The Oxford Science Lecture Series

DR MARION WOOLDRIDGE

Central Veterinary Laboratory

"From fear of flying to risky shift - approaches to risk in an uncertain world"

University Museum, Oxford, 19th October 2000

Risk can be defined as the possibility that human actions or events will result in at least one unwanted outcome. It therefore arises in situations where there is a degree of uncertainty about the end result. Like many other everyday concepts, risk is a term that is used loosely without reference to its scientific meaning, and it is widely assumed that it belongs to the domain of chance, probability and luck. But there are important differences. We do not undertake pursuits such as bungee jumping or parachuting on the recommendation that they are statistically 99.7% safe and leave matters to chance, because the consequences of bad luck resulting in the 0.3% probability that something goes wrong are too drastic. We want to evaluate meaningful assessments of what can go wrong, and ensure that every possible step has been taken to guard against failure of any kind at every point. Chance then enters only in a freak chain of events that could not have been foreseen because there was no previous experience of such events. An example of the latter is the disaster of the shuttle Challenger in January 1986; the failure of the O-rings to seal as designed at low temperatures was not a calculable risk because such failures were not a perceived hazard.

Nowadays, as perhaps never before, the public watches hawklike over what it interprets as preventable risks, whether in purchasing food, operating machinery, travelling, undergoing medical or cosmetic surgery ... and has developed a blame culture with high media involvement. People expect zero risk in matters where they do not have sole control and choice, but in a real world risk cannot be reduced to zero.

Because risk studies involve people, opinions and behaviour, risks contain both objective and subjective factors. The objective element, Assessed Risk, can be defined as the mathematical probability of a known hazard occurring. In the case of BSE, the risk of contaminated animal foodstuffs causing fatal human illness is the product of the risks of each definable step in the long connecting chain. But the subjective element, Perceived Risk, is a 'fickle factor' that does not stand up to scientific scrutiny and can be inflated or diminished according to the nature of the consequences and the degree of control involved. Perceived Risk is unreasonably high when it embraces phobias (e.g. fear of flying), or can be trivialized with increasing familiarity of a situation (e.g. in stunt flying). It is also established that groups behave more 'recklessly' than do individuals within the same group.

The effects of the consequences of an activity can unwittingly exercise control over Perceived Risk. Some degree of risk will be considered acceptable if the activity in question promises large benefits at low cost, but the precise balance of benefit and cost is itself highly subjective. There may be physical, emotional or social trade-offs, and the individual consciously or sub-consciously manipulates the level of risk accordingly. Whether this is self-delusion, cheating, or a vital mechanism for survival and progress is not clear, but what is more certain is that caution is not flung to the winds in cases of involuntary risk, for example of pollution or radiation. It is in such involuntary situations that the public expects zero risk as of right, and while that is not precisely achievable, risk management teams can carry out risk analyses to identify and quanitify the perceived hazards. Unfortunately it seems impossible to avoid attracting media attention too, and the rational scientific results are all too often submerged and distorted by a collective Perceived Risk.

It is essential to communicate the results of risk analyses in terms that are both intelligible to the non-specialist and totally faithful to the scientific facts. Complex explanations involving terms that mean little to the uninitiated can drive a wedge of suspicion between the risk scientists and the affected public, while genuine attempts to simplify the explanations can result in charges of clouding the truth, thereby increasing the Perceived Risk out of all proportion. Prejudice, societal pressures and personal agendas are not factors that are expected to bias scientific statements in the ascetic environment of the laboratory, but risk analysis clearly has a different set of conditions to contend with. Above all its workings must be transparent, and available for independent checking at all stages. Marion Wooldridge has these matters well under control as Head of Risk Research at the Central Veterinary Laboratory. And with a commercial pilot's licence newly under her belt she clearly believes that a helping of daily risks adds a refreshing spice to life.