«Afollow-up study oflungfunction among ex-asbestos workers with and withoutpleuralplaques». Back
ground: Pulmonaryfunction testing is widely accepted as an integraipari ofmedicai surveillance ofoccupational
lung diseases. There are several cross-sectional studies evaluating lungfunction among asbestos-exposed workers,
but onlyfew longitudine surveys bave been performed Objectives: To evaluate, over ameanfollow-up period of
3.7 (SD 1.8) years, the loss oflungfunction in agroup of103 workers with previous exposure to asbestos (mainly
ship building/repairing), according to thepresence or absence ofpleuralplaques at radiologica! examination. Methods:
Chest radiographic examination was used to ascertain the presence/absence ofpleuralplaques. Ifchest X-ray
films werepositiveforpleuralplaques, HRCT (High Resolution Computed Tomography) was used to exclude any
parenchymal disease. The assessment oflungfunction over time included repeated measurement of vital capacity
(VC),forced expiratory volume in one second (FEVJ and total lung capacity (TLC). Smoking was assessed in
terms ofpack-years. AGeneralized Estimating Equations (GEE) approach to repeated spirometrie measurement
was usedto investigate the relationship between the loss ofpulmonaryfunction and (i) presence/absence ofpleural
plaques, (ù) smoking status, and (Hi) work seniority in workplaces with exposure to asbestos. Results: In the exasbestos
workers, mean age at thefirst examination was 49 (SD 6) years and work seniority averaged 25 (SD 7)
years; 36% were non-smokers, 27% smoked <15pack-years, and 37% smoked >15pack-years. Thirty-six workers
showedpleuralplaques at radiological examination. Overall, 236 measurements of VC and FEVb and 234 determinations
ofTLC were available. Multivariate GEE approach to age- and height-adjusted spirometrie data
showed thatpleuralplaques were not associated with asignificant loss ofpulmonaryfunction during thefollowup.
When compared with non-smokers, heavy smokers (>15pack-years) showed on average asignificant loss ofVC
(-5.30/0, IC 95o/o: -9.4-1.2%), FEV, (-8.40/0, IC 95o/o: -13.2-^-3.5o/o), and TLC (-4.0%, IC 95%: -7.4-0.5%).
An occupational history ofprevious exposure to asbestos was significante associated with an 10-year decrease in VC
(-3.10/0, IC 95o/o: -5.9-O.30/0) andFEV, (-4.9% IC 95o/o: -8.3—1.5%). Conclusions: The results ofthisfollowup
study showed that smoking andprevious asbestos exposure were associated with amild, but statistically signifi
cant, loss oflungfunction. Radiologicaifindings ofpleuralplaques were not related to deterioration oflungfunction
over thefollow-up period.
