A cohort study of bronchial carcinomas in workers producing chromate pigments.

A cohort study of the incidence of bronchial cancer in male workers in a small company producing chromate pigments is presented. Altogether 133 workers had been employed by the company from the time production was started in 1948 until the end of 1972. Workers with more than three years employment were included in the study, and three cases of bronchial carcinoma were found among the 24 workers who fulfilled this requirement. Based on the data of the Cancer Registry of Norway the risk of bronchial cancer for a corresponding group of the general population was found to be 0.079, which gives a risk ratio for exposed workers of approximately 38. The average age of the cancer patients was as low as 50 years at the time of diagnosis. All workers in the company had been exposed mainly to zinc chromate dust, and the exposure levels of the workers developing bronchial cancers had probably been from 0-5 to 1-5 mg Cr/m-3 for six to nine years. Two of the three patients were smokers. It is assumed that exposure to chromate pigments, and probably to zinc chromate, may be related to the increased incidence of bronchial cancer in this group of workers. The possibility of a contributing effect of tobacco smoking in at least two of the three cases cannot be ruled out.     

Mortality study among workers producing chromate pigments in France

In a follow-up study of 294 men who had worked for at least 6 months in a chromate-producing factory in France between 1958 and 1987, only 16 were lost to follow-up and the number of person-years in the study was 5207. Occupational data were provided by the administration of the plant. The causes of deaths were ascertained from hospital and general practitioners' records. The observed numbers of deaths were compared with the expected numbers based on local rates with adjustment for age, sex and calendar time (standardized mortality ratio, SMR). The overall mortality did not differ significantly from that expected (SMR = 1.20, 95% CI = 0.98–1.47), whereas mortality due to lung cancer was in significant excess (SMR = 3.60, 95% CI = 2.13–5.68). Significantly higher lung cancer SMRs were found for workers whose duration of employment was more than 10 years. A non-significant excess was observed for all forms of digestive tract cancer (SMR = 1.30, 95% CI = 0.60–2.47). There were two cases of brain cancer when 0.24 was expected (SMR = 8.44, 95% CI = 1.02–30.49). No previous report has mentioned an association of brain cancer with chromate pigments; however, because of the small numbers involved, a chance excess should be considered.     

Texaco mortality study: III. A cohort study of producing and pipeline workers

While there have been numerous epidemiology studies of refinery workers, no studies have been done on producing and pipeline workers. This is a retrospective follow-up study of all persons who were employed for at least 6 months at a Texaco producing or pipeline location and who worked at some time during the period 1946-1980. Of the 11,098 white men in the cohort, 8,964 were alive, 1,886 were known to be dead, and the vital status of the remaining 248 as of December 31, 1980 was unknown. The standardized mortality ratio (SMR) of 63 for all causes was significantly low, on the basis of 2,976 expected deaths. Statistically significant deficits also were seen for all major causes of death. Mortality patterns were also examined for the major job categories in these departments. Similar patterns of mortality were seen, although there was a significant excess of thyroid cancer in those employed as pumper-gaugers. However, it was based on only four cases.     

Occurrence of lung cancer in workers producing chromium pigments.

The results of a follow-up study on the incidence of lung cancer in 133 workers producing zinc chromate pigments are presented. By the end of 1972 three cases of lung cancer had occurred in a sub-cohort of 24 workers who had been employed for over three years. The same group of workers has now been followed up to December 1980 and three further cases of lung cancer were found. The observed/expected ratio was 44 in this group, virtually the same as at the end of 1972. Five of the six patients smoked. Only one had been exposed to chromates other than zinc chromates.     

Lung cancer mortality among workers making lead chromate and zinc chromate pigments at three English factories.

Lung cancer mortality among 1152 men working at three English chromate pigment factories was studied from the 1930s or 1940s until 1981. Workers at factory C were exposed only to lead chromate and experienced normal mortality (Obs/Exp deaths 7/6.45). Workers at factories A and B were exposed to both lead and zinc chromate; mortality was normal among those who had only low exposure (O/E 7/6.95). For workers with high or medium exposure lung cancer mortality was significantly raised among men remaining at least a year after entering service at factory A during 1932-54 (O/E 21/9.45) and at factory B during 1948-67 (O/E 11/2.50). At factory A, 1933-46 entrants staying only 3-11 months were not affected (O/E 6/5.04) and 1955-63 entrants also appeared unaffected (O/E 2/2.00); working conditions there improved in 1955. The hazard at factories A and B affected workers who left after one year as well as those with longer service, and latent intervals were unusually short. The results indicate that moderate or heavy exposure to zinc chromate may give rise to a severe risk of developing lung cancer, but that exposure which is relatively mild or lasts less than a year may not constitute an effective risk. The results provide no indication that lead chromate induces lung cancer in man, even under conditions conducive to lead poisoning.     

