Longitudinal changes in some respiratory parameters (FEV1 and VC) have been examined in a sample of cement workers (163 male subjects differently exposed to cement dusts); the subjects have been surveyed over a period of 10 years performing yearly spirometric tests (Vital capacity--VC and Forced Expiratory Volume in 1 second--FEV1 measurements). Three possible risk indicators have been considered: occupational exposure, smoking habit and age. 65.6% and 60.7% of the cases showed significant individual annual decreases of VC and FEV1 throughout the time of follow up. According to our results the occupational risk indicator has not significantly influenced the normal trend of decreases of the respiratory parameters; instead age brings about an increase of longitudinal changes of VC and smoke habit an increase of longitudinal changes of FEV1, (but only in the younger group, people less than forty years old). 16 subjects characterized by abnormal losses (more than 100 ml/year) have been selected as "VC-FEV1, losers".