Nuclear methods and environmental science

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Nuclear methods and environmental science

• John Dodson
• Head, Institute for Environmental Research

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Matter is composed of stable and radioactive
isotopes. There is a constant rain of isotopes
on Earth and these permeate all environmental
systems. Humans have changed some of these
systems. At ANSTO we follow these to help
understand how environmental systems work.
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Applications of nuclear science to environmental
science

• Tracing materials and flows in systems
• Age of materials, processes and landforms
• Identifying solar variability
• ANSTO uses state of the art nuclear technology to
  address environmental issues including
• Climate change
• Water resource sustainability
• Air pollution
• Human impacts
• Waste in the environment

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Stable Isotopes

• Using Isotope Ratio Mass Spectrometry (IRMS)
• 13C and 15N in organic material
• Used in AMS radiocarbon dating and identifying
  aquatic trophic pathways
• 2H and 18O in waters
• Used for investigating the hydrological cycle eg
  evaporation, transpiration, sources and mixing

IMS-Pyr-OH fr water analysis
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AMS leg
IBA leg
STAR Accelerator at ANSTO
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Artefact dating

• Radiocarbon dating on the development of
  agricultural systems in east Asia
• wheat, rice, barley, millet 2200 BC

• Dating of aboriginal rock art in Australia for
  heritage studies.

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Nuclear Methods in Tracing Human Impacts
Reconstruction of the effects of human impacts
vs. climate variability on the environment in
the Australasian Region.
Excess 210Pb
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Conclusion Since 1970 Algal Blooms are a regular
occurrence in the Reservoir. Main cause is Major
inflow after rainfall events.
Plankton in the water Column showing
variability, caused by major inflow events
Reconstruction from sediment cores of the
occurrence of algal blooms in Warragamba
Dam. ANSTO/ANU/SCA Collaboration
chronology based on
Isotope Dating
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SW Water Security
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ANSTO Research into SW Australia Water Security

• Rainfall variability over 1000 years
• Groundwater age
• Link of groundwater and rainfall
• Relationship of environmental change to water
  resources land cover change, climate

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SW Australias rainfall recorded at Moondyne Cave
a. 1930-1955 Moisture from Lower Latitudes
(Higher 18O/16O ratio in H2O) b.
1970-1985 Moisture from Higher Latitudes (Lower
18O/16O ratio in H2O
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Sydney, on clear and polluted days
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ANSTO Fine Particle Sampling Sites in NSW
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Samples Collected on Teflon Filters
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Ion Beam Analysis and Fine Particles

• IBA techniques at ANSTO allow measurement of
• total mass of fine particles
• sources that contribute to total mass
• Clear seasonal variations in most sources except
  soil.
• smoke and autos higher in the winter
• Secondary sulphur and sea higher in summer
• This is a truly quantitative, non destructive
  method (filters not destroyed)

Typical fine particle source contributions in
Sydney (3 year period)
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Australian East Coast Aerosol Dust Sampling
(AECADS)
ANSTO Heron Is ASP unit

• Since 1 July 2007 AECADS has been operating
  sampling sites at Heron Is on the Barrier Reef,
  Mt Stromlo in Canberra and Fowlers Gap at Broken
  Hill in collaboration with Monash, ANU and
  University of California, Davis, (UCD).
• Aims
• to characterise and quantify fine dust movements
  across the Australian east coast and onto the
  Great Barrier Reef
• to better understand the role of nutrients in
  dust and their effects on the reef, the oceans
  and climate change.

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Revealing Chinas history
Early writing, east Asian bronze, wheat To do
initiate stable isotopes for palaeo diets of
humans and early domesticated animals, plus
paleoenvironmental conditions
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