Table 1

 Participating studies: geographic units, period of data gathering, and number of children, aged 6–12 years, with information on age, sex, and parental smoking

StudyNumber of study areasData collectionNumber of childrenAge range (years)
CESAR, Central European Study on Air pollution and Respiratory health.
Austria, Linz Survey8 areas in 1 townJan 1996–Dec 199837766–8
Bulgaria, CESAR study4 areas in 3 townsFeb–May 199629737–11
Czech Republic, CESAR study4 areas in 1 townFeb–May 199629627–11
Germany, Bitterfeldt study3 areas in 3 townsAug 1992–Jul 199319726–12
Hungary, CESAR study5 areas in 5 townsFeb–May 199630317–11
Italy, Sidria study29 areas in 22 townsOct 1994–Mar 199590736–10
Holland, 24 school study24 areas in 19 townsApr 1997–Jul 199819137–12
North America, 24 city study24 areas in 24 townsSep–Nov in 1988–90148458–11
Poland, CESAR study4 areas in 4 townsFeb–May 199626437–11
Russia, 10-city study13 areas in 10 townsApr–May 199954128–12
Slovakia, CESAR study4 areas in 3 townsFeb–May 199625317–11
Switzerland, Scarpol study10 areas in 10 townsOct 1992–Mar 199327486–12
Total 132 areas in 105 towns53879