The first Dounreay Hot Particle was identified and recovered from the Dounreay foreshore in 1983 and a single Particle was recovered from Sandside the following year. It was not until 1996, however, that significant numbers of Particles were recovered. Since that time, an extensive research and development programme has been undertaken to identify the source of Particles, their movement and lifetimes in the marine environment and their effects on human and environmental health. Particles were released to the North Atlantic Ocean in the mid to late 1960s and early 1970s. There is no evidence of an on-going source of Particles from the Dounreay site.
The source of Particles recovered from the Dounreay foreshore and from local beaches is the cache currently residing in marine sediments adjacent to Dounreay. Sediment modelling studies indicate that the Dounreay Particles are generally transported subparallel to the coast in a north easterly direction. Studies to define contact frequencies and risks to human health suggest that the health risks associated with Particles are insignificant. There is, however, a significant perception of risk and UKAEA hopes to define a long-term Particle management programme via the development of a best practical environmental option (BPEO) facilitated through consultation with all stakeholders.