Epidemiological study on passive smoking among Japanese infants and smoking behavior of their respective parents: a nationwide cross-sectional survey.

摘要

BACKGROUND: Passive smoking is a well-known health hazard for infants. This study was conducted to: (1) estimate the prevalence of passive smoking among Japanese infants and (2) clarify the prevalence of indoor smoking and associating factors among parents having infants. METHODS: Subjects were all 53,575 infants born throughout Japan on January 10-17, 2001 or July 10-17, 2001. When the infants reached 6 months of age, the questionnaires were mailed to the homes. Family members answered questions that included information about the current smoking behavior of the parents. RESULTS: A total of 44,562 questionnaires (83.2%) were analyzed. The prevalence of smoking among the mothers and the fathers were 17.1% and 63.5%. The percentages of mothers and fathers who smoked indoors were 12.1% and 36.2%. The percentage of households where mothers and/or fathers smoked indoors was 37.5%. Multivariate logistic analysis indicated that young age, having a spouse who was a smoker, infants having many siblings, the mother not breast-feeding, and lower annual incomes had significantly higher odds ratios for both the mother's and the father's indoor smoking. CONCLUSIONS: Passive smoking is common among Japanese infants. To protect Japanese infants from passive smoking, further public health measures must be taken.