Tsai S P, Waddell L C, Gilstrap E L, Ransdell J D, Ross C E
Corporate Medical Department, Shell Oil Company, Houston, TX 77252-2463, USA.
Am J Ind Med. 1996 Jan;29(1):89-98. doi: 10.1002/(SICI)1097-0274(199601)29:1<89::AID-AJIM11>3.0.CO;2-W.
This paper reports the mortality experience from 1948 to 1989 of 2,504 maintenance employees who had a minimum of one year of employment in jobs with potential exposure to asbestos at a Texas refinery and petrochemical plant. For the purposes of this study, "potential exposure" is equated with those jobs or crafts having the greatest direct potential proximity to, or which worked directly with, asbestos-containing materials, especially asbestos-containing thermal insulation. Approximately one-half of the study population had 10 years or longer potential exposure, and 80% had their first potential exposure before 1970. The total population exhibited significantly lower mortality for all causes, the standardized mortality ratio (SMR = 77); and for all cancer (SMR = 85), as compared to residents in the surrounding communities. Statistically significant deficits in mortality were also observed in a number of noncancerous diseases such as heart disease (SMR = 78; 95% CI = 69-88), nonmalignant respiratory disease (SMR = 70; 95% CI = 50-95), and cirrhosis of the liver (SMR = 44; 95% CI = 22-79). Mortality among employees who had 20 years or longer since their first potential exposure was also examined; the pattern of mortality was similar to that exhibited by the total cohort, with a slight increase in the SMR for most of the causes. The only statistically significant excess of mortality found was a fourfold increase in mesothelioma (5 observed and 1.2 expected deaths) the SMR was 428 (95% CI = 139-996) for the total cohort and was 469 (95% CI = 152-1093) for those who had 20 years or more since first potential exposure. In contrast to asbestos industry worker studies, mortality for lung cancer was substantially lower than the general population (SMR = 81; 95% CI = 63-103). The observed number of deaths for cancer of the larynx was virtually the same as expected (3 observed vs. 2.8 expected). This study also showed decreased mortality for cancers of gastrointestinal organs such as the esophagus (SMR = 78), stomach (SMR = 63), large intestine (SMR = 91), rectum (SMR = 55), or pancreas (SMR = 90)--cancers that have been reported to be elevated in studies of various industry workers directly exposed to asbestos.
本文报告了2504名维修员工1948年至1989年的死亡情况，这些员工在得克萨斯州一家炼油厂和石化厂中至少有一年从事可能接触石棉的工作。在本研究中，“可能接触”等同于那些与含石棉材料，尤其是含石棉隔热材料有最大直接潜在接触可能性或直接与之打交道的工作或工种。约一半的研究人群有10年或更长时间的潜在接触史，80%的人在1970年前首次有潜在接触。与周边社区居民相比，总体人群的全因死亡率显著较低（标准化死亡比[SMR]=77）；所有癌症的死亡率也较低（SMR=85）。在一些非癌症疾病中也观察到了统计学上显著的死亡率不足，如心脏病（SMR=78；95%置信区间=69 - 88）、非恶性呼吸道疾病（SMR=70；95%置信区间=50 - 95）和肝硬化（SMR=44；95%置信区间=22 - 79）。还对首次潜在接触后有20年或更长时间的员工的死亡率进行了检查；死亡率模式与整个队列相似，大多数病因的SMR略有上升。唯一在统计学上显著的死亡率过高情况是间皮瘤增加了四倍（观察到5例死亡，预期1.2例死亡），整个队列的SMR为428（95%置信区间=139 - 996），首次潜在接触后有20年或更长时间的员工的SMR为469（95%置信区间=152 - 1093）。与石棉行业工人的研究不同，肺癌死亡率显著低于一般人群（SMR=81；95%置信区间=63 - 103）。观察到的喉癌死亡人数与预期几乎相同（观察到3例，预期2.8例）。本研究还表明，食管（SMR=78）、胃（SMR=63）、大肠（SMR=91）、直肠（SMR=55）或胰腺（SMR=90）等胃肠道器官癌症的死亡率有所下降，而在直接接触石棉的各类行业工人研究中，这些癌症的死亡率据报道有所上升。
