be skeptical enough to question anything, while being open-minded enough to consider everything. • And ……quartz……rant • And….…worry….…rave