ÖйúAƬ

Knowing nothing about BSE, I find that I have to rely on the expertise of microbiologists such as Professor Lacey. I am puzzled, however, by his article, "Science has failed to deliver the facts" (THES, March 20). Why on earth does he think this worth drawing to our attention? The list of things on which science has failed to deliver the facts is pretty well endless.

Here are a few that may be answered at some point in the future but, as far as I am aware, have not been yet: are carbon dioxide emissions causing global warming? what is an effective cure for male pattern baldness? is there a threshold effect of radiation on human health? does beta carotene cause lung cancer? is there a memory property of water? will the earth be hit by a meteorite in the next 100 years? can you catch BSE from a comet? are breast implants safe? As regards implants, the studies that have been performed turn up an embarrassing lack of evidence of any excess risk with monotonous regularity, but this does not prevent society ignoring science and transferring billions of dollars to lawyers and their clients from manufacturers, who as a result have now learned the other meaning of bust.

In fact, it seems to be more or less a condition of scientific advance that for every question answered, a good few more are raised. In this way our ignorance increases more rapidly than our knowledge, and we scientists can say thank goodness for that.

Is Professor Lacey perhaps claiming that another approach, not involving science, would do better? If so, I hope that he will tell us what it is in a follow-up article. Perhaps he is claiming that some scientists have been slacking and falling short on the annual quota of BSE facts to be delivered. In which case, to save the rest of us - physicists, chemists, geologists, and even medical statisticians - from being tarred with the same brush, please do not be coy. Name the guilty microbiologists.

Stephen Senn. Professor of pharmaceutical and health statistics. University College London