Waarom kan ik een laptop maar beter niet als schootcomputer gebruiken?

maandag, 05 maart 2012 - Categorie: Veel gestelde vragen

Het antwoord leest u in onderstaande bijdrage van de meest gelezen gerenommeerde Amerikaanse arts Dr. Mercola, gepubliceerd op 5 maart 2012:

Warning: Why You Should Avoid Using Your Laptop as Recommended

Story at-a-glance

Use caution with any laptop use, especially if you’re a pregnant woman, and if you choose to use it on your lap, only do so with a lap pad or cushion that is about one foot thick
You may be able to lessen EMF exposure during laptop use by using an external keyboard (as even typing on your laptop may expose you to high EMFs) and only using it while it’s battery-powered, not while plugged in, as the power supply from a laptop induces strong electric current densities
Separate research has also shown that laptops may be harmful to sperm, with samples exposed to a wireless internet-connected laptop showing a significant decrease in sperm motility and an increase in sperm DNA fragmentation
Researchers concluded your lap is an “improper site” for use of a laptop computer, and suggested the devices be renamed so as not to “induce customers towards an improper use”
Electromagnetic fields (EMFs) produced by five commonly used laptops of different brands were found to be “considerably higher” than the values recommended by two recent guidelines for computer monitors magnetic field emissions
New research shows spending long hours with a laptop on your lap -- the use for which it is intended -- is likely harmful

Auteur: Dr. Mercola

Using your laptop computer on your lap is, paradoxically, not a safe way to use it.

Just as research is emerging showing that cell phones should not actually be held right next to your head (for instance, the iPhone manual states the phone must be at least 5/8 inch away from your body or ear for ''safe operation''), research is showing that spending long hours with a laptop on your lap -- the use for which it is intended -- is likely harmful.

Ironic, isn't it?

Researchers Warn Laptop Computers Should be Renamed to Protect Users' Health

New research published in the Archives of Environmental and Occupational Health evaluated five commonly used laptops of different brands.

After measuring the EMF exposure produced, researchers found EMF values were within the guidelines put forth by the International Commission on Non-Ionizing Radiation Protection (ICNIRP), but ''considerably higher than the values recommended by 2 recent guidelines for computer monitors magnetic field emissions, MPR II (Swedish Board for Technical Accreditation) and TCO (Swedish Confederation of Professional Employees), and those considered risky for tumor development.''

Further they noted that the EMF values became alarmingly high when the laptop was used close to the body:

''When close to the body, the laptop induces currents that are within 34.2% to 49.8% ICNIRP recommendations, but not negligible, to the adult's body and to the fetus (in pregnant women).

On the contrary, the power supply induces strong intracorporal electric current densities in the fetus and in the adult subject, which are respectively 182-263% and 71-483% higher than ICNIRP 98 basic restriction recommended to prevent adverse health effects.''

This led them to conclude:

''Laptop is paradoxically an improper site for the use of a LTC, which consequently should be renamed to not induce customers towards an improper use.''

Even Typing on a Laptop May Expose You to Unsafe Levels of EMFs

If you use your laptop on a desk, as opposed to your lap, does this mean you're safe? If you want to be sure your health is not at risk, not only should your laptop not be put on your lap, but you should not type on it either. As I explain below, I have used a gauss meter on many notebook computers, and found EMF levels higher than 100 milligauss on most of them; safe ranges are less than 0.3.

My Personal Experience with Laptops

I have used a 13-inch notebook for many years as I travel. It was a marvelous way to keep productive during my travels on a plane and as a passenger in a car. For some reason it never occurred to me to measure the EMF radiation coming from the device. Recently I used a gauss meter on my notebook computer, and on those of a number of my staff.

I was shocked to find that the EMF levels were off the chart on the device and most readings were higher than 100 milligauss. Safe ranges are less than 0.3. I do still use my notebook computer, but needless to say I have made some VERY serious adjustments to using it -- and I would strongly encourage you to do the same. Most of the radiation decreases about 2-3 inches away from the computer. So I have been using an external keyboard ever since I found out that the readings were so high. I never put the device on my lap unless there is a 1-foot cushion under the notebook, as that is about how far the field extends out.

If you don't believe me on this one I would strongly encourage you to get a gauss meter and measure your own notebook computer and see for yourself. Fortunately my favorite gadget, the iPad, measures within acceptable ranges so I continue to use that without an external keyboard.

However there are additional considerations on using a notebook computer, which I discuss below.

Why Your Reproductive Health May be Especially at Risk

If you're a man who uses a laptop often, and you would like to have children in the future, or simply protect your reproductive health, consider this a warning … In the first study to evaluate the direct impact of laptop use on human sperm, published in the journal Fertility and Sterility, those exposed to a wireless internet-connected laptop showed a significant decrease in sperm motility and an increase in sperm DNA fragmentation. And this was after just four hours of exposure. Researchers concluded:

''We speculate that keeping a laptop connected wirelessly to the internet on the lap near the testes may result in decreased male fertility.''

