Bridlewood Electromagnetic Fields (EMFs) Information Service

United Kingdom Childhood Cancer Study and Responses


Power lines not linked to cancer - researchers

London, United Kingdom, December 3, 1999 (Reuters) - Radiation from power lines and household appliances does not increase a child's risk of developing leukaemia or other cancers, British researchers said on Friday.

Results of the UK Childhood Cancer Study, published in The Lancet medical journal, showed no link between electromagnetic radiation and childhood cancer.

``This is a very powerful study for the levels found in the UK. No other study has investigated so many cases of cancer in children over such a long period of time,'' said Professor Nick Day of the University of Cambridge, who led the study.

The eight-year research project compared levels of electromagnetic fields (EMF) in the homes, schools and nurseries of 2,226 children with cancer and an equal number of healthy children.

EMFs are generated by the electricity running through power lines ranging from giant cables to the small lines feeding household power outlets. Recent studies have suggested that the fields might cause cancer.

The researchers also compared the annual rate of exposure to electromagnetic fields in the year before each child was diagnosed with cancer and the exposure of a healthy child on corresponding date.

Even in the 10 percent of homes with the highest exposure levels there was no increase risk of childhood leukaemia, brain tumours or other cancers.

``The magnetic component of EMFs has been under suspicion for some time, but this major study provides firm evidence that exposure to the levels of magnetic fields found in the UK does not augment risk for childhood disease,'' said Richard Doll, the chairman of the UK Childhood Cancer Study.

A separate study by researchers in New Zealand, which was also published in The Lancet, also found no link between electric and magnetic fields and leukaemia.

Both Lancet studies were published just days after researchers from the University of Bristol in western England reported that people living and working near high voltage electricity cables are more exposed to airborne cancer-causing pollutants.

Professor Dennis Henshaw and his colleagues said their findings, which were published in the International Journal of Radiation Biology, could be relevant to reported associations between power lines and childhood and adult leukaemia.

``The dosage rates that we have calculated in this internationally peer reviewed paper suggest there is a need for further studies,'' Henshaw said in a statement.

Link to Lancet Issue

Lancet Commentary
Volume 354, Number 9194
December, 4, 1999 

Link between electromagnetic fields and childhood cancer unresolved

The long-awaited UK Childhood Cancer Study (UKCCS) on exposure to power-frequency magnetic fields and risk of childhood cancer published in today's Lancet does not support the hypothesis that exposure to magnetic fields, associated with the use or transmission of electricity in the UK, increases the risk of childhood leukaemia, central nervous system tumours, or any other childhood cancer.

Reviews of epidemiological studies conducted by the US National Research Council,1 WHO,2 and the National Institute of Environmental Health Sciences (NIEHS)3 have suggested that there is a weak link between exposure to power-frequency magnetic fields and childhood leukaemia, with an odds ratio of about 1·5. Using the International Agency for Research on Cancer criteria for classifying potential carcinogens, an international working group convened by the NIEHS3 rated exposure to power-frequency fields as a category 2B, a possible human carcinogen.

WHO, through its International EMF Project, has been promoting research that attempts to address this 2B classification. From WHO's viewpoint, although the UKCCS is very large and well conducted, it is not the "definitive" study many scientists have been hoping for.

The first reason is that this study was designed many years ago, so the exposure assessment relies on time-weighted average (TWA) fields. TWA has been used in many studies but does not relate to any known mechanism of action of low-frequency fields in tissues. A recent WHO report4 recommends that, although TWA should continue to be used in future epidemiological studies for comparison purposes, other measures that relate to known mechanisms should also be included in the exposure-assessment protocol. Key among these measures is an assessment of any rapid changes in the magnetic field (transients) that occur when appliances are used, and in transients from distribution lines. Currents induced by power transients can produce signals in cells above the cell's normal electrical-noise levels.5