Lung cancer mortality among workers making lead chromate and zinc chromate pigments at three English factories

Lung cancer mortality among 1152 men working at three English chromate pigment factories was studied from the 1930s or 1940s until 1981. Workers at factory C were exposed only to lead chromate and experienced normal mortality (Obs/Exp deaths 7/6.45). Workers at factories A and B were exposed to both lead and zinc chromate; mortality was normal among those who had only low exposure (O/E 7/6.95). For workers with high or medium exposure lung cancer mortality was significantly raised among men remaining at least a year after entering service at factory A during 1932-54 (O/E 21/9.45) and at factory B during 1948-67 (O/E 11/2.50). At factory A, 1933-46 entrants staying only 3-11 months were not affected (O/E 6/5.04) and 1955-63 entrants also appeared unaffected (O/E 2/2.00); working conditions there improved in 1955. The hazard at factories A and B affected workers who left after one year as well as those with longer service, and latent intervals were unusually short. The results indicate that moderate or heavy exposure to zinc chromate may give rise to a severe risk of developing lung cancer, but that exposure which is relatively mild or lasts less than a year may not constitute an effective risk. The results provide no indication that lead chromate induces lung cancer in man, even under conditions conducive to lead poisoning.     

铬盐生产工人维生素丙负荷试验的观察

本文对铬盐生产工人进行了维生素丙负荷试验观察。负荷试验结果显示,接铬组工人尿中维生素丙的排出量明显低于对照组;接铬组工人吸烟与否,尿中维生素丙排出量井无差异,而且均低于对照组。表明接铬工人维生素丙负荷后排出量少系与体内六价铬作用有关。对接铬工人给予多量的维生素丙,似可防护六价铬对机体的损害。     

A cohort mortality study of construction workers

This report presents a mortality study among the 17,344 members of the Construction Workers' Health Insurance Society of Mie Prefecture in Japan. The study period was between 1973 and 1993. During this period, 480 members died. Age-specific mortality rates of Mie Prefecture were used as comparison standards. Significantly elevated standardized mortality ratio (SMR) and proportionate mortality ratio (PMR) were observed for “accidents and adverse effects.” In addition, the PMRs of all cancers and “cancers of trachea, bronchus and lung” were also significantly elevated. The job classifications were reorganized into three groups, according to the frequency of asbestos exposure the workers experienced on the construction sites. The asbestos exposure was based on job classifications among 7,411 workers who had completed a self-administered survey questionnaire. In the frequent-exposure group, the PMR was significantly elevated for all cancers. In the medium-exposure group, the SMRs were significantly elevated for all cancers and “cancer of trachea, bronchus and lung.” The PMR was significantly elevated for “cancer of trachea, bronchus and lung.” In the less-exposure group, the PMR was significantly elevated for “accidents and adverse effects.” This study provided support for the hypothesis that working in the construction industry might be associated with high risks for asbestos-associated cancers and accidental deaths. Am. J. Ind. Med. 32:35-41, 1997. © 1997 Wiley-Liss, Inc.     

橡胶工人恶性肿瘤回顾性队列研究

本文对黄石市橡胶行业1971年1月1日至1973年12月31日在岗1223名工人进行恶性肿瘤回顾性队列研究表明,橡胶恶性肿瘤占死因首位,其全部肿瘤,男、女肿瘤死亡分别为112.03/10万、158.26/10万、62.49/10万,与对照组比较,标准化相对危险度(SRR)分别为2.50、2.62、2.27;与当地人群比较SMR分别为257、208、220,均有统计学意义。RSMR分析提示男性肝癌、胃癌、鼻咽癌,女性白血病、乳腺癌等多个部位肿瘤死亡增加。本研究还提示该行业恶性肿瘤高发可能与亚硝胺类、防老剂D、苯等有害因素的联合作用有关。     

