Evaluation of infants' exposure to environmental tobacco smoke using salivary cotinine measurements

Many studies have elucidated the relationship between exposure to environmental tobacco smoke (ETS) and damage to health in children. The World Health Organization (WHO) (1999) performed a large-scale systematic review concerning the effects of exposure to ETS on infant health, and indicated that the risk of diseases of the lower respiratory tract increased 1.7 times in children with mothers who smoked, and was 1.3 times higher in children living with smoking fathers than in children not exposed to ETS. Furthermore, the risk of acute or chronic otorhinological diseases increased by 1.2%–1.4% in children living with two smoking parents compared to children living with non-smoking parents, and the risk of sudden infant death syndrome was five times greater in children whose mothers smoked than in children whose mothers did not. Furthermore, childhood exposure to ETS is associated with learning disabilities, behavioural problems, and speech disorders. DiFranza et al (2004) reported that living with two smoking parents increased the risk of paediatric asthma associated with exposure to ETS by 1.37%, and that exposure to ETS was associated with behavioural problems, cognitive impairment, and increased likelihood of smoking during adolescence. The WHO (2007) claims that ‘smoke-free policies protect health; where they are introduced, exposure to second-hand smoke falls and health improves’. Therefore, promoting smoke-free environments is essential to protect infant health.