assessing risks of soil contaminated with asbestos

ASBESTOS RISK REDUCTION & MEASUREMENT OF ASBESTOS FIBRE CONCENTRATIONKrakow Poland, September 28-29, 2006

Environmental control

Fibrecount NV Boomsesteenweg 56 / 1 B-2630 Aartselaar

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URL: www.fibrecount.com e-mail: [email protected]

ASSESSING RISKS OF SOIL CONTAMINATED WITH ASBESTOS

B. Hermans

http://www.fibrecount.com/

mailto:[email protected]

Soil contamination is often

a result of industial activities of the past



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Asbestos mining

Crocidolite mine in South Africa Chrysotile mine on Cyprus





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Asbestos cement industry and uncarefull demolition of buildings





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Asbestos in soil as a result of a fire





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Asbestos in soil : two main categories

Firmly bound asbestos

• asbestos cement • asbesos in polymeric materials (floor tiles)

Loosely bound asbestos

• sprayed asbestos• asbestos insulation boards (Pical)• cords• paper• …..

!!! Weathering can make asbetos cement product very friable !!!





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Behaviour of asbestos in soil

- Only physical transport of asbestos in soil is of importance- The nature of soil plays an important role

-Clay will immobilize asbstos much more than sand

For particles from 0,1 to 2 µm, the speed of migration isfrom 1 to 10 cm in 3000 to 40 000 years !

-Animals such as rabbits, rats and moles contribute only to small extent to bring asbestos to the surface!

Only human activities are of importance in moving asbestos in soil





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Human exposure to asbestos particles from soil

Background concentration in asbestos fibres : about 70/m³ in US

(Alewife Study Group – 1995)

Primary emission (directly from source)

• short-term acute emission by disturbing ACM• long-term diffuse emission by natural erosion factors (wind)

Secondary emission (from settled dust)





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Factors affecting the human exposition

Properties of ACM

• Bounding grade of material• Kind of asbestos• Fraction of respirable fibres

from RIVM rapport711701034/2003

F.A. Swartjes and al.





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Factors affecting the human exposition

Characteritics of soil

• Kind of soil (clay vs sand)• Local relief• Humidity• Vegetation• …..

Weather factors

• Humidity of air• Rain• Frost• Wind• …..

Activities on site

• Kind of activity• Duration of activities

Extent of pollution

• Concentration of asbestos• Volume or surface of polluted area• Depth of pollution• Distance to source of asbestos• …..





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Acceptable fibres concentration

Negligible risk : 10 -6 by lifetime (10 -8)/year

Acceptable risk : 10 -4 by lifetime (10 -6)/year

But different values are associated with different kinds of asbestos

Risk increase for mesothelioma and lung cancer

Notion of fibre equivalent

1 fibre Chrysotile = 1 fibre equivalent1 fibre Amphibol = 10 fibres equivalent





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Acceptable fibres concentration

Negligible risk 1000 Fibreeq/m³

Acceptable risk 100 000 Fibreeq/m³





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Airborne asbestos concentration as a function of Asbestos concentration in soil

Bound asbestos from RIVM rapport 711701034/2003F.A. Swartjes and al.





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Airborne asbestos concentration as a function of Asbestos concentration in soil

Loosely bound asbestos

from RIVM rapport 711701034/2003F.A. Swartjes and al.





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Determination of a limit value for asbestos in soil

Concentrationof asbestos in soil mg/kg

Airb

orn

e a

sbe

stos co

nce

ntra

tion

fib

res/m

³

from RIVM rapport 711701034/2003F.A. Swartjes and al.





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Determination of a limit value for asbestos in soil

Asbestos concentration No Activity Activity

No Activity Activity

(mg/kg) Bound asbestos Not bound asbestos

<5 - - - -

5-100 - - - +/-

100-1000 - +/- +/- +

> 1000 +/- + ++ ++





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NEN 5707 – Soil –Investigation, sampling and analysisof asbestos in soil and soil stockpiles

Structure of the norm

• Phasing of the survey• Preliminary investigation• Exploring investigation• Detailed investigation• Analysis





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Preliminary investigation :

Collection of data about former and present use of the soil andthe direct environment of it, possible causes of pollution (from documents and visit on site).

Exploring investigation :

Investigation conducted with relatively limitated efforts to confirmthe suspicion of pollution.





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Detailed investigation :

Investigation of the contamination with the aim of-determination of the concentration of asbestos per surface unit based on visual inspection and random sampling-if needed , the determination of the limits of the pollution based systematic sampling





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Analysis of samples :

On site collection and preparation of samples

On site analysis of the coarse fraction

Preparation of samples (drying, sieving)

Analysis of fraction >4 mm





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Analysis of samples :

Analysis of the fractions2-4 mm, 1-2 mm and 0,5-1mm

Not boundAsbestos ?

Analysis of the fractions2-4 mm, 1-2 mm and 0,5-1mm

Qualitative analysis of the fraction <0,5mm

Analysis of the fine fraction

PLM

SEM





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Commonwealth of Massachussets

Asbestos in soil streamlining regulation and management

Aim : adress the assesment and clean-up of three situations

-asbestos in buildings components that have been buried-asbestos in debris improperly disposed in or on the ground-unconsolidated asbestos fibres found in soil





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Problem : need for a cheap and performant analytical method !

The superfund method for the determination of releasable asbestos in soiland bulk material (EPA 540-R-97-028)





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Tedious and quite expensive method !





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MassDEP has developed a cheaper PLM method basedon sieved fractions

Sieve Analysis ResultsConcentration of Debris Containing Releasable Asbestos ("DCRA")

andElutriator Results

Concentration of Asbestos Fibers in Respirable Dust

0

50

100

150

200

250

300

350

02A 05A 03A 12A 11A 01A 09A 14A 06A 08A

Sample ID

mg

DC

RA

per

Kg

so

il

Elu

tria

tor

Res

ult

s: s

tru

ctu

res/

gP

M10

(x

10E

-06)

2

4

6

8

10

12

15

0





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A pilote project in Flanders

Waste of asbestos cement pipe production has been usedunder lanes and path.The percels where asbestos has been used haven recently beenidentified in a big survey conducted for OVAM (public FlemishEnvironmental authority).A clean-up test has been conducted in March 2005 by excavation of contaminated soil.Airborne asbestos measurement (PCM) where never above 0,010 f/ml





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Conclusion

Pollution of soil by asbestos can cause elevated concentrationin airborne asbestos (in particular by high activity grade on site).

Protection of workers involved in clean-up process

PCM is adequate

Diffuse pollution can also occur and could be of significanceby adverse meteorological conditions.

Effects of very low concentration of asbestos fibres isup to now relatively wide unknown.

Only electronical analysis is adequate




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A few pictures of our laboratory in Rotterdam

Dry-sieving machine Wet-sieving machine

Inside the depressurized part



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Many thanks for your kind attention !

Never again without adequate protection !!!

assessing risks of soil contaminated with asbestos

Documents

asbestos fibres

source of asbestos

asbestos particles

soilconcentrationof

moving asbestos

analysisof asbestos

behaviour of asbestos

physical transport of