Lung cancer mortality among workers at a nuclear materials fabrication plant

BACKGROUND: The Oak Ridge, Tennessee Y-12 plant has operated as a nuclear materials fabrication plant since the 1940s. Given the work environment, and prior findings that lung cancer mortality was elevated among white male Y-12 workers relative to US white males, we investigated whether lung cancer mortality was associated with occupational radiation exposures. METHODS: A cohort of 3,864 workers hired between 1947 and 1974 who had been monitored for internal radiation exposure was identified. Vital status was ascertained through 1990. RESULTS: Over the study period 111 lung cancer deaths were observed. Cumulative external radiation dose under a 5-year lag assumption was positively associated with lung cancer mortality (0.54% increase in lung cancer mortality per 10 mSv, se=0.16, likelihood ratio test (LRT)=5.84, 1 degree of freedom [df]); cumulative internal radiation dose exhibited a highly-imprecise negative association with lung cancer mortality. DISCUSSION: The positive association between external radiation dose and lung cancer mortality was primarily due to exposure occurring in the period 5-14 years after exposure (0.97% increase in lung cancer mortality rate per 10 mSv, se=0.28, LRT=6.35, 1 df). The association between external radiation dose and lung cancer mortality was negative for exposures occurring at ages<35 years and positive for exposures occurring at ages 35-50 and 50+years. CONCLUSIONS: There is evidence of a positive association between cumulative external radiation dose and lung cancer mortality in this population. However, a causal interpretation of this association is constrained by the uncertainties in external and internal radiation dose estimates, the lack of information about exposures to other lung carcinogens, and the limited statistical power of the study.     

Seroprotection to vaccine‐preventable diseases among workers at a Victorian tertiary hospital

Objective : To determine seroprotection for the vaccine‐preventable diseases (VPDs) measles, mumps, rubella, varicella and hepatitis B among new employees seen at a Victorian tertiary hospital staff clinic. Methods : Employees who presented to the staff clinic for immunisation assessment between 1 January 2012 and 31 December 2013 were included. Demographic data, self‐reported disease history and previous vaccination status were reviewed retrospectively to determine impact on serological results. Results : A total of 1,901 new employees were included, 83% of whom were at risk of direct contact with blood or body substances. Overall, the proportion of workers seropositive to measles was 88%, mumps 90%, rubella 78%, varicella 93% and hepatitis B 80%. Staff born before 1966 were more likely to have positive measles or mumps serology but negative rubella or hepatitis B serology (p<0.05 for each). Staff who self‐reported measles (99% vs. 93%, p=0.03) or varicella infection (98% vs. 92%, p<0.001) were more likely to be seropositive, but those reporting previous vaccination to measles, mumps or rubella were no more likely to be seropositive. Conclusions and implications : This study demonstrated levels of seropositivity of 78–93% for the five VPDs. Despite recognised limitations of serological testing, 10–20% of new employees to a healthcare institution lacking seroprotection represents a potentially unacceptable risk of nosocomial transmission of these VPDs. Our findings support ongoing serological testing of new healthcare staff at risk of direct contact with blood or body substances.     

Clinical and immunological reactions to Aspergillus niger among workers at a biotechnology plant

The workforce at a biotechnology plant producing citric acid by fermentation of molasses with a strain of Aspergillus niger was studied. A combination of a respiratory questionnaire and clinical assessment identified 18 subjects (4.9% of the workforce) with work related bronchospasm. In nine of these evidence of sensitisation to A niger was obtained by skin prick tests and radioallergosorbent test (RAST) using as an antigen an extract of the A niger culture fluid from the process. Of the 325 subjects without work related bronchospasm, only nine (2.7%) had a positive prick test. There were no subjects with symptoms of extrinsic allergic alveolitis. Investigation into the source of the antigen showed that whereas, in some areas of the plant, A niger spores were present, in others there were no detectable spores. In these areas, however, extracts of filters from air samplers were shown by RAST inhibition to contain A niger antigens, indicating that the culture fluid was generating airborne antigen. RAST inhibition studies showed that the A niger culture fluid used in the process contained antigens that were not present in a commercially available A niger extract, thus emphasising the importance in this type of investigation of using antigens prepared from material to which the workers are exposed.     

