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2nd Mineral Dust Workshop 10 -12 September 2003, Paris

2nd Mineral Dust Workshop 10 -12 September 2003, Paris. W aste I solation P ilot P lant. Underground repository for transuranic waste. Located in Chihuahuan Desert near Carlsbad, NM. Disposal rooms 2150 feet underground in ancient salt caverns. WIPP-EM Aerosol Sampling Stations. On Site.

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2nd Mineral Dust Workshop 10 -12 September 2003, Paris

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  1. 2nd Mineral Dust Workshop 10 -12 September 2003, Paris

  2. Waste Isolation Pilot Plant • Underground repository for transuranic waste • Located in Chihuahuan Desert near Carlsbad, NM • Disposal rooms 2150 feet underground in ancient salt caverns

  3. WIPP-EM Aerosol Sampling Stations On Site

  4. Ambient Aerosol Sampling Schedule Week 1 Week 2

  5. 239,240Pu in aerosol (TSP) samples shows a strong seasonal cycle

  6. A seasonal cycle in 239,240Pu has been previously observed.* But the causes for the seasonal cycles in the current vs. historical data are different. *Perkins & Thomas, 1980

  7. Current data suggests an association of 239,240Pu with aluminum, an indicator of mineral dust

  8. 239,240Pu activities are correlated with aluminum, and the 239,240Pu/Al relationships are similar at all sites

  9. Where does the 239,240Pu (and 241Am) come from?

  10. Carlsbad is not a Pu hotspot—the Pu is probably associated with resuspended global fallout Current 239,240Pu Levels in Soils (courtesy H. Beck) Carlsbad Beck, H. L., and B. G. Bennett, Historical overview of atmospheric nuclear weapons testing and estimates of fallout in the continental United States, Health Physics, 82, 591-608.

  11. …but about half of the 239,240Pu activity is in the PM10 fraction, implying contributions from local sources Intercept = -1.2 E-10 Slope = 0.58 R2 = 0.57

  12. How strong is the radionuclide/dust link globally?

  13. Novaya Zemlya Totsk Semipalatinsk Kapustin Yar • Lop Nor NTS Alamagordo (USA) Johnston Is. Reggane (FR) Christmas Is. Enewetak Malden Is. Bikini Mururoa Fangataufa Monte Bello Is. Emu Maralinga (USA) (USA) Deserts sites were used for the atmospheric testing of nuclear weapons Non-Polar Arid Lands http://geography.about.com/gi/dynamic/offsite.htm?site=http%3A%2F%2Fpubs.usgs.gov%2Fgip%2Fdeserts%2Fwhat%2Fworld.html Atmospheric Nuclear Test Sites (adapted from Beck & Bennett, 2002)

  14. A recent study indicates that Asian dust also is contaminated with plutonium! Recent trends of plutonium fallout observed in Japan: plutonium as a proxy for desertification K. Hirose , Y. Igarashi , Michio Aoyama , C. K. Kim , C. S. Kim and B. W. Chang Abstract:Plutonium in monthly deposition samples collected in Tsukuba (the Meteorological Research Institute), Japan from 1990 to end of 2001 is reported, together with monthly plutonium deposition in Nagasaki and Yonaguni in 2000. The annual deposition of 239,240Pu during the period from 1990 to 2001 shows no systematic inter-annual variation.However, monthly 239,240Pu depositions show a typical seasonal variation with a maximum in spring season (March to April), which corresponds to seasonal cycle of soil dusts originating from the East Asian arid area. Plutonium isotopic ratios in the deposition samples suggest that significant amounts of the recent 239,240Pu deposition observed in Japan are attributed to the resuspension of plutonium-bearing surface soil particles; resuspended plutonium originates from the East Asian arid areas. The recent increased tendency of 239,240Pu content in residues in deposition samples may reflect desertification in the East Asian continent. J. Environ. Monit., 2003, 5 (2), 302 - 307

