The quality of air outside and inside the home: associations with emotional and behavioural problem scores in early childhood.

<bold>Background: </bold>This study explored the role of outdoor air pollution [nitrogen dioxide (NO2) and sulphur dioxide (SO2)] and indoor air quality (measured with damp or condensation and secondhand smoke exposures) at age 9 months in emotional, conduct and hyperactivity problems at age 3 years.<bold>Method: </bold>Data from 11,625 Millennium Cohort Study children living in England and Wales were modelled using multilevel regression.<bold>Results: </bold>After adjusting for a host of confounders, having a damp or condensation problem at home was related to both emotional and conduct problems. Secondhand smoke exposure was associated with all three problem types. Associations with outdoor air pollution were less consistent.<bold>Conclusions: </bold>Exposures to damp or condensation and secondhand smoke in the home are likely to be risk factors for child emotional and behavioural problems. Parents should continue to be educated about the dangers of exposing their children to poor air quality at home. [ABSTRACT FROM AUTHOR]