1. Atmospheric mercury monitoring in relation to model testing and validation
John Munthe and Ingvar Wängberg
IVL Swedish Environmental Research Institute

2. Presentation topics Mercury species in air Mercury in wet deposition
Mercury deposition in forested areas/throughfall, litterfall
Monitoring needs for model testing and evaluation

3. Mercury species in air
GEM (Gaseous Elemental Mercury), Hg0, elemental mercury vapour. Normally >98% of total mercury in air, long residence time, global distribution. Sampled on gold traps with filter to remove TPM and denuder to remove RGM
RGM (Reactive Gaseous Mercury), operationally defined but thought to be mainly HgCl2. Sampled on KCl coated denuders.
TPM, (Total Particulate Mercury),HgP,particulate mercury. Hg(II) or Hg0, associated with particles. Sampled on filters, usually quartz.
TGM (Total Gaseous Mercury). Sum of GEM and RGM. Sampled on gold traps without filter and denuder.

4. Mercury species in air - availability of monitoring data -TGM
TGM at a few sites in Northern Europe with varying time resolution (from hourly to weekly samples)
Manual and automated methods are used
Variability relatively small, hemispherical background of 1.5 ng/m3, peaks of 2-4 ng/m3 from European emission
Need high time resolution for model validation
New EU directive will require more extensive monitoring from 2006/7
Question of priorities.

5. Mercury species in air - availability of monitoring data - RGM and TPM
RGM. No routine measurements in Europe. Campaigns as part of research projects.
TPM. Monitoring at few sites in northern Europe
High variability from <2 to 100 pg/m3.
Direct emissions (RGM) from (some) combustion sources, formation in atmosphere (OH, halogens)= large local and temporal variability
Manual and automated methods available but relatively work intensive for RGM, easier for TPM
Voluntary in EU directive, should be at "super stations"

6. TGM from Mace Head
Ralf Ebinghaus, GKSS

7. TGM from MOE 1997-1998 (5 campaigns)

8. TGM 600 m from point source (Chlor alkali plant), annual emissions 50 kg/yr5 10 15 20 25 30 35 40
16/12
19/12
22/12
25/12
28/12
31/12
3/1
13/12
TGM ng m-3

9. RGM from MOE 1997-1998 (5 campaigns)

10. TPM from MOE 1997-1998 (5 campaigns)

11. RGM Automated (NEU) and manual (RÖR)
Ralf Ebinghaus, GKSS, J. Sommar, Göteborgs Universitet

12. TPM, november 1999

13. Mercury species in air, measurements for modelling purposes
TGM: Methods well developed and available. Need high time resolution to be able to identify small peaks above background.
RGM: Methods relatively complicated, could be simplified? Need data with temporal and spatial resolution, better emission data, better understanding of chemistry
TPM: Methods available. Need data with temporal and spatial resolution, higher time resolution.

14. Field Measurements at Cabo de Creus, Spain MERCYMS
42o19’ N, 3o 19’ W
MERCYMS
FP 5 project, coordinated by N Pirrone, CNR IIA
Measurements at 5 coastal stations, 4 campaigns in 2004
Several ship cruises
Measurements in Spain conducted by IVL and Göteborg University in cooperation with Ministry of Environment and MCV

16. MERCYMS TPM Results Autumn 2003 Winter 2004 Summer 2004 Spring 2004
0.0
5.0
10.0
15.0
20.0 21 10 22 23 24 25 26 27 28 29 30 31 1 11
TPM pg m -3
2003
Autumn 2003
0.0
5.0
10.0
15.0
20.0 19 01 20 21 22 23 24 25 26 27 28 29 30
TPM pg m -3
2004
Winter 2004
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0 26 04 27 28 29 30 1 05 2 3 4 5 6 7
2004
Spring 2004
0.0
5.0
10.0
15.0
20.0 19 07 20 21 22 23 24 25 26 27 28 29 30 31 1 08
TPM pg m -3
2004
Summer 2004

17. MERCYMS RGM Results Autumn 2003 Winter 2004 Spring 2004 Summer 2004 222 4 6 8 10 22 23 24 25 26 27 28 29 30 31
1 11
Day
Night
Autumn 2003
RGM pg m -3 2 4 6 8 10 19 01 20 21 22 23 24 25 26 27 28 29 30
Day
Night
Winter 2004
RGM pg m -3 2 4 6 8 10
26 04
00:00
28 04
30 04
02 05
04 05
06 05
08 05
Manual
Automatic
RGM pg m -3
Spring 2004 4 8 12 16 20
19 07
00:00
21 07
23 07
25 07
27 07
29 07
31 07
02 08
RGM pg m -3
Summer 2004
Manual
Automatic

18. MERCYMS Summary of results
Average mercury concentrations at Cabo de Creus
Season
TGM
TPM
Manual
Autom
DGM
RGM
RGM -3 -3 -3 -3 -3
ng m
pg m
pg m
pg m
ng m
Autumn
1.64
9.6
2.3 - -
Winter
1.47*
9.1
0.2 - -
Spring
2.00*
9.5
1.2
1.9 -
Summer
2.13*
11.2
1.3
4.8 24
*0.5 h average values collected within the wind sector o at wind speeds > 4 m s-1

19. Mercury in precipitation-examples from Swedish network
Monthly sampling period
Bulk samplers
HCl preservatives added
2 samplers in parallel
Analysis using CVAFS
4 stations in Sweden, 1 in Finland (1999)
3 stations in Sweden, 1 in Finland (2001)
2 stations in Sweden, 1 in Finland (2004)
1 station in Sweden, 1 in Finland (2005)

20. Wet deposition

21. Precipitation amounts using different collectors
100
EMEP 90
Hg bulk 80
HM bulk 70 60 50 40 30 20 10 01 03 05 07 09 11
Total
Total
Total
Total
Total
Total

23. Investigation of sampler design and collection efficiency
Investigation conducted at 33 stations in Sweden
Parallel samplers at all sites
Bucket and funnel in summer and “snow sack” during winter

24. Precipitation amounts at different stations and %difference between 2 funnel & bottle collectors

25. Precipitation amounts at different stations and %difference between 2 snow sack collectors

26. Precipitation measured with 4 different samplers

27. Precipitation sampling
Occasional large variability in individual samples between different types of samplers
Not systematic
“Snow sack” samplers give higher total precipitation amounts
Need standardised methods and/or correct to common precipitation fields

28. Deposition in forested ecosystems
OF 10 g/km2
Litterfall 20 g/km2
TF 20 g/km2
Reemission ? g/km2
Runoff 2 g/km2
Total deposition = wet + dry-reemission = Throughfall + litterfall - reemission = 40 g/km2

29. Deposition of total mercury in forests

30. Deposition in relation to critical loads
2 different critical load models for Hg, one based on limitations in fish concentrations, the other on accumulation in soil
For calculating accumulation in soils, need total deposition
EMEP measurements only wet deposition, total deposition 2-4 times higher in forested areas
Reemissions unknown
Models include the above but very little data available to verify and test model output.

31. Final words
A successful implementation of protocols on mercury will require larger efforts on measurements from most countries
Air concentrations (species), wet deposition, total deposition in forested ecosystems, air surface exchange
Super stations are recommended (see conclusions from previous TFM&M meetings and CLRTAP Heavy metal workshops)
Currently no EU funded research projects on atmospheric mercury - FP7?
EU directive may lead to better situation