  15. Chemical Composition of Atmospheric Aerosols from Zhenbeitai, People’s Republic of China, and Gosan, South Korea, during ACE-Asia R. Arimoto, X. Zhang, B. J. Huebert, C.H. Kang, J. M. Prospero, D. Savoie, S. Sage, C. A. Schloesslin, and H. Khaing

  16. 60 N o 50 N o Rishiri Dunhuang Beijing 40 o N Zhenbeitai Sado Seoul Tango Qingdao Hachijo Gosan Midway Fukue 30 o N Linan Chichijima Amami Wan-li Hong Kong Lan-yu 20 o N 10 o N 100 o E 120 o E 140 o E 160 o E 180 o ACE-Asia Ground Station Network

  17. Sampling & Analyses Zhenbeitai IMPROVE-type sampler (PM2.5)IC & ICP-MS at CEMRC TSP sampler IC at UH, PIXE at IEE/BNU Gosan High-volume bulk sampler IC & ICP/MS at CEMRC (Same sampler used for PEM-West)

  18. ACE-Asia At Zhenbeitai Cations are correlated with aluminum Water Soluble (WS) Cations in Aerosol Samples from Zhenbeitai (ZBT): Concentrations and Relationships to Aluminum

  19. ACE-Asia At Gosan Alkali/alkaline earths, major cations and Al are generally correlated Correlation Matrix Numbers of sample pairs Correlations (r-values) Bold, p < 0.01 Plain, p < 0.05, Blanks , ns.

  20. At Zhenbeitai  both WS and total Ca are correlated with aluminum  water-soluble calcium is about equal to total calcium

  21. At Gosan (compared with Zhenbeitai)  Ca & Al concentrations are lower  a smaller percentage of Ca is water soluble  both WS and total Ca are correlated with Al, but the ratios to Al are lower

  22. Zhenbeitai: large particle sulfate sometimes accompanies the dust TSP, North Winds TSP, South Winds PM2.5 Al & sulfate are correlated in TSP samples, but not PM2.5 Aluminum vs Sulfate N r TSP (North) 50 0.67 PM2.5 8 0.11

  23. At Zhenbeitaiduringhigh dust events (> 40 µg m‑3 soluble Ca) Sulfate/WS Ca2+ molar ratio averages 0.090 ± 0.035 Nitrate/WS Ca2+ molar ratio averages 0.015 ± 0.005 TSP, North Winds TSP, South Winds PM2.5 Sulfate and nitrate in dust prior to mixing?

  24. ACE-Asia At Gosan the sulfate/WS Ca2+ molar ratio is about 5 to 10X higher than at ZBT the correlation between sulfate and Al is lower than at ZBT (r = 0.35), but still significant Daily Multi-day

  25. Observations and Possible Explanations The sources for dust at ZBT and GOS are different Differences in Ca and WS(Ca2+) concentrations at ZBT & GOS Calcium and especially WS Ca2+ are preferentially removed relative to Al during transport Higher percentage of WS(Ca2+) at ZBT Higher sulfate/WS(Ca2+) ratio at GOS Sulfate/Al correlation lower at GOS Pollution sources mix non-crustal proportions of Ca, Al and sulfate with the dust

  26. Summary: There’s (probably) dirt on that dust! Dust from Carlsbad, NM is contaminated with transuranic radionuclides Asian dust/major ion relationships Al vs. cation relationships demonstratedAl & sulfate tend to be correlated, but there’s a need to better constrain element/ion relationships in source materials Ca results are perplexing--need to evaluate source differences vs. differential removal vs. weathering reactions

  27. Relationship between 239,240Pu and wind speed Wind threshold-distance (Wt,d) is the sum of the products of the wind velocities (V) above the threshold (t) and duration (T) Wt,d measures wind travel and has units of meters

  28. Relationships between wind threshold-distance and 239,240Pu activity vary as a function of threshold velocity

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