Update of cancer incidence among workers at a copper/nickel smelter and nickel refinery

Objectives: To assess cancer risk among nickel-exposed workers. Methods: We updated cancer incidence among 1388 workers employed for at least 3 months at a copper/nickel smelter and nickel refinery in Harjavalta, Finland. There were 1155 workers exposed to nickel during the period 1960–1985 in the smelter (566 workers), repair shop (239 workers), or refinery (418 workers). Cancer incidence was followed through the files of the Finnish Cancer Registry up to 31 December 1995. For overall cancer and for a priori selected specific cancer types the ratio of observed to expected numbers of cases was computed as a standardized incidence ratio (SIR), controlled for age, gender, and calendar period and using the region-specific rates as a reference. Results: The overall cancer incidence among both nickel-exposed and unexposed subcohorts was at the expected level. A small increase in lung cancer incidence, which reached statistical significance among workers with a latency exceeding 20 years, was observed among the smelter workers exposed to insoluble nickel compounds. Among workers in the refinery, who were exposed primarily to nickel sulfate at levels below 0.5 mg/m³ as well as to low concentrations of other nickel compounds, there was an increased risk for nasal cancer (SIR 41.1, 95% CI 4.97–148), positively associated with latency and duration of employment, and an excess risk for stomach (SIR 4.98, 95% CI 1.62–11.6) and lung (SIR 2.61, 95% CI 0.96–5.67) cancers. Conclusions: Since elevated nasal and lung cancer risks were confined to the refinery, where the primary exposure was to nickel sulfate, it is likely that nickel sulfate is mainly responsible for the elevated respiratory cancer risk. We cannot rule out whether the excess stomach cancer risk is a chance finding, or related to the working environment. Received: 11 September 1997 / Accepted: 17 October 1997     

Polycyclic aromatic hydrocarbons (PAHs): a possible cause of lung cancer mortality among nickel/copper smelter and refinery workers.

A retrospective industrial hygiene investigation was undertaken to explain the cause of a statistically significant excess lung cancer mortality observed in a subset of a large cohort of nickel workers involved in mining, smelting, and refining of nickel and copper in Ontario. The focus of this paper is to demonstrate how an industrial hygiene follow-up assessment of an epidemiologic finding can help to identify a likely cause. Polycyclic aromatic hydrocarbons (PAHs) alone or in association with particulate and gaseous contaminants (e.g., SO2) were likely the causative agents of the excess lung cancer observed among the lead welders, cranemen, and arc furnace workers of the copper refinery.     

Cancer incidence among finnish rubber workers

Summary A follow-up study was carried out among workers in the processing and tire and tube fabrication departments of a Finnish rubber plant. A total of 1,331 workers were followed up for cancer through the files of the Finnish Cancer Registry from 1953 to 1976 (11,709 person years). The expected number of cancer cases was calculated on the basis of the age and sex-specific incidence rates for the urban population of the surrounding province. Twenty-one cancer cases were found against 18.9 expected (RR 1.1, 95% confidence interval 0.7–1.7). The risk of cancer of the digestive organs, respiratory organs, and urinary bladder was higher than expected, and the risk increased with the length of the follow-up time. However, the differences were not statistically significant.     

Cancer incidence and mortality among temporary maintenance workers in a refinery/petrochemical complex in Korea

Abstract

Background:

Petrochemical plant maintenance workers are exposed to various carcinogens such as benzene and metal fumes. In Korea, maintenance operations in petrochemical plants are typically performed by temporary employees hired as contract workers.

Objectives:

The purpose of this retrospective study was to evaluate cancer risk in temporary maintenance workers in a refinery/petrochemical complex in Korea.

Methods:

Subjects consisted of 14 698 male workers registered in a regional petrochemical plant maintenance workers union during 2002–2007. Cancer mortality and incidence were identified by linking with the nationwide death and cancer registries during 2002–2007 and 2002–2005, respectively. Standardized mortality ratios (SMRs) and standardized incidence ratios (SIRs) were calculated for each cancer.

Results:

Increased SMR 3·61 (six cases, 95% CI: 1·32–7·87) and SIR 3·18 (five cases, 95% CI: 1·03–7·42) were observed in oral and pharyngeal cancers.

Conclusion:

Our findings may suggest a potential association between oral and pharyngeal cancers and temporary maintenance jobs in the petrochemical industry. Future studies should include a longer follow-up period and a quantitative exposure assessment.     

