上海某冶炼厂铅接触工人肿瘤死亡的回顾性队列研究

目的 了解职业铅接触工人肿瘤死亡情况，探讨职业铅接触与肿瘤的关系。方法 1985年1月1日前在本厂工人1年以上，且1985年1月1日仍存活的男性工人共6971名组成全队列，其中3344名在铅接触车间工作的工人组成的亚队列为接触队列。随访从1985年1月1日至1997年12月31日。以上海市人口的肿瘤死亡率作为标准对照，计算标化死亡比（SMR）；以本厂非接触人群作内对照计算相对危险度（RR）；估计累计接触剂量进行剂量－反应关系分析。结果 全队列6971人共观察87576人年，接触队列3344人共观察41505人年。全队列中，肺癌的SMR（95％CI）为128．0（101．1－159．7）。1965年后入厂的工人肺癌的SMR为463．7（P＜0．01）。有铅接触工作史且工龄超过20年的工人鼻咽癌的SMR＝408．0（P＜0．01），肺癌的SMR＝156．6（P＜0．01）。肿瘤总计、恶性肿瘤总计、食管癌、胃癌、肝和胆道癌、肺癌和膀胱癌的RR（95％CI）分别为3．25（2．43－3．89）、3．28（2．54－4．32）、3．57（1．08－10．47）、2．93（1．15－4．87）、4．58（2．03－9．97）、8．58（4．82－15．11）、6．66（2．83－13．01）。将累计接触剂量分为高、中、低3个组，中、高组工人恶性肿瘤RR分别为1．62（P＜0．05）和1．70（P＜0．05），且有随累计接触剂量增加危险性升高的趋势。中、高组工人的肺癌RR分别为2．55（P＜0．05），和2．31（P＜0．05）。结论 工人肿瘤死亡危险性升高可能与铅接触有关，但还需要在控制其他职业有害因素接触和非职业性有害因素接触的情况下作进一步的研究。

Cancer mortality of workers exposed to lead:A retrospective cohort study in a smeltery

Objective　To determine the mortality of cancer and relative risk of long-term lead exposure workers and to study the relation between occupational lead exposure and cancer. Methods　A cohort study including 6 971 male workers employed for at least one year before Jan 1,1985 and still alive at this time,and a subcohort of 3 344 of them worked at lead-exposed workshop was conducted.The study was followed up from Jan 1,1985 to Dec 31,1997.Standardized mortality ratios(SMR) and relative risks(RR) were calculated.Cumulative exposure dose was used for a dose-response analysis. Results　For 6 971lead exposure workers,SMR and its 95%CI for lung cancer were 128.0(101.1～159.7).SMR for lung cancer was 463.7(P<0.01) among lead exposure workers employed after Jan 1,1965.SMR for nasopharyngeal cancer was 408.0(P<0.01),lung cancer 156.6(P<0.01),among workers with lead-exposed history and length of more than 20 years.RR and 95%CI for neoplasms(in total),malignant neoplasms(in total),oesophageal cancer,stomach cancer,liver and biliary tract cancer,lung cancer,bladder cancer were 3.25(2.43～3.89),3.28(2.54～4.32),3.57(1.08～10.47),2.93(1.15～4.87),4.58(2.03～9.97),8.58(4.82～15.11),6.66(2.83～13.01) respectively.RR for malignant neoplasms at medium (0.1～0.5 mg*m-3*a-1) and high(0.5～ mg*m-3*a-1) cumulative exposure doses were 1.62(P<0.05) and 1.70(P<0.05) respectively and there was an increasing trend of RR as the doses raised.RR for lung cancer at medium and high exposure doses were 2.55 (P<0.05) and 2.31(P<0.05) respectively. Conclusions　The increased death risks may relate to lead exposure.However,further study under controlling the harmful factors of other occupational exposure and non-occupational exposure is necessary.