Oxidative effect of low-intensity microwave radiation in the model of developing quail embryos

ABSTRACT

Objective: Exposure of humans to low-intensity microwave (MW) radiation under some circumstances leads to several medical conditions, including headache, chronic fatigue, and even cancer. Mechanisms of these effects in many cases may depend on oxidative stress caused by MW exposure. Our study aims to assess oxidative stress features in embryonic cells under low-intensity MW exposure in the first stage of embryogenesis. Methods: Embryos of Japanese quails were exposed in ovo to low-intensity MW of global system for mobile communication (GSM) 900 MHz (0.25 μW/cm2) during 158-360 h discontinuously (48 c – ON, 12 c – OFF) before and in the initial stages of development. The levels of superoxide (O₂•−), nitrogen oxide (NO•), and 8-oxo-2’-deoxyguanosine (8-oxo-dG) were assessed in cells of 38-h, 5-, and 10-day exposed embryos and compared to the control group. Lucigenin-enhanced chemiluminescence was used for assessment of GSM modulation role in MW-induced oxidative effects. Results: A significant persistent overproduction of superoxide, nitrogen oxide, and 8-oxo-dG in GSM MW-exposed embryonic cells during all periods of analyses was detected. Conclusion: Exposure of developing quail embryos to low-intensity MW of GSM 900 MHz during the first stages of embryogenesis resulted in a significant overproduction of superoxide and nitrogen oxide and oxidative damages of DNA in embryonic cells. These effects were interpreted to be depended on the GSM modulation of MW.

The article can be found here.

Comment: This is a very interesting and important study. Embryos of Japanese quails were exposed to radiofrequency (RF) radiation using GSM 900 MHz. The average intensity of RF radiation on the surface of hatching eggs in the exposed group was 2 500 μW/m² (0.25 μW/cm²). SAR was calculated to 3 μW/kg. A control group with no exposure was used. A statistically significant overproduction of reactive oxygen species (ROS) and oxidative damage of DNA in living cells was reported. The exposure was far below the guideline still provided by ICNIRP for RF radiation as 2 to 10W/m² depending on frequency and 2 W/kg to the brain. The results in the study show that the ICNIRP guidelines are outdated, see our previous discussion. Moreover, using a safety factor of 10 would give 250 μW/m² as guideline, a level easily exceeded in many places, see our measurements at Stockholm Central Railway Station and Stockholm Old Town.

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New results from Interphone confirm glioma risk associated with use of mobile phones

The Interphone study included 13 countries during the study period 2000 – 2004. The major results were published after a delay of 6 years in 2010. In a new publication 12 years after the study period, the intracranial distribution of glioma in relation to radiofrequency (RF) radiation from mobile phones was analyzed. Tumour localization for 792 regular mobile phone users was analyzed in relation to distance from preferred ear for mobile phone use.

In Table 2 five categories for the distance were used with > 115.01 mm as the reference category (α = 1.0).  An association with distance from preferred side of mobile phone use to center of tumour was found; the closer the distance the higher the risk. The highest risk was found in the group with the closest distance (0-55 mm) yielding α = 2.37, 95 % Confidence Interval (CI) = 1.56-4.56.

The same association was seen if distance was based on point with highest Specific Absorption Rate (SAR) instead of preferred ear and if using a model assuming that the preferred side of phone use was not exclusively used (“mixing proportion”). The latter model generated higher risk estimates than the other two but with wider confidence intervals.

In Table 3 tumour size, duration of phone use, cumulative phone use, cumulative number of calls were analyzed. Although not statistically significant, higher risks with decreasing distance were found in the upper levels of these dichotomized covariates.

α and 95 % CI in shortest distance group 0-55 mm from preferred ear to tumour center

Tumour size                        α                    95 % CI

≤18 cm³                              1.96               1.51 – 3.66

18 cm³                                4.09               1.90 – 12.0

Duration of phone use

<6 years                              2.02               1.31 – 4.28

≥6 years                              3.27               1.92 – 11.3

Cumulative phone use

<200 hours                          1.57                1.29 – 3.36

≥200 hours                          4.06                2.03 – 11.6

Cumulative number of calls

<4,000                                 1.55                  1.25 – 3.42

≥4,000                                 3.56                 2.05 – 9.88

The authors concluded that ‘Taken together, our results suggest that ever using a mobile phone regularly is associated with glioma localization in the sense that more gliomas occurred closer to the ear on the side of the head where the mobile phone was reported to have been used the most. However, this trend was not related to amount of mobile phone use, making it less likely that the association observed is caused by a relationship between mobile phone use and cancer risk.’

