Table 7– Prevalence of chest radiograph findings by timing of exposure^#

	Subjects n	Males %	Smokers %	Play in piles %	FVC % pred mean±se	Profusion ≥1/0 %		Plaque %		DPT or CAO %
						No	Yes	No	Yes	No	Yes
Before 1976
25–40 yrs of age	571	42.2	35.5	51.1	107.25±0.56	99.8	0.2	97	2	99.6	0.3
41–50 yrs of age	582	43.8	47.6	43.5	103.82±0.59	99.1	0.2	94.8	4.8	99.1	0.9
51–60 yrs of age	642	41.1	54.7	29.3	100.92±0.66	97.2	0.3	86.8	12.1	98.7	0.8
61–90 yrs of age	777	42.3	57.3	16.3	94.62±0.72	92.5	1.3	78.8	18.3	93.2	4.9
All subjects	2572	42.4	49.6	33.4	101.08±0.34	96.8	0.5	88.4	10.1	97.4	1.9
After 1976
25–40 yrs of age	260	40.4	40.8	25	106.9±0.83	100	0	99.2	0.4	100	0
41–50 yrs of age	293	39.2	47.4	7.8	106.1±0.74	99.7	0	97.9	1.4	100	0
51–60 yrs of age	153	38.5	56.9	5.9	101.95±1.31	98	0	94.8	2.6	98.7	0.6
61–90 yrs of age	85	36.5	63.5	1.2	97.31±2.13	96.5	1.2	94.1	4.7	100	0
All subjects	791	39.2	48.8	12.4	104.61±0.53	99.1	0.1	97.3	1.6	99.7	0.1

FVC: forced vital capacity; % pred: % predicted; DPT: diffuse pleural thickening; CAO: costophrenic angle obliteration. ^#: excluding non-tremolite asbestos-exposed subjects, Grace workers and household contacts.