单项选择题

Not long ago, it seemed that there would come a day quite soon when science would reveal that every food would be toxic and every practice lethal. Or, at any rate, that is how things appeared to many ordinary people.
The supposition was based on half-digested and partially understood scientific reports. As a code of belief it still has its disciples—only the other day I found myself sitting at dinner between women who, to hear them talk, seemed to imagine that every article in the supermarket was deadly. But I am pleased to report that, at long last, I detect the first signs that my fellow citizens are beginning to emerge from the gloomy depression in which it has been fashionable to hide for the past 20 years or so.
There are now a handful of daring souls who are prepared once again to eat the odd spoonful of strawberry’ jam and take the consequences. They have noticed, perhaps, that for all the talk about refined sugar, the strawberry jam, mortality rate is somewhat lower than they had previously been led to expect.
The loss of nerve, from which the ordinary person seems to be recovering, was caused by several factors. First, he was told by various professional watchdogs, public analysts and medical officers of health that it would be a good thing if he knew the contents of all the foods he bought. But when he saw the lists of ingredients dutifully printed on the sides of packets and bottles, he trembled and feared for his safety.
The second thing which once frightened the timid but which, I do believe, is now frightening them less, was the remarkable scientific advance which, all unremarked by the general public and its legislators, has been revolutionising analytical chemistry. What this galloping advance in analytical acuity means is that scientists can now isolate the tiniest amounts of harmful substances in foods which ,hitherto, have always been considered safe, or in some cases beneficial.
Now there are sophisticated tests which can detect poisons in the tiniest amount—not even enough to kill a mouse. Over the years the general public has been bombarded with half-correct newspaper reports of the increasing number of foods which detailed investigation has proved contain harmful substances in some degree. And so it came to pass that few foods could face the charge of toxicity with equanimity.
Gradually, I do believe, a still small voice has come to be heard amid the hubbub—the voice of common sense. Surprisingly, it was first heard in the United states. Prolonged tests on mice had shown that saccharin was—even to a minuscule degree—carcinogenic. A few years ago, such a finding would have led to public turmoil and the exclusion of all saccharin from the American scene. This time, however, there was a pause for reflection. If even a huge intake of saccharin could only be expected to give you cancer 70 or 80 years hence, did it really matter Or should one insist on the government protecting one from being poisoned, not merely during one’s lifetime, but after one’s death as well
Nitrosamines will undoubtedly posion you—if you take a poisonous dose. But when it was found recently that tiny traces can be detected in whisky, people kept their nerve and reckoned that, just as the minute amounts of gold which every schoolboy knows can be found in seawater do no one any good, so the picograms of nitrosamines did them no harm. I salute the dawn of common sense.
The author is optimistic that we are now beginning to realise that ______.