A cohort mortality study of foundry workers

Since the 1970s, hygienic improvements have led to a reduction in the level of airborne pollutants in Danish foundries. This mortality study reflects the exposure situation prior to 1970, and the findings may be used as a baseline for future evaluations of the preventive impact of reduced exposure. Mortality data were derived from a historical cohort study in which 3,056 foundry workers were compared with 43,024 workers employed in other industries. The foundry workers' life-long risk of dying from pneumoconioses averaged 2% and the corresponding standardized mortality ratio (SMR) equaled 7,368 (95% confidence interval (95% CI): 4,029–12,363). Excess mortality was also seen for chronic bronchitis and emphysema (SMR = 132, 95% CI: 98–185). Nonsignificant increases were seen for buccal cancer, stomach cancer, colon cancer, and urothelial cancer. In conclusion, Danish foundry workers exposed prior to 1970 seem to suffer an excess risk of devastating lung disease of occupational origin. Am. J. Ind. Med. 32:223-233, 1997. © 1997 Wiley-Liss, Inc.     

A cohort study of graphite workers in Sri Lanka

A cohort of workers from a graphite mine in Sri Lanka was studiedin 1987, 1990 and 1993. Radiographic lesions were found in 8.5%,8.9% and 4.1% of the workers in these respective rounds. Whenworkers with radiographic lesions were clinically examined,a total of 18 cases of graphite pneumoconiosis and seven casesof active pulmonary tuberculosis were detected in the threerounds. The prevalence of both these diseases showed a declinein 1993 when compared to 1987. This favourable situation wasprobably the result of dust control measures introduced in themine after 1972. Five workers developed graphite pneumoconiosisin the course of the study. They had worked in the mine forart average of 22.6 years. The right lung appeared to be morevulnerable than the left.     

A cohort study on cancer incidence in offspring of male printing workers.

We used multistep register linkage to measure the occurrence of cancer in offspring of male members of the Oslo unions of printers. A file of their children was established through linkage with the Central Population Register. Children born 1950-1987 (N = 12,440) were traced for cancer during 1965-1987 in the Cancer Registry of Norway (193,406 person-years). We found 33 cases of cancer. The standardized incidence ratio was near expected for person-years after age 14 (25 cases observed) but lower than expected for person-years in the age group 0-14 years (eight cases observed, standardized incidence ratio 0.58, 95% confidence interval 0.25-1.14). This negative association was stronger when more precise criteria for time of exposure were applied, especially for children 0-14 years with fathers in categories exposed to lead 1 year before the child's birth. Methodologic problems with this approach are nondifferential exposure misclassification and the need for large data sets. The method could serve as an alternative to the case-control design in reproductive epidemiology.     

Long term mortality study of chromate pigment workers who suffered lead poisoning.

Long term mortality was studied in a group of 57 chromate pigment workers who suffered clinical lead poisoning, mostly between 1930 and 1945. One death was attributed to lead poisoning and there were significant excesses of deaths from nephritis (observed/expected 3/0.24) and cerebrovascular disease (9/2.20), as well as non-significant excesses for respiratory diseases (7/3.59) and accidents and violence (3/1.13). The deaths from nephritis followed long spells of service exceeding 10 years. Poisoning appeared to have more adverse long term effects on older workers: 15 men aged 40 or over at the time of acute poisoning experienced generally high mortality, and 30 years later or by the end of 1981 only two survived instead of the seven expected. The risk of cerebrovascular disease appeared to be unrelated to duration of exposure and affected even men employed for under one year. Excluding the 57 lead poisoned men, other contemporary workers at the factories showed no excess mortality from cerebrovascular disease.     

A prospective cohort study of chromium plating workers in Japan

A prospective cohort study was conducted in 415 small-scale chromeplating plants in Japan to examine the mortality of platers employed between 1970 and 1976. A group of 1,193 male metal platers was identified in 1976 and divided into a chromium plater subgroup (n = 626) and a nonchromium plater subgroup (n = 567). Both subgroups were followed from 1976 through December 1987. Among specific causes of death, only lung cancer was found to be significantly higher than expected for all platers (16 observed, 8.9 expected; SMR 179; 95% CI 102-290). This elevated SMR, however, was not statistically significant in either of the two plater subgroups. The SMR for lung cancer of the chromium plater subgroup was highest among those exposed for the shortest period and among those exposed in the most remote calendar years.     

A prospective cohort study of manipulative dexterity in vibration-exposed workers

Objectives

To investigate the relation between manipulative dexterity and vibration exposure, ergonomic risk factors, and upper limb disorders in a group of workers exposed to hand-transmitted vibration (HTV).