The culprit? Once again, it appears the electromagnetic radiation generated during use of wireless devices, similar to that generated during cell phone use, may have a devastating impact on your fertility.

Previous studies have found that laptop use may damage sperm through a thermal effect, that is, by heating up the scrotum during use (this occurred even when a lap pad was used, most likely because the mens' closed leg position, required to balance the laptop, also contributed to the heating effect).i However the current study found laptop use also leads to non-thermal adverse effects, which means even if you manage to avoid the heating effect, laptop use, on your lap, may still damage your fertility.

This is an area that deserves immediate and serious attention, considering use of wireless technologies is growing at an exponential rate. And it's not only laptops that are the problem … According to a study published in Fertility and Sterility in 2008,ii statistically significant changes were found in mens' sperm count and health of the sperm based on cell phone use, too. Their conclusion?

''Use of cell phones decreases the semen quality in men by decreasing the sperm count, motility, viability and normal morphology. The decrease in sperm parameters was dependent on the duration of daily exposure to cell phones, and independent of the initial semen quality.''

EMFs Well-Known to Cause DNA Damage

Dr. Martin Blank, PhD, of Columbia University and one of the most experienced researchers of the cellular and molecular effects of EMFs in the United States, gave an informative speech at the November 18, 2010 Commonwealth Club of California program, ''The Health Effects of Electromagnetic Fields,'' co-sponsored by ElectromagneticHealth.org.

Dr. Blank spoke with deep experience and commanding authority on the impact of EMFs on cells and DNA, and explained why your DNA, with its 'coil of coils' structure, is especially vulnerable to electromagnetic fields of all kinds. As described in the International Journal of Radiation Biology, DNA possesses the two structural characteristics of fractal antennas, electronic conduction and self-symmetry.iii

These properties contribute to greater reactivity of DNA to electromagnetic fields than other tissues, making the long-term consequences of repeated microwave exposures to our genetic material of great concern. Dr. Blank is adamant when he says that there IS evidence of harm, and that the harm can be significant. He also points out that the science showing harmful effects has been peer-reviewed, published, and that the results have been replicated, evaluated and ''judged by scientists capable of judging it.''

Even barring all the scientific evidence, it simply makes sense that laptops, cell phones and other wireless technology can impact the human body once you understand that your body is bioelectric. Your body contains electrons that keep an electrical current flowing, and inside every cell are mitochondria, the 'power plants' of the cell that respond to the body's natural electromagnetic fields.

As Dr. Maret explains in an interview with ElectromagneticHealth.org, your body is a complex communication system where cells, tissues, organs, and organisms ''talk'' -- it's a veritable ''electronic symphony in your body.''iv This communication includes finely tuned bio-electrical transmitters and receivers, which are tuned like tuning into a radio station. And when you expose a radio antenna to a significant amount of external noise, you get static, and that is what is happening to your body in today's EMF-saturated environment.

Why it May be Better to Use a Battery-Powered Laptop

Laptop computers are a high-energy source of both electric- and magnetic fields, so, as mentioned, avoid putting a laptop directly on your lap. You can block the thermal effects by using a lap pad if you also avoid sitting with your legs held closely together, and you can shield against the electric field by adding a reflective material or metal to it, but you cannot block the magnetic field component …

What's worse is that computer-charging devices are ungrounded, so ideally you'll only want to use a laptop when it's running on battery -- not when it's plugged into an outlet and charging. The same goes for iPads, Kindle's and even cell phones. Pregnant women should be especially careful using these types of technologies while plugged in. According to Vickie Warren, former executive director of the Bau-Biologie Group for the United States, the amount of EMF you're exposed to from a laptop that is plugged in compared to a laptop that is running on battery is about 100 times higher!

The current Archives of Environmental and Occupational Health study also suggested that the power supply from a laptop induces strong electric current densities in the fetus when the laptop is used at close contact with a woman's womb, so taken together the research suggests that both men and women should use due care when considering whether or not to use a laptop, especially in close proximity to their bodies.

However, my measurements show that the EMF coming from the device is still unacceptable even when it is plugged in, so, as I mentioned above, I would strongly encourage you to only use your notebook computer with an external keyboard.


i Fertility and Sterility November 8, 2010
ii Fertility and Sterility January 2008, Volume 89, Issue 1, Pages 124-128
iii International Journal of Radiation Biology April 2011, Vol. 87, No. 4 , Pages 409-415
iv ElectromagneticHealth.org October 4, 2011

Voor de originele publicatie zie:
articles.mercola.com/sites/articles/archive/2012/03/05/avoiding-emf-exposure-on-laptops.aspx?e_cid=20120305_DNL_art_2 .

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