Since 1987, the number of pupils with diseases of the digestive system has doubled; the number with kidney and urinary diseases has trebled; and the number with osteoporosis, flat feet and other limb problems has quadrupled.

In the same period the proportion of school-leavers with chronic illnesses has grown from 43.9 per cent to 75 to 80 per cent.

A health ministry report, which reveals conditions reminiscent of Victorian England, says the deterioration in children’s diets is a key factor. One in five Russian families lives below the poverty line; the number of children in care has leapt up to nearly 600,000; between 6 and 8 per cent of Russian schoolchildren are abnormally small - “the result of prolonged undernourishment”.

Dmitry Shilov, a ministry official, admitted that the health problems were a “national catastrophe”, but said that the government’s policy was to train ealth education specialists to degree standard and provide refresher courses for working teachers.

In recent months attention has focused on the health problems of final-year secondary pupils, who face tough competition for university places. The pressure on boys is intensified because a place on certain courses is the best means of avoiding army call-up.

These pupils have to spend 42 hours per week studying in the classroom, plus 12 hours’ homework and in many cases extra weekend lessons.

At a recent educationists’ conference Efim Rachevsky, director of a Moscow school, said city education authorities had issued a special instruction to cut the hours of final-year pupils.

Echoing many teachers, he said action was urgent to end a “catastrophe” of illness among final-year pupils, including alcoholism, drug dependency and nervous conditions.

The social trauma of the past decade has exacerbated the problems of sexually transmitted diseases and teenage pregnancy. One in 10 school-leavers in 1997 had illnesses of the reproductive system.