Letter: Beef: `meat products' may be infected, but only a few people wi ll ever get CJD

Sir: Professor Woodland's letter on Scrapie/BSE (23 March) states that "pasture remains infective for some years after [scrapie infected] sheep are removed."

This leads me to ponder why the disposal of BSE infected carcasses is permissible in landfill sites (not all are incinerated) which are not unknown for their production of polluted effluents?

Incidentally, how efficacious are the incinerators employed for carcass destruction and what competent authority spot checks them for their performance in completely destroying tissues, flesh and bones, so that only sterile ash remains? This stricture also applies to open pit burning, which cannot guarantee complete destruction.

A further complicating factor is that abattoir wastes can be spread on or in agricultural land (as "soil improvers"). This may be cheap waste disposal but where are the guarantees of environmental and biological safety from these procedures? Deregulation can be carried too far, and insecure disposal of any biologically active animal wastes or remains is the last thing we need.

Professor A Porteous

Professor of Environmental

Engineering

The Open University

Milton Keynes