The second reason why the study is not definitive is the low numbers of children in the higher exposure categories. As the UKCCS investigators state, only 2·3% of their controls had been exposed to magnetic fields over 0·2 µT. Although this percentage is similar to that in Germany (2%),6 in the US study7 it was 11·4% and in the Canadian study8 15·4%. This difference reflects, in part, the line voltage in North America of about 110 V, and in Europe of 220 V. Thus for the same power consumption North Americans use twice as much current as Europeans do, and so are exposed to about double the magnetic-field strength. Another factor influencing the level of magnetic-field exposure between the two continents relates to how the power is distributed--for example, how electrical wiring is configured in homes and how the currents are earthed. Whatever the explanation, the small numbers in the higher exposure categories mean that the UKCCS provide evidence only for exposures of up to 0·2 µT.

The third reason is that the small numbers of cases and controls in the higher exposure categories are unlikely to significantly affect the results of previous meta-analyses and reviews suggesting a weak link between power-frequency magnetic-field exposure and childhood leukaemia. 1-3 An analysis, funded by the European Union, which includes the UKCCS, is near completion.

Today's Lancet also carries a research letter reporting some new data from a previously published New Zealand study .9 However, the study has the same inadequacies as the UKCCS.

A major childhood leukaemia study is being done by Japan's National Institute of Environmental Studies. This study will take account of transients in the assessment of exposure to magnetic fields. 1500 cases (1000 leukaemia and 500 brain tumours) and a similar number of matching controls will be recruited. Because Japan is highly industrialised, the study is expected to have large numbers in the high-exposure groups. This study, in conjunction with those being done in Germany and Italy, may be one of the last hopes of finally resolving the vexing issue of whether there is truly an increased risk of childhood cancer from exposure to magnetic fields or whether the weak association is occurring by chance.

*Michael H Repacholi, Anders Ahlbom
----------------------------------------
*Division of Occupational and Environmental Health, World Health Organization, CH-1211, Geneva 27, Switzerland; and National Institute of Environmental Medicine, Karolinska Institutet, Sweden

1 National Research Council. Possible health effects of exposure to residential electric and magnetic fields. National Research Council, Washington: National Academy Press, 1996.

2 Repacholi MH, Greenebaum B. Interaction of static and extremely low frequency electric and magnetic fields with living systems: health effects and research needs. Bioelectromagnetics 1999; 20: 133-60.

3 Portier CJ, Wolfe MS (eds). National Institute of Environmental Health Sciences Working Group Report. Assessment of health effects from exposure to power-line frequency electric and magnetic fields (NIH publication no. 98-3981). Research Triangle Park: NIEHS, 1998.

4 McKinlay AF, Repacholi MH, eds. Exposure metrics and dosimetry for EMF epidemiology: Proceedings of an International Workshop held at the National Radiological Protection Board, Chilton, UK, Sept 7-9, 1998. Radiation Protection Dosimetry 1999; 83 (1-2): 1-194.

5 Electric Power Research Institute. Residential transient magnetic field research: interim report, project RP2966-07 (report TR-103470). Palo Alto, California: EPRI, 1994.

6 Michaelis J, Shuz J, Meinert R, et al. Combined risk estimates for two German population-based case-control studies on residential magnetic fields and childhood acute leukemia Epidemiology 1998; 9: 92-94.

7 Linet MS, Hatch EE, Kleinerman RA, et al. Residential exposure to magnetic fields and acute lymphoblastic leukemia in children. N Engl J Med 1997; 337: 1-7.

8 McBride ML, Gallagher RP, Thériault G, et al. Power-frequency electric and magnetic fields and risk of childhood leukemia in Canada. Am J Epidemiol 1999; 149: 831-42.

