The study of the characteristics and influencing factors of pneumoconiosis among workers exposed to dusts in an iron mine / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To analyze the prevalence characteristics and influence factors of pneumoconiosis of workers exposed to dusts in an iron mine, to provide the base of preventive measures for pneumoconiosis of iron mine.</p><p><b>METHODS</b>The subjects of cohort study were all workers exposed to dusts for at least one year registered in an iron mine during 1960 to 1974, and followed-up to the end in 2003. The cases with pneumoconiosis were diagnosed by the local diagnosis group of pneumoconiosis, according to the national diagnostic criteria of pneumoconiosis. The risk factors were analyzed with Cox risk model.</p><p><b>RESULTS</b>A total of 3647 miners were included in the cohort study and were followed up by 132 574.4 person years. There were 316 cases with pneumoconiosis, and the incidence of pneumoconiosis for a year was 0.24 per thousand. There were 274 cases (86.7%) with pneumoconiosis in workers exposed to dusts before 1960, the incidence of pneumoconiosis for a year was 0.40 per thousand, which was significantly higher than that (0.07 per thousand) of workers exposed to dusts after 1960. The average latency of pneumoconiosis was 26.0 +/- 7.3 years. The average durations of upgrade from stage 0(+) to I , I to II and II to III were 5.3 +/- 3.2, 6.6 +/- 5.2 and 11.3 +/- 5.0 years, respectively. However, 164 cases with pneumoconiosis were diagnosed after ceasing exposure to dusts for mean 8.3 years. The risk of pneumoconiosis in iron miners increased with exposure doses, and there was an obvious dose-effect relationship. The average cumulative exposure dose of cases with pneumoconiosis was 173.7 +/- 91.6 mg/m3 x y, which was significantly higher than that (112.1 +/- 64.8 mg/m3 x y) of workers without pneumoconiosis. Also the tuberculosis (HR = 5.9, P < 0.001) and smoking (HR = 1.7, P < 0.01) were the main risk factors.</p><p><b>CONCLUSION</b>There was an obvious dose-effect relationship between the cumulative exposure dose and pneumoconiosis incidence. Tuberculosis and smoking were the main risk factors influencing the pneumoconiosis incidence.</p>

Investigation on mental health of residents living in a mineral area in Hubei province / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the effect of mining operations on the mental health of residents living in a mining area in Hubei province.</p><p><b>METHODS</b>Villagers (n = 93) living in the mining area were compared with a control group of residents (n = 101) in mental health status, and knowledge of environment and health. The mental health status of villagers was assessed using the Symptom Checklist 90 (SCL-90), State-Trait Anxiety Inventory (STAI); The knowledge of environment and health was evaluated using a self-designed questionnaire. The urine and hair samples were collected from some subjects. The lead, cadmium, arsenic, copper and zinc contents were detected as well as the total protein, NAG, d-ALA in the urine.</p><p><b>RESULTS</b>The occurrence rate of lead, cadmium, arsenic exposure symptoms was significantly higher in the exposed group than in the control group. The urine cadmium, the hair cadmium, the hair arsenic and hair lead were significantly higher in the exposed group than in the control group (P < 0.05). The positive symptom detection rate of SCL-90 in the exposed group was 8.60% compared with 0.99% of the control group. For the SCL-90, the total scale, somatization, obsessive-compulsive, interpersonal sensitivity, depression, anxiety, hostility, paranoid ideation, psychoticism, other symptom in the exposed groups were significantly higher than those in the control group (P < 0.05), indicating the status of the psychological hygiene of the exposed group was worse than the control group. The total S-AI (anxiety) score and the sex-specific value in the exposed group were higher than the control group (P < 0.05, P < 0.01), which showed that the anxiety of the exposed group was more evident. The total T-AI score and the sex-specific value in women of the exposed group were significantly higher than the control group (P < 0.01), showing that the anxiety were more significant in the exposed group, especially the women of the exposed group.</p><p><b>CONCLUSION</b>The mental health status of the residents who living in a mining area is affected and they have a higher S-AI and T-AI scale than those living a non-mining area.</p>

Cohort mortality study of dust exposed miners in iron mine / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the main diseases jeopardizing the health of the iron miners and to explore the relationship between dust exposure and malignancies as well as other diseases.</p><p><b>METHODS</b>A retrospective study with a cohort of 7,469 workers employed between January 1, 1972 and December 31, 1974 in Daye Iron Ore Mine Co. in Hubei Province was conducted. Standardized mortality ratio (SMR) was calculated for the main causes of death using Chinese national mortality rates for reference.</p><p><b>RESULTS</b>All subjects were followed up through December 31, 2003 with an accumulation of 199, 108.0 person years. A total of 1,752 workers died. The cumulative mortality was 23.5%. The cancers, cerebrovascular diseases, non-malignant respiratory diseases and cardiovascular diseases were main diseases that threatened workers' life span. The SMR for all subjects was a little higher than expected based on the Chinese national mortality rates. The diseases causing the significantly higher death rate were the nasopharynx cancer, liver cancer, lung cancer, pneumoconiosis and accident with SMR 1.84, 1.51, 1.83, 14.94 and 1.25 respectively. Increased mortality was observed among dust-exposed workers in the cohort. The cumulative mortality from all causes such as stomach cancer, lung cancer, nonmalignant respiratory diseases, cardiovascular diseases and accident in dust exposed workers were significantly increased compared with those in non-exposure workers with RR 1.35, 1.83, 1.61, 2.27, 1.34 and 1.69 respectively.</p><p><b>CONCLUSION</b>The risk factors especially dust exposure affect the health and lifespan of the iron mine workers.</p>