1. Tools for assessment of corrosion and soiling in the multipollutant situation
Johan Tidblad and Vladimir Kucera
Corrosion and Metals Research Institute, Stockholm, Sweden

2. Corrosion trends in Europe in the multipollutant situation

3. Fifth Framework Programme,
MULTI-ASSESS ( )
Fifth Framework Programme,
Energy, Environment and Sustainable Development
Key Action: City of Tomorrow and Cultural Heritage Contract number: EVK4-CT

4. Partners and subcontractors
Swedish Corrosion Institute, Stockholm (co-ordinator)
Academy of Fine Arts, Inst. of Sciences and Technologies In Art, Vienna, Austria
Bavarian State Department of Historical Monuments, Munich, Germany
Swiss Federal Labs. for Materials Testing and Research (EMPA), Dubendorf
Swedish Environmental Research Institute Ltd. (IVL), Gothenburg
CNR Institute for Atmospheric Pollution, Rome, Italy
University of Athens, Department of Applied Physics, Greece
Middlesex University, School of Health and Social Sciences, London, UK
SVUOM, Prague, Prague/Czech Republic
Building Research Establishment (BRE), Watford, UK
Norwegian Institute for Air Research (NILU), Kjeller
Institute of Precision Mechanics, Warzaw, Poland
Riga Technical University, Centre for Conservation of Stone Materials, Latvia
LISA - Université Paris XII, France
Estonian Environment Research Centre (EERC), Tallinn
University of Antwerpen, Department of Chemistry, Belgium

5. Expected main results

6. Passive samplers for the ”missing” pollutants : nitric acid and particles

7. HNO3 concentration 44
0.0
0.5
1.0
1.5
2.0
2.5 5
HNO3 21 24 35 23 26 34 27 46 7 41 10 49 8 40 3 50 1 45 16 15 14 36 31 33 13 43

8. Relation of particle deposition and PM10 concentration

9. Dose-response functions, ICP Materials (period 1987-95)

10. Dose-response functions multi-pollutant/MULTI-ASSESS programme incl
Dose-response functions multi-pollutant/MULTI-ASSESS programme incl. HNO3 and PM10 ( )

11. SO2 dependence

12. Tolerable corrosion and pollution
The tolerable level is the maximum level at which a tolerable corrosion/soiling occurs. It should be based on experiences from restoration / maintenance work for cultural heritage objects.

13. Soiling, limestone DRF: ΔR/R0 = [1-exp(- klimestone x PM10 x t)]
ΔR/R0, relative loss of reflectance
k, soiling constant
PM10, in µg m-3
t, time in years
Critical soiling level ΔR/R0 = 35%

14. Tolerable pollution levels in the multi-pollutant situation
Definition of a tolerable corrosion rate, Kt, depending on use and material, implicitly defines a tolerable multi-pollution situation, which can be reached by reducing one or several of the multi-pollutants:
Kt= fdry(T, RH, [SO2]t, [HNO3]t, ...)
+ fwet(Rain[H+]t)

15. Summary of DRF, tolerable effects and target levels

16. Air Quality Directive 99/30/EC
Limit values of pollutants, µg m-3

17. Use of DRF for mapping: Steel, Czech Republic (2001)
The tolerable corrosion rate is 20 µm

18. Kit for assessment of deterioration and pollution
Carousel with limestone specimens
Soiling sampler Passive samplers
pollutants
Steel and zinc specimens

19. Tools developed for assessment of corrosion and soiling
FOR NATIONAL AND INTERNATIONAL POLICY
Dose-response functions for multipollutant situation:
- Tolerable deterioration, tolerable pollution levels
- Mapping of areas with exceedance
- Calculation of cost of damage
FOR LOCAL MANAGEMENT STRATEGIES
DRF – tolerable pollution levels, tolerable deterioration
Kit for rapid assessment of corrosion and soiling
Passive samplers for nitric acid and particles

20. Conclusions and gaps of knowledge
The new corrosion functions for the multi-pollutant situation involve, besides the effect of SO2, also the effect of particulate matter and HNO3.
Assessment of target levels for materials show that they are at least as sensitive to pollution as human beings and therefore cultural heritage should be considered in future assessment of limit values for pollutants.
The effect of traffic, in particular in the vicinity of main roads, is only in part covered by the new equations. Therefore, future efforts should focus on the corrosion and soiling effects of particular matter, nitric acid and other pollutants, for example those associated with the use of alternative fuels, in the traffic situation.

21. <Additional figures>

22. Dose-response function for zinc from ICP Materials (N=98, R2=0.84)
ML = Dry deposition + Wet deposition =
1.4[SO2]0.2·e0.02Rh + f(T)·t Rain[H+]·t
ML = Corrosion attack (mass loss)
T = Temperature
RH = Relative humidity
[SO2] = SO2 concentration (air)
Rain = Amount of precipitation
[H+] = [H+] concentration (precipitation)
t = exposure time

23. Tolerable corrosion rates
For practical purposes, tolerable corrosion rates (Kt) can also be defined as a multiple (n) of the background corrosion rate (Kb), where n is based on experiences from restoration / maintenance work for cultural heritage objects:
Kt = n · Kb

24. Tolerable corrosion rate based on background corrosion rates and n=2.5

25. Example of use: tolerable SO2 levels