Wallby T, Hjern A.
Uppsala Academic Hospital, Uppsala, Sweden.
Acta Paediatr 2008;97:1542–5.
Editor’s note: The present authors studied regional variations in the risk of second-hand smoke exposure for infants in Uppsala, Sweden. They obtained data from the Swedish Child Health Records and Swedish National Registers in order to investigate smoking patterns according to country of birth and socioeconomic status of the infants’ parents.