Cancer incidence and mortality among temporary maintenance workers in a refinery/petrochemical complex in Korea

Background:

Petrochemical plant maintenance workers are exposed to various carcinogens such as benzene and metal fumes. In Korea, maintenance operations in petrochemical plants are typically performed by temporary employees hired as contract workers.

Objectives:

The purpose of this retrospective study was to evaluate cancer risk in temporary maintenance workers in a refinery/petrochemical complex in Korea.

Methods:

Subjects consisted of 14 698 male workers registered in a regional petrochemical plant maintenance workers union during 2002–2007. Cancer mortality and incidence were identified by linking with the nationwide death and cancer registries during 2002–2007 and 2002–2005, respectively. Standardized mortality ratios (SMRs) and standardized incidence ratios (SIRs) were calculated for each cancer.

Results:

Increased SMR 3.61 (six cases, 95% CI: 1.32–7.87) and SIR 3.18 (five cases, 95% CI: 1.03–7.42) were observed in oral and pharyngeal cancers.

Conclusion:

Our findings may suggest a potential association between oral and pharyngeal cancers and temporary maintenance jobs in the petrochemical industry. Future studies should include a longer follow-up period and a quantitative exposure assessment.     

Determination of nickel in lung specimens of thirty-nine autopsied nickel workers

Summary Lung specimens from 39 nickel refinery workers autopsied during the period from 1978 to 1984 were analyzed for nickel. Fifteen of the workers were employed in the Roasting and Smelting Department, where exposure to nickel was predominantly in the form of nickel-copper oxides, Ni₃S₂ and metallic dust. The remaining 24 men worked in the Electrolysis Department. Exposure in this group was considered to be mostly to the water-soluble compounds, NiSO₄ and NiCl₂, but also to a lesser degree to water-insoluble nickel compounds such as nickel-copper oxides and sulphides. The arithmetic mean ± SD for nickel concentration in lung tissues expressed in gg^–1 dry wt for the 39 workers was 150 ± 280. In the workers employed in the Roasting and Smelting Department, the average nickel concentration was 330 ± 380; for those who worked in the Electrolysis Department it was 34 ± 48. Lung tissue from 16 autopsied persons not connected with the refinery had an average nickel concentration of 0.76 ± 0.39. Statistical analysis based on log-normal distributions of the measured nickel concentrations allowed three major conclusions to be formulated: (1) nickel refinery workers exhibit elevated nickel levels in lung tissues at autopsy; (2) workers of the Electrolysis Department and the Roasting Smelting Department constitute distinct groups with respect to the accumulation of nickel in lung tissue; (3) workers who were diagnosed to have lung cancer had the same lung nickel concentrations at autopsy as those who died of other causes.     

Air sampling of nickel in a refinery

Air monitoring was conducted in a nickel base metal refinery to determine compliance with occupational exposure limits. The hypothesis stated that levels of airborne dust may pose a risk to worker health if compared to the relevant exposure limits. Exposure limits for nickel species are set for the inhalable nickel dust fraction. Personal air samples, representative of three selected areas were collected in the workers' breathing zones, using the Institute of Occupational Medicine (IOM) samplers. Real-time personal samples were collected randomly over a two-month period in three nickel production areas. Filter papers were treated gravimetrically and were analysed for soluble and insoluble nickel through inductive coupled plasma-mass spectrometry (ICP-MS). Measured concentrations were expressed as time weighted average exposure concentrations. Results were compared to South African occupational exposure limits (OELs) and to the threshold limit values (TLVs) set by the American Conference of Governmental Industrial Hygienists (ACGIH) to determine compliance. Statistical compliance was also determined using the National Institute for Occupational Safety and Health procedure as prescribed by South Africa's Hazardous Chemical Substances Regulations in 1995. In two of the areas it was found that exposure concentrations complied with the OELs. Some exposures exceeded the OEL values and most exposures exceeded the TLV values in the other area concerned. A comprehensive health risk assessment needs to be conducted to determine the cause of non-compliance.     

