Our popular societal images of children are usually dewy focuses of rosy tots finger-painting or frolicking in the playground. But if you walk down Grafton Street on a cold winter Saturday the image can be shattered by street-wise young entrepreneurs busking and begging in a business-like manner. For millions of children, especially in Africa, childhood is over as soon as they have the co-ordination to heft a brick.
The vexed question of child labour comes to the fore at an international conference starting today in the Norwegian capital, Oslo. People from all over the world will wrestle with the issue: why hundreds of millions of children aged between five and 14 are losing both childhood and hope of a fulfilled adulthood by being forced into a school of very hard knocks - work, in its most raw and physical form.
The four-day conference is sponsored by the United Nations Children's Fund and the International Labour Organisation, and hosted by the Norwegian government, in a similar fashion to the international congress on sexual exploitation of children held in Sweden in August 1996. There is a considerable overlap of the two issues, as getting children into the sex trade is often the easiest way for families at the bottom of society to make money.
The latest estimates are that more than 250 million children of what is considered school age are working full-time, instead of being educated, across the world. Although the prevalent image is of undernourished children labouring long hours in countries like Bangladesh and the Philippines, the International Confederation of Free Trades Unions has reported that more than 20,000 children are illegally employed - and in hazardous occupations - in the US. In this special and depressing category around 50 are killed and more than 100,000 injured in work-related accidents every year.
Children are doing such work as polishing gemstones, cutting ceramic tiles, making bricks and taking ropes down mines. The work is mostly repetitive, unskilled, sometimes requiring surprising strength and dexterity from small bodies. In the west we might generally associate reign-of-terror conditions of employment for defenceless children with Dickens's worst tales; but 127 years after the great Victorian storyteller's death millions of children are labouring in mines and factories in conditions even worse than he knew.
Another uncomfortable truth for the relatively well-off consumers of the EU and industrialised countries is that children who should be playing or in school have often contributed to the goods they buy, and their affordability. As close to home as Italy there are between 500,000 and 1.5 million children working, some of them gluing together the elegant and expensive shoes for which that country is famed.
The Oslo conference will assemble ministers of labour, education, social welfare, justice and development co-operation from 40 countries. Trade union representatives, leaders of employers' organisations, NGOs and UN agencies will all take part.
The International Labour Organisation has been pro-active in this area, and its convention No. 138 requires member-states to take "effective steps for the effective elimination of child labour". But there are few illusions about the social and economic pressures which put small children into the labour force.
The situation is worse for girls because girls are used for domestic service and prostitution. The plight of the girl-child working as a domestic servant can be particularly hard, say papers prepared for the Oslo meeting: "Young girls employed as domestic servants may well be among the most exploited children of all. They are sometimes obliged to work very long hours, deprived of family contact, schooling, leisure, emotional support and social interaction. They are also frequently subjected to beatings, insults and social abuse."
The problem is also widespread in Asia, although there has been a slowdown because of improved economic conditions - which however may be at risk because of the recent turbulence in currencies and investments in the region.
"The main lesson that can be learned [from the conference] is that child labour is not an insoluble problem," says Ms Maura Quinn, executive director of UNICEF Ireland. "With political will on the part of governments and the mobilisation of sufficient public support, much can be done to reduce the extent of child labour and the harm it does children."