Objective: To explore the association between dust exposure and the incidence of hypertension in male coal miners. Methods: Using the method of retrospective cohort study,a hypertension cohort of colliery in Henan Province was established in January 2006. From 2006 to 2017,all the male coal miners in a colliery who were exposed to dust were selected into the exposure group including tunneling, mining,auxiliary and combining workers, and workers from administrative logistics departments who were not exposed to dust were selected into the control group. The eligible participants should satisfy following conditions: working more than one year, with clear and complete record of occupation change, and with complete archives and reliable diagnosis of occupational health surveillance. The exclusion criteria of participants were with hypertension at the baseline of study or with heart,liver,kidney diseases and malignant tumors. A total of 12 647 participants were enrolled in this study (11 663 in the exposure group and 984 in the control group). The follow-up period was from January 2006 to December 2017,with a total follow-up of 89 259.75 person-years. Questionnaires and physical measurements were used to collect general demographic characteristics, occupational exposure history and occupational health surveillance data of all participants. The Cox proportional hazards regression model was used to estimate the association between the dust exposure and the incidence of hypertension. Results: During the follow-up period, 2 549 new-onset hypertension patients were identified with an incidence density of hypertension about 2 855.71 per 100 000 person-years. The incidence density of hypertension was 2 967.58 per 100 000 person-years in the exposure group, and 1 643.85 per 100 000 person-years in the control group. The results of multivariate Cox proportional hazards regression model showed that after the adjustment of marriage, age, smoking, alcohol drinking and body mass index,the risk of hypertension was higher in the exposure group compared with the control group (HR=1.692, 95%CI: 1.410-2.032). Further analysis showed that compared with workers from administrative logistics departments,the risk of hypertension in tunneling,mining and auxiliary working was 1.629(1.345-1.973),1.677(1.374-2.046) and 1.782(1.475-2.151),respectively. Conclusion Dust exposure may increase the risk of hypertension in male coal miners.

Objective: To investigate the prevalence and influencing factors of lower respiratory tract disease. Methods: The health physical examination data of 4000 coal dust exposed workers who had physical examination in the Institute of Occupational Disease Prevention and Treatment in 2016 were collected and analyzed with SPSS 20.0 software. Results: Out of the 4000 coal workers, the Prevalence rate of pulmonary tuberculosis, chronic bronchitis, CWP were 1.00% (40/4000) , 0.63% (25/4000) , 0.43% (17/4000) . 17 coal workers suffered from coal workers. The prevalence of workers both exposed to silicon and coal dust was 1.15% (2/174) , which was higher than that of other the job type. The prevalence of CWP among age groups, length of service and occupational category were found significant difference (P<0.05) , raising with the increase of duration of dust exposure and age increasing (χ²_trend=17.171, 5.344, P<0.05) . The prevalence of emphysema and chronic bronchitis between different working years and different ages are all statistically significant (P<0.05) , increasing with duration of dust exposure (χ²_trend=9.906, 10.118, P<0.05) . Conclusion The prevalence rate of CWP is not high, and closely related with duration of dust exposure and dust species. The prevalence of lower respiratory tract disease is higher in the tunneling and mining workers and raising with the duration of dust exposure.