9 Dockerty JD, Elwood JM, Skegg DCG, Herbison GP. Electromagn Electromagnetic field exposures and childhood cancers in NeCancer Causes Control 1998; 9: 299-300 (erratum in 1999; 10: 641)


Official Bristol University update for EMF-L

As posted on the EMF-L mailing list
Date: Sat, 8 Jan 2000 16:02:40 -0600 (CST)
From: "Roy L. Beavers"
To: emfguru
Subject: Power line **proximity** is the key!! ... says **Official** Bristol University update for EMF-L (Philips).. X-MIME-Autoconverted: from QUOTED-PRINTABLE to 8bit by host.ott.igs.net id RAA09993
Hi everybody:

This is a most important message......!!

......Guru thanks Bristol University and Alasdair Philips for the following: an update concerning the recent U.K. study..... It needs to be carefully read, fully understood -- and widely circulated!!!

I quote a paragraph from the report below, for emphasis:

"The UKCCS (U.K. Powerline childhood cancer study) confirms the previous findings of other studies that some feature of powerlines other than the magnetic fields is responsible for the association with childhood cancer."

This confirms how badly "the press" screwed-up -- yes "screwed-up" -- the original stories which were published some weeks ago ... at the time of the release of the study results...... (Hope our press friends on this list will get busy and set the record straight.)

It is now being made clear -- again -- that **proximity** to the power lines is the key ... NOT the 'magnetic field'!!!

That could mean that Professor Henshaw's aerosols (contaminants suspended in the air) are to blame (guru's first choice!) ... or it could mean that one of the other metrics (electrical field, transients, etc.) are to blame...... In any event, the **risk factor** appears to be the **proximity to power lines.**

Don't let that FACT -- again -- be distorted, obfuscated or lied about by the power companies!!!

Cheerio.....

Roy Beavers (EMFguru) roy@emfguru.com

.....It is better to light a single candle than to curse the darkness.....
NEW!!! Website
...................People are more important than profits.................

---------- Forwarded message ----------
Date: Sat, 08 Jan 2000 19:36:35
From: Alasdair Philips
To: "Roy L. Beavers"
Subject: Official Bristol University update for EMF-L

The UK Childhood Cancer Study: The Lancet Vol. 354, p1925-1931, 1999.
Childhood Cancer and High-voltage Powerlines

There is some confusion as to the nature of the findings of the UK Childhood Cancer Study, UKCCS(1) with regard to proximity to high voltage powerlines.

The study actually finds increased childhood cancer in relation to proximity to high voltage powerlines.

Both the UK Co-ordinating Committee on Cancer Research, UKCCCR (2.Dec.99) and the Electricity Association press release (1.Dec.99 !) led with the similar headline "Major study finds no link between overhead power cables and childhood cancer."

This, however, is contrary to the finding reported in the paper. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

On page 1930 para 4 line 8, the paper states "More cases than controls were included through their proximity to high-voltage powerlines (p = 0.04, table 5)."

In table 5 (on page 1929) 31 cases were found near high-voltage powerlines against 17 controls, an odds ratio of 1.82.

This is statistically significant at the 95% confidence level (p = 0.04).

[...... Comment inserted by Alasdair Philips: In fact, there are many more cases and controls within 200 metres of HV power lines for which the electricity companies have so far NOT responded with load data. The whole analysis should be published within the next few months, but is believed to confirm the fact that more leukemia cases lived closer to lines than healthly control children...... ]

The caption to table 5 reads "Estimated exposure before and after adjustment for historical line-load data, among those with relevant external-source questionnaires." This means those cases and controls near high-voltage powerlines for which the electricity companies have responded with data.

There are considerably more cases and controls living near high voltage powerlines for which the UKCCS has distance data for which the electricity companies have not yet replied with line-load data. Therefore, although more data may become available, the key finding now is of increased childhood cancer in children living near high voltage powerlines. (132 kV and above ~ in fact MAINLY 132 kV as very few lived near higher voltage lines!).

Within the resolving power of the study, no association with magnetic fields was found, despite the association with proximity to powerlines. This is in agreement with the 1996 US National Academy of Sciences – National Research Council(2) meta-analysis of various studies, which shows that the association of childhood cancer with distance to powerlines is stronger than that of either measured or calculated magnetic fields.

