USA: The Wall street Journal over het bomenonderzoek Alphen aan de Rijn. Uitglijder Kennisplatform.

In een uitgebreid artikel bericht The Wall Street Journal over het opzienbarende bomenonderzoek in Alphen aan de Rijn en Wageningen met quotes van believers en non-believers, gevolgd door een commentaar van Stopumts:

The Wall Street Journal 10 dec. 2010

Auteur: Carl Bialik

My print column this week examines recent reports of Wi-Fi networks’ ill effects on trees. These reports, based on some preliminary investigations in the Netherlands, overstate the evidence that trees have been harmed by the electromagnetic radiation from these signals.

There were really two separate reports. One was conducted by the Dutch municipality of Alphen aan den Rijn, of some troubling abnormalities in the city’s trees. The other, funded by the town, was a laboratory experiment pitting some trees exposed to Wi-Fi signals to others that weren’t. This study found some damage to the Wi-Fi-exposed trees, though the nature of that damage was different than the damage seen in the city’s trees.

Niek van ‘t Wout, who heads Alphen aan den Rijn’s green space, is the driving force behind these studies. His town examined 600 trees and found 70% had abnormalities — which led to articles world-wide claiming that 70% of urban trees are sick. Another investigation of the city’s trees found a lower, though still alarming, figure of 39%.

In an interview, van ‘t Wout applied the figure of 70% to all European urban trees. Asked if the prevalence in his hometown necessarily applies, he said, “If it’s even half that rate, then it’s absurd to neglect that.” It is unclear how dangerous these abnormalities are. Van ‘t Wout estimated 3% of trees in his city die each year, compared to 1% before he noticed protrusions on the trees, but he isn’t sure the protrusions are to blame nor whether the sick-looking trees are more likely to die than are others.

To some other researchers, photographs of the trees reveal growths seen on other trees with various environmental stresses. “I’m sure these folks are sincere in their concern for their trees and puzzled by what they see, but they show little reason to be credible sources of tree pathology information,” said Kevin T. Smith, a tree physiologist and pathologist for the U.S. Forest Service’s Northern Research Station.

When these sick trees emerged, van ‘t Wout was concerned. The tree damage’s repercussions are “aesthetical and financial” in addition to environmental, van ‘t Wout said. “We must know what is the problem here.”

He began reaching out to other cities, seeking examples of such damage elsewhere. He received emailed photographs from other cities in Europe. His checks of forests found no such tree damage. And, with help from local researchers, he ruled out some biological causes. So he turned his attention to the idea that wireless electromagnetic signals — from Wi-Fi, cellular networks and other sources — might be the culprit. He has long suspected that is the cause, even writing in a 2007 email to another researcher, “Personally I believe that EM fields is the cause. But we have to find scientific prove for this.”

“As we know, all living creatures are susceptible to energy,” van ‘t Wout wrote in an email this week. “We must think in an open mind about what is going on for the trees. As a tree you are condemned to the place were you grow. There is no other way for a tree than to adapt to his surroundings.”

This stance worries Ronald van der Graaf, a microbiologist and general secretary of the Dutch Knowledge Platform on Electromagnetic Fields, funded by the Dutch national government. “He could influence the results.” **

Van ‘t Wout said he hasn’t let this belief affect his inquiries. “I must” keep them separate, he said.

His town did fund an experiment seeking to investigate whether Wi-Fi signals might harm trees. The experiment used Wi-Fi routers not because these were suspected as the major culprits — cellphone network signals generally are stronger — but because experimenters aren’t allowed to use cellular network transmitters, and besides it is difficult to find an environment without any cellular wireless signal as a control. It also isn’t clear why trees would be suffering only recently, while cellphone networks have existed for decades.

The study’s preliminary results got picked up in a local gardening publication, then in the Dutch press, then world-wide, with some of the details embellished. “I saw things like ‘Wi-Fi killer,’ ‘trees are dead,’ and all sorts of strange things we have never talked about,” said André van Lammeren, lead author of the study and an associate professor of plant cell biology at Wageningen University, about an hour’s drive east of Alphen aan den Rijn.

“If you write something about Wi-Fi, it’s all over the news immediately, whether the study was good or bad,” said Lambert H. Lumey, an epidemiologist at Columbia University’s public-health school.

