|
|
|
Nuclear pollution, childhood leukaemia and brain tumours in Gwynedd and Anglesey Wards near the Menai Straits, North Wales 2000-2003
Chris Busby, PhD For HTV Bangor
Report 04/1A; January 2004 Aberystwyth: Green Audit
1. Background The Irish State previously funded Green Audit to study cancer in North Wales using Wales Cancer Registry small area data covering the period 1974-1990 [Busby, 2000] in order to examine the possible effects of nuclear pollution from Sellafield on the coast of Ireland. The reports drew attention to the discovery in the data of a sea-coast effect in cancer and leukaemia in adults and also in children. This effect showed itself as a sharp rise in risk in small areas close to the coast in north Wales, particularly in towns near coastal areas where there was intertidal sediment contaminated with radioactive material from Sellafield or other historical sources e.g. weapons fallout or Chernobyl fallout after 1986. As well as adults, the findings showed high relative risks for cancer in children, mainly brain tumours and leukaemia. These were highest in 0-4 year olds living within the coastal towns near the Menai Strait in particular Bangor and Caernarfon toward the latter half of the period studied, 1982-1990. Table 1 shows the numbers and risks for leukaemia.
Table 1 Areas of Residence with more than one case and also high (>3) relative risk of leukaemia in the 0-4 age group in the north Wales area from 1982-1990 (Wales Cancer Registry validated data).
(a) based on England and Wales, 1979
Leukaemia has been connected with radiation exposure since the original discovery of high rates in those exposed to the A-bomb radiation at Hiroshima and Nagasaki. In 1984, childhood leukaemia became associated with exposure to material from nuclear sites following the discovery of a cluster of cases in Seascale near Sellafield. It should be noted, in what follows, that the number of cases involved in this rare condition is very small. In Seascale and the coastal villages (Drigg, Carleton, Bootle, Waberthwaite and Muncaster) there were 2 deaths from leukaemia within 4 deaths of all cancers in the 0-14 year age group in the 16 years between 1963 and 1982. There were 9 cases (incidence) of childhood cancer in Seascale and the coastal villages in the same period (Beral et al, 1993). This area has been extensively studied and the effect of Sellafield radiation exposures have been hotly disputed since the 1983 discovery of the elevated rates. Since then also there have been reports of similar excesses from areas near the other two European nuclear reprocessing plants, Dounreay in Scotland and La Hague in France. Leukaemia clusters have also been reported from areas near many other nuclear sites, particularly those where contaminated river, estuary or sea sediment is involved, or particles of radioactive material are dispersed to the atmosphere [ECRR2003]. The effect in Wales is not restricted to leukaemia. The WCR data showed risks for brain tumours in children 0-4 of RR= 11 in Bangor (2 cases) and RR=14 in Llandudno (3 cases), RR= 10 in Prestatyn (2 cases) in the period 1974 to 1989. In the coastal strip of mean distance from the sea of 0.8km the overall risk in 16 AORs was RR=3.0 with 12 cases (4.04 expected), falling sharply to RR=1.6 in the next zone from the sea from 0.9 to 2km. The explanation given by Green Audit (GA) was that sea to land transfer of radioactive particles followed by inhalation represented a risk to those living in the 0-1km coastal strip since the particles could be translocated from the lung to the lymphatic system resulting in leukaemia and other cancers and also producing germ cell damage and foetal damage in utero leading to effects in children. The cancer findings were based on data supplied by the Wales Cancer Registry (WCR) in 1995. However, immediately after the data were released to Green Audit, WCR was suddenly closed and its personnel dispersed. The computer files given to GA were wiped from the mainframe computer. GA obtained a second copy of the data from the Statistical Directorate of the Welsh Office in 1996. In 1997, the cancer registration system was taken over by a new independent agency, the Wales Cancer Intelligence and Surveillance Unit (WCISU). Their Director, Dr John Steward, denied the existence of any excess cancer or leukaemia risk in children in North Wales and attacked the Green Audit report following the BBC Cymru TV documentary Sea of Troubles broadcast in February 1999. Steward made representations to the Committee on Medical Aspects of Radiation in the Environment who had been asked by the Welsh Assembly to comment. COMARE accepted Stewards position despite many serious problems with the way in which his data could be shown to differ from the WCR data. Steward later published new data in which 15% of the cancers in children aged 0-4 had been removed from the entire WCR database without explanation. It became clear that these cases were those that had contributed to the coastal effect. However, WCR had themselves, in 1994, already drawn attention [WCR 1994] to apparently high levels of childhood cancer in North Wales and in a meeting with Green Audit and The Low Level Radiation Campaign in 1995 had agreed that these figures had been validated by the Childhood Cancer Research Group in Oxford. CCRG has since denied this and stated in public that the discrepancy between the WCR and WCISU numbers arises out of misclassification of adults as children. But curiously, this effect appears to be specific to the coastal areas where the risks were apparently high. The matter has been one of dispute and contention ever since, and is presently part of the deliberations of the new Committee Examining Radiation Risks from Internal Emitters (CERRIE). Meanwhile, Green Audit has been attacked by COMARE, by the nuclear industry, and by the Welsh Assembly for refusing to concede that the new data created by WCISU represents the real picture and to withdraw its position on the childhood cancer and leukaemias in North Wales. Green Audit, on its part, has continued with epidemiology of areas close to the sea and estuaries contaminated with radioactive material and consistently found the sea-coast effect in cancer and leukaemia. Such an effect in estuaries was, in any case, originally reported in the literature by Alexander et al in 1990. Since cancer registries no longer provide small area data, the truth of the matter can no longer be tested using official data that can be trusted. People, however, will only stand so much. It is therefore very welcome that relevant information has been independently gathered by HTV researchers as a result of interviews and snowball sampling carried out in North Wales. The data obtained in this manner is accurate and believable. The children's names, their illness and where they lived are largely known. We can therefore re-examine the position and see if there is indeed a problem with cancer and leukaemia in children in the coastal area of North Wales.
2. The Data The data is from various confidential sources and is collected together below in Table 2 and 3. Table 2 has the cases from North West Wales and Table 3 has some data on deaths from various sources with occurred in the last 8 years. It is assumed that these cases and deaths are not the entire number, just those which have been obtained by interviews among those parents and carers of some of the children listed. They do however provide a baseline for estimating the risks and examining the situation.
Table 2 Cancer cases from interviews in North West Wales (from snowball interviews by HTV reporter)
Note: ALL = Acute lymphoblastic leukaemia, AML = Acute myeloid leukaemia; NHL = non Hodgkin lymphoma
Table 3 Cancer deaths in children 0-14 in North Wales since 1996 according to interviews with families and friends.
|