Radiation doses and cause-specific mortality among workers at a nuclear materials fabrication plant

A historical cohort mortality study was conducted among 6,781 white male employees from a nuclear weapons materials fabrication plant for the years 1947-1979. Exposures of greatest concern are alpha and gamma radiation emanating primarily from insoluble uranium compounds. Among monitored workers, the mean cumulative alpha radiation dose to the lung was 8.21 rem, and the mean cumulative external whole body penetrating dose from gamma radiation was 0.96 rem. Relative to US white males, the cohort experienced mortality deficits from all causes combined, cardiovascular diseases, and from most site-specific cancers. Mortality excesses of lung and brain and central nervous system cancers were seen from comparisons with national and state rates. Dose-response trends were detected for lung cancer mortality with respect to cumulative alpha and gamma radiation, with the most pronounced trend occurring for gamma radiation among workers who received greater than or equal to 5 rem of alpha radiation. These trends diminished in magnitude when a 10-year latency assumption was applied. Under a zero-year latency assumption, the rate ratio for lung cancer mortality associated with joint exposure of greater than or equal to 5 versus less than 1 rem of both types of radiation is 4.60 (95% confidence limits (CL) 0.91, 23.35), while the corresponding result, assuming a 10-year latency, is 3.05 (95% CL 0.37, 24.83). While these rate ratios, which are based on three and one death, respectively, lack statistical precision, the observed dose-response trends indicate potential carcinogenic effects to the lung of relatively low-dose radiation. There are no dose-response trends for mortality from brain and central nervous system cancers.     

Carpal tunnel syndrome prevalence: an evaluation of workers at a raw poultry processing plant

Objectives: Evaluate the prevalence of carpal tunnel syndrome (CTS) among workers at a raw poultry processing plant and categorize jobs on the basis of hand activity and force.

Methods: A cross-sectional survey among 191 workers assessed CTS defined by self-reported CTS symptoms, a hand symptom diagram, and measurements of nerve conduction parameters. We categorized jobs based on American Conference of Governmental Industrial Hygienists’ (ACGIH®) limits for hand activity and force, and examined the relationships with CTS occurrence.

Results: A total of 64 workers (34%) had CTS after adjusting for non-occupational factors. Overall, 81% of jobs were above the ACGIH action limit; 59% were above the ACGIH threshold limit value®. CTS prevalence did not differ significantly between exposure groups (PR = 0.82, p = 0.35).

Conclusions: These findings suggest that poultry processing jobs continue to be hazardous with workers at risk for CTS. Recommendations for the study population were provided to reduce exposure and CTS risk among workers.     

Clinical and immunological reactions to Aspergillus niger among workers at a biotechnology plant.

The workforce at a biotechnology plant producing citric acid by fermentation of molasses with a strain of Aspergillus niger was studied. A combination of a respiratory questionnaire and clinical assessment identified 18 subjects (4.9% of the workforce) with work related bronchospasm. In nine of these evidence of sensitisation to A niger was obtained by skin prick tests and radioallergosorbent test (RAST) using as an antigen an extract of the A niger culture fluid from the process. Of the 325 subjects without work related bronchospasm, only nine (2.7%) had a positive prick test. There were no subjects with symptoms of extrinsic allergic alveolitis. Investigation into the source of the antigen showed that whereas, in some areas of the plant, A niger spores were present, in others there were no detectable spores. In these areas, however, extracts of filters from air samplers were shown by RAST inhibition to contain A niger antigens, indicating that the culture fluid was generating airborne antigen. RAST inhibition studies showed that the A niger culture fluid used in the process contained antigens that were not present in a commercially available A niger extract, thus emphasising the importance in this type of investigation of using antigens prepared from material to which the workers are exposed.     

