Risk of Respiratory Cancer around a Sewage Plant in Prato,Italy

In this study, the authors evaluated the risk of respiratory cancer related to environmental pollutants among a population that resided near a sewage plant in Prato, Italy. Subjects included lung cancer deaths (1987-1996) and incident cases of lung and laryngeal cancers (1987-1994) among residents of Prato. The authors used the mortality or incidence rates for the entire population of Prato (by gender and by 5-yr age group) to calculate the expected cases in each census unit. Data were analyzed and adjusted for an index of social deprivation (Stone test). Among males, the excess risk of lung cancer mortality decreased as distance from the plant increased for 2 time periods (1987-1996 [p = .008] and 1990-1996 [p = .030]) and for lung cancer incidence during 1987-1994 (p = .011). Similar results were obtained when sewage plant workers were excluded from the analysis. A similar, but not statistically significant, trend was observed among female incident lung cancer cases, as well as among male incident laryngeal cancer cases. Despite methodological limitations common to geographic studies, the results were consistent with those previously published on mortality excesses for lung cancer among plant workers under study. The role of environmental pollutants as a risk for respiratory cancer must be further clarified with additional epidemiological studies and an environmental monitoring program.     

Small area study of mortality among people living near multiple sources of air pollution

OBJECTIVE: In the area of Malagrotta, a suburb of Rome (Italy), a large waste disposal site, a waste incinerator plant, and an oil refinery plant became operational in the early 1960s and have represented three major sources of air pollution. To evaluate the potential health risk due to airborne contamination around these point sources, a small area analysis of mortality was conducted. Cancer of the liver, larynx, lung, kidney, lymphatic, and haematopoietic systems were evaluated. METHODS: Sex and age specific mortality (1987-93) and population denominators (1991) were available for the census tracts of the metropolitan area of Rome. Standardised mortality ratios (SMRs) were computed separately for males and females in bands of increasing distance from the plants, up to a radius of 10 km. Stone's test for the decline in risk with distance was performed with increments in radius of 1 km; SMRs were also computed after adjusting for a four level index of socioeconomic status. RESULTS: No overall excess or decline in risk with distance was found for liver, lung, and lymphohaematopoietic cancers in either sex. For laryngeal cancer, an increased but not significant risk was found at 0-3 km and at 3-8 km. A significant decline with distance in mortality from laryngeal cancer was found among men (p = 0.03); the trend remained after adjusting for the socioeconomic index (p = 0.06). CONCLUSIONS: The study showed no association between proximity to the industrial sites and mortality for most of the several conditions considered. However, mortality from laryngeal cancer declined with distance from the sources of pollution. This result is interesting, as previous findings of an increased risk of laryngeal cancer near incinerators have been controversial.     

Occupation and lung cancer mortality in a nationally representative U.S. Cohort: The National Health Interview Survey (NHIS)

OBJECTIVE: The objective of this study was to assess the risk of lung cancer mortality in a nationally representative sample of U.S. workers by occupation. METHODS: National Death Index linkage identified 1812 lung cancer deaths among 143,863 workers who participated in the 1987, 1988, and 1990-1994 National Health Interview Surveys. RESULTS: Current and former smoking status was predictive of lung cancer mortality (hazard ratio [HR] = 15.1 and 3.8, respectively). Occupations with significantly higher risk for age- and smoking-adjusted lung cancer mortality included heating/air/refrigeration mechanics (HR = 3.0); not specified mechanics and repairers (HR = 2.8); financial records processing occupations (HR = 1.8); freight, stock, and materials handlers (HR = 1.5); and precision production occupations (HR = 1.4). CONCLUSION: Although tobacco use continues to be the single most important risk factor for lung cancer mortality, occupational exposure to lung carcinogens should be targeted as well to further reduce the burden of lung cancer.     

Lung cancer mortality in a cohort of workers in a petrochemical plant: occupational or residential risk?

