Dilemmas in conservation for applied biologists

Prevention of the use of DDT has been made the target of a powerful propaganda drive in certain prosperous countries because, it is stated, DDT is a danger to man and harms wild life. On the other hand, DDT is by far the most economical, effective and safe insecticide for many uses, particularly for protecting men from certain insect-borne diseases and for enabling cotton to be grown in poor countries. Some risks can be reduced by eliminating those uses of DDT for which adequately safe, economical and effective substitutes exist, whether chemical or not; other risks can be reduced in other ways. The known risks to men are trivial, except when DDT concentrate is deliberately drunk, and the scare is made up of unknown risks -which could equally exist with any object or material, new or old. Risks to wild life have been greatly exaggerated and scares depending on falsehoods have become current. The postulated threat of progressive accumulation of DDT along a long food chain is not adequately supported by evidence, much of which has been misinterpreted. Thus the main dilemma is how to balance the great and undoubted benefits of DDT to millions of men, women and children against harm to wild life, sometimes genuine and remediable and sometimes dubious. People who campaign for banning have possibly failed to recognize this dilemma. On the other hand, they may have made a deliberate choice in favour of wild life. In that case, to be logical, they should also oppose all other means of preventing premature death of other people, which they might justify as a means of postponing over-population. The use or abuse of DDT is a minor component in the rise of the worl's population.