Italian pool of asbestos workers cohorts: asbestos related mortality by industrial sector and cumulative exposure.

OBJECTIVE: Italy has been a large user of asbestos and asbestos containing materials until the 1992 ban. We present a pooled cohort study on long-term mortality in exposed workers. METHODS: Pool of 43 Italian asbestos cohorts (asbestos cement, rolling stock, shipbuilding, glasswork, harbors, insulation and other industries). SMRs were computed by industrial sector for the 1970-2010 period, for the major causes, using reference rates by age, sex, region and calendar period. RESULTS: The study included 51 801 subjects (5741 women): 55.9% alive, 42.6% died (cause known for 95%) and 1.5% lost to follow-up. Asbestos exposure was estimated at the plant and period levels. Asbestos related mortality was significantly increased. All industrial sectors showed increased mortality from pleural malignancies, and most also from peritoneal and lung cancer and asbestosis, with exposure related trend. Increased mortality was also observed for ovarian cancer and for bladder cancer. DISCUSSION: The study confirmed the increased risk for cancer of the lung, ovary, pleura and peritoneum but not of the larynx and the digestive tract. A large increase in mortality from asbestosis was observed.

Factors Affecting Asbestosis Mortality Among Asbestos-Cement Workers in Italy.

OBJECTIVES: This study was performed with the aim of investigating the temporal patterns and determinants associated with mortality from asbestosis among 21 cohorts of Asbestos-Cement (AC) workers who were heavily exposed to asbestos fibres. METHODS: Mortality for asbestosis was analysed for a cohort of 13 076 Italian AC workers (18.1% women). Individual cumulative asbestos exposure index was calculated by factory and period of work weighting by the different composition of asbestos used (crocidolite, amosite, and chrysotile). Two different approaches to analysis, based on Standardized Mortality Ratios (SMRs) and Age-Period-Cohort (APC) models were applied. RESULTS: Among the considered AC facilities, asbestos exposure was extremely high until the end of the 1970s and, due to the long latency, a peak of asbestosis mortality was observed after the 1990s. Mortality for asbestosis reached extremely high SMR values [SMR: males 508, 95% confidence interval (CI): 446-563; females 1027, 95% CI: 771-1336]. SMR increased steeply with the increasing values of cumulative asbestos exposure and with Time Since the First Exposure. APC analysis reported a clear age effect with a mortality peak at 75-80 years; the mortality for asbestosis increased in the last three quintiles of the cumulative exposure; calendar period did not have a significant temporal component while the cohort effect disappeared if we included in the model the cumulative exposure to asbestos. CONCLUSIONS: Among heaviest exposed workers, mortality risk for asbestosis began to increase before 50 years of age. Mortality for asbestosis was mainly determined by cumulative exposure to asbestos.

Role of asbestos clearance in explaining long-term risk of pleural and peritoneal cancer: a pooled analysis of cohort studies.

OBJECTIVES: Models based on the multistage theory of cancer predict that rates of malignant mesothelioma continuously increase with time since first exposure (TSFE) to asbestos, even after the end of external exposure. However, recent epidemiological studies suggest that mesothelioma rates level off many years after first exposure to asbestos. A gradual clearance of asbestos from the lungs has been suggested as a possible explanation for this phenomenon. We analysed long-term trends of pleural and peritoneal cancer mortality in subjects exposed to asbestos to evaluate whether such trends were consistent with the clearance hypothesis. METHODS: We used data from a pool of 43 Italian asbestos cohorts (51 801 subjects). The role of asbestos clearance was explored using the traditional mesothelioma multistage model, generalised to include a term representing elimination of fibres over time. RESULTS: Rates of pleural cancer increased until 40 years of TSFE, but remained stable thereafter. On the other hand, we observed a monotonic increase of peritoneal cancer with TSFE. The model taking into account asbestos clearance fitted the data better than the traditional one for pleural (p=0.004) but not for peritoneal (p=0.09) cancer. CONCLUSIONS: Rates of pleural cancer do not increase indefinitely after the exposure to asbestos, but eventually reach a plateau. This trend is well described by a model accounting for a gradual elimination of the asbestos fibres. These results are relevant for the prediction of future rates of mesothelioma and in asbestos litigations.

