Brain Cancer Risk Increases with the Amount of Wireless Phone Use
maandag, 30 september 2013 - Categorie: Onderzoeken
Bron: www.saferemr.com/2013/09/brain-cancer-risk-increases-with-amount.html .
26 okt. 2013
New research indicates that brain cancer risk increases with more years of cell phone and cordless phone use and more hours of use.
Dr. Lennart Hardell and his colleagues in Sweden just published the third in a series of papers on the use of wireless phones, including cell phones and cordless phones, and the risk of malignant and non-malignant brain tumors. The latest paper describes a new case-control study that examines the association between mobile phone use and brain cancer risk. In these studies, the cases were diagnosed with brain tumors between 2007 and 2009. (1)
The study updates earlier research from case-control studies conducted by the Hardell group and extends the prior research by examining the effects of wireless phone use, i.e., cell phone and cordless phone use, on brain tumor risk for people who have used these phones for up to 25 or more years.
Overall, the research found that people who used wireless phones for more than a year were at 70% greater risk of brain cancer as compared to those who used wireless phones for a year or less. Those who used wireless phones for more than 25 years were at greatest risk—300% greater risk of brain cancer than those who used wireless phones for a year or less.
The total number of hours of wireless phone use was as important as the number of years of use. A fourth of the sample used wireless phones for 2,376 or more hours in their lifetime which corresponds to about 40 minutes a day over ten years. These heavier users had 250% greater risk of brain tumors as compared to those who never used wireless phones or used them for less than 39 hours in their lifetime.
A similar analysis reported in the 13-nation Interphone study funded partly by the World Health Organization found a 182% greater risk of brain cancer among those who used cell phones for 1,640 or more hours in their lifetime.
In the current study, for all types of wireless phone use, brain cancer risk was found to be greater in the part of the brain where the exposure to wireless phone radiation was highest—in the temporal or overlapping lobes of the brain on the side of the head were people predominantly used their phones.
Given consistent results from multiple case-control studies that long-term use of mobile phones (i.e., ten or more years) is associated with brain cancer especially near where the phone is predominantly used, the International Agency for Research on Cancer should strengthen its 2011 assessment of radiofrequency energy from “possibly carcinogenic” to “probably carcinogenic” to humans.
More importantly, governments around the world should heed the results of these studies. The public must be educated about the need to take simple precautions whenever using wireless devices. Governments must strengthen regulatory standards for wireless radiation and must fund research independent of industry to develop safer technologies.
The paper was published online in the peer-reviewed journal, International Journal of Oncology. The abstract and a link to this paper appears below along with the abstracts for the Hardell group’s two prior papers from this study. All three papers are open access. (1-3)
(1) Lennart Hardell, Michael Carlberg, Fredrik Söderqvist, Kjell Hansson Mild. Case-control study of the association between malignant brain tumours diagnosed between 2007 and 2009 and mobile and cordless phone use. International Journal of Oncology. Published online September 24, 2013.
Previous studies have shown a consistent association between long-term use of mobile and cordless phones and glioma and acoustic neuroma, but not for meningioma. When used these phones emit radiofrequency electromagnetic fields (RF-EMFs) and the brain is the main target organ for the handheld phone. The International Agency for Research on Cancer (IARC) classified in May, 2011 RF-EMF as a group 2B, i.e. a ‘possible’ human carcinogen. The aim of this study was to further explore the relationship between especially long-term (>10 years) use of wireless phones and the development of malignant brain tumours.
We conducted a new case-control study of brain tumour cases of both genders aged 18-75 years and diagnosed during 2007-2009. One population-based control matched on gender and age (within 5 years) was used to each case. Here, we report on malignant cases including all available controls. Exposures on e.g. use of mobile phones and cordless phones were assessed by a self-administered questionnaire. Unconditional logistic regression analysis was performed, adjusting for age, gender, year of diagnosis and socio-economic index using the whole control sample.
Of the cases with a malignant brain tumour, 87% (n=593) participated, and 85% (n=1,368) of controls in the whole study answered the questionnaire. The odds ratio (OR) for mobile phone use of the analogue type was 1.8, 95% confidence interval (CI)=1.04‑3.3, increasing with >25 years of latency (time since first exposure) to an OR=3.3, 95% CI=1.6-6.9. Digital 2G mobile phone use rendered an OR=1.6, 95% CI=0.996-2.7, increasing with latency >15-20 years to an OR=2.1, 95% CI=1.2-3.6. The results for cordless phone use were OR=1.7, 95% CI=1.1-2.9, and, for latency of 15-20 years, the OR=2.1, 95% CI=1.2-3.8. Few participants had used a cordless phone for >20-25 years. Digital type of wireless phones (2G and 3G mobile phones, cordless phones) gave increased risk with latency >1-5 years, then a lower risk in the following latency groups, but again increasing risk with latency >15-20 years. Ipsilateral use resulted in a higher risk than contralateral mobile and cordless phone use. Higher ORs were calculated for tumours in the temporal and overlapping lobes. Using the meningioma cases in the same study as reference entity gave somewhat higher ORs indicating that the results were unlikely to be explained by recall or observational bias.
