INRS poster in International Conference on Monitoring and Surveillance of Asbestos-Related Diseases 11-13 February 2014, Finland

1. COMPARISON OF PHASE CONTRAST AND ELECTRON MICROSCOPIC
COUNTING FOR EVALUATION OF OCCUPATIONAL ASBESTOS EXPOSURES
C. Eypert-Blaison*, M.C. Starck, F. Clerc, A. Roméro-Hariot
*INRS - Centre de Lorraine, Rue du Morvan - 54500 VANDOEUVRE LES NANCY –
FRANCE
CONTEXT
METHODOLOGY
MAIN RESULTS
CONCLUSIONS
2009: the French agency for environmental and occupational health protection (ANSES) published a report
on the toxicity of short and fine asbestos fibers, which are systematically present in workplace areas.
Comparison of PCOM evaluation and ATEM analyses on 205 sampling filters, representative of 25
worksites types (ACM/removal technique combinations).
൳ Sampling of 2 hours at 3 L.min-1 on opened cassettes with an ester cellulose membrane of 37 mm
diameter
൳ Direct preparation of filters for PCOM evaluations (according to standard AFNOR XP X 43-269)
൳ Indirect Preparation of filters for ATEM evaluations (according to standard AFNOR NF X 43-050)
൳ A complete and consistent study in the air of workplaces on various worksites representative of “material – removal/technical process” combinations.
A comparison of methods conducted on the same sample filters.
൳ Undeniable limitations of PCOM and indisputable technical advantages of the ATEM for the assessment of exposure of workers to asbestos fibers.
൳ Risk of insufficiently protecting operators in the case of assessments based on PCOM.
൳ Confirmation of the necessity of adopting, as France has done since July 1st 2012, ATEM to evaluate the exposure of the workers to asbestos fibers,
as already done for ambient air.
൳ Need for further studies, especially:
൳ On the toxicity of SAFs,
൳ In order to establish protection factors of respiratory protection devices in work situations based on ATEM analyses
൳ In order to acquire knowledge about dust level by ATEM (maintenance operations)…
2010: The French Directorate-General for Labor (DGT) launched an asbestos exposure measurement
investigation using ATEM:
൳ to establish a method and validate the feasibility of sampling airborne asbestos fibers in the
occupational environment with an ATEM analysis
൳ to ascertain the dust level generated by the various “Asbestos containing material (ACMs) – Technical
process” combinations when measured by ATEM, in order to implement technical rules minimizing the
release of dust into the air and determine protective measures adapted to these levels
൳ to established the particle size distribution of the different classes of fibers on the sampling filters
ANSES recommended, especially, using ATEM in
replacement of PCOM for the evaluation of the
asbestos level concentration in workplace areas.
ATEM filter preparation: Depending on the level of dust, for one
sampling:
൳ Both filters were treated together (very low dust),
൳ The ½ of each filter were treated together (low dust)
൳ The ¼ of each filter were treated together (strong dust)
൳ The 1/8 of each filter was treated together (very strong dust)
൳ No distinction of asbestos
fibers from other fibers
൳ No observation of the finest
fiber always present in the
air of workplaces
൳ Disadvantage of direct
preparation method in the
case of overload of dust
൳ Specific analysis method
that allows to observe the
finest fibers and analyzing
unambiguously on the
basis of morphology,
chemistry and
crystallography
൳ Advantage of indirect
preparation method in the
case of overload of dust
WHO
L5µm
0,2µmd3µmSAFs
L5µm
d3µm
TAFs
L5µm
d0,2µm
Schematic representation of the particle size distribution of asbestos fibers in workplace area
Fibers: L/d 3
©INRS
PCOM Limitations: ATEM Benefits:
F1
(1 hour)
C1 by ATEM C’1 by PCOM
(Average C ½ F1 – C ½ F2)
F2
(1 hour)
Nature of asbestos fibers
WHO WHO+TAFs
Mean Std Dev Mean Std Dev
Serpentines 4.31 9.42 14.92
37.14
Amphiboles 0.39 0.67 0.58 0.78
Nature of ACM
WHO WHO+TAFs
Plaster asbestos 18.6 94.5
Paints coatings 15.1 41.1
Asphalt asbestos 0.5 2.2
Nature of removal/technical process
WHO WHO+TAFs
Grinding - sanding 13.3 41.8
Very or Ultra High Pressure 11.1 124.3
Cutting - Sawing - Chainsaw 0.2 0.9
1
10
100
1000
10000
100000
1 10 100 1000 10000 100000
ATEM(F.L-1)
PCOM (F.L1)
WHO
WHO+TAFs
ATEM/PCOMratiosdifferdependingon: