SOFIA Johnson (letters Jan 25) likens the cover up of risks associated with Agent Orange and the recent lead poisoning in Michigan with research into the alleged risks of Wi-Fi and mobile phones.

She could hardly be more wrong.

First the obvious difference – those cover ups were rapidly exposed when investigated (in about a year in the Michigan case) whereas in the case of Wi-Fi and mobile signals the overwhelming majority of studies have found no evidence of harm.

And most of those which did suggest a risk were too small or too poorly constructed to be significant. Which brings me to Olle Johansson.

Sofia is correct that the Karolinska Institute is a very fine institution, which is perhaps why it has dissociated itself from Johansson’s findings as have other researchers in the field.

The reason being his track record of exaggerated claims based on small and methodologically unsound studies.

Good for attracting funding but poor science.

His other claims have included that TV and FM signals are implicated in lung cancer and that mad cow disease might be caused by mobile phone use.

So I am not persuaded.

Let me unpick the magical thinking issue.

If someone decides, after considering the evidence accurately, that however small the risk might be they prefer not to use Wi-Fi or mobile phones then I certainly have no reason to object.

I might disagree but we make our own decisions.

If however someone grossly misrepresents the evidence, uses sophistry to undermine the very notion of evidence and yet upholds thoroughly disproven nonsense such as homeopathy, astrology and so on then I will continue to argue the point.

For that is magical thinking and more harmful than Wi-Fi is likely to be.

Jim Watson