Ten to 14-year-old smokers are more likely to say they are doing badly at school than their clean-breathing peers, a new study says.

The Youth Smoking Survey of 19,000 students across Canada found that 28 per cent of smokers said they were lower-than-average students compared with 6 per cent of non-smokers.

The finding mirrors studies of adult smokers, says Dr Murray Kaiserman, who directed the research for Canada’s Tobacco Control programme.

“Adult smokers tend to come from a lower socio-economic stratum and are less well-educated. As well, drop-outs tend to have a higher percentage of smokers.”

Twelve per cent of smokers considered themselves to be better- than-average students compared with the 40 per cent of non-smokers who considered themselves about average.

The study also found that 40 per cent of smokers told researchers they almost never read for fun.

Smoking rates in this age group have dropped from 7 per cent in 1994 to 3 per cent, or a total of 54,000 young people.