27/04/2005 - BBC change their tune on leukaemia, newspapers take up the flawed conclusions
Give credit where it is due, the BBC have now somewhat moderated their comments, replacing "almost completely rules out" powerlines and vitamin K to an ambiguous quote from the Leukaemia Research Fund stating "The more implausible theories I think we can now dismiss". The BBC current official line seems now to be that there is good evidence supporting exposure to infection having an effect on development of leukaemia in children, which we agree with.
However, the main national newspapers have continued where the original BBC articles left off, citing that the report conclusively said that "powerlines and electro-magnetic fields in the home did NOT cause leukaemia" (The Sun, April 23, 2005, their emphasis). The following is a brief analysis of which papers said what:
"It also offers the best evidence yet that exposure to radiation such as pylons, neonatal use of vitamin supplements and other common theories are not causes of the illness." - The Times, April 23 2005, Page 8
"An analysis of more than 6,000 children aged two to 14 for the UK Childhood Cancer Study says that exposure to infection at the start of life is the likeliest explanation." - The Daily Telegraph, April 23 2005, Page 13
"The study, financed by the Leukaemia Research Fund, said environmental radiation or vitamin K often given to babies did not cause the cancer." - Daily Mirror, April 23 2005, Page 21
"The 15-year study rules out links between power lines, or natural radiation, as causes of the disease." - Daily Mail, April 23 2005, Page 14
"The report also said that power lines and electro-magnetic fields in the home did NOT cause leukaemia." - The Sun, April 23 2005, Page 14
Each of these are non-scientificly based statements made by the media with little basis in fact. Some newspapers did a more balanced piece on the story: both the Guardian (April 23 2005, Page 9) and the Independent (April 23 2005, Page 16) ran the story and quoted the researchers as discounting electromagnetic fields and ionising radiation, but did not word the conclusions as fact.
The most balanced article came from the Daily Express (April 23 2005, Page 7), which stuck purely to the facts and merely covered the conclusions of the study without adding the non-scientific extra comments from the researchers - this may have had something to do with the article only being 5 sentences long, but we will allow them the benefit of the doubt!
Previous UKCCS papers have reported on electromagnetic fields etc., however there has been much disagreement about how to interpret the results. We have previously reported on these; see the following Powerwatch news articles:
However, as we have already established in our previous article that the current BMJ report does not cover nor make any assumptions on any other cause of childhood leukaemia, we will instead look at research indicating equally significant risks from other sources:
1. Ionising Radiation
Dr Richard Wakeford, from British Nuclear Fuels plc, spoke at the CHILDREN with LEUKAEMIA scientific conference last October about what is currently known about ionising radiation's impact on childhood leukaemia. His presentation spoke about current risk models suggesting that 25% of childhood leukaemia in Britain may be caused by natural background radiation, and displayed the results of relevant published science suggesting good supporting evidence for this. Although he refutes that man-made radiation is a significant cause of childhood leukaemia, other radiation scientists believe that it is, and this is still actively under investigation.
- PDF version of the presentation slideshow - (287 KB)
Please bear in mind that this presentation is purely the intellectual property of Dr Wakeford and may not be reproduced in full or in part in any form without his express consent.
2. Electromagnetic Radiation
Professor Anders Ahlbom, of the Karolinska Institute in Sweden, spoke at the same conference about the current research looking into the possibility of EMFs increasing childhood leukaemia risk, and made the summary that at electromagnetic fields of greater than 0.4µT (field strength that is commonly exceeded within 100m of powerlines and is found around various household appliances) there appeared to be a doubling in childhood leukaemia.
- PDF version of the presentation slideshow - (119 KB)
3. Air Pollution
Childhood leukaemia is known to be associated with traffic pollution. Near powerlines increased lung deposition of inhaled electrically charged pollutants is expected. This phenomenon could explain the association between high voltage powerlines and childhood leukaemia. The phenomenon also suggests that further research should be undertaken to ascertain whether other cancers or non-cancer illnesses are associated with living near high voltage powerlines. The University of Bristol is currently doing extensive research into pollutant aerosols and their effect on childhood leukaemia, and initial results suggest that people's exposure to pollutant aerosols increases up to 3-fold under powerlines.
Some researchers from Berkeley University in California have produced some very good evidence suggesting that regular consumption of bananas, oranges and orange juice before the age of 2 halved the risk of developing childhood leukaemia. Taken into context this becomes just as significant as the exposure to infection - both are available options to the entire population and both have a similar effect on leukaemia rates.
- PDF of the abstract from the study - (178 KB)
Part of the problem when looking at this type of information is the percentage of the population at risk from the postulated mechanism. To take a fictional set of data, we will say that 1% of all children contacted leukaemia (exaggerated to illustrate the example). If attendance in formal child-care (which may represent early exposure to infection) halves leukaemia incidence, and was made available to the whole population, all parents sending their infants children to day centers would cut leukaemia incidence from 1% to 0.5% of the population. Say that living under powerlines quadruples leukaemia incidence, but only 1% of the population lived under powerlines. In this case, leukaemia incidence would nationally increase to 1.03%, which is relatively far less significant looking at the total population, but much more significant to those living near powerlines who would have 4 times the risk.
The is also evidence that even regardless of these factors, some people appear to have a level of inherent genetic susceptibility. Some recent work published by Nori Nakamura has demonstrated that some people are born with an ionising radiation damage susceptibility gene. These people need to avoid ionising radiation more carefully than people without this susceptibility gene, which clearly makes epidemiological studies of populations much more difficult to interpret. We are awaiting for permission to post a link to this work.
So in conclusion, it seems like there is good supporting evidence that exposure to infection as a child may decrease future risk of contracting leukaemia. It also seems reasonable to think that there are other environmental factors that have a significant effect. There is a study called the "Draper Report" coming out in the middle of this year (current expected date 3rd of June) looking to relative risk attached to living near powerlines.
» Powerwatch September 2004 comment on the delayed Draper Report