Definition of occupational exposure
Occupational exposure was defined using differing but
comparable protocols among the studies. For BOLD and
PLATINO, occupational exposure was based on self-report of
exposure to ‘‘dusty work’’ for at least but not limited to 1 yr or
more at any point in time [3, 4]. For the ECRHS II analysis,
exposure was based on baseline interview (ECRHS I) selfreport
of ‘‘vapours, gas, dust or fumes’’ at the current or any
previous job and/or (at ECRHS II follow-up) any interval of
employment for at least but not limited to 3 months in an
occupation with a high likelihood of exposure to dust
(biological or inorganic), or gases or fumes based on a job
exposure matrix [6, 8]. Site- and sex-specific durations of
adverse working conditions were also analysed for each study,
as another measure of occupational exposure.