Endemic work-related febrile respiratory illness among construction workers

Construction workers building Denver International Airport (DIA) reported work-related respiratory and flulike symptoms of several months duration. We performed a cross-sectional interview study of 495 randomly selected DIA workers from six contractors in comparison with preplacement workers. We defined cases as workers with two work-attributed lower respiratory symptoms and one work-attributed systemic symptom. Case rates were significantly higher among DIA workers (34%) compared with those who had never worked at DIA (2%). Risk factors for illness included exposure to fireproofing (OR, 4.21; 95% CI, 1.95–9.08), work in tunnels and adjoining areas (OR, 3.07; 95% CI, 1.84–5.12), length of DIA employment (OR, 0.65; 95% CI, 0.46–0.92), and preexisting bronchitis (OR, 2.43; 95% CI, 1.17–5.05). Our industrial hygiene investigation revealed alkaline dust (pH 11) present at a worksite associated with elevated risk of illness, and we identified airborne Penicillium mold widely distributed indoors at DIA. Clinical evaluation of 26 self-identified symptomatic DIA employees, including bronchoalveolar lavage and biopsy in 10, revealed work-related asthma in three workers and histologic evidence of chronic bronehitis in four who had never smoked. We concluded that future investigations of endemic work-related febrile respiratory illness among construction workers should evaluate its association with indoor exposure to dusts from alkaline fireproofing, Penicillium mold, mycotoxins, and bacterial bioaerosols.     

Cancer mortality among workers in a thermoelectric power plant

At a thermoelectric power plant in Turbigo (Milan, Italy), an analysis of the technological process has shown the presence of exposure to several carcinogens: polycyclic aromatic hydrocarbons, asbestos, hydrazine, polychlorinated biphenyls, chromium, nickel, and beryllium. An epidemiologic study was carried out to quantify the effect of the detected exposures on the workers, and the cancer mortality of the cohort was compared with the corresponding rates from the closest town and with cancer register data from a nearby province. Excess mortality was found for workers with 10 or more years of employment; the median latency time was about 20 years.     

Mortality among workers at a butadiene facility

Several studies of styrene-butadiene rubber (SBR) workers have reported excess cancers at various sites; however, little could be concluded concerning specific etiologic agents because of the multiple exposures encountered by these groups. The current study examined cause-specific mortality in a cohort of 2,586 male workers employed for at least 6 months between 1943 and 1979 in a butadiene manufacturing plant that supplied butadiene to two SBR plants. Standardized mortality ratios were calculated using national (NSMR) and local (LSMR) comparison populations. The all-cause NSMR was 80 (p less than 0.05) and the all-cancer NSMR was 84; the corresponding LSMRs were 96 and 76 (p less than 0.05). No significant excesses were observed for any cause of death except lymphosarcoma and reticulum cell sarcoma (NSMR = 235). When the cohort was subdivided into routine, nonroutine, and low-exposure groups, the SMRs were consistently elevated for this cause of death in all three groups. However, direct comparisons between each of the two exposure groups and the low-exposure group were inconsistent. This suggests butadiene may not be responsible for the excess, but the association deserves close attention in future studies.     

Pancreatic cancer among workers processing synthetic resins

A nested case-control study was conducted to investigate whether an excess of pancreatic cancer, identified in a cohort mortality study with follow-up from 1946 through 1988. was associated with potential workplace exposures at a New Jersey plastics manufacturing and research and development facility. The study population included 28 male pancreatic cancer cases and 140 randomly selected controls, matched on year of birth and at risk (alive) at the time of the case death. Using plant work history records, department assignments for the two groups were compared according to duration and time since first assignment. Workers assigned to a work area that processed vinyl resins and polyethylene (PE) were shown to be at increased risk. Men assigned more than 16 years to this department had a significantly increased risk ratio of 7.15 (95% confidence intervals [CI]: 1.28–40.1). No excess was seen with shorter duration assignments. Seven of the nine cases began working in this area in the 1940s. Average latency was 32 years, and all but three cases worked 20 years or more in this unit. Over the study period, significant exposure-related process changes occurred, in addition to the use of numerous chemical additives. Although vinyl and PE processing operations could not be analyzed separately, the pancreatic cancer excess is more likely to be related to vinyl processing. Identification of a causative agent or combination of agents would require investigations with more detailed exposure information.     

