Prevalence and associated factors of passive smoking in Thai infants.

Background: Passive smoking or exposure to environmental tobacco smoke (ETS) is associated with an increased risk of several respiratory illnesses for infants.

Objective: To assess the prevalence and the associated factors of ETS exposure in Thai infants.

Methods: A cross-sectional survey based on interviews with parents of infants aged 1 year old, conducted during October 2001-August 2003, under the Prospective Cohort study of Thai Children.

Results: A total of 3256 parents (76.7% of eligible subjects) provided the required information. The prevalences of father or mother smoking in the same room as the infants were 35.1 and 0.3% respectively. Smoking in the presence of an infant was significantly associated with paternal age of 25-34 or more than 44 years, education at or less than secondary school, and a Muslim father.

Conclusions: The results suggest that ETS exposure is common in Thai infants and the main source of exposure is from a smoking father. This finding is different from other studies in Western countries where both the father and mother made substantial contributions to infant exposure to ETS. Interventions should be considered to reduce infant exposure to ETS.