Airborne arsenic and urinary excretion of metabolites of inorganic arsenic among smelter workers

Summary The relationship between airborne concentrations of arsenic and the urinary excretion of inorganic arsenic metabolites (inorganic arsenic + methylarsonic acid + dimethylarsinic acid) have been studied among smelter workers exposed to arsenic trioxide. The urinary concentrations of arsenic metabolites were found to increase steadily during the first day of the working week (after 2–3 d off from work), whereafter they reached a steady state. The concentration in the late evening after a day of exposure was very similar to that in the early morning after. Both were well correlated to the total daily excretion. In the second part of the study, comprising 18 subjects, the first-void morning urine of each participant was collected for 2 to 3 d during the steady-state phase. Total concentration of arsenic in the breathing zones was measured by personal air samplers. Airborne arsenic (8-h values) varied between 1 and 194 g As/m³, and urinary arsenic between 16 and 328 g As/g creatinine. With the urinary arsenic concentrations (mean values of 2–3 d for each subject) plotted against the corresponding airborne arsenic concentrations, the best fit was obtained by a power curve with the equation y = 17 x x^0.56. However, four of the participants were found to excrete far more (105–260%) arsenic in the urine than possibly could have been inhaled, most likely due to oral intake of arsenic via contaminated hands, cigarettes or snuff. If these four were excluded, the best fit was obtained by a straight regression line with the slope 2.0 and the intercept 29 g As/g creatinine (coefficient of correlation 0.92; P < 0.001).     

Reference values for cobalt, copper, manganese, and nickel in urine among women of the general population in Japan

Objective: The present study was initiated to establish the reference levels of Co, Cu, Mn, and Ni in urine of women in the general Japanese population. Methods: Stored urine samples were subjected to the analysis. The samples were collected from 1,000 adult women all over Japan, who had no occupational exposure to these elements. Co, Cu, Mn, and Ni in urine were analyzed by graphite furnace atomic absorption spectrometry. The concentrations were distributed log-normally, and were presented in terms of geometric mean (GM) and geometric standard deviation, as observed or after correction for creatinine concentration or a specific gravity of urine of 1.016. Results: The GM values of observed levels (i.e., with no correction for urine density) and of the levels after correction for creatinine (cr) concentration (values in parenthesis) were 0.68 g/l (0.60 μg/g cr) for Co, 13.4 g/l (11.8 g/g cr) for Cu, 0.14 μg/l (0.12 g/g cr) for Mn and 2.1 g/l (1.8 g/g cr) for Ni. There was a life-long age-dependent increase in Cu. Mn levels reached the maximum at 60 to 69 years of ages. In contrast, age-dependency was not substantial in Co and Ni. Conclusions: Comparison with values reported in literatures for other areas showed that Co and Ni levels in urine of Japanese women are higher than, Cu level is comparable with, and Mn level is lower than others. The reasons for high Co and Ni levels deserve further study.     

Cancer mortality among printing plant workers.

A proportionate cancer mortality study was conducted among employees of the U.S. Government Printing Office. Although limited by small numbers, there was a significantly higher proportion of deaths from multiple myeloma, leukemia, Hodgkin's disease, and colon cancer. The excess deaths from myeloma were confined to white workers in the composing room, where lead is the major occupational exposure, while deaths from leukemia occurred primarily in bindery workers who may have had exposure to benzene. Despite methodologic limitations, these findings are consistent with other epidemiologic and experimental studies suggesting that printers are at higher risk for certain cancers.     

Cancer risk in oil refinery workers: a pooled mortality study in Italy

Background:Oil refinery workers are exposed to several well-established carcinogens and working in this type of industry has been classified by IARC as probable carcinogen to humans (Group 2A).Objectives:To examine the mortality experience of workers employed in four Italian oil refineries.Methods:The cohort included 5112 male workers ever employed between 1949 and 2011. The average follow-up period was 49 years. Standardized mortality ratios (SMR) and 95% Confidence Intervals (CI) were calculated using as reference age-gender-calendar specific regional rates. Analyses by duration of employment and latency were performed.Results:In the whole cohort, pleural cancer (6 deaths, SMR 1.59; 95% CI 0.71-3.53), brain cancer (14 deaths, SMR 1.47; 95% CI 0.87-2.49) and lymphatic leukemia (LL) (8 deaths, SMR 1.81; 95% CI 0.91-3.62) showed increased risks. All pleural cancers occurred after 10 years of latency and the highest risk was observed among workers with duration ≥20 years; the brain cancer excess was confined in the shortest duration and latency. The LL (and chronic lymphatic leukemia in particular) excess regarded workers with latency and duration longer than 20 years. Four deaths from acute myeloid leukemia (AML) were observed and all occurred after 20 years of latency (SMR 1.55, 95% CI 0.58-4.12); a two-fold-increased risk was observed in the longest duration. No increased risk for skin cancer has been observed in our study population.Conclusion:Our findings are consistent with recent evidence of an increased mortality from pleural and hematopoietic malignancies (AML and LL) among oil refinery workers. However, the lack of individual quantitative exposure data and the small number of observed events prevent the identification of the possible causal role of individual chemicals, including benzene, especially at the current very low exposure levels.Key words: Cohort study, cancer mortality, benzene, petrochemical industry, standardized mortality ratios     

