Incidence of asthma by age and working time (n=1082) Age Asthma Allergic asthma Yarn Factory1 (n,%) Sewing company 2 (n,%) Total (n,%) p1, 2 Yarn Factory 1 (n,%) Sewing company 2 (n,%) Total (n,%) p1, 2 20 - 29 2 (2, 6) 6 (2, 8) 8 (2, 7) 0, 942 * 2 (2, 63 4 (1, 86) 6 (2, 06) 0, 684 * 30 - 39 14 (10, 4) 25 (7, 0) 39 (7, 9) 0, 211 13 (9, 63) 12 (3, 34) 25 (5, 06) 0, 004 40 - 49 9 (10, 6) 15 (12, 9) 24 (11, 9) 0, 613 4 (4, 70) 6 (5, 17) 10 (4, 98) 0, 881 * ≥ 50 7 (9, 9) 2 (11, 8) 9 (10, 2) 0, 816 * 3 (4, 23) 2 (11, 76) 5 (5, 68) 0, 228 * total 32 (8, 7) 48 (6, 7) 80 (7, 39) 0, 240 22 (5, 98) 24 (3, 36) 46 (4, 25) 0, 043 p-age group 0, 331 * 0, 008 * 0, 002 0, 247 * 0, 158 * 0, 260 Working time <10 years 11 (6, 7) 12 (3, 2) 23 (4, 2) 0, 057 9 (5, 52) 6 (1, 58) 15 (2, 76) 0, 010 10 - ≤ 20 8 (11, 3) 22 (8, 3) 30 (9, 0) 0, 442 7 (9, 86) 11 (4, 16) 18 (5, 37) 0, 059 >20 years 13 (9, 7) 14 (20, 0) 27 (13, 2) 0, 039 6 (4, 48) 7 (10, 0) 13 (6, 37) 0, 125 Total 32 48 80 22 24 46 p-working time 0, 463 <0, 001 <0, 001 0, 287 0, 001 0, 044 *) Fisher's Exact Test Comment: The highest incidence of asthma in 40 - 49 group, the lowest one in 20-29 group.