RT Journal Article SR Electronic T1 The great indoors JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP 729 OP 730 DO 10.1136/thx.2004.024091 VO 59 IS 9 A1 B Brunekreef YR 2004 UL http://thorax.bmj.com/content/59/9/729.1.abstract AB