sábado, 11 de dezembro de 2010

OS PERIGOS DA RADIAÇÃO


Habitual destaque semanal para a crónica do físico Robert Park:

"EMF EXPOSURE: DOES WAVING OF THE TREES MAKE THE WIND BLOW?

Identifying the cause of disease is the first step in its treatment. Epidemiology, the branch of medicine concerned with causation, seeks to establish correlation between exposure to a possible cause and actual occurance of the disease. Data must be taken over a period of years to allow for latency; if no effect is seen, a longer latency period is assumed. Since there is no record of individual usage, people are asked to recall what they did years earlier. Exposure to electromagnetic fields (EMF) in modern society is ubiquitous, but with the exception of a few crackpots it was not thought to be a problem until 1989 when the New Yorker ran a series of hopelessly misinformed articles by Paul Brodeur linking EMF to cancer. The articles were turned into a series of books with lurid titles like Currents of Death. Brodeur had zero background in science but he managed to arouse the anti-science monster that had been in hiding since World War II. The media, trained to give both sides of the story, even if one side is the babbling of an idiot, was no help. It did not end until 1996 when the National Academy of Sciences, persuaded that the public would not accept an argument based on quantum mechanics, released a three-year study that found no effect of EMF on the human body. Almost overnight power lines stopped causing cancer. The anti-science monster had been chained, but it was still alive."

Robert Park

7 comentários:

Anónimo disse...

A ciência é útil e importante, mas a nossa intuição supera-a e mal de nós quando não for assim.

Anónimo disse...

A nossa intuição supera-a? É pá então voa sem avião construido com base nas leis da aerodinâmica. E deita fora o Galileu porque toda a gente vê sem a menor dúvida o movimento do Sol à volta da Terra, etc.

Anónimo disse...

Os curandeiros também se baseiam na intuição. E vão mais longe do que um Ressonância magnética o que prova que a intuição supera a ciência.

Anónimo disse...

Quando se fala de EMF fala-se de coisas tão diferentes como alhos e bugalhos, desde um equipamento de ressonância magnética a uma máquina de barbear... de um cabo de alta tensão a uma instalação eléctrica doméstica...

E quando se tenta reduzir os efeitos dos EMF sobre a saúde às neoplasias, está tudo dito sobre a boa fé ou a cultura, como se não existissem centenas de estudos sobre os efeitos neurológicos, hematológicos ou imunológicos...

Enfim...

Anónimo disse...

Estaremos perante uma conversa... surrealista?! JCN

ABS disse...

Caros, creio que deviam ter publicado a segunda parte do texto de Robert Park, sem o qual este pedaço dá a sensação de faltar qualquer coisa (e dá - foi por isso que resolvi ir espreitar o sítio). Deixo-a aqui, porque é importante e muito, muito actual. Se acharem que estou a infringir alguma regra de copyright sintam-se livres para apagar o comentário.
Armando Brito de Sá
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2. EPIDEMIOLOGY: FUNDAMENTAL LAWS OF NATURE TAKE PRECEDENCE.

With the abrupt emergence of cell-phone technology a decade ago, the anti- science monster talked its way out of bondage. Devra Davis, who is not quite a scientist, but has a PhD in something called Science Studies, has donned the mantle of Paul Brodeur to write Disconnect: The Truth About Cell Phone Radiation, What Industry Has Done to Hide It, and How to Protect Your Family. What's missing is what was missing from Paul Brodeur: the universe is governed by quantum physics. Einstein pointed out a century ago that electromagnetic radiation behaves like units of energy called photons equal to Planck's constant times the frequency. They don't cause any trouble unless their energy matches some natural excitation. There isn't much to excite until they reach the energy of molecular vibrations in the microwave region. This is the part of the spectrum used in cell phones, so in principle your cell phone might cook your goose, but it would take a very long time. At even higher frequencies you reach the red end of the visible spectrum, then yellow, green and finally blue. Not until you reach the extreme blue end of the visible spectrum is there a problem. At that energy, photons can eject photoelectrons, creating mutant strands of DNA that can become a cancer. This is the lowest energy at which an incident photon can induce cancer. Photons of this energy are about a million times more energetic than a microwave photon, but cannot penetrate very deeply and therefore induce only skin cancers. However, in the last few days there have been reports that children exposed to cell phones radiation while in the womb have an increased risk of behavior problems several years after birth. At this point we can expect a wilder and wilder claims of effects from cell phone radiation. ------------

Anónimo disse...

Sim, sim. O que vale é que a ciência muda muitas vezes de opinião, algo tomado com bastante naturalidade - diga-se. É o que vale para limpar a face!!! Quem deseja ser cego, que seja, façam favor. Pretendo ser mais de que uma equação matemática.

Direitos e dever(es)

Texto gentilmente oferecido por Carlos Fernandes Maia, professor de Ética.   O tema dos direitos e deveres desperta uma série de interrogaçõ...