Harry Kroto

With all advances come some small drawbacks, but that doesn't mean technologies shouldn't be developed at all

We are continually bombarded by emotive campaigns. You name it: for and against GM beans on organic toast, for and against homeopathic Viagra substitutes, for and against cloning gerbils - the list is endless. They are often propagated by groups with a poor understanding of the intrinsic scientific issues involved and the global problem. And all are complicated matters on which self-appointed experts foist poorly substantiated claims on an all-too-credulous public.

The most recent is over nanotechnology. A participant in last week's Today programme said that environmental groups were "getting very worried about it", and a recent Business Week article on nanotechnology carried the headline "Attack of the killer dust", together with an illustration showing a man wearing (surprise, surprise) a white coat, and holding (surprise, surprise) a test tube from which emanated a cloud consisting of self-replicating nano-piranhas (supposedly 1 billion times smaller than a real piranha).

When I was on a recent Start the Week to pontificate on nanotechnology, Andrew Marr, the BBC's political editor, called it the "eerie and disturbing world of the very small". I objected to this description afterwards, but he said he had to go to one or other extreme - that seems to sum up the media in a nutshell. Furthermore, one of my co-participants said he could do without technology (except possibly for medicine). I asked whether he really would have preferred to live in times when people worked 12 hours a day, seven days a week, merely to survive and he would not have been able to write his book. He replied yes. As I was scrambling about under the table, trying to find the jaw I'd just dropped, I missed the opportunity to suggest he put his money where his mouth was and elect to undergo open-heart surgery (if and when he needed it) without an anaesthetic.

Back to the Today programme expert who explained that nanotechnology "is at the level of atoms and moleculesI you can alter things atomically, you might be able to create new structures with new properties". This is an almost perfect definition of chemistry, which is what nanotechnology is.

Question: "What are the concerns?" Answer: "Environmentalists are worried that with great potential benefits come potential dangers." Cor blimey, guv, what's new? When man made the first bow and arrow, perhaps to kill deer for food, I doubt it took long before someone got killed.

There have been problems in the past and there are going to be problems in the future, and we must not underestimate what any powerful technology might lead to. One has to be realistic, however, and recognise that we have always balanced the advantages against the disadvantages. Furthermore, I am convinced that it is almost impossible to put any limits on the scientific discovery process. What's out there will, in time, be discovered, and if research is banned in one place, it is sure to be carried out in another. I cannot believe that genies can be kept in bottles indefinitely, especially if one does not know if there is a genie inside in the first place or what sort it is - as is, invariably, the case in the fundamental sciences.

Imagine what would have happened if in 1903 all future chemistry was banned because activists had foreseen the extraction of ricin by terrorists or accidents such as that in Bhopal. As a result, we would not have penicillin and millions would still be dying of syphilis. We would not have artificial fertilisers and billions more would be starving. We would not have had DDT and countless millions would have died of malaria. We would not have computer chips, washing-up bowls, surfboards, mobile phones, television, windsurfer sails, paints and so on. This is the context in which blanket campaigns against the development of any powerful technology must be considered.

I suspect that most would agree that the benefits to society of technology have, by and large, outweighed the disadvantages. Mistakes will be made in the future as they have in the past, but the challenge is to maintain this beneficial imbalance. Clearly, we are more likely to make wise judgements on the basis of good understanding rather than on ignorance. Our guardian agencies, such as Greenpeace, do us an injustice if they do not enlist the best expert advice. They must not accentuate the dangers without recognising the benefits, and this needs a good understanding of how science works. Equally, protagonists must not gloss over doubts about the dangers of new technologies. When we are intimately involved with emotive issues we must be careful, as trust should be inversely proportional to vested interest and thus the arguments that must be most carefully scrutinised are our own.

Sir Harry Kroto is professor of chemistry at Sussex University. He won the 1996 Nobel prize for chemistry.