The purpose of the present study is to examine the role of environmental (non occupational) exposures in lung cancer risk among petrochemical workers at a large petrochemical plant built on the Sicilian coast in the immediate vicinity of the town of Gela, Italy in 1960. The cohort included workers employed in the Gela petrochemical plant in 1960-1993. We looked at mortality rates for the period 1960-2002. An internal comparison was performed between two categories of workers with different likelihood of residence in Gela during the period of employment. The rate ratio of mortality from lung cancer comparing "probable residents" with "possible non residents," adjusted for age, calendar period, andjob classification (only blue collar, only white collar and both), was 1.66 (90% Confidence Interval 1.07-2.58). Although the information collected is quite sparse and no inferences can be made about risk sources, the results show a possible excess of residential/environmental risk from lung cancer mortality for those workers more likely to have been residents in Gela.     

Mortality in a cohort of sugar refinery workers in Arezzo Province, Italy

BACKGROUND AND OBJECTIVES: The aim of this study was to investigate mortality of a cohort of 1,767 male workers employed in a sugar refinery plant located in the Province of Arezzo, Italy, where asbestos had been used from the 1960's for the insulation of thermohydraulic systems and for furnaces. In 1987-88 workers removed the asbestos-cement insulation from the plant. METHODS: The cohort was composed by male workers who were employed in the plant between 1 March 1962 and 1 February 1996, and had worked for at least 2 months. Follow-up started on 1 March 1962, and ended on 31 May, 2003. The population mortality for Tuscany Region was used as the reference. The relative risk was estimated by Standardized Mortality Ratio (SMR) and the confidence intervals were calculated at a 95% level (95% CI). RESULTS: The majority of workers were employed during the summer only. Significant decreases in mortality were observed for overall mortality (SMR = 78; 95% CI = 69-88), all cancers (SMR = 80; 95% CI = 65-97), cardiovascular diseases (SMR = 64; 95% CI = 50-81), lung cancer (SMR = 66; 95% CI = 43-98), and gastrointestinal diseases (SMR = 53; 95% CI = 26-98). Non-significant increases were observed for kidney cancer (SMR = 229; 95% CI = 92-472), and diseases of the nervous system (SMR = 155; 95% CI = 71-294). Kidney cancer mortality for workers employed for > = 5 years was significantly higher (SMR = 508; 95% CI = 105-1485). CONCLUSIONS: Mortality for asbestos-related diseases did not show any increase. The higher kidney cancer mortality for workers employed for > = 5 years could be due to exposures to various carcinogens, that occurred not only in the sugar refinery plant, given that the workers were seasonal and did other jobs during the rest of the year. Asbestos-related deaths could occur in the future among some workers who in 1987-88 were employed on the removal of asbestos-cement insulation from the plant.     

Cancer risks among iron and steel workers in Anshan,China, part II: Case-control studies of lung and stomach cancer

Nested case-control interview studies of lung cancer (610 incident cases), stomach cancer (292 incident cases), and 959 controls were conducted to follow up leads from a proportional mortality analysis of deaths among male workers in a large integrated iron-steel complex in Anshan, China. For lung cancer, after adjusting for the significant non-occupational risk factors (smoking, other pulmonary disease, family history of lung cancer, and low consumption of fruit or tea), risks were significantly elevated for those employed for 15 or more years in smelting and rolling (OR = 1.5, CI = 1.1–2.2), in the fire-resistant brick factory (OR = 2.9, CI = 1.4–5.9), in general loading (OR = 2.5, CI = 1.0–6.1), and as coke oven workers (OR = 3.4; CI = 1.4–8.5). For stomach cancer, after adjusting for consumption of pickled vegetables, prior gastric diseases, family history of stomach cancer, low intake of fruits and vegetables, and education, risks were significantly elevated for those employed for 15 or more years in ore sintering and transportation (OR = 2.1, CI = 1.0–4.4), in the fire-resistant brick factory (OR = 2.5, CI = 1.1–5.8), in general loading (OR = 3.2, CI = 1.2–8.9), as boilerworkers and cooks (OR = 2.6, CI = 1.2–5.6), and as coke oven workers (OR = 5.4, CI = 1.8–16.0). For both lung and stomach cancers, significant dose-response gradients were observed for exposure to total dust and benzo(a)pyrene, but not for specific chemical components of dust. Overall, long-term steel workers with exposure to workplace pollutants had a 40% increased risk of both lung and stomach cancers. These case-control studies confirm many of the occupational findings reported in the proportionate mortality analysis, and suggest avenues for further work to evaluate the carcinogenicity of individual components of dust. (This article is a US Government work and, as such, is in the public domain in the United States of America.) © 1996 Wiley-Liss, Inc.     

