Introduction to asbestos Presented by Jane Tierney July 2015 - - PowerPoint PPT Presentation

INSTITUTE OF OCCUPATIONAL MEDICINE www.iom-world.org

Asbestos in Soil

Introduction to asbestos

Presented by Jane Tierney July 2015

Presentation brief

• What is asbestos, naturally occurring
• Where does it come from, importation into UK
• Health effects and ongoing legacy
• Why was it used – unique properties
• Asbestos in buildings/structures – where was it used
• Locate, manage, remove/remediate
• Brief on methods etc.
• Asbestos in soils: how did it get there
• Locate, manage, remove/remediate
• Brief on methods etc.

Today

• The World Health Organization (WHO)

estimates that 125 million people around the world are annually exposed to asbestos in the workplace, and the International Labor Organization says about 100,000 workers die each year from a related disease.

Asbestos

• Naturally occurring minerals which have crystallised

to form long thin fibres and fibre bundles.

• 90-95% of world production: Chrysotile (white

asbestos)

• World production peaked at 5.1 million tonnes

(1975)

• Asbestos is still mined and used in the developing

world – Russia, Brazil, China, India and Kazakhstan

• Asbestos was banned in many countries, however a

legacy of former use remains

Asbestos Mines

Troodos Mountains, Cyprus – defunct Chrysotile mine Libby mine, Montana, USA Jeffrey mine, Quebec, Canada

ASBEST, Russia, ab asbestos mine on eastern slope of Ural Mountains

(taken from article in New York Times 2013)

Asbestos Veins/minerals

• Chrysotile

fibres

• Crocidolite

vein

Asbestos

• Asbestos was banned in UK in 1999,

although there was a voluntary ban on Crocidolite in 1970 and on Amosite in 1980, with a mandatory ban on both in 1985

• Like many countries there remains a legacy
• f use

Worldwide Asbestos

Extract taken from www.asbestos.com

Types of Asbestos

• 6 identified types -commercially exploited
• 2 mineral groups, serpentines and amphiboles
• sheet & chain silicates
• Chrysotile: White Asbestos
• Long, thin, flexible, inelastic & silky fibres
• Amosite (Grunerite): Brown Asbestos
• short needle like fibres
• Crocidolite: Blue Asbestos - short needle like fibres
• short needle like fibres
• Anthophyllite
• Straight, needle-like, flexible & elastic fibres
• Tremolite
• Actinolite

Chrysotile

Chrysotile is the major asbestos type in world due to; Most abundant naturally occurring, and therefore commercially mined. Initial type used (1880s) and last type prohibited in Europe (1999). Most ‘versatile’ – woven into fabrics Added to most products – cement, tiles, coatings Still used for some products in USA and

• ther countries

Still mined in Canada

Amosite

• Amosite asbestos in currently more commonly identified than crocidolite,

but much less than chrysotile:

• Smaller areas of commercial exploitation (South Africa, Zimbabwe,

Zambia).

• Acronym of Asbestos Mines Of South Africa.
• Voluntary import ban c1980.
• Used in insulating boards.

Crocidolite

• Crocidolite is less commonly found, due to;
• Voluntary import ban in 1970.
• Smaller areas of commercial exploitation, mainly in South Africa

(2% of world production)

Health effects

Health Effects

• Why is Asbestos Dangerous?
• Level of Exposure - Dose

(concentration / duration/ frequency)

• Diseases
• Asbestosis
• Lung Cancer
• Mesothelioma

Health Effects cont.

• Although asbestos is a

hazardous material, it

• nly poses a risk to

health if the asbestos fibres become airborne and are then inhaled

• ACMs only release

fibres into the air when the material is disturbed

Why is Asbestos Dangerous?

• Splits into long respirable

fibres

• Long Fibres (>15µm) not

cleared from lungs

• Cells die – release toxins
• Toxins cause scar tissue
• Amphiboles more resistant

than Chrysotile

• Amphiboles cause problems

for many years 10 20 30 40 50 60 70 80 90 1st Qtr 2nd Qtr 3rd Qtr 4th Qtr East West North

Can a Single Exposure Lead to an Asbestos- Related Disease?

All exposures to asbestos should be avoided, however, that does not mean that you should necessarily worry about a one-off exposure. Your risk of developing an asbestos-related disease depends how much asbestos you are exposed to, for how long and on how many different occasions. A one-off short-term exposure is unlikely to be of concern, but each time you are exposed, the risk increases a little bit more – like smoking!

