The prevalence of allergic rhinitis caused by cotton dust followed age group Age group Yarn Factory1 Garment Company2 Total p1, 2 n% n% n% < 30 19 24, 7 20 9, 0 39 13, 0 <0, 001 30 - 39 33 24, 4 32 8, 9 65 13, 2 <0, 001 40 - 49 17 20, 0 20 17, 2 37 18, 4 0, 618 ≥ 50 12 16, 9 2 11, 8 14 15, 9 1, 000 * Total 81 22, 0 74 10, 4 155 14, 3 p 0, 559 0, 066 0, 277 *) Fisher's Exact test The prevalence of allergic rhinitis caused bycotton dust among workers in the age group under 30 years and group (30 - 39 years) in the yarn factory was higher in the garment company (p <0.05).