Lung cancer case-control study of beryllium workers

BACKGROUND: Cohort mortality studies have found elevated lung cancer mortality among beryllium-exposed workers, but none evaluated the association between beryllium exposure level and lung cancer risk. A nested case-control study of lung cancer within a beryllium processing plant was conducted to investigate the relationship between level of beryllium exposure and lung cancer. METHODS: Lung cancer cases were identified by mortality follow-up through 1992 of a cohort of male workers at a beryllium alloy production plant. Each of 142 lung cancer cases was age-race-matched to five controls. Calendar-time-specific beryllium exposure estimates were made for every job in the plant and were used to estimate workers' cumulative, average, and maximum exposures. The potential confounding effects of smoking were also evaluated. RESULTS: Lung cancer cases had shorter tenures and lower lifetime cumulative beryllium exposures than controls, but higher average and maximum exposures. However, after applying a 10- and 20-year lag, exposure metrics were higher for cases. Odds ratios in analyses lagged 20 years were significantly elevated for those with higher exposure compared to the lowest exposure category. Significant positive trends were seen with the log of the exposure metrics. Smoking did not appear to confound exposure-response analyses. CONCLUSION: Increased lung cancer among workers with higher lagged beryllium exposures and lack of evidence for confounding by cigarette smoking, provide further evidence that beryllium is a human lung carcinogen. Published 2001 Wiley-Liss, Inc.     

Mortality among chemical plant workers exposed to acrylonitrile and other substances.

OBJECTIVES: To examine the association between exposure to acrylonitrile (AN) and cancer mortality by performing an independent and extended historical cohort study of workers from a chemical plant in Lima, Ohio included in a recent NCI-NIOSH study. METHODS: Subjects were 992 white males who were employed for three or more months between 1960 and 1996. We identified 110 deaths and cause of death for 108. Worker exposures were estimated quantitatively for AN and qualitatively for nitrogen products. Statistical analyses included U.S. and local county-based SMRs and internal relative risk regression of internal cohort rates. RESULTS: No statistically significant excess mortality risks were observed among the total cohort for the cancer sites implicated in previous studies: stomach, lung, breast, prostate, brain, and hematopoietic system. We observed a statistically significant bladder cancer excess based on four deaths (SMR=7.01, 95% CI=1.91-17.96) among workers not exposed to AN. Among 518 AN-exposed workers, we observed a not statistically significant excess of lung cancer based on external (SMR=1.32, 95% CI=.60-2.51) and internal (RR=1.98, 95% CI=.60-6.90) comparisons. Although the trends were not statistically significant, exposure-response analyses of internal cohort rates showed monotonically increasing lung cancer rate ratios with increasing AN exposure, with RRs exceeding 2.0 in the highest exposure categories. CONCLUSIONS: With the possible exception of lung cancer, this study provides little evidence that exposure to AN at levels experienced by Lima plant workers is associated with an increased risk of death from any cause including the implicated cancer sites.     

An updated mortality follow-up study of Florida phosphate industry workers

We have added 14 years of mortality follow-up to a previously studied cohort of 18,446 white and 4,546 nonwhite male workers in the Florida phosphate industry. Follow-up was performed for the years 1949–1992. Based on comparisons with national rates, lung cancer standardized mortality ratios (SMR) were slightly elevated among white (SMR = 1.19; 354 observed) and nonwhite males (SMR = 1.13; 105 observed). However, no lung cancer excesses were found relative to local county rates (SMR = 0.98 for whites, SMR = 0.94 for nonwhites). Based on internal analyses of lung cancer mortality, using Poisson regression modeling, there were no associations of lung cancer with cumulative exposures to total dust, silica, or acid mists. There were weak trends or lung cancer risk with alpha and gamma radiation among white males, but no associations with radiation in nonwhites. No relation was found between acid mist exposures and laryngeal cancer. We conclude that there have not been large excesses of lung cancer or other diseases related to workplace exposures in this cohort. © 1996 Wiley-Liss, Inc.     

