However, certain work activities can give rise to significantly enhanced exposures that may need to be controlled by regulation.
Material giving rise to these enhanced exposures has become known as naturally occurring radioactive material (NORM).
Pb activity (half-life = 22.3 years) to determine the rate of sediment accumulation.
About 5 g of dried sample, from various depths of the sediment core, is required.
The UCL Environmental Radiometric Facility is located within the Department of Geography, University College London and uses low-background hyper-pure germanium gamma spectrometers capable of measuring low-level environmental radioactivity.
The facility currently employs two ORTEC HPGe GWL series coaxial well-type gamma detectors and one HPGe LOAX planar coaxial detector, each housed in a 100mm thick lead shield.
This means that although they are very similar chemically, they have different masses.
30-50g of dried sample is required for analysis using a standard gamma spectrometer or 5g using a Well detector.There is no radiochemical processing required with this technique.The samples are simply packed into petri dishes or vials, left to equilibrate for three weeks and then counted on a High Purity Germanium (HP-Ge) gamma spectrometry system.I wish to reconstruct pollution history and derive sedimentation rates in such a system.Please note that sediment core samples have not yet been collected.