I am replying to Robin Spokes's letter about the cause of so many people having coughs and chest congestion (Oxford Mail, May 27).

I have suffered from hay fever for many years, mainly runny nose and eyes, but for the last two or three years, have also suffered tightness in the chest.

A colleague suffering from hay fever for the first time last year, was told by his GP that it is caused by the huge amount of fields of oilseed rape.

When I investigated, I realised that it is related to the mustard plant.

When you think what mustard gas did to soldiers' lungs in the First World War, it makes sense.

Apparently, it has been banned for animal food, but is all right for mere humans.

While out of the country for a week, I was fine, walking miles without getting breathless, but within a day or two of returning home, I was getting hay fever once more.

Linda King, Cowley, Oxford