Exposure to asbestos and exposure monitoring at Helsinki Asbestos 2014

© Finnish Institute of Occupational Health – www.ttl.fi13.03.14 Timo Tuomi
Exposure to asbestos and
exposure monitoring
Timo Tuomi

© Finnish Institute of Occupational Health – www.ttl.fi/en
Exposure periods to asbestos,
historical perspective
13.03.14 2Timo Tuomi
* still going on in Asia-Pasific, Russia, China, Kazakhstan,Brazil, India, Pakistan,
Vietnam etc

“An estimated 125 million people are exposed to
asbestos at work and 107 000 people die of
asbestos-related diseases every year. These
diseases will increase greatly in the coming
years."(WHO)

Asbestos in Finland (Rantanen et al, 2014)

War times –boosters for
industrial use of asbestos
• The First World War -> enormous increase
in shipbuilding -> increased the use of
asbestos as fire retardants in warships.
• At that time, the dangers of asbestos to
shipyard workers were not even considered.
• The Second World War -> even more
asbestos use -> rise in production from that
time.

The industrial use of asbestos
•More than 80% of all asbestos has been used
in asbestos cement production
•Insulation material
•Numerous applications of asbestos containing
products, ACP, and materials, ACM
About half of the asbestos put in buildings are
there in place (Finland) ! ! !

© Finnish Institute of Occupational Health – www.ttl.fi/en13.03.14 Timo Tuomi
Asbestos exposure today !
• Occupational exposure (in BAN countries):
• asbestos removal workers
• workers in waste handling
• repair and maintenance in premises with ACM
• Environmental and domestic exposure:
• maintenance and "homeimproving" activities in houses
and dwellings with asbestos containing material in
structures
• after failing of dust control in asbestos removal worksite
Occupational exposure (in countries with new
asbestos use/production)
The epidemics of asbestos related diseases
will continue !

Asbestos minerals

Formation of fibrous minerals
Mg
Fe
Si
O
Ca
Na

Asbestos minerals
Asbestos is the collective term for six
naturally occurring fibrous silicate minerals

Asbestos under scanning EM
6000X
• Kuvia asbestista
• Vesi ruoka !!!!
Crocidolite Anthophyllite
Chrysotile Tremolite

Exposures resulting of
widespread commercial use

High exposure took place –
asbestos spraying
• spraying of asbestos was one
of the most dangerous forms of
application
• sprayed asbestos is extremely
friable, fibres are very likely to
be emitted into the ambient air
• a large amount of sprayed
asbestos can be found in
civilian and military ships which
were built using this technique.
The air concentrations of fibers
during the spraying were up to
100-200 f/cm3

Occupational exposure
Hagelmeyer et al, 2006, Riala, 1991
1950-54 1970-74 1980 1990
Textile industry
Production of
•gaskets
•asb. cement
•brake pads
(Germany)
10-200 5-20 1-15 0,1-2
Production of
•asbestos
cement
•ACP
•building
•abatement
•brake
maintenance
•misc.
installations
(Finland)
- 0,1-80 0,1-8 0,1-1
(f/cm3
)

Asbestos cement production:
mean fiber concentrations in different
operations

Environmental exposure to
asbestos
Environmental and indoor exposure today,
fibers/cm3
•Outdoor, rural-urban 0,00001–0,0001
•Outdoor, ind. sources 0,01
•Indoor air 0,00003-0,006
- industrial sources (asbestos mine or factory,
demolition site, or improperly protected
asbestos-containing waste site)
- Indoor concentrations depend on indoor sources,
insulation, floor tiles, ceiling etc.
(ATSDR, 2001)

Exposure limit values in
Finland (all asbestos types)

Current limit value, EU
• Workplace air:
0,1 f/cm3
for fibers longer than 5 µm, thinner than 3 µm and
length/width > 3
• "Asbestos free air":
0,01 f/cm3

Common building materials
containing asbestos
Paint in outer walls Asbestos cement boards
Heating pipe insulation
Sprayed asbestos
PVC tiles and bitumen glue Insulation material, soft
board and ropeFixing plaster
Cast magnesiamass
(floors)

Measurement and analysis of
asbestos
• Airborne fibers
• during asbestos work
• inside respirator
• in the exhaust air of a filtering unit
• after cleaning and dismantling of the enclosed area
• Settled dust (asbestos contamination) on
surfaces
• floors, tables, pipe canals, inside ventilation ducts
• archive folders, office papers, shelfs, etc
• Asbestos as a constituent
• in building materials
• in rocks, ores and soils
• in water, (earlier in beverages, wine)
• Asbestos burden inhuman body
• in human lung tissue, (post mortem or surgical samples)
13.03.14 Timo Tuomi

Asbestos under light
microscope (disp. staining)

© Finnish Institute of Occupational Health – www.ttl.fi/en9.10.2012
Source :
Heli Lallukka/FIOH
Method of exposure
measurement
(air samples)
•The air concentration of asbestos fibers is determined from
filter with electron microscopic counting and analysis with
energy dispersive x-ray analysis (EDS) with standardized
procedures. Fibers with a minimum length of 5 µm and
maximum width of 3 µm and the length to width ratio of at
least 3:1, are counted
Filter holder
to sampling pump
elektronimikroskooppi

