GABRIEL Millar (Letters, December 9) cites the sad case of Jenny Fry as if it was a fact that she was allergic to the Wi-Fi in her school.

She, and her mother, may have believed that was the case but no evidence has been produced to support the claim.

The symptoms (headaches, tiredness, nausea etc) are very generic and common to a wide range of conditions.

If it is correct as reported that she never consulted a doctor with her symptoms then who can say what the cause might have been.

All we can say is that no convincing evidence for EHS (electromagnetic hyper sensitivity) has been produced and that those who claim to suffer from it cannot when blind tested differentiate between the presence or absence of Wi-Fi.

Of course it is open to anyone to adopt an extreme precautionary principle if they choose, particularly when a viable alternative such as wired internet is readily available. But please don’t misstate the evidence.

If we must worry about invisible dangers why not choose radon instead? It is estimated to cause over 1,000 lung cancer deaths a year in the UK.

But it is a natural gas seeping from the rocks beneath our feet rather than a made made product and therefore it may not appeal to the technophobic tendencies of some.

Jim Watson

Selsley