Retrospective follow-up study of foundry and engine plant workers

A retrospective follow-up study of 21,013 workers employed at a foundry and two engine manufacturing plants was conducted to determine if these workers had an unusual mortality experience. A total of 2,235 deaths occurred during the follow-up period of 1970–1987. Mortality from all causes was lower than expected. Men experienced a 6–13% excess of lung cancer deaths, depending on the choice of the comparison group. The data displayed evidence of a positive trend between lung cancer mortality and increasing duration of employment (p = 0.008). White men experienced a statistically significant excess of deaths from stomach cancer (standardized mortality ratio [SMR] = 158; 95% confidence interval [CI] = 101–234). Black men had increased mortality from pancreatic cancer, especially among engine plant workers (SMR = 303; CI = 121–624), and an excess of prostate cancer, concentrated among foundry workers (SMR = 234; CI = 112–430). © 1993 Wiley-Liss, Inc.     

Retrospective cohort mortality study of cancer among sewage plant workers

There is little known about the incidence of cancer among sewage workers. In this paper we examine findings from a retrospective cohort study of 487 white male sewer authority workers employed between January 1950 and October 1979. Vital status was ascertained for 93% of the cohort yielding a total of 6,886 person years. Total mortality from all causes was comparable to that of the general white male U.S. population (Standardized Mortality Ratio [SMR] = 0.91, 95% Confidence Interval [CI] = 0.77-1.07). The cohort was subdivided into those not exposed, and sewer workers who were exposed to sewage effluent, sludge, or wastewater containing chemicals including potential carcinogens. Among the nonexposed group, mortality from all causes was significantly low (SMR = 0.55, 95% CI = 0.33-0.88). Among the exposed sewer workers, mortality from all causes was not significantly different from that of the general white male U.S. population (SMR = 1.00, 95% CI = 0.84-1.19). Mortality from all cancers among exposed sewer workers was slightly higher than that of the general population (SMR = 1.19, 95% CI = 0.79-1.7). Statistically significant elevated mortality ratios were seen for cancer of the larynx (SMR = 7.93, 95% CI = 1.59-23.96), and cancer of the liver (SMR = 5.4, 95% CI = 1.10-16.05). Careful study of the medical and occupational histories of these cases suggested that larynx cancer was possibly work-related, while liver cancer was not. A group estimated to be the highest exposed, composed predominantly of operatives, had a higher directly adjusted death rate from all malignant neoplasms combined compared to all other workers (rate ratio = 1.64). These findings of increased risk of cancer among exposed sewage workers, especially operators, are based on small number of cases and should be interpreted with caution. Studies of larger cohorts are needed to clarify the risk of these cancers among sewage workers.     

An update of cancer mortality among chrysotile asbestos miners in Balangero, northern Italy.

The mortality experience of a cohort of chrysotile miners employed since 1946 in Balangero, northern Italy was updated to the end of 1987 giving a total of 427 deaths out of 27,010 man-years at risk. A substantial excess mortality for all causes (standardised mortality ratio (SMR) = 149) was found, mainly because of high rates for some alcohol related deaths (hepatic cirrhosis, accidents). For mortality from cancer, however, the number of observed deaths (82) was close to that expected (76.2). The SMR was raised for oral cancer (SMR 231 based on six deaths), cancer of the larynx (SMR 267 based on eight deaths), and pleura (SMR 667 based on two deaths), although the excess only reached statistical significance for cancer of the larynx. Rates were not increased for lung, stomach, or any other type of cancer. No consistent association was seen with duration or cumulative dust exposure (fibre-years) for oral cancer, but the greatest risks for laryngeal and pleural cancer were in the highest category of duration and degree of exposure to fibres. Although part of the excess mortality from laryngeal cancer is probably attributable to high alcohol consumption in this group of workers, the data suggest that exposure to chrysotile asbestos (or to the fibre balangeroite that accounts for 0.2-0.5% of total mass in the mine) is associated with some, however moderate, excess risk of laryngeal cancer and pleural mesothelioma. The absence of excess mortality from lung cancer in this cohort is difficult to interpret.     

