Serum type III procollagen peptide (PIIIP), a degradation product of the type III collagen precursor, has been put forward as an exposure marker for mineral dust We evaluated PIIIP levels as a marker of exposure to and effects of coal dust in retired coal miners (n = 104) To this end: (a) the individual cumulative dust exposure was calculated from job-exposure matrices, and (b) in addition to routine chest radiography (CR) of all miners according to the criteria of the International Labour Organisation (ILO), a subgroup (n = 46) was screened by high-resolution computed tomography (HRCT) Profusion score (CR and HRCT) tended to increase with cumulative dust exposure, even in the absence of CR evidence for pneumoconiosis (i e CR < 0/1, N = 35) In contrast to our previous findings in active miners, PIIIP levels were not increased in miners as compared with non-dust-exposed controls (n = 29), and no differences were observed between miners without (ILO = 0/0) and miners with coal workers' pneumoconiosis (CWP; ILO > 0/1) No trend in PIIIP versus pneumoconiosis stage was present, either by CR or by the more sensitive HRCT score. PIIIP was also unrelated to any lung function parameter (FEV 1, FVC, impedance, diffusion capacity). Age, medication, medical history and smoking habits had no significant effect on PIIIP levels In the miners