Methods

Manipulative dexterity was investigated on 115 HTV workers (82 forestry workers and 33 stone workers) and 64 control men over 1-year follow-up period. The Purdue pegboard method was used to test manipulative dexterity which was scored for the dominant hand, non-dominant hand, and both hands. Information about individual, work and health history was obtained by means of a standardised questionnaire. Vibration exposure was assessed in terms of tool vibration magnitudes, daily and total exposure duration, and cumulative vibration dose.

Results

On the cross-sectional investigation, Purdue pegboard scores were significantly lower in the HTV workers than in the controls (0.001 < P < 0.05). Over 1-year follow-up period, Purdue pegboard scores were found to be inversely related to age, smoking and use of vibratory tools (0.001 < P < 0.05). Moreover, deterioration of some measures of manipulative dexterity was significantly associated with sensorineural and vascular symptoms in the fingers of the HTV workers. Random-intercept linear regression analysis showed that Purdue pegboard scores decreased with the increase of vibration exposure. The reduction of assembly score (i.e. number of pins, collars, and washers assembled in a 60-s period) was significantly associated with the increase in vibration exposure and ergonomic stress (neck-upper arm posture, hand-intensive work, and total ergonomic score). Purdue pegboard scores tended to improve over the follow-up period in both the controls and the HTV workers, suggesting a possible learning effect over time.

Conclusion

The findings of this longitudinal study suggest an association between deterioration of manipulative dexterity and neurovascular symptoms in the fingers of HTV workers. There was evidence for a significant relation between loss of precise manipulation and exposures to hand-transmitted vibration and ergonomic risk factors.

     

1例铬酸盐制造业工人肺癌报告

目的探讨铬酸盐与肺癌的关系。方法对患者的职业史、工作场所职业病危害因素调查及临床资料进行综合分析。结果患者在生产金属铬过程中接触六价铬化合物10年后发生肺癌,并于患病18个月后死亡。工作场所中铬化合物浓度超过国家标准。结论长期反复接触六价铬化合物能引起肺癌,应减少作业工人六价铬化合物的接触机会。     

Leukaemia in benzene workers: a retrospective cohort study.

A retrospective cohort study was conducted in 233 benzene factories and 83 control factories in 12 cities in China. The benzene cohort and the control cohort consisted of 28,460 benzene exposed workers (178,556 person-years in 1972-81) and 28,257 control workers (199,201 person-years). Thirty cases of leukaemia (25 dead and 5 alive) were detected in the former and four cases (all dead) in the latter. The leukaemia mortality rate was 14/100,000 person-years in the benzene cohort and 2/100,000 person-years in the control cohort; the standardized mortality ratio was 5.74 (p less than 0.01 by U test). The average latency of benzene leukaemia was 11.4 years. Most (76.6%) cases of benzene leukaemia were of the acute type. The mortality due to benzene leukaemia was high in organic synthesis plants followed by painting and rubber synthesis industries. The concentration of benzene to which patients with a leukaemia were exposed ranged from 10 to 1000 mg/m3 (mostly from 50 to 500 mg/m3). Of the 25 cases of leukaemia, seven had a history of chronic benzene poisoning before the leukaemia developed.     

Mortality among workers from a plastics producing plant: a matched case-control study nested in a retrospective cohort study

Earlier proportional mortality studies of workers in a plastics producing plant in Massachusetts indicated excess mortality from certain digestive and genitourinary cancers. To more definitively examine mortality among these workers a retrospective cohort study was conducted for 2,490 male wage earners who worked at least one year during 1949-1966. Vital status was determined as of Dec. 31, 1976, for 99.7% of the cohort and death certificates were obtained for 98.0% of 603 observed deaths. Comparison with the local county white males revealed a slight excess in digestive system cancer (standard mortality ratio [SMR] = 101.8) and a statistically significant excess (p less than .05) in genitourinary cancer (SMR = 153.6). A relationship was suggested between cancer of the rectum, liver, and pancreas and both the duration and interval from onset of exposure. A secondary matched case-control study was conducted to determine if particular jobs or work areas were related to the excesses found in the primary study. This analysis did not support the hypothesis that digestive or genitourinary cancer was related to a general plant exposure or date of hire. Possible associations warranting continued surveillance were found between rectal cancer and cellulose nitrate production and between prostatic cancer and polystyrene processing. Digestive and genitourinary cancers other than rectal and prostate were not related to employment in any of 21 occupational exposure categories examined.