An update of cancer mortality among chrysotile asbestos miners in Balangero, northern Italy

The mortality experience of a cohort of chrysotile miners employed since 1946 in Balangero, northern Italy was updated to the end of 1987 giving a total of 427 deaths out of 27,010 man-years at risk. A substantial excess mortality for all causes (standardised mortality ratio (SMR) = 149) was found, mainly because of high rates for some alcohol related deaths (hepatic cirrhosis, accidents). For mortality from cancer, however, the number of observed deaths (82) was close to that expected (76.2). The SMR was raised for oral cancer (SMR 231 based on six deaths), cancer of the larynx (SMR 267 based on eight deaths), and pleura (SMR 667 based on two deaths), although the excess only reached statistical significance for cancer of the larynx. Rates were not increased for lung, stomach, or any other type of cancer. No consistent association was seen with duration or cumulative dust exposure (fibre-years) for oral cancer, but the greatest risks for laryngeal and pleural cancer were in the highest category of duration and degree of exposure to fibres. Although part of the excess mortality from laryngeal cancer is probably attributable to high alcohol consumption in this group of workers, the data suggest that exposure to chrysotile asbestos (or to the fibre balangeroite that accounts for 0.2-0.5% of total mass in the mine) is associated with some, however moderate, excess risk of laryngeal cancer and pleural mesothelioma. The absence of excess mortality from lung cancer in this cohort is difficult to interpret.     

Railways and asbestos in Japan (1928-1987)--epidemiology of pleural plaques, malignancies and pneumoconioses-

Asbestos has been an indispensable insulating material for railway industries, especially steam locomotives (SLs). This review (1928-1987) consists of three parts. 1) Pleural plaques: Since the 1970s, pleural plaques have been regarded as evidence of past asbestos inhalation, and more recently recognized as a risk factor of asbestos-related malignancies. For diagnostic criteria on plain radiographs, the modified ILO 1980 International Classification of Radiographs of Pneumoconioses was used. Most cases had pleural plaques with normal lungs. Large plant workers showed a significantly higher rate of plaques than workers in smaller plants. Bilateral plaques were dominant followed by the left, then the right lung, and chest wall plaques were dominant over the diaphragm. The manifestation of pleural plaques was more correlated to years since the onset of the asbestos exposure than the sum of asbestos work years, although the result was not significant. The boilermen of railway ferry steamers had a significantly higher plaque rate than other seamen. CT studies on plaques started in 1978. 2) Asbestos-related malignancies: Five retrospective cohort studies 1960-1970 were made on primary lung cancer incidence and mortality among 350,000 active railway men with smoking information. The follow-up period was 20 yr at the longest. Almost all plant workers showed a tendency of higher incidence or mortality than the controls. Two cases of mesothelioma were reported in 1980. 3) Pneumoconioses: Most studies (1928-1975) had relatively low prevalence rates among SL-related workers.     

Mortality in retired coke oven plant workers.

A previous study on 536 retired coke oven plant workers in Lorraine Collieries (France) reported an excess of deaths from lung cancer (standardised mortality ratio (SMR) = 251) compared with the French male population. Occupational exposures during working life were retraced for each subject, but the number of deaths during the observation period (1963-82) was small, and smoking habits were known only for dead subjects. In 1988, the cohort was re-examined (182 deaths occurred between 1963 and 1987) and smoking habits were determined for all the subjects. This study confirmed the excess of lung cancer (SMR = 238, p < 0.001). It showed an excess of mortality from all causes (SMR = 141, p < 0.001), overall cancers (SMR = 133, p < 0.05), and cardiovascular diseases (SMR = 133, p < 0.05). A significant excess of deaths was found for subjects who worked near the ovens for all causes (145, p < 0.01), lung cancer (SMR = 252, p < 0.01), colon cancer (SMR = 381, p < 0.05), and cardiovascular diseases (SMR = 155, p < 0.05). A significant excess mortality was also found from all causes (176, p < 0.05) and stomach cancer (SMR = 538, p < 0.01) in subjects who worked in byproducts, from lung cancer (SMR = 433, p < 0.001) in those in the workshops, and from cirrhosis of the liver and alcoholism (SMR = 360, p < 0.01) in those underground; but, due to small numbers, these figures were not robust. An excess of mortality from all causes (SMR = 163, p<001), lung cancer (SMR = 228, p<0.05) and cardiovascular diseases (SMR = 179, p<0.01) was shown also for non-exposed or slightly exposed subjects. The fact that, on the whole, mortality of various exposed groups was similar to that of non-exposed or slightly exposed workers may be explained in part by the selection at hiring and the healthy worker effect. As an increased risk of lung cancer was noted among subjects who worked in the old generations of plant compared with the other workers (although the relative risk was not significant) it is concluded that the role of occupational hazards could not be excluded.     

