[Effects of rush-mat dust on the health of exposed workers].

Objective: To evaluate the effect of exposure to rush-mat dust on the health of workers.

Methods: A cross sectional study of 661 workers (349 men, 312 women) from 35 rush-mat plants was carried out by using occupational health investigation, questionnare and physical examination.

Results: The geometric mean total dust concentration in the workshop was up to 20.00 mg/m3, and the geometric mean respirable dust concentration reached 8.22 mg/m3. The mean free SiO2 concentration of accumulated dust was 25.6%. The prevalence of radiographic small opacities profusion category > or = 1/0, according to the China Classification for pneumoconiosis (GB 5906-2000), and compared with the ILO 1980 system, was 2.57%. Even more, one man had category 2 pneumoconiosis with progressive massive fibrosis. However, the incidence of pneumoconiosis (1/0 at least) was correlated with work duration and dust concentration(r = 1.156, P < 0.001; r = 0.106, P = 0.006, respectively). Some positive correlations were found between the incidence of cough or expectoration and occupational exposure (r = 0.085, P = 0.028; r = 0.094, P = 0.016, respectively).

Conclusion: To our knowledge, this is the first report of rush pneumoconiosis in China. The results have offered the possibility of a dose-response relationship between rush-mat dust and pneumoconiosis. More investigation in this area is need.