Table 3

Prevalence of chronic respiratory and irritant symptoms (n (%)) in historical controls (HC) and male workers stratified by exposure to wood dust expressed in terms of the cumulative dust exposure index

Symptoms		HC n=200		Exposure (y.mg/m³)		p Value^3-150
Symptoms		HC n=200		0 n=13	⩽70 n=28	p Value^3-150		70–110 n=28	110–160 n=25	>160 n=33
Chronic bronchitis	3 (1.5)	1 (8)	1 (4)	0 (0)	1 (4)	2 (6)	—^3-151
Cough or phlegm	20 (10)	1 (8)	3 (10)	3 (10)	3 (12)	4 (12)	0.14
Bouts of bronchitis	—	0 (0)	2 (7)	0 (0)	1 (4)	1 (3)	—^3-151
Dyspnoea	33 (17)	0 (0)	4 (14)	1 (4)	5 (20)	1 (3)	—^3-151
Asthma	5 (2.5)	0 (0)	2 (7)	1 (4)	2 (8)	1 (3)	—^3-151
Red (burning) eyes	—	0 (0)	1 (4)	9 (32)	2 (8)	4 (12)	0.47
Runny nose	—	0 (0)	2 (7)	7 (25)	6 (24)	7 (21)	0.10
Sore throat	—	0 (0)	0 (0)	2 (8)	2 (8)	6 (18)	0.03
Dry cough	—	0 (0)	0 (0)	0 (0)	1 (4)	2 (6)	—^3-151

↵3-150 Logistic regression after adjustment for sex, age and smoking.
↵3-151 Small size of the samples precluded statistical analysis.