Asbestosis

• Fibrosis or scarring
• Effects both lungs
• Caused by inhalation of fibres
• 10-20 years after exposure
• Associated with high exposure over a period
• f time
• More common in smokers
• Incurable

Lung Cancer

• Increased incidence of all lung cancers associated

with exposure sufficient to cause asbestosis

• Incidence increases with smoking and asbestos

exposure – synergistic effect

individuals who are exposed to both tobacco smoke and asbestos have roughly a 30- to 50-fold increase in risk of developing lung cancer

Mesothelioma

• Affects lung or intestine
• 20-60 year latency
• No treatment
• Invariably fatal
• Average life expectancy 6 - 18 months
• 1200 new cases each year and this figure is
• n the increase

UK Asbestos Imports and Predicted Mesothelioma Deaths

1920 1960 1980 2000 2020 2040 1940

UK Imports of asbestos UK mesothelioma deaths

Year After Peto et al 1995 About 1,000 deaths for 1997 175,000 tons/year Chrysotile by 1970 3,400 deaths/ year by 2020 25,000 tons/year Amphibole by 1960

Why Was It Used?

• Thought of as a “wonder” material
• Very useful commercial properties,
• Acid/Alkali resistance
• Fire resistance
• Thermal insulation
• Mechanical strength
• Sound insulation
• Electrical insulator
• Can be woven into textiles

History

• Funeral dress for the cremation of kings
• Napkins & tablecloths – Charlemagne,

‘magic tablecloth’

• Marco Polo was shown items made from

asbestos cloth on his travels

• Greek & Romans, slave clothing
• Strengthening pots

Variety of uses

Asbestos in the movies

• Wizard of Oz, poppy field snow scene
• Wicked witch of the west had an asbestos

broomstick

Asbestos in Buildings

General uses

• Insulating boards
• Lagging
• Sprayed coatings
• Flooring materials
• Reinforced cement products
• Textured coatings
• Loose insulation
• Electrical insulator
• Textiles

General photographs

General photographs cont.

Locate, manage, remove/ remediate

• Duty to manage
• Assessment of presence
• Assessment of work
• Prevention or reduction of exposure
• Duty to prevent or reduce spread

Brief on methods

• HSG 264, The survey guide
• Types of surveys, Management,

refurbishment/demolition

• HSG 248, The analyst’s guide
• Methods for sampling and analysis of air

and bulk, PCOM, PLM

• HSG 247, The contractors guide

Removal techniques, control measures, PPE, training

Why We Need To Manage Asbestos

• In UK approximately 4,000 people a year

die from asbestos related diseases

• This is more than those associated with road traffic accidents
• Within the next 25 years 50,000

Mesothelioma deaths will occur in Britain – this equates to 150,000 asbestos deaths

• 25% of these people will have worked in

building trades

• Each week approximately 8 joiners, 6 electricians & 4 plumbers die from asbestos related diseases

Asbestos in the ground

• Deliberately placed – tunnels, ducts, services,

below ground buildings, bunkers, registered and unregistered waste sites

• Below ground structures may remain following demolition
• f original buildings
• Surplus material, overspray, off cuts remaining

from construction

• Incomplete asbestos removal prior to demolition
• Building collapse or damage – fires, floods,

explosions

• Fly tipping
• Demolition rubble, crushed and spread across site
• ‘Clean’ imported material spread across site

Sites & stockpiles

Locate, manage, remove/ remediate

• Cannot undertake an asbestos survey in

terms of HSG264 guidance

• Site investigation
• Desk top site review
• Surface inspection
• Below surface investigation
• Methodical but non-biased sampling
• Asbestos screening
• Asbestos quantification
• Interpretation of results

Locate, manage, remove/ remediate

• Decisions re licensed, non-licensed,

notifiable non-licensed activities

• Informed decisions regarding re-use and

associated future liabilities

Brief on methods

• CIRIA C733, asbestos in soils and made ground, a guide to

understanding and managing the risks

• HSG 248, The analyst’s guide
• Methods for sampling and analysis of air and bulk, PCOM, PLM
• HSG 247, The contractors guide, Removal techniques,

control measures, PPE, training Not necessarily suitable for land remediation projects e.g. 1 Monitoring needs greater detection limits e.g. SEM analysis e.g. 2 Quantification of asbestos in soils requires additional accreditation

Activity based sampling

US EPA

Activity based sampling

UK

Any Questions