STATES OF EMERGENCY - Patrick Lagadec

182 Technological crises and the actors involvedshould note that we often neglect the presence of PCBs themselves. Here, theanalyses performed a week later proved that there were large amounts.Certain writers have stated that the Villeurbanne experience should teachus to be less hasty in the future. That may well be true as far as thecontamination of the water table is concerned, but it's easy to say so after thefact. There are a lot less volunteers for Russian roulette than for the statelottery.P.L.: What do these two cases have in common?L. ABENHAIM: I chose these two examples because they illustrate the kindsof choices facing public health practitioners more and more today. We haveto make decisions in environments full of uncertainty. Worse yet, theproblems are posed in scientific terms (e.g. risks, toxic effects), but science isin fact unable to provide formal answers.There are more than 60,000 commercially available chemical compounds,and 1000 more hit the market each year. We have knowledge of the acuteeffects of some of them, but we only have epidemiological data on the longtermeffects of a few dozen, less than a hundred of them. It takes years tostudy a compound sufficiently and to understand its chronic effects on humanbeings.Animal experiments have been done and have revealed teratogenic orcarcinogenic effects, under conditions that are incomparable, in terms ofeither dosage or exposure, to the conditions encountered by human beings. Atthose levels, you almost always find some effect in animals. On the otherhand, some substances are carcinogenic for humans but not for animals.Should we wait for proof that a substance is dangerous for humans, orrather, in the absence of proof that it is innocuous, should we assume there isa hazard?For the public, we understandably have to take the fewest risks possible,but the dilemma lies in the fact that these decisions themselves are not neutralor risk-free. To cite the examples I've given, banning work on VDTs for allwomen of childbearing age would undoubtedly lead to unemploymentproblems, with non-negligeable consequences that can also affect health. Ifnothing else, declaring that working on computer terminals was dangerouswould lead to job-site discrimination, in an age when computers are evermore commonplace. In the same way, thousands of people cannot beevacuated without a certain amount of stress, and without re-entry problems.What's more, recent incidents in France have shown that large-scaleevacuations are very difficult to carry out.Often, populations are exposed to a hazard through an accident, or duringthe introduction of a new technological procedure. Under thesecircumstances, that means there is practically no scientific knowledge aboutthe conditions created by exposure. In other words, the expert's evaluation isbased on judgment and on an interpretation of the data, which necessarilyleaves a wide margin of uncertainty. The expert is called on to make noneother than an educated guess based on the information available.