Italian pool of asbestos workers cohorts: mortality trends of asbestos-related neoplasms after long time since first exposure.

OBJECTIVE: Asbestos is a known human carcinogen, with evidence for malignant mesothelioma (MM), cancers of lung, ovary, larynx and possibly other organs. MM rates are predicted to increase with a power of time since first exposure (TSFE), but the possible long-term attenuation of the trend is debated. The asbestos ban enforced in Italy in 1992 gives an opportunity to measure long-term cancer risk in formerly exposed workers. METHODS: Pool of 43 previously studied Italian asbestos cohorts (asbestos cement, rolling stock, shipbuilding), with mortality follow-up updated to 2010. SMRs were computed for the 1970â€"2010 period, for the major causes, with consideration of duration and TSFE, using reference rates by age, sex, region and calendar period. RESULTS: The study included 51 801 subjects (5741 women): 55.9% alive, 42.6% died (cause known for 95%) and 1.5% lost to follow-up. Mortality was significantly increased for all deaths (SMR: men: 1.05, 95% CI 1.03 to 1.06; women: 1.17, 95% CI to 1.12 to 1.22), all malignancies combined (SMR: men: 1.17, 95% CI to 1.14 to 1.20; women: 1.33, 95% CI 1.24 to 1.43), pleural and peritoneal malignancies (SMR: men: 13.28 and 4.77, 95% CI 12.24 to 14.37 and 4.00 to 5.64; women: 28.44 and 6.75, 95% CI 23.83 to 33.69 and 4.70 to 9.39), lung (SMR: men: 1.26, 95% CI 1.21 to 1.31; women: 1.43, 95% CI 1.13 to 1.78) and ovarian cancer (SMR=1.38, 95% CI 1.00 to 1.87) and asbestosis (SMR: men: 300.7, 95% CI 270.7 to 333.2; women: 389.6, 95% CI 290.1 to 512.3). Pleural cancer rate increased during the first 40 years of TSFE and reached a plateau after. DISCUSSION: The study confirmed the increased risk for cancer of the lung, ovary, pleura and peritoneum but not of the larynx and the digestive tract. Pleural cancer mortality reached a plateau at long TSFE, coherently with recent reports.

[Mortality study in a cohort of workers employed in the hot working processing of plastics and rubber]. / Studio di mortalità in una coorte di esposti nella lavorazione a caldo di materie plastiche e gomma.

OBJECTIVES: to study mortality rates among workers in companies manufacturing thermoplastic and rubber articles (excluding tyres). DESIGN: cohort study. SETTING AND PARTICIPANTS: the cohort includes 4,543 workers employed up to 2000 in 131 companies in the Province of Bologna (Emilia-Romagna Region, Northern Italy) exposed to emissions from hot processing of plastics (3,937) and rubber (606). MAIN OUTCOME MEASURES: general- and cause-specific Standardized Mortality Rates (SMR), with 95% confidence intervals; entire reference population resides in the Emilia-Romagna Region. RESULTS: excess mortality for all causes (116 Obs; SMR: 1.20; 95%CI 1.00-1.44) and for lung cancer (18 Obs; SMR: 1.67; 95%CI 1.05-2.65) in men of the rubber factories. Increased mortality rates for oesophageal cancers in women (3 Obs; SMR: 5.41; 95%CI 1.74-16.8) and in men (6 Obs; SMR: 2.16; 95%CI 0.97-4.81), for malignant tumours of pancreas (16 Obs; SMR: 1.65; 95%CI 1.01- 2.70), rectum (11 Obs; SMR: 2.17; 95%CI 1.20-3.92) and kidney (11 Obs; SMR: 1.98; 95%CI 1.10-3.58) in men occupied in plastic processing. CONCLUSION: in this study, we observed an excess of mortality rates for lung cancer in men of rubber factories and for malignant tumours of the digestive tract, pancreas, and kidney in workers employed in the production of plastic articles. Nevertheless, these results must be interpreted with caution, because exposures to non-occupational risk factors, like tobacco smoke or other occupational exposures outside the companies concerned, are not known. The results suggest to continue epidemiological surveillance.