Asbestos under electron
microscope (SEM)
Point of the elemental analysis

Fiber 1: crushing
EDS-Spectrum of tremolite fibers from a metal ore mine
Fiber 2: crushing
Fiber 3: crushing Standard tremolite (IOM)
Source :Heli Lallukka/FIOH
samples coated with gold (Au)

Summary data from measurements
after 2004 (Finland):
• asbestos fiber concentration inside
respirator
• typically less than 0,01 f/cm3 (exceptions exist !!)
• air concentration during asbestos removal
(outside respirator)
• sprayed asbestos, 50-200 f/cm3
• vinyl tile removal 0,1–0,5 f/cm3
• pipe insulation removal 2,0–10 f/cm3

Asbestos is still mined and
manufactured

Concentrations of airborne fibers
(> 5 µm) and dust in mining and milling (Uralasbest,
1995) (Tossavainen et al, 1999 , Am J Ind Med)
Fiber conc.
SEM (f/cm3)
Fiber conc.
Light micr.
(f/cm3)
Dust conc.
(mg/m3)
Quarry 0,08
(0,01-0,27)
0,52
(<0,1-2,8)
Plant No. 4 4,61
(0,18-14,0)
3,62
(0,11-11,6)
2,33
(0,1-12,4)
Plant No. 6 0,69
(0,03-5,60)
0,63
(0,03-5,1)
0,83
(<0,1-4,5)
”Dust levels about the same as in mines and factories in Canada
Zimbabwe and India, All fibers were chrysotile” (Tossavainen et al, 1999 , Am J Ind Med)

Chrysotile fiber concentrations (>1 µm) in
lung tissue of autopsy cases, Asbest Town
Hospital (Tossavainen etal, Am J Ind Med, 2000)
Type of
exposure
Mean
chrysotile fiber
conc. (f/g)
N
>1x106
(f/g)
N
Chrysotile
Mining
8,0
0,9-24,5
7 * 8
Chrysotile
milling and
manuf.
11,6
2,0-50,6
11 11
Unknown
occup. in
chrysotile
industry
13,1
0,8-26,3
4 5
Unknown
exposure
2,6
0,1-14,6
13 23
* the amount of tremolite fibers was about 10% of the chrysotile fibers

ARD diagnostics and epi research:
Evaluation of asbestos exposure from
work history
• Interview, employment records
• Probability of exposure (for studies):
• Definite, asbestos manufacture, -spraying, insulation
• Probable, construction, shipbuilding,pipefitting
• Possible, mining, car repair, maintenance
• Unlikely, office work, education, health care, agriculture
• Counting of fiber years (cumulative dose,
individual):
• Faserjahre- approach (Germany, BK-Report
2013)
• number of work days per year X mean fiber (air) concentration
during work day
• work description (asbestos exposure) of different
works/occupations
• example: 240 days x 1 f/ml = 1 fiber year (Germany)
• 25 fiber years = lung cancer risk is doubled

Fibers stay in the lungs
• the adverse heath effects
of asbestos are caused by
inhalation of asbestos dust
=airborne fibers
• asbestos fibers stay in the
lungs and clearance is
slow (chrysotile behaves
differently from
amphiboles)

The body burden – what we have
learned of exposure and fibers in
the lung (Helsinki Criteria, 1997)
Highly indicative to past occupational exposure to
asbestos:
•Pulmonary fiber concentration (> 1 µm):
1 million f/g dry tissue or 0,1 million f/g dry
tissue (amphibole fibers)
•"Asbestos body" concentration in BAL-fluid
> 1 AB/ml (BAL) or 1000 AB/g dry tissue
The relative risk of lung cancer risk is 2:
•Pulmonary fiber concentration (> 5 µm):
> 2 million f/g (amphibole fibers)
Pulmonary fiber concentration (> 1 µm):
> 5 million f/g (amphibole fibers)
5000-15000 AB/g dry tissue or 5-15 AB/ml
(BAL)

Asbestos exposure of today
and tomorrow
1. We have still millions of tonnes in place as
a source of exposure
2. New asbestos is produced and used
• Removing all existing asbestos is a goal
(EU Parliament Initiative, 2012)
• Safe removal and waste management is
needed and has to be developed further
• Reliable low cost methods to identify
asbestos have to be developed for
countries with modest resources
• Where ACM are found, what does it look like, history of
the building and material use

Thank You !
Warm thanks to Heli Lallukka, Juhani
Piirainen, Panu Oksa, Jorma Rantanen

Health Council of the Netherlands,
2012. Asbestos: risks of environ-
mental and occupational exposure
Risk level OEL (TEM)
corresponding to
the risk level
(f/cm3
)
Chrysotile Mixed (max. 20 %
amphibole
100 % amphibole
4x10-3
0,2 0,13 0,042
4x10-5
0,002 0,0013 0,00042

Exposure to asbestos and exposure monitoring at Helsinki Asbestos 2014

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Exposure to asbestos and exposure monitoring at Helsinki Asbestos 2014