Radioactivity in Food and the Environment, 2002

This report contains the results of radiological monitoring of food and the environment throughout the
United Kingdom, the Channel Islands and the Isle of Man. The primary purpose of the monitoring
programmes is to provide an independent check on the effects of discharges made by users of radioactive
materials in the United Kingdom, and to ensure that any radioactivity present in food and the environment
does not compromise public health. For the first time, it represents a comprehensive summary of results
across the United Kingdom from programmes sponsored by the Environment Agency, the Environment and
Heritage Service, the Food Standards Agency and the Scottish Environment Protection Agency.
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The results of these monitoring programmes demonstrate that in 2002 even the most exposed members
of the public received radiation doses from food and other pathways that were below the statutory United
Kingdom annual dose limit to members of the public of 1 mSv (millisievert), European Union limits and
Government targets. <P> The highest radiation doses were received by a group of high-rate consumers of fish and shellfish in Cumbria.
The doses received by these consumers are a combination of contributions from liquid discharges from both
Sellafield and from radioactivity in the environment as a result of past discharges from the Rhodia Consumer
Specialties Ltd. (formerly Albright and Wilson) plant at Whitehaven. The dose to these high-rate consumers
(including external doses) from Sellafield discharges was estimated to be 0.19 mSv in 2002 compared with
0.15 mSv in 2001. Concentrations in food and dose rates were largely unchanged in 2002 though there were
some small increases in concentrations of tritium, carbon-14 and technetium-99 in seafood. The main reason
for the increase in dose was an increase in the amount of seafood eaten. This group also received an estimated
dose of 0.42 mSv from enhanced levels of natural radioactivity due to the legacy of past operations at the
Rhodia Consumer Specialties Ltd. works at Whitehaven. Operations at this site ceased at the end of 2001 and
the plant will be demolished in 2003. By definition, other groups will have received lower doses.
<P>In terms of radiation exposure, the next most important group was people living in houseboats in the
Ribble estuary in Lancashire. Their dose was from external radiation and was 0.12 mSv in 2002, similar
to 0.14 mSv in 2001. The main source of their exposure was radioactive contamination in estuary mud
arising from past Sellafield discharges. The highest exposures in Scotland were to the group of
terrestrial food consumers around Chapelcross who received an annual dose of 0.055 mSv as a result of
gaseous discharges including a component due to inhalation. The second highest exposure was wholly
attributable to Sellafield. It relates to a group of consumers of seafood, spending time over inter-tidal
areas, who were estimated to receive annual doses of 0.045 mSv. In 2001, this group was estimated to
have received a similar dose of 0.040 mSv.
Doses due to gaseous discharges from Sellafield were 0.038 mSv, similar to the dose in 2001 of 0.037 mSv.
The assessment included the consumption of milk, vegetables, fruit and meat and external exposure from
gaseous discharges. The contribution from gaseous discharges of argon-41 reduced by about a factor of
five in line with operations at Calder Hall. Most of the seafood and external exposure that can be
attributed to Sellafield was from historic discharges. Recent and current discharges of technetium-99
contributed 0.030 mSv, which is around 15% of the dose to the Sellafield seafood consumers.<P>
The next most significant site was Dungeness where gaseous discharges from the two power stations
resulted in exposure of 0.12 mSv in 2002, mostly from argon-41 in external radiation pathways. At
Heysham, high-rate seafood consumers were estimated to receive 0.066 mSv but most of this was
attributable to Sellafield discharges. Gaseous discharges from Chapelcross and Sizewell �A� power stations
gave similar doses, about 0.054 mSv. High concentrations of tritium have been found in food and the
environment near Cardiff where radiochemicals for research, medicine and industry are produced. However,
doses to high-rate seafood consumers were estimated to be relatively low at 0.031 mSv in 2002, similar to
0.036 mSv in 2001. Most of the dose was due to tritium and carbon-14 in fish from the Bristol Channel.