Environmental tobacco smoke (ETS) has been shown to be carcinogenic for humans¹ and has emerged as an important public health problem in recent years.^2,3 In Southern European countries like Spain, this problem is especially relevant because of the high prevalence of smoking.⁴ Yet, unlike for active smoking, we have little objective data about the extent of ETS exposure in the general population. This study provides an updated estimate of the prevalence of exposure to major sources of ETS and analyses some relevant related factors in a representative sample of the general population in a South European urban context.

The population frame was the non-institutionalised population of the Spanish city of Barcelona in the year 2000 (1 600 000 inhabitants). Data were collected as part of the Barcelona Health Interview Survey 2000,⁵ a cross sectional survey carried out approximately every five years since 1983. We …