This presentation will be available to view as a discussion poster at the 7th International Conference on the Science of Exposure Assessment - X2012. It will be presented on 03 July 2012 from 09.30 - 11.45 am followed by a chaired discussion of all posters in this session on modelling Exposure. Appointments with the authors are available to book at https://x2012discussionposters.acuityscheduling.com

1. The use of dustiness test for assessing
exposures from asbestos in soils
Garry Burdett* and Laurie Davies
Health and Safety Laboratory, Harpur Hill, Buxton SK17 9JN, UK.
Garry.Burdett@hsl.gov.uk
• Although the presence of asbestos in soil is
a hazard, it will only pose a risk to workers
and others, when it is made airborne and
inhaled.
• However, attempting to measure and
assess the peak and cumulative airborne
exposure of asbestos outdoors in the UK
can be a frustrating and imprecise
experience with UK weather conditions.
• Wet weather surpresses dust release to air
from on-site activity based sampling (e.g.
as shown in use in the USA.)
• An alternative solution is to simulate
disturbance on “dry” samples using a
standardised laboratory based, “Dustiness
Tester” to measure the “realisibility” of
asbestos fibres to air, from fragments of
asbestos products and asbestos fibres in
soils.

2. Re-design and calibration of the rotating drum
dustiness tester.
• The calibration of the size selection
was carried out using methods
previously used to calibrate
cyclones.
• A TSI inc. Areodynamic Particle
Sizer (APS) calibrated against a
series of standard polystyrene
spheres was used to calibrate for
respirable (see figure), thoracic and
PM10 fractions.
• The respirable fraction was selected
using coarse porous foams with an
average pore diameters of 1920 µm,
which minimised interception losses
of fibres and changes to the fibre
length distribution.

3. Results from ACM fragments recovered from
waste land
• Examples of results from ACM
fragments recovered from waste
land are given in figure 4
standardised to a ~ 55 g test
sample.
• These results show order of
magnitude variations between
material types.
• Results and are similar to peak
workplace personal measurements
with the same materials.

4. Results from soils with fine asbestos fibres:
• Dispersions of fine asbestos fibres
in soils have also been tested.
• Dry soils can be very dusty so the
sampling times were limited to two
minutes to prevent overloading of
the filter.
• The worst-case situation for fibre
release is shown, where crocidolite
asbestos was dispersed for five
minutes with an ultrasonic probe
and mixed with a sandy soil matrix
and then dried.

5. Conclusions
• A modified rotating drum test based on
EN 15051: 2006 has been developed
which can be used to measure the
release of respirable asbestos fibres to
air from fragments of ACMs and soils.
• The results from these tests can be used
to support risk assessments and
estimate the potential maximum peak
emission levels to workers during dry
periods.
• Results from the test are helpful to
surveyors, analysts and risk assessors
for ranking and prioritising areas for
management and remediation and
checking the effectiveness of any clean-
up, without waiting for the sun to shine.