TNO, a Dutch think tank, had to issue a corrective to media reports that the group was involved in the research. “It is always difficult to correct online sources,” said Maarten Lörtzer, a spokesman for TNO. “They copy news from another site and are on to the next story, and god bless, and have a nice day.”

Some researchers who also have seen evidence of plant damage from wireless networks applauded the work. “This is pioneering and important work that needs to be extended further,” said Andrew Goldsworthy, a retired lecturer in biology at Imperial College London.

Volker Schorpp, a retired German physicist who is on the board of PULS-SCHLAG e.V., an association for the protection of humans, animals and plants from artificial electromagnetic fields, agreed. “For me it’s sure, there is no doubt, that plants are affected” by electromagnetic waves such as wireless signals, Schorpp said. “Industry knows this problem since 20 years or more, but they fight against it.” He has conducted his own research and also referenced other studies.

Biologist Alfonso Balmori pointed to several studies on the topic, including one this year of aspen seedlings.

The World Health Organization, however, sees little cause for alarm about wireless base stations.

Chris Guy, a systems engineer at the University of Reading in the U.K., is skeptical, because Wi-Fi signals are low-power, and fall off with the square of distance from the base. “It is so unlikely that Wi-Fi signals could affect trees in any way that it is highly probable that there is another explanation for what has happened here,” Guy wrote in an email. He added, “To have any meaning there would have to be a proper blind trial, with a control group. One group of trees exposed to radiatiFn and one not, with the observer unaware of which group was which. They would have to be sufficiently close to experience the same soil and weather conditions but far enough apart for the Wi-fi signals to be close to one but effectively zero at the other. Then we might start to believe the results.”

Other researchers also downplayed the Wi-Fi study’s results. “Replication is critically important in experiments,” said John Stufken, head of the department of statistics at the University of Georgia. “In this particular instance it would require the use of multiple chambers with wireless access points as well as multiple chambers without wireless access points.”

Francis Tuerlinckx, a statistician at the University of Leuven in Belgium, wrote in an email, “Given that (1) there is no written account (let alone a peer reviewed paper) and given that (2) the authors themselves have reservations, I would not pay any attention to the study. It seems much more interesting to find out why the news spread so rapidly, why people pay so much attention to it, etc.”

“I fully agree with everybody who is saying, this is not a final experiment,” van Lammeren said.

Van ‘t Wout would like to see other groups step up to fund follow-up studies. “It is now not a problem for the municipality of Alphen aan den Rijn,” he said. “it is a problem for the world. You could think, other governments will say, ‘Thank you municipality, but now we will look at it.’ “

Leest u het origineel met interessante hyperlinks, waaronder zelfs e-mail correspondentie tussen enkele wetenschappers op:
blogs.wsj.com/numbersguy/trees-and-wi-fi-may-co-exist-after-all-1018/ .

** Opm. Stopumts:

Het Kennisplatform voor Elektromagnetische Velden en Gezondheid blijkt zich op grond van de hier geciteerde uitlating zich niet bezig te houden met haar zogenaamde doel; ''Het Kennisplatform EMV bundelt kennis op het gebied van elektromagnetische velden met als doel wetenschappelijke informatie over het onderwerp te duiden en beschikbaar te maken''.

In bovenstaande berichtgeving van Carl Bialic in de Wall Street Journal eind 2010 beschuldigt het Kenniosplatform bij monde van haar secretaris de heer van der Graaf zonder een enkel bewijs dat. N. van't Wout uitkomsten van het onderzoek bij de Universiteit Wageningen zou hebben beïnvloed.

Een tweede overheidsinstantie, naast het antennebureau, die zich op een misleidende wijze uitlaat. Zij gaat hierbij zelfs zo ver dat zij beschuldigingen uit zonder dat zij hier ook maar een enkele aanwijzing voor heeft. Alles lijkt er op gericht om geen enkele discussie aan te hoeven gaan als het gaat om de effecten van elektromagnetische straling.

Zoals al eerder bekend is gemaakt vindt er momenteel een replica-onderzoek plaats over de effecten van EM op bomen, net zo als vorig jaar. De redactie van Stopumts is zeer benieuwd naar de uitkomsten van dit onderzoek.

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