The Government Laboratory has just published its annual report on radioactivity monitoring, revealing less radioactive pollution from Sellafield than for some time.
 
All seafood, worldwide, contains traces of man-made radioactivity, arising from weapon tests as well as use, nuclear accidents, leaks and discharges, all dispersed by natural processes. Amounts in locally caught seafood most recently were affected by Sellafield’s discharges authorised by the UK in the mid 1990s, however the report shows that the radioactivity has now fallen to the pre-discharge levels. Even at the peak levels measured fifteen years ago anyone eating even large quantities would have been well within internationally recognised safe limits for human consumption.
 
The decrease in radioactivity levels in fish and shellfish is a trend which should continue, assuming Sellafield’s waste treatment plants continue to work efficiently and there is no future expansion in nuclear fuel reprocessing work.
 
The monitoring report explains how a trace amount of the Sellafield waste isotope, Technetium-99 found in locally caught lobsters, is partly due to the ‘remobilisation’ of Tc-99 trapped on seabed sediments closer to Sellafield. Natural processes such as storms can disturb radioactivity on the seabed, which is then transferred by currents towards the Isle of Man coast. Notably the levels in Cumbrian lobsters are much higher.
 
Although far too low to be any hazard to people handling seaweed, traces of Sellafield’s radioactivity continue to be detected in seaweed around the Isle of Man; however the amount absorbed by seaweed is now less than one tenth of the concentration detected a decade ago.
 
The monitoring work carried out by the Government Laboratory also includes a check on the background radiation level in harbour sediments and on beaches, with radiation levels found to be consistently low and not a hazard to people using these areas.
 
Foods such as milk, meat and vegetables have also been tested, with no significant levels detected.
 
Although the results from monitoring in 2012 are reassuring, the Government Laboratory will continue to exercise its ‘watching brief’ on Sellafield and maintain its monitoring activities to ensure that the earliest possible warning can be given in the event of any significant radioactive pollution.