Published in The Herald Sun (Melbourne), 28 July 2009

WHEN it comes to risks such as swine flu and nuclear accidents, we’re often no wiser than Forrest Gump. “Life is like a box of chocolates,” he said. “You never know what you’re gonna get.”

That’s bad enough, but what if your chocolate box contains a few inedible pieces? Does that mean you have to throw out the whole box?

It’s strange how bad we are at intuitively dealing with risks. Whether we panic or remain calm does not necessarily have anything to do with the actual probabilities involved.

Tasmania’s recent swine flu alert is a good example. Health Minister Lara Giddings has just warned that within the next few weeks 100,000 Tasmanians would catch the virus.

Of those who get sick, about 1000 will need hospital treatment and up to 40 will die, she told us. While this dire forecast made headlines, it failed to cause panic. So far there have been no queues at ports and airports of people desperate to escape from the island.

Maybe Tasmanians are just rationally weighing their survival chances, and indeed they are not too bad. Given a population of about half a million people, the average Tasmanian has a 99.992 per cent chance of surviving the flu season.

In other words, they are more likely to die in a road accident this year than to be killed by the virus.

While people instinctively showed the appropriate reaction to the new threat, in other areas of life our ability to deal with probabilities is less well developed.

How else would you explain that a few weeks ago half of Australia queued at newsagents to buy tickets for the $100 million Oz Lotto prize?

In their lottery daydreams, people who would never buy a swine flu protective mask were suddenly decorating new villas and pondering the colour of their new supercar.

Sadly, winning the $100 million jackpot was 3630 times less likely than dying of swine flu. Or having a car accident, falling from a ladder or being murdered. Not necessarily all of the above and in that order, of course.

The harm in playing the lottery against all odds is limited to a few dollars a ticket, but in other cases our inability to properly deal with risks can be costly.

Our attitude to nuclear power is a case in point. There’s widespread agreement that we should eventually move away from fossil fuels to other sources of energy.

Climate change may be one reason for this. Reducing our reliance on oil from countries such as Iran and Venezuela is perhaps an even better argument. Yet, in any case, there will be a huge energy gap that needs to be closed by an alternative.

Nuclear power is often mentioned as such an alternative, not least by mining companies such as Rio Tinto. They have urged Canberra to allow the use of nuclear power in Australia, but many people feel uneasy about it. Haven’t nuclear accidents demonstrated that it is too big a risk to take?

Perhaps a more rational look at the figures would put this risk into perspective. The West’s worst accident in nuclear power’s history happened at Three Mile Island in 1979 – and yet nobody was injured in this event.

A long-time study of its health effects concluded there was no evidence that radioactivity released in the accident had a major impact on the mortality of residents near the power plant.

The East’s worst accident in Chernobyl in 1986 was worse. Yet even this accident was not as apocalyptic as is often reported. The United Nations’ Chernobyl Forum estimates that 56 people died at the event.

Chernobyl was undoubtedly a tragedy, but every major plane crash produces higher fatalities. Road traffic, in comparison, is an even more dangerous killer. Yet nobody would abolish civil aviation or car transport.

Properly assessing the risks of nuclear power alone is not enough to decide whether we should opt for this technology. But without proper risk analysis we will not be able to make rational choices at all.

Whether you should throw out a whole box of chocolate because of a few inedible pieces ultimately depends on the size of the box.