HEAVY smoking by parents can increase the risk of lethal infections such as meningitis and blood poisoning in their young children, research has revealed. A study from the Communicable Disease Surveillance Centre, in London, found that children aged five and under who were exposed to smoke from more than 30 cigarettes a day were more than seven times as likely to suffer from meningococcal infection as children from non- smoking homes. The findings are published in Epidemiology and Infection.