Table 2 shows the proportion of respiratory symptoms reported by the rice mill workers and controls. A signifi-cantly greater proportion of the rice mill workers complained of phlegm (40.8 %), dyspnea (44.2 %), chest tightness (26.7 %), cough (21.7 %), and nose irritation(27.5 %).
Table 3 shows the proportion of respiratory symptoms reported by the rice mill workers by duration of employment. Respiratory symptoms were higher in workers with duration of employment longer than 20 years, when compared with the other two groups; whereas, workers with a work history ranging from 10 to 19 years in the industries appeared to be less symptomatic compared with the groups with work history10 years.