火山石加工人员尘肺病发病情况调查

目的 了解火山石加工行业尘肺病发病情况,分析火山石加工与尘肺病发病关系,为制定火山石加工行业尘肺病防控策略提供依据。 方法 对腾冲县所有工商注册登记石材加工户开展火山石加工作业场所的流行病学调查,对接尘劳动者进行职业健康检查,对加工场所空气中粉尘浓度及游离二氧化硅含量进行测定,采用描述性流行病学方法对调查资料进行分析。 结果 共调查工商注册石材加工户228户,生产工人958名,粉尘作业场所游离二氧化硅含量1.14%~7.67%;石材切割岗位4个点空气中粉尘时间加权平均浓度0.01~3.10 mg/m3,平均浓度0.80 mg/m3。完成职业健康体检209户,857人,体检率89.5%,其中男性占85.65%(734/857),女性占14.35%(123/857);年龄最大74岁,最小16岁,平均37.8岁;从事石材加工最长31年,最短7 d,平均4.46年;检出尘肺壹期2人,患病率0.23%(2/857)。 结论 长期接触火山石粉尘可引发尘肺病,应加强石材加工人员尘肺病的防控。     

Causes of death among workers in a bearing manufacturing plant

Recent studies identify digestive cancer excesses among workers exposed to cutting fluids, abrasive dusts, and oil smoke. Standardized proportional mortality and mortality odds ratio studies were carried out for a ball bearing plant. Cause of death and work histories were obtained for 702 of 768 hourly employees with ten or more years' service who died between 1969 and 1982. Union and company records were used to define exposure measures. The major findings were significant excesses in proportional mortality ratios (PMR) from stomach cancer (PMR = 2.0) and rectal cancer (PMR = 3.1) among white men. After control for age at death, there was a significant association between stomach cancer and precision grinding exposures, consisting primarily of direct contact with water-based cutting fluids (usually emulsified oils) and their aerosols. Some straight oils and synthetic cutting fluids were used as well. The pattern of stomach cancer is consistent with previous findings and suggests an association with the soluble oil cutting fluids.     

Mortality patterns among workers in a US pharmaceutical production plant

PURPOSE: To examine mortality among workers in a pharmaceutical production plant and to address community concerns about 1980 to 1990 increases in local county cancer mortality rates. METHODS: Subjects were 1999 workers with some full-time employment during the period between 1970 and 1996. We identified deaths through the year 2000 and reconstructed exposures to nine chemical agents with available exposure measurements. Data analyses included standardized mortality ratios (SMRs) and time trends in local cancer mortality rates. RESULTS: We observed deficits in deaths from all causes combined, all cancers combined, and most cause of death categories examined. Male workers with potential plant exposure had excesses in deaths from all lymphatic-hematopoietic tissue cancers (LHTC), in particular non-Hodgkin's lymphoma (NHL), and respiratory system cancers (RSC) that were larger among long-term workers, but the pattern of findings suggested the excesses were probably not related to occupational factors at the plant. The increase in local county cancer mortality rates was simply the upward cycle of a periodic trend that peaked in 1990 and returned to 1980 levels in 2000. CONCLUSIONS: With the possible exceptions of LHTC, in particular NHL, and RSC, this study provided no evidence of elevated total or cause-specific cohort mortality risks. It does not appear that plant factors played a role in the 1980 to 1990 increases in local county cancer mortality rates.