29/02/2008 - ELF EMF increases other cancer risks as significantly as childhood leukaemia

Professors Mike O'Carroll and Denis Henshaw have now published their paper looking at aggregated statistical associations on the evidence of health effects from extremely low frequency electromagnetic fields. We briefly covered some of the key statistical points of their paper in the table on our news story about the poor HPA advice at the end of last month.

In essence, whilst the methodology is designed to be "indicative" and not "conclusive", it shows quite clearly that the evidence supporting an increase in risk for cancer other than childhood leukaemia is particularly strong.

Their paper looks specifically at the IARC (International Agency for Research on Cancer) and CDHS (California Department of Health Services) reviews, and covers childhood leukaemia, adult leukaemia, adult brain cancer, miscarriage and amyotrophic lateral sclerosis (ALS), a form of motor neurone disease.

Statistical Background

In epidemiological research, a p-value of 0.05 broadly means that there is a confidence level of around a 2.5% that the result could be raised (or lowered) to the level found by chance. A result is generally considered significant if this value is lower than 0.05 (thus the chance of the result being coincidental is less than 2.5%), otherwise it is not considered significant. One would therefore expect to find perhaps 2 statistically significant positives and 2 statistically significant negatives from a set of 80 ORs entirely by chance.

The purpose of this paper was to find an objective way of "pooling" disparate epidemiological studies to find the confidence that the overall total number of positive and negative studies (and significant positive and negative) could be by chance when looked at as a whole. If, out of 43 ORs, we can find 14 statistically significant (p < 0.05) positives and 0 statistically significant negatives (as was found in table I below), then this is a hugely significant result when viewed as a whole.

The following two tables show the statistical summaries of each review looking specifically at the increase in risk for adult leukaemia (In each case, 1 OR was selected from each paper):

Table I - Summary of California findings on Adult Leukaemia

Table II - Summary of IARC findings on Adult Leukaemia

Whilst the methodology of this study prevents these findings from being conclusive, it shows very clearly that the IARC review, by using predominantly subjective methods of aggregated analysis, largely missed the evidence in their own set of data. Whilst ideally a more sophisticated aggregation technique such as meta-analysis is more preferable to draw solid conclusions from, this easy method of analysis provides a very good indicator of the level of confidence of where the evidence appears to be pointing.

This study shows clearly that, despite having publicly come to very different conclusions, the evidence within the analysed research is very similar for both of the separate groups. It also shows very clearly that the evidence of longterm health effects from extremely low frequency electromagnetic fields appears to be stronger than any of the main statutory bodies currently suggest.

Further evidence from recent studies

There have been two papers in the last 6 months that have gone even further to confirm these findings that ELF EMF exposures at levels typical to those of residential proximity to powerlines (~60-100 metres) have a very real risk of making a significant contribution to adverse health in the general population.

Lowenthal RM et al, (September 2007) Residential exposure to electric power transmission lines and risk of lymphoproliferative and myeloproliferative disorders: a case-control study, Intern Med J. 2007 Sep;37(9):614-9 [View Abstract]

In light of the published associtions between electromagnetic fields and childhood leukaemia, the aim of this paper was to determine whether there is an increased risk of lymphoproliferative disorders (LPD) or myeloproliferative disorders (MPD) associated with residence 300m or less from high-voltage powerlines. The results were particularly striking, with adults living less than 300m from powerlines within the first 15 years of life having a 3-fold increase in risk (CI 1.26-8.29), and within the first 5 years of life having a 5-fold increase in risk (CI 0.98-22.9). They conclude that "Although recognizing that this study has limitations, the results raise the possibility that prolonged residence close to high-voltage power lines, especially early in life, may increase the risk of the development of MPD and LPD later".

Garcia AM et al, (February 2008) Occupational exposure to extremely low frequency electric and magnetic fields and Alzheimer disease: a meta-analysis, Int J Epidemiol. 2008 Feb 2 [Epub ahead of print] [View Abstract]

This paper is the first systematic review and meta-analysis of published epidemiological studies on the effect of ELF EMFs on Alzheimer disease (AD). Fourteen different studies (nine case-control and five cohort studies) accomplished were included, of which all followed standardized criteria for AD diagnosis and most of them obtained quantitative estimates of exposure.

Pooled estimates suggest a doubling of risk of AD from case-control studies (CI 1.38-3.00) and a 60% increase from cohort studies (CI 1.16-2.27), with moderate to high statistical heterogeneity in both cases. Cohort studies showed a doubling in risk for exposed men (CI 1.51-2.80).

