Ch.4. Asbestos in the Environment

Introduction Properties and uses Brief history Environmental hazards

IntroductionAsbestos: asbestoz “inquenchable” “inextinguish-

able”Fibrous silicate minerals: serpentine & amphiboles

○ White, brown, blue & others

tremolite

crocidolite

chrysotile

Asbestos fibre

From http://en.wikipedia.org/wiki/Asbestos

Properties & UseProperties:

○ Mineral: insulation (heat, electricity), resistance against fire & chemical reaction, incombustibility

○ Fibre: flexibility, capability of being woven, sound-absorbing

Uses○ (See the table on the next page)

Properties Application examples

Fire resistance,flame retardance,heat insulation

Building materials- interior and outsideFire-proof materials, e.g. clothsSeals for heaters and ovensHeat insulators

Electric insulationInsulators for pipes and electrical devicesCommutators

Resistance against chemical reactions (corrosion)

Chemical filters, PaintsGasketsExperimental apparatuses

Sound absorption Sound absorbing board

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Brief HistoryB.C. ca. 3,000 Scandinavian remains – used in

porcelain and filler among the logs1C : Greek island Evvoia – Asbestos mining

querryEarly Greek-Roman: unflammable clothes and

building materialsPliny the Elder: Thought to be used for the pro-

tection from the curse

Pliny the Elder (23-79), a.k.a. Caius Plinius Secundus, Gaius Plinius Secundis. Author of the grand encyclopedia "Naturalis Historiae".

Ancient Egyptian: Used for Parao’s mummyAncient Persian: Imported from China, Used for

the cloths for deaths, thought as feather of sara-manda (phoenix)

Others: Lamp wick of tomb, Cure for itching

Saramanda on a tile from ancient Iranian heritage

http://www.metmuseum.org

Marco Polo (1254-1324): “Livres des merveilles du monde” Clothes being cleaned in fire?

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In medieval times, asbestos was frequently used for the insulation of armor

Some fraud merchants made cross with asbestos and deceive people with it as if that was a part of the cross on which Jesus Christ was nailed (hung, executed)

19C: Industrial revolution also trigger modern application of asbestos○ Used as heat insulator in USA & Canada in 1860’s○ First commercial asbestos mine in Quebec,

Canada, in 1879.20C: rapid increase of asbestos consumptionAfter 1970’s: Health threats (hazards) by as-

bestos became obvious invoke lot of regula-tions against asbestos usage. Ban of asbestos usgae Sudden decrease of asbestos con-sumption

Asbestos production and consumption

Global production (10,000 ton/year)Japan (ton/year)

China

Korea

Now, the usage of asbestos is banned or limited in most countries

For Korea,○ From 2009.09, asbestos is banned to be used in

any industrial product○ From 2007.07, any product containing asbestos is

banned to import, produce, or use.

World Asbestos Resources

Country Reserve Base

(By Principal Countries)  

Brazil Moderate

Canada Large

China Large

Kazakhstan Large

Russia Large

USA Large

Zimbabwe Moderate

Other Countries Large

World Total Large

Source : Mineral Commodity Summaries, 2004.

World Asbestos Producers

Country 2001 2002 2003

(By Principal Countries) Production of Asbestos(in '000' tonnes)

Brazil 173 195 231

Canada 262 216 174

China 258 220(e) 210(e)

Kazakhstan 271 291 353

Russia 735 775(e) 878(e)

Zimbabwe 119 168 130

Other Countries 82 135 24

World Total 1900 2000 2000

Source : World Mineral Production. 1999-2003.