Altogether these findings suggest that the FEV1 decline
associated with occupational exposure is likely caused by airway
disease. However, the possibility of occupational irritants being a
risk factor of emphysema has not previously been explored. Silica
and coal exposure was formerly linked with emphysema in
experimental studies and workforce cohorts of miners, including
autopsy studies [9–11]. Lifetime occupational exposure occurring
during the jobs most commonly done by COPD patients includes
inhalation of mineral and biological dusts and gases/fumes, but
the likelihood of these groups of agents producing emphysema has
not been analyzed.