Indeed, Dr Charles Stevens, the NAS-NRC Panel Chairman, stated on National Public Radio(3) on 10th November 1996: "There is a statistical association between living near a power line and an increased incidence of childhood leukaemia. That’s for sure. The question is what caused that association." The UKCCS confirms the previous findings of other studies that some feature of powerlines other than the magnetic fields is responsible for the association with childhood cancer.

It is not clear why the incomplete Table 5 was included in the Lancet paper but, as it was, this important initial confirmation of the NAS-NRC meta-analysis – of increased childhood cancer with proximity to powerlines - should have been highlighted.

The two recent publications from Bristol University(4,5) address the question of whether electric fields from powerlines are responsible for the observed association between childhood cancer and proximity to powerlines. Both papers demonstrate the increased exposure to airborne pollution under and near powerlines.

Such pollution, both chemical and radioactive, is accepted as being linked to childhood leukaemia. In particular, the paper on corona ions shows effects on average 200 metres from powerlines, although in two cases effects up to 500 metres away were seen. The Bristol researchers propose that increased exposure to this pollution near powerlines may account for the observed increase in childhood leukaemia near powerlines, now also seen in the UK Childhood Cancer Study.

see http://www.electric-fields.bris.ac.uk/

References

1. N Day, lead author of UK Childhood Cancer Investigators, Exposure to power-frequency magnetic fields and the risk of childhood cancer. The Lancet, Vol. 354, 1925-1931, 1999.

2. National Academy of Sciences & National Research Council Possible Health Effects of Exposure to Residential Electric and Magnetic Fields. National Academy Press (Washington DC), 1997 .

3. Quoted in Microwave News, Vol XVI No.6, November/December 1996.

4. A P Fews, D L Henshaw, R J Wilding and P A Keitch, Corona ions from powerlines and increased exposure to pollutant aerosols. International Journal of Radiation Biology, Vol. 75, no. 12, 1523-1531, 1999.

5. A P Fews, D L Henshaw, P A Keitch, J J Close and R J Wilding: Increased exposure to pollutant aerosols under high voltage powerlines. International Journal of Radiation Biology, Vol. 75, no. 12, 1505-1521, 1999.

Professor D L Henshaw, H H Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol, BS8 1TL, UK, December 1999.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Alasdair Philips, BSc(Eng), DAgE, MIAgE
Director, UK Powerwatch, (aphilips@gn.apc.org)
EMC Engineer and EMF-bioeffects researcher
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

ADDENDUM

Date: Sun, 9 Jan 2000 10:35:18 -0600 (CST)
From: "Roy L. Beavers"
To: emfguru
Subject: Power line **proximity** is the key!! ... says **Official** Bristol University update for EMF-L (Philips).. (fwd)
......An addition to Alasdair's previous message.....

---------- Forwarded message ----------
Date: Sun, 09 Jan 2000 14:57:20
From: Alasdair Philips
To: emfguru
Subject: Power line **proximity** is the key!! ... says **Official** Bristol University update for EMF-L (Philips)..
Roy

One important clarification. UKCCS only cleared magnetic fields as not being a causal factor in UK childhood cancer ~ fields over here are less than a half of those in the USA and Canada. They hardly found any cases or controls abouve 0.2 uT or 2 mG which is the suggested threshold where magnetic field effects might start to occur.

The UKCCS tells us nothing useful about whether 3mG or above magnetic fields will increase the incidence of childhood cancer.

I should have made this clear. Please circulate this extra message. It has not put power-frequency magnetic fields in the clear!

Thanks.
Alasdair

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Alasdair Philips, BSc(Eng), DAgE, MIAgE
Director, UK Powerwatch, (aphilips@gn.apc.org)
EMC Engineer and EMF-bioeffects researcher
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


REVISED JANUARY 2000
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