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Asbestos concerns in the 21st century: The Libby, Montana issue Mickey Gunter University of Idaho Moscow, Idaho plus, other thoughts
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Talk overview Libby overview Critical thought(s) Basic (?) knowledge Teaching idea, approach & information Good mineral, bad mineral What’s the “real” environmental concern(s)
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Libby overview Am Min (1959)
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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…. Seattle Post
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Death statistics (U.S.A./year) - 2,100,000: deaths - 600,000: heart diseases - 500,000: cancer - 150,000: lung cancer - 435,000: smoking cigs - 400,000: (too much) food - 85,000: (too much) booze - 43,000: auto accidents “The dose makes the poison” (Paracelsus, 1567). 2 9 0, 0 0 0, 0 0 0
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Death statistics (asbestos and…) - asbestosis ~ 300 - silicosis ~ 100 - mesothelioma ~ 300 - airlines & lightning ~ 150 - mad cow disease ~ 0 - snake bites ~ 0 - SARs & countless others < 10
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Risk of death vs Fear of death risk of death fear of death - self imposed - by ignorance
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Teaching idea
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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”?
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Obtaining (accurate) information
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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
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Silicosis & asbestosis deaths in the U.S.A. Gunter 1999
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Lung cancer deaths in the U.S.A.
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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
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Zonolite insulation & respirable asbestos bag weight = 6,000 grams < 177 m = 65 grams
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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) - 10 g / m 3 (of 5 m 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)
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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
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Asbestos: good mineral, bad mineral?
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Overview of real “superfund” site(s)
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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
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