review

The innocence didn't last long, relatively speaking - only a few decades at most. For that untroubled time radiation was a magic cure-all - used to remove unwanted hair (which it did, along with great clumps of the wanted kind), to fit our children's shoes, to irradiate healthful draughts of radium water, to energise enfeebled virility by means of radioactive jock-straps. You look now at these devices (shown off in Sunday night's Geiger Sweet Geiger Sour ) with a little thrill of horror; it's the sight of children playing happily at the edge of a cliff, unreachable and unwarnable.

Then came the fall, a 43-second silent drop from the belly of the Enola Gay to the instant of explosion, 1,900 ft above Hiroshima. Since then radiation stirs different thoughts in us - it is the silent killer, an insidious poison which only announces itself through malignancy and tumour, a pollution which hides in fresh green leaves and limpid water. Mendacity seems to be a side-effect too, thrown off as copiously as alpha particles. Wield a lie detector around the subject and that erratic tick soon crowds to a constant screech, triggered by the politic evasions, the fingers- crossed predictions of risk, the jerry-built justifications. "One wouldn't be responsible if one didn't know," said a scientist in Geiger Sweet Geiger Sour, uncomfortably responding to the accusation that terminally ill patients had been given experimental plutonium injections.

What would we do without the regret, though? It has become precious to us, as you can tell from the commemorative programmes clustered around the anniversary of the dropping of the atomic bomb. The event has become the hypocentre for a particular kind of plangent reverence (Latin, plangere, to beat the chest in grief), into which, you sense, all kinds of other melancholies have been compounded. Nagasaki Journey (BBC2) was a case in point, a beautifully crafted truism. It hardly needs saying, after all, that the bomb was a terrible object, or that it wrought terrible damage. But such programmes aren't intended to convert the belligerent or sober up the incorrigibly light-hearted. They are part of a ritualised act of memory and they unwind to their own mournful music.

Nagasaki Journey included moral lessons as clearly cut as pokerwork mottoes - "I found myself hating not just the war itself but all the parents who had not opposed it," recalled one survivor; "I think I wanted to be kinder to people. I didn't ever want to have to kill anyone again," said a GI, remembering a moment of shared communication with a Japanese father whose son-in-law was missing. Both remarks were repeated on the soundtrack, to drive them home to us as texts for contemplation, but though they may have counted as epiphanies in 1945, they have inevitably faded over the years, in the bright, uncontested light of Never Again. The real revelations were more incidental, a sharpness underfoot where you weren't quite expecting it. Sumiteru Taniguchi, who was 16 in 1945, was delivering mail when the bomb dropped. Despite terrible burns, he gathered together the scattered letters and placed them carefully beside his bicycle. It was a touching persistence of habit in the middle of catastrophe - a pre-lapsarian assumption that there would still be addresses to match the envelopes. Isuko Okubo, searching for her son at his medical college, entered a shattered room to find herself walking barefoot through incinerated skeletons - an extraordinary image of the living turned to dust. The footage of GIs docking in the city was remarkable too, a vision of vacancy where a city had been, but the result of the whole was strangely undisturbing. It will be interesting to see whether Tony Harrison's television poem, The Shadow of Hiroshima, screened on the anniversary this Sunday, can bring something new to the ceremony of regret.