An analysis of the main causes of death in different industrial systems in Guangzhou

Abstract

OBJECTIVE: To study the main causes of death in workers from different industries in Guangzhou. METHODS: The industrial systems in Guangzhou were classified into six categories according to the Chinese Public Health Inspection Statistical Report. Baseline data on 79,547 workers, age > or = 35, were retrieved from individual health records under the Guangzhou Occupational Health Surveillance Record System established in 1989-1992. In this prospective cohort study, the workers' vital status and causes of death were followed up until 31 December 1998. Using SPSS 10.0, crude death rates were calculated and relative risks(RR) (95% CI) were estimated using Cox proportional-hazard models. RESULTS: (1) Among 79,547 workers were 49,355 men and 30,192 women, with mean age of (43.8 +/- 6.5) years, and 64% were aged 35-44. The mean age difference of workers in different industries was +/- 1 year. At baseline, 41% had been exposed to occupational hazards. Exposure was most prevalent in petroleum chemical industry(53.9%), followed by metallurgical industry, and the lowest exposure was in mechanical industry (30.2%). (2) The mean follow-up period was (8.0 +/- 1.3) years with 633,510 person-years. 1,577 workers had died with a total death rate of 248.9 per 100,000 person-years. The death rate in rubber industry was the highest, followed by metallurgical and petroleum chemical industries. Malignant neoplasms, vascular and respiratory diseases were most common, constituting 80.3% of all causes of death. (3) For all causes of death and the three main categories, the top three crude death rates were observed in rubber and petroleum chemical industries, and in the metallurgical industry except for vascular causes. The rubber industry had the highest crude death rate for all and vascular causes, and the metallurgical industry for malignant neoplasms and respiratory causes. (4) With the light industry as a reference (RR = 1.0), the metallurgical industry had the highest adjusted relative risks (RR) (95% CI) of 1.62(1.20-2.18) and 7.42(3.38-16.31) for malignant neoplasms and respiratory causes, respectively. The rubber industry had the highest RR of 1.69(1.40-2.04) for all causes. A significant RR of 2.03(1.43-2.88) for vascular causes was observed only in the rubber industry. CONCLUSIONS: The main causes of death varied from industry. Malignant neoplasms and respiratory diseases were the leading causes in metallurgical and petroleum chemical industries. In rubber industry, vascular and respiratory causes were most common. Preventive measures for disease control should be tailor-made for each industry.

目的 比較廣州市不同工業行業職工的主要死因。方法 將廣州市工業系統參照中國衛生監督統計報告表行業分類分為 6個行業 ,以 1989～ 1992年實施職業健康監護系統中建立的 795 4 7名年齡≥ 35歲的工廠職工個體健康檔案為基礎資料 ,按前瞻性隊列研究方法 ,隨訪至 1998年 12月 31日 ,登記隊列中職工的生存狀態和死亡原因 ,計算粗死亡率 ,用Cox比例風險模型計算RR及 95 %CI。結果 (1) 795 4 7名職工中 ,男 4 935 5人、女 30 192人 ,平均年齡 (43.8± 6 .5 )歲 ,6 4 %的職工年齡在 35～4 4歲 ,各行業職工年齡相近 ,相差± 1歲 ;4 1%的職工接觸職業有害因素 ,石化行業職業有害因素接觸率最高 (5 3.9% ) ,冶金行業次之 ,機械行業最低 (30 .2 % )。 (2 )截至 1998年 12月 31日 ,平均追蹤 (8.0±1.3)年 ,共 6 335 10人年 ;共有 15 77名職工死亡 ,總死亡率為 2 4 8.9/ 10萬人年 ,其中橡膠行業總死亡率最高 ,其次為冶金和石化行業 ,主要死因為惡性腫瘤、血管疾病和呼吸系統疾病 ,占總死亡人數的 80 .3%。(3)全死因和血管疾病的粗死亡率橡膠行業排第一位 ,惡性腫瘤和呼吸系統疾病粗死亡率則為冶金行業排第一位。 (4)調整各相關因素后 ,以輕工行業為對照(RR為1.0 ) ,發現冶金行業的惡性腫瘤和呼吸系統疾病的要死因為血管疾病, 其次是呼吸系統疾病;工業行業職工疾病的控制應有針對性。