04/04/2006 - Best evidence yet that mobile phones could be causing brain cancer
* 18/09/2006 -- There is now user feedback and a full response to this
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Summary:
The latest study [1] on brain tumours and phone use
shows the biggest increase of any study so far, and is statistically significant
in all areas. The new study on 905 malignant brain tumour cases shows a 1.7 to
5.9-fold increase in risk for long-term mobile phone and cordless phone users.
The current criteria upon which phone exposure is normally assessed is the
SAR value. Regarding exposure from
cordless phones, the HPA-RPD (ex NRPB) website states:
"Measurements of the SAR values from cordless phones are not generally
available, however it is possible to scale the range of typical values reported
for mobile phones operating at full power (0.2-1.4 W/kg). Assuming physical
factors (such as the antenna types and positions in relation to the head) are
similar to those with mobile phones, this suggests that DECT cordless phone SAR
values would be expected to be in the range 0.008-0.06 W/kg, at least 30
times below the ICNIRP guidelines."
Drs Lennart Hardell, Michael Carlberg and Kjell Hansson Mild, combined two
studies on malignant brain tumours diagnosed during 1997-2003 included answers
from 905 (90%) cases and 2,162 (89%) controls aged 20-80 years. The results are
shown in the table below. In the multivariate analysis all phone types increased
the risk and were statistically significant.
| Cumulative lifetime use for > 2,000 hours of
use cellular phones |
| All malignant tumours |
| |
OR |
CI |
| Analogue phone |
5.9 |
2.5 - 14.0 |
| Digital phones |
3.7 |
1.7 - 7.7 |
| Cordless phones |
2.3 |
1.5 - 3.6 |
| Ipsilateral (tumour on side of head where
phone handset was usually held) |
| Analogue phone |
2.1 |
1.5 - 2.9 |
| Digital phones |
1.8 |
1.4 - 2.4 |
| Cordless phones |
1.7 |
1.3 - 2.2 |
| High-grade astrocytoma for more than 10 years
mobile / cordless phone use |
| Analogue phone |
2.7 |
1.8 - 4.2 |
| Digital phones |
3.8 |
1.8 - 8.1 |
| Cordless phones |
2.2 |
1.3 - 3.9 |
OR = Odds Ratio (the risk of tumours in users' brains compared with
non-users)
The Confidence Interval (CI) ranges given in brackets below represent a 95%
confidence level that the actual OR lies between the two numbers given
(p=0.05).
Conclusion:
Increased risk was obtained for both cellular and cordless phones, highest in
the group with more than 10 years use of mobile or cordless phones.
As we
have mentioned before SAR values seem to be a totally inappropriate metric to
measure the potential risk of the phone (as cordless phones appear to be having
just as pronounced effects as mobile phones despite having about one twentieth
(5%) of their SAR value). It seems that some other characteristic (the nature of
the pulsing signal perhaps?) is causing the increase in cancer, by a mechanism
we have not yet discovered. Now there is so much more evidence such as this
study being published, surely it is now time to accept that the risk is now
likely and to investigate other factors than simple power absorption that may be
responsible for these increases.
References
[1] - Hardell L, Carlberg M, Hansson Mild K, Department of Oncology,
University Hospital, 701 85, Orebro, Sweden
Pooled analysis of two case-control studies on use of cellular and cordless
telephones and the risk for malignant brain tumours diagnosed in 1997-2003,
Int Arch Occup Environ Health. 2006 Mar 16; [Epub]
PMID: 16541280 [PubMed - as supplied by publisher]
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