Cefas contract report C2848 Radiological Habits Survey: Heysham, 2011 2012 Environment Report RL 02/12 This page has been intentionally left blank Environment Report RL 02/12 Final report Radiological Habits Survey: Heysham, 2011 C.J. Garrod, F.J. Clyne, V.E. Ly and P. Rumney Peer reviewed by G.J. Hunt Approved for publication by W.C Camplin 2012 The work described in this report was carried out under contract to the Environment Agency, the Food Standards Agency and the Health and Safety Executive. Cefas contract C2848 FSA Project PAU 198 / Lot 7 / ERI006 This report should be cited as: Garrod, C.J., Clyne, F.J., Ly, V.E. and Rumney, P., 2012. Radiological Habits Survey: Heysham, 2011. RL 02/12. Cefas, Lowestoft A copy can be obtained by downloading from the Cefas website: www.cefas.defra.gov.uk © Crown copyright, 2012 2 Radiological Habits Survey: Heysham, 2011 CONTENTS SUMMARY .............................................................................................................................................. 7 1 INTRODUCTION ........................................................................................................................... 11 1.1 Regulatory framework ........................................................................................................... 11 1.2 Radiological protection framework ........................................................................................ 12 2 THE SURVEY ............................................................................................................................... 14 2.1 Site activity ............................................................................................................................ 14 2.2 Survey objectives .................................................................................................................. 15 2.3 Survey areas ......................................................................................................................... 15 Figure 1. The Heysham aquatic survey area ................................................................................ 17 Figure 2. The Heysham terrestrial (outer ring) and direct radiation (inner ring) survey areas ..... 18 2.4 Conduct of the survey ........................................................................................................... 19 3 METHODS FOR DATA ANALYSIS ............................................................................................. 22 3.1 Data recording and presentation ........................................................................................... 22 3.2 Data conversion .................................................................................................................... 22 3.3 Rounding and grouping of data ............................................................................................. 22 3.4 Approaches for the identification of high rates ...................................................................... 24 3.5 Data quality ........................................................................................................................... 25 4 AQUATIC RADIATION PATHWAYS ........................................................................................... 26 4.1 Aquatic survey area .............................................................................................................. 26 Figure 3. Morecambe Bay sandflats (looking south-east from Bardsea). .................................... 26 Figure 4. Walney Channel, near the Jubilee Bridge. .................................................................... 28 Figure 5. East of Rampside. ......................................................................................................... 30 Figure 6. Near Jenny Brown’s Point. ............................................................................................ 32 Figure 7. Morecambe. ................................................................................................................... 33 Figure 8. Red Nab......................................................................................................................... 34 Figure 9. The Lune Estuary at Sunderland Point. ........................................................................ 35 4.2 Commercial fisheries ............................................................................................................. 36 4.3 Destination of seafood originating from the aquatic survey area .......................................... 38 4.4 Hobby fishing, angling and non-commercial shellfish collecting ........................................... 39 4.5 Wildfowling ............................................................................................................................ 40 4.6 Other pathways ..................................................................................................................... 40 4.7 Food consumption data ......................................................................................................... 41 Table A. Summary of adults’ consumption rates of foods from the aquatic survey area .............. 41 Table B. Summary of children’s and infants’ consumption rates of foods from the aquatic survey area .................................................................................................................................... 43 4.8 Intertidal occupancy .............................................................................................................. 43 Table C. Summary of adults’ intertidal occupancy rates .............................................................. 44 Table D. Summary of children’s and infants’ intertidal occupancy rates ...................................... 45 4.9 Gamma dose rate measurements......................................................................................... 46 4.10 Handling of fishing gear and sediment .................................................................................. 46 Table E. Summary of adults’ handling rates of fishing gear and sediment .................................. 47 4.11 Water based activities ........................................................................................................... 47 5 TERRESTRIAL RADIATION PATHWAYS .................................................................................. 49 5.1 Terrestrial survey area .......................................................................................................... 49 5.2 Destination of food originating from the terrestrial survey area ............................................ 50 5.3 The transfer of contamination off-site by wildlife ................................................................... 50 5.4 Food consumption data ......................................................................................................... 50 Table F. Summary of adults’ consumption rates of foods from the terrestrial survey area ........... 51 Table G. Summary of children’s and infants’ consumption rates of foods from the terrestrial survey area .................................................................................................................................... 52 3 CONTENTS 6 DIRECT RADIATION PATHWAYS .............................................................................................. 53 6.1 Direct radiation survey area .................................................................................................. 53 6.2 Residential activities .............................................................................................................. 54 6.3 Leisure activities .................................................................................................................... 54 6.4 Commercial activities ............................................................................................................ 55 6.5 Educational activities ............................................................................................................. 55 6.6 Occupancy rates ................................................................................................................... 55 Table H. Summary of direct radiation occupancy rates ................................................................ 56 6.7 Gamma dose rate measurements......................................................................................... 57 7 USES OF HABITS DATA FOR DOSE ASSESSMENTS ............................................................. 58 7.1 Combined pathways .............................................................................................................. 58 7.2 Foetal dose assessment ....................................................................................................... 58 7.3 Total dose assessment ......................................................................................................... 58 8 COMPARISONS WITH THE PREVIOUS SURVEY ..................................................................... 60 8.1 Aquatic survey area .............................................................................................................. 60 Table I. Comparison between 2006 and 2011 consumption rates of aquatic food groups for adults ............................................................................................................................................. 60 Table J. Comparison between 2006 and 2011 intertidal occupancy