Lung function and the duration of occupational exposure across the study population (in years).

Table 5: Lung function and the duration of occupational exposure across the study population (in years).

Duration of occupation across study population
Spirometry test	Percentage of predicted	< 5	5 to 10	11 to 15	> 15	Total	P-Value
FEV1	< 30%	0	0	1	8	9
	30-49%	1	2	14	41	58
	50-79%	14	20	19	16	64
	> 80%	100	48	30	6	184
	Total	115	70	64	71	320	0.001
FEV1/FVC	< 0.7	5	7	25	59	96
	> 0.7	110	63	39	12	224
	Total	115	70	64	71	320	0.001

*p < 0.05