某锡冶炼厂工人职业性接触性皮炎患病情况

目的分析某锡冶炼厂工人职业性接触性皮炎的患病情况,为职业性皮肤病防治提供科学依据。方法对在2001—2010年健康检查中发现的接触性皮炎患者作回顾性分析。结果锡冶炼作业工人职业性接触性皮炎发病率与空气中砷浓度为正相关关系(r=0.956 1,P0.01),空气中砷浓度越大,发病率越高,且主要发生在粗炼、精炼、电解车间,发病率分别为5.35%、5.63%、5.88%;平均发病年龄为32.5岁,平均发病工龄为13.5 a。结论改善劳动条件,降低车间内含砷粉尘浓度,是减少职业性接触性皮炎发病的根本措施。     

Cancer risk among workers at Danish companies using trichloroethylene: a cohort study

Trichloroethylene is an animal carcinogen with limited evidence of carcinogenicity in humans. Cancer incidence between 1968 and 1997 was evaluated in a cohort of 40,049 blue-collar workers in 347 Danish companies with documented trichloroethylene use. Standardized incidence ratios for total cancer were 1.1 (95% confidence interval (CI): 1.04, 1.12) in men and 1.2 (95% CI: 1.14, 1.33) in women. For non-Hodgkin's lymphoma and renal cell carcinoma, the overall standardized incidence ratios were 1.2 (95% CI: 1.0, 1.5) and 1.2 (95% CI: 0.9, 1.5), respectively; standardized incidence ratios increased with duration of employment, and elevated standardized incidence ratios were limited to workers first employed before 1980 for non-Hodgkin's lymphoma and before 1970 for renal cell carcinoma. The standardized incidence ratio for esophageal adenocarcinoma was 1.8 (95% CI: 1.2, 2.7); the standardized incidence ratio was higher in companies with the highest probability of trichloroethylene exposure. In a subcohort of 14,360 presumably highly exposed workers, the standardized incidence ratios for non-Hodgkin's lymphoma, renal cell carcinoma, and esophageal adenocarcinoma were 1.5 (95% CI: 1.2, 2.0), 1.4 (95% CI: 1.0, 1.8), and 1.7 (95% CI: 0.9, 2.9), respectively. The present results and those of previous studies suggest that occupational exposure to trichloroethylene at past higher levels may be associated with elevated risk for non-Hodgkin's lymphoma. Associations between trichloroethylene exposure and other cancers are less consistent.     

Cancer mortality risk among biology research workers in France: first results of two retrospective cohorts studies

OBJECTIVE: To investigate all-cause and cancer mortality of biological research laboratories workers of the French Atomic Energy Commission (CEA) and the National Institute of Health and Medical Research (INSERM). METHODS: Two cohorts, bioCEA (N = 3,509) and bioINSERM (N = 4,966) were followed from 1968 to 1994 and 1980 to 1993, respectively. The mortality of each cohort was compared with that of the French population by computation of the standardized mortality ratio (SMR) with their 90% confidence interval (90% CI). Trend and heterogeneity tests were computed in order to study SMRs variation by job characteristics. In the bioCEA cohort individual dosimetry data being available, a trend test was also computed according to ionizing radiation cumulative dose. RESULTS: The SMRs were significantly below one in both cohorts for all-cause mortality (bioCEA: SMR = 0.52 [0.46-0.59], bioINSERM: SMR = 0.56 [0.46-0.67]) and for all-cancer mortality (bioCEA: SMR = 0.66 [0.54-0.80], bioINSERM: SMR = 0.55 [0.39-0.75]). There were some specific cancer sites for which the SMR was higher than 1, but not significantly. In the bioCEA cohort a positive trend was observed between ionizing radiation cumulative doses and all-cause as well as all-cancer SMRs. CONCLUSION: This study on two French cohorts of biological research workers found a favorable mortality pattern. These findings are consistent with recent publications. The positive trend of cancer mortality according to ionizing radiation exposure among bioCEA cohort needs to be confirmed with more precise assessment of exposures and information on individual risk factors.     

