Incidence of asthma following to the factories (n=1082) The factories Asthma Allergy asthma yes (n,%) no (n,%) p yes (n,%) no (n,%) p Yarn Factory (n=368) 32 (8, 7) 336 (91, 3) 0, 240 22 (5, 98) 346 (94, 0) 0, 043 Sewing company (n=714) 48 (6, 7) 666 (93, 3) 24 (3, 36) 690 (96, 6) Total (n=1082) 80 (7, 39) 1002 (92, 6) 46 4, 25) 1036 (95, 7) Comment: The rate of bronchial asthma in the Nam Dinh factory is 8.7%; The incidence in the garment company is 6.7% (p> 0.05).