This study confirmed previous results of an association between mobile and cordless phone use and malignant brain tumours. These findings provide support for the hypothesis that RF-EMFs play a role both in the initiation and promotion stages of carcinogenesis.
(2) Lennart Hardell, Michael Carlberg, Fredrik Söderqvist, Kjell Hansson Mild. Pooled analysis of case-control studies on acoustic neuroma diagnosed 1997-2003 and 2007-2009 and use of mobile and cordless phones. International Journal of Oncology. 43(4):1036-1044. October 2013.
We previously conducted a case-control study of acoustic neuroma. Subjects of both genders aged 20-80 years, diagnosed during 1997-2003 in parts of Sweden, were included, and the results were published. We have since made a further study for the time period 2007-2009 including both men and women aged 18-75 years selected from throughout the country. These new results for acoustic neuroma have not been published to date.
Similar methods were used for both study periods. In each, one population-based control, matched on gender and age (within five years), was identified from the Swedish Population Registry. Exposures were assessed by a self-administered questionnaire supplemented by a phone interview. Since the number of acoustic neuroma cases in the new study was low we now present pooled results from both study periods based on 316 participating cases and 3,530 controls. Unconditional logistic regression analysis was performed, adjusting for age, gender, year of diagnosis and socio-economic index (SEI).
Use of mobile phones of the analogue type gave odds ratio (OR) = 2.9, 95% confidence interval (CI) = 2.0-4.3, increasing with >20 years latency (time since first exposure) to OR = 7.7, 95% CI = 2.8-21. Digital 2G mobile phone use gave OR = 1.5, 95% CI = 1.1-2.1, increasing with latency >15 years to an OR = 1.8, 95% CI = 0.8-4.2. The results for cordless phone use were OR = 1.5, 95% CI = 1.1-2.1, and, for latency of >20 years, OR = 6.5, 95% CI = 1.7-26. Digital type wireless phones (2G and 3G mobile phones and cordless phones) gave OR = 1.5, 95% CI = 1.1-2.0 increasing to OR = 8.1, 95% CI = 2.0-32 with latency >20 years. For total wireless phone use, the highest risk was calculated for the longest latency time >20 years: OR = 4.4, 95% CI = 2.2-9.0. Several of the calculations in the long latency category were based on low numbers of exposed cases. Ipsilateral use resulted in a higher risk than contralateral for both mobile and cordless phones. OR increased per 100 h cumulative use and per year of latency for mobile phones and cordless phones, though the increase was not statistically significant for cordless phones. The percentage tumour volume increased per year of latency and per 100 h of cumulative use, statistically significant for analogue phones. This study confirmed previous results demonstrating an association between mobile and cordless phone use and acoustic neuroma.
(3) Michael Carlberg, Fredrik Söderqvist, Kjell Hansson Mild, and Lennart Hardell. Meningioma patients diagnosed 2007–2009 and the association with use of mobile and cordless phones: a case–control study. Environmental Health 2013, 12:60. Published online Jul 19, 2013.
Background To study the association between use of wireless phones and meningioma.
Methods We performed a case–control study on brain tumour cases of both genders aged 18–75 years and diagnosed during 2007–2009. One population-based control matched on gender and age was used to each case. Here we report on meningioma cases including all available controls. Exposures were assessed by a questionnaire. Unconditional logistic regression analysis was performed.
Results In total 709 meningioma cases and 1,368 control subjects answered the questionnaire. Mobile phone use in total produced odds ratio (OR) = 1.0, 95% confidence interval (CI) = 0.7-1.4 and cordless phone use gave OR = 1.1, 95% CI = 0.8-1.5. The risk increased statistically significant per 100 h of cumulative use and highest OR was found in the fourth quartile (>2,376 hours) of cumulative use for all studied phone types. There was no statistically significant increased risk for ipsilateral mobile or cordless phone use, for meningioma in the temporal lobe or per year of latency. Tumour volume was not related to latency or cumulative use in hours of wireless phones.
Conclusions No conclusive evidence of an association between use of mobile and cordless phones and meningioma was found. An indication of increased risk was seen in the group with highest cumulative use but was not supported by statistically significant increasing risk with latency. Results for even longer latency periods of wireless phone use than in this study are desirable.
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