The first part although correct is misleading. The correct statement would be that the risk was highest for glioma closer to the ear as would be expected based on the exposure to RF radiation. The last sentence should have indicated that although not statistically significant, the risk was highest in the group with longest duration of phone use, highest cumulative phone use and number of calls. This is a pattern one would expect if there is an association between mobile phone use and glioma.

A similar tendency to not correctly downplaying the association is found in the abstract: ‘The association was independent of the cumulative call time and cumulative number of calls.’ Since many persons read only the abstract, as also presented in PubMed, correct presentation of the results including αs and 95 % CIs would have been more relevant.

The correct interpretation of this study is simply that it confirms an increased risk for glioma associated with mobile phone use.

 

Footnote: The α values represent the change in risk of observing a tumor within the given interval in comparison with the baseline intensity.

Belgium to restrict use of mobile phones among children

More information is given below:

22/10/2013

Children’s mobile phones may no longer be sold. Besides this, the specific absorption rate (SAR) has to be listed for every mobile phone at the point of sale.

New regulation for the sale of mobile phones as of 2014

As of 1 March 2014, new regulations will apply to the sale of mobile phones. On the one hand the sale of mobile phones that have been specially manufactured for young children (under 7s) will be prohibited. On the other hand the SAR value will have to be listed everywhere where mobile phones are sold: in stores as well as for distance sales over the Internet.

Sale of children’s mobile phones prohibited

As of 1 March 2014, mobile phones that are specially designed for young children may no longer be introduced to the Belgian market. This concerns customised mobile telephones suitable for children younger than 7 years of age, for instance having few buttons and a shape attractive for children. Additionally, from this date forward, no advertising may be made for mobile phone use among the same age group.
The specific absorption rate (SAR) to become mandatory consumer information
When you purchase a new mobile phone, from now on you will be able to choose your new device based on the specific absorption rate (SAR). The SAR value is different for every mobile phone. The SAR value will have to be indicated along with the other technical specifications, not only in the shop, but also for distance sales over the Internet.

Why these measures?

As a precaution. According to the International Agency for Research on Cancer (IARC, 2011) there may be an increased risk of brain cancer due to the intensive use of a mobile phone. The IARC has therefore classified radio frequency as “possibly carcinogenic”. Measures are being taken pending clearer scientific conclusions. The intention is to raise awareness among mobile phone users.

You can reduce your average exposure by choosing a mobile phone with a lower SAR value. But it is not the intention to use it for hours at a time: the way in which you use your mobile phone also determines your exposure. Using an earpiece, text messaging and not phoning in places with poor reception are a few tips that can significantly reduce your exposure. You can find more tips on our page “sensible mobile phone use ”.

Children already come into contact with mobile phones from a very young age. The overall exposure during their lifetime will thus be greater than that of today’s adults. Moreover, children absorb more mobile phone radiation than adults (twice as much in the brain and 10 times more for skull bone marrow). This is already a reason for additional caution, given the classification of radio frequency as “possible carcinogenic” by the International Agency for Research on Cancer (IARC).

Want to know more?

Then check out our list of frequently asked questions.
You can find more information about sensible mobile phone use and the IARC’s classification on this page.
You can download the Royal Decree on the ban of mobile phones for children here.
The Royal Decree which makes the mention of the SAR value mandatory for mobile phone sales and which prohibits advertising for children can be downloaded here.

http://www.health.belgium.be/eportal/19089508_EN#.UmpvaVO3Nad

 

Note that the classification Group 2B of exposure to radiofrequency electromagnetic fields holds for the whole radiofrequency frequency and not only mobile phones. Thus it included base-station antennas, Wi-Fi, smartmeters etc., see below:

Robert Baan, PhD, is the principal author of the 2011 IARC Monograph on the carcinogenicity of radiofrequency radiation. He provided this interpretation of the May 31, 2011 classification by IARC of RFR as a Possible Human Carcinogen (a 2B classification). Baan says that the IARC RFR classification as a Possible Human Carcinogen applies to all types of RFR exposures including smart meters.

“So the classification 2B, possibly carcinogenic, holds for all types of radiation within the radiofrequency part of the electromagnetic spectrum, including the radiation emitted by base-station antennas, radio/TV towers, radar, Wi-Fi, smart meters, etc.”