Mortality from a Chinese asbestos plant: Overall cancer mortality

The cancer mortality in a Chinese asbestos plant using only chrysotile was studied. Opened in the 1950s, all workers with at least 1 year of employment by 1972 were followed through 1994. Most workers were female. Excess cancer mortality, compared to local city data, was found for lung cancer, including many cases among nonsmoking women, and stomach cancer. Plant asbestos levels have been high in the past but have consistently come down over the decades. Am. J. Ind. Med. 32:442–444, 1997. © 1997 Wiley-Liss, Inc.     

Mortality and lung cancer in ceramic workers in the Netherlands: Preliminary results

A retrospective cohort study in 1974 male ceramic workers in the Netherlands was carried out to analyze the lung cancer risk in relation to crystalline silica exposure and silicosis. They had all been employed for two years or longer in ceramic industries between 1972 and 1982. During a health survey, 124 cases of simple pneumoconiosis were diagnosed: after 14 years of follow-up, 161 deaths had occurred. No increased overall and cause-specific mortality was found in the total group of ceramic workers, and a statistically significant cumulative dose-response relation for silica exposure and lung cancer did not emerge. An excess lung cancer mortality appeared among workers with simple pneumoconiosis. The authors conclude that the disease process resulting in silicosis in the ceramic industry carries an increased risk of lung cancer, which is supportive of a nongenotoxic pathway. © 1996 Wiley-Liss, Inc.     

The Occupational Cancer Incidence Surveillance Study (OCISS): risk of lung cancer by usual occupation and industry in the Detroit metropolitan area

This case-referent study assesses occupational risk factors associated with lung cancer, utilizing colon and rectum cancer referents. Complete occupational and tobacco use histories were obtained by telephone interview for 5,935 incident lung cancer cases and 3,956 incident colon and rectum cancer referents. The analysis included 43 usual occupational groups and 48 usual industry groups comprised of at least 10 cases. Among all cases, there were significant elevated risks for excavating and mining workers (OR = 4.01), furnace workers (OR = 3.11), armed services personnel (OR = 3.10), agricultural workers (OR = 2.05), driver sales (OR = 2.21), mechanics (OR = 1.72), painters (OR = 1.96), and drivers (OR = 1.88). Industries with significant elevated lung cancer risk included farming (OR = 2.21), mining (OR = 2.98), and primary ferrous metals manufacturing (OR = 2.43). Analyses of white and black men separately revealed that the excess of lung cancer among mechanics is restricted to black males (OR = 4.16). The risk of lung cancer among armed services personnel is higher among black men (OR = 10.54) than among white men (OR = 3.06). Five of the occupations observed more often among lung cancer cases have probable exposure to diesel exhaust.     

Cancer mortality of cadmium workers.

Several epidemiological studies of workers exposed to cadmium indicate an increased risk of lung and prostatic cancer. The increase is statistically significant in some of the studies but the SMR is greater than 100 in almost all. A cohort study of the mortality among 522 Swedish workers exposed to cadmium for at least one year in a nickel-cadmium battery plant support the earlier findings. The SMR for lung and prostatic cancer increased with increasing dose and latency but did not obtain statistical significance. A combination of all the available data from the most recent follow up of causes of death among cadmium workers in six different cohorts shows 28 cases of prostatic cancer (SMR = 162) and 195 cases of lung cancer (SMR = 121). This new analysis suggests that long term, high level exposure to cadmium is associated with an increased risk of cancer. The role of concomitant exposure to nickel needs further study.     

Cancer mortality of cadmium workers

Several epidemiological studies of workers exposed to cadmium indicate an increased risk of lung and prostatic cancer. The increase is statistically significant in some of the studies but the SMR is greater than 100 in almost all. A cohort study of the mortality among 522 Swedish workers exposed to cadmium for at least one year in a nickel-cadmium battery plant support the earlier findings. The SMR for lung and prostatic cancer increased with increasing dose and latency but did not obtain statistical significance. A combination of all the available data from the most recent follow up of causes of death among cadmium workers in six different cohorts shows 28 cases of prostatic cancer (SMR = 162) and 195 cases of lung cancer (SMR = 121). This new analysis suggests that long term, high level exposure to cadmium is associated with an increased risk of cancer. The role of concomitant exposure to nickel needs further study.