Concluding that "Available epidemiological evidence suggests an association between occupational exposure to ELF-EMF and AD", this is further evidence that any health risks arising from residential proximity to overhead powerlines and other extremely low frequency electromagnetic radiation sources may not be limited to childhood leukaemia.

Conclusions

Since the release of the SAGE report in April 2007, much of the advice and official comments (from the Health Protection Agency and other advisory bodies) has only considered the association between powerlines and childhood leukaemia to be of any merit. Bearing in mind the relative rarity of childhood leukaemia (when compared to adult leukaemia and brain cancer) it is now urgent that this attitude is changed to reflect the possibility that the health implications are more widespread.

References

O'Carroll MJ, Henshaw DL, (February 2008) Aggregating Disparate Epidemiological Evidence: Comparing Two Seminal EMF Reviews, Risk Analysis 2008;28(1) [View Abstract]

Lowenthal RM et al, (September 2007) Residential exposure to electric power transmission lines and risk of lymphoproliferative and myeloproliferative disorders: a case-control study, Intern Med J. 2007 Sep;37(9):614-9 [View Abstract]

Garcia AM et al, (February 2008) Occupational exposure to extremely low frequency electric and magnetic fields and Alzheimer disease: a meta-analysis, Int J Epidemiol. 2008 Feb 2 [Epub ahead of print] [View Abstract]

Also in the news

House of Commons questions on health and power lines

Following the lead from CHILDREN with LEUKAEMIA, The following five questions were tabled to the House of Commons at the beginning of this month by Tim Loughton:

To ask the Secretary of State for Health:

1. what plans he and his Ministerial colleagues have to hold discussions with stakeholders on the implementation of the Health Protection Agency's advice to Government on the SAGE First Interim Assessment on power lines and property, wiring in homes and electrical equipment in homes; [185059]
2. what steps have been taken since 27 November 2007 to implement the Health Protection Agency's guidance to Government on the SAGE First Interim Assessment on power lines and property, wiring in homes and electrical equipment in homes; and if he will make a statement; [185060]
3. what the timing of the current round of consultation on the SAGE First Interim Assessment on power lines and property, wiring in homes, and electrical equipment in homes is; and if he will make a statement; [185072]
4. what (a) meetings and (b) other contacts there have been between officials from his Department and other Departments and devolved administrations on the implementation of the Health Protection Agency's guidance to Government on the SAGE First Interim Assessment on power lines and property, wiring in homes, and electrical equipment in homes; [185090]
5. if he will take steps to reduce the exposure of children to electromagnetic radiation. [185500]

View questions and the response from Dawn Primarolo on Hansard Online...

Public petition to Scottish Parliament on health and power lines

The Scottish Parliament Public Petitions Committee have made very positive forward progress in applying an evidence-based precautionary approach to guidance and advice regarding the possible long term health effects of proximity to powerlines.

Petition PE812, submitted by Caroline Paterson (on behalf of Stirling before Powerlines), called for "the Scottish Parliament to urge the Scottish Executive to acknowledge the potential health hazards associated with long-term exposure to electromagnetic fields from high voltage transmission lines and to introduce as a matter of urgency effective planning regulations to protect public health." back in April 2005. The petition has made steady progress and is now being taken seriously by the committee with regards to how it should impact precautionary guidance.

The committee met again on the 19th of February 2008 to discuss further progress on the issue. The meeting was initiated by drawing parallels with passive smoking (an "unproven" cause of long term health effects where it has been deemed there is sufficient evidence for pre-emptive legislation), and that as the evidence of possible harm seems to be steadily growing, it may be appropriate to initiate a precautionary approach to advice before the risks to health (if later shown to be strong and real) have become irreversibly widespread.

- Minutes from the 19th February 2008 meeting
- Beauly-Denny overhead powerline enquiry

REVOLT issue 252 update on national power lines news

Mike O'Carroll has produced a further newsletter (Issue 252) covering the following issues related to powerlines and UK/EIRE news:

1. Call from the Irish Government to set up a study into undergrounding powerlines
2. Implications of the study in the Beauly-Denny enquiry and further SAGE work
3. Update and information on the group Meath Pylon Pressure and their actions, including their name change to North East Pylon Pressure (NEPP)
4. An update on Scottish petition PE812 (mentioned in the previous AITN)
5. Commentary on the parliamentary questions and responses in the 1st AITN
6. French survey sponsored by concerned local residents, faced with the prospect of living near a new 400 kV powerline
7. Details on a case near Wolverhampton where a powerline conducter is illegally close to the chimneystack of a residence, including mention of the fact that there is no wayleave present
8. A story from Tintagel where a local is campaigning to have a proposed substation relocated because of health concerns

- View full issue on REVOLT site