Association between GSTO2 polymorphism and the urinary arsenic profile in copper industry workers

Two members of the recently identified Omega class glutathione S-transferase enzymes (GSTO1 and GSTO2) have been proposed to play a role in the response to arsenic exposure. Therefore, polymorphisms in these genes could be related with variations in the arsenic excretion profile and, consequently, with the individual response to chronic exposure. Exons and flanking regions of GSTO2 gene have been screened in two different ethnic groups (20 Europeans and 20 Chilean Indians), and the urinary arsenic patterns and the GSTO2 Asn142Asp polymorphism have been investigated in 207 copper mine workers occupationally exposed to arsenic. Three polymorphisms of GSTO2 already described were detected in Europeans and Chilean Indians, although with significant different allele frequencies. The genotyping for the Asn142Asp polymorphism revealed that almost no significant association exists between this change and the arsenic excretion profile. However, 142Asp change seems to be correlated with an increase in DMA excretion after age and total urinary arsenic adjustment (OR=3.61; P=0.05). Altogether, our findings indicate that ethnical differences should be taken into account for correlation studies between GST Omega polymorphisms and arsenic susceptibility, and that the 142Asp allozyme could modulate arsenic biotransformation and thereby arsenic toxicity.     

Exposure to nickel compounds and smoking in relation to incidence of lung and nasal cancer among nickel refinery workers.

OBJECTIVES: To investigate the relation between occupational hazards among nickel refinery workers and their exposure to different forms of nickel over time and the interaction between smoking and total exposure to nickel. METHODS: The cohort consisted of 379 workers with first employment 1916-40 and at least three years of employment and 4385 workers with at least one year of employment 1946-83. Data on smoking (ever or never) were available for almost 95% of the cohort. Two analyses were used, indirect standardisation from observed and expected numbers and Poisson regression. RESULTS: During the follow up 1953-93, 203 new cases of lung cancer were observed v 68 expected (standardised incidence ratio (SIR) 3.0, 95% confidence interval (95% CI) 2.6-3.4) and 32 cases of nasal cancer were observed v 1.8 expected (SIR 18.0, 95% CI 12-25). The Poisson regression analysis showed an excess risk of lung cancer in association with exposure to soluble forms of nickel, with a threefold increase in relative risk (RR) (P < 0.001) and a multiplicative effect of smoking and exposure to nickel. The RRs were 1.1 (95% CI 0.2-5.1) for exposed workers who had never smoked and 5.1 (95% CI 1.3-20.5) for exposed workers who smoked. CONCLUSION: It is not possible to state with certainty which specific nickel compounds are carcinogenic, but a significant excess risk was found for workers exposed to soluble nickel alone or in combination with other forms of nickel. The present study suggests a multiplicative effect of smoking and nickel exposure.     

Micronucleus frequency in peripheral blood lymphocytes and buccal mucosa cells of copper smelter workers,with special regard to arsenic exposure

Occupational exposure in copper smelters may produce various adverse health effects including cancer which, according to available epidemiologic data, is associated mainly with exposure to arsenic. Despite a number of well-documented studies reporting an increased risk of cancer among copper smelters workers, the data on genotoxic effects in this industry are scarce. In view of the above, an assessment of micronuclei (MN) frequency in peripheral blood lymphocytes and buccal epithelial cells from copper smelter workers was undertaken. Additionally, the clastogenic/aneugenic effect in lymphocytes was assessed with the fluorescence in situ hybridization (FISH). The study was conducted in three copper smelters in southwestern Poland. The subjects (n = 72) were enrolled among male workers at departments where As concentration in the air was up to at 80 μg/m³. Exposure was assessed by measurement of arsenic concentration in urine and toenail samples. The control group (n = 83) was recruited from healthy male individuals living in central Poland who did not report any exposure to known genotoxins. The results of our study showed a significant increase in MN frequency in peripheral blood lymphocytes and in buccal epithelial cells of smelter workers, compared to the controls (7.96 ± 4.28 vs. 3.47 ± 1.70 and 0.98 ± 0.76 vs. 0.50 ± 0.52, respectively). The FISH technique revealed the presence of clastogenic and aneugenic effects in peripheral blood lymphocytes in both groups. The clastogenic effect was slightly more pronounced in the smelter workers; however, the difference was not statistically significant. The mean arsenic concentrations in urine (total arsenic species) and in toenail samples in the exposed group were 54.04 ± 42.26 μg/l and 7.63 ± 7.24 μg/g, respectively, being significantly different from control group 11.01 ± 10.84 μg/l and 0.51 ± 0.05 μg/g. No correlation between As content in urine or toenail samples and the genotoxic effect was found under study.