[Time trend in mesothelioma and lung cancer risk in asbestos workers in Italy]. / Valutazione della variazione temporale del rischio di mesotelioma e di tumore del polmone nelle coorti di esposti ad amianto per lavoro in Italia.

This study aims at investigating, in asbestos exposed workers, the time trend of their risk of mesothelioma and of other neoplasm after very long latency and after the cessation of asbestos exposure. We pooled a large number of Italian cohorts of asbestos workers and updated mortality follow-up. The pool of data for statistical analyses includes 51,988 workers, of which 6,058 women: 54.2% was alive at follow-up, 42.6% was dead, and 2.8%was lost. Cause of death is known for 94.3%: 2,548 deaths from lung cancer, 748 frompleural cancer, 173 fromperitoneal cancer, and 434 from asbestosis. An exposure index is being developed to compare the different cohorts. Data analysis is in progress. This study will have the size for analysing not only time trends in mesothelioma, but also the occurrence of rarer diseases and cancer specific mortality in women.

[Mortality in a cohort of railway rolling stock construction and repair workers in Bologna]. / Mortalità in una coorte di addetti alla costruzione e riparazione di carrozze ferroviarie in un'azienda di Bologna.

BACKGROUND: A private company in Bologna worked for the Italian State Railways (FS) from 1919 to 1998; since the early '60s it used asbestos for new carriage insulation and renovation of carriages already circulating which were entirely spray-coated with asbestos. OBJECTIVES: The study aimed to investigate all causes mortality, in particular mortality from asbestos-related neoplasms in blue-collar workers. METHODS: The cohort consisted of 1,849 people, active in 1960 or hired in 1960-86: 1,704 (92.2%) blue-collar workers and 145 (7.8%) white-collar workers. The end date of the follow up was established as 31/12/2008. Regional reference mortality rates were used. RESULTS: Mortality from all causes (SMR = 1.16; 95% CI 1.08-1.25) and from malignant neoplasms (SMR = 1.20; 95% CI 1.06-1.35) significantly exceeded expected rates. In particular, a statistically significant increase was observed for pleural malignant cancer (SMR = 24.43; 95% CI 17.37-34.37), lung cancer (SMR = 1.24; 95% CI 1.00-1.53), peritoneal cancer (SMR = 6.35; 95% CI 2.64-15.25) and bladder cancer (SMR = 1.71; 95% CI 1.03-2.84). The excess lung cancer SMR was highly significant after 20 years of exposure and with a latency longer than 40 years. An association between pleural malignant cancer and duration of exposure and latency (trend test p value < 0,0001) was observed CONCLUSION: This study on a cohort of asbestos-exposed workers showed an increase in lung cancer SMRs by risk that was statistically significant in workers exposed for at least 20 years and after 40 years of latency. The neoplasm of pleura was strongly associated with both duration of exposure and latency.

[Determinants of occupational injuries in the construction of the "high speed train" Bologna-Florence]. / I determinanti degli infortuni sul lavoro nella costruzione della linea ferroviaria "treno ad alta velocità" Bologna-Firenze.

OBJECTIVE: to study determinants of occupational injuries in tunnel construction using data from the surveillance system which had been implemented in order to monitor accidents during the construction of the "high speed train tracks in the Italian Regions Emilia-Romagna and Tuscany. DESIGN: retrospective cohort study. SETTING: 16 sites for the construction of 14 tunnels of the high speed railway-tract Bologna-Firenze, in Italy. PARTICIPANTS: 1,602 workers (of 3,000 employed in the underground tunnelling), aged 18 - 67 years, operating during excavation with traditional method in 1999-2002. A total of 549 injuries occurred among 385 workers. The number of worked hours were used as time at risk. MAIN OUTCOME MEASURES: incidence rate ratios (IRR) and 95% confidence intervals for all injuries, serious injuries and first injuries were considered in separate multiple regression analyses (Poisson). RESULTS: residence, task and working phase were taken into consideration. An increased risk was found for younger workers, for carpenters (IRR "all-events" = 2.33; 95% CI=1.85-2.94; IRR" first-events" = 2.12; 95% CI 1.62-2.77) and miners (IRR "all-events" = 1.76; 95% CI 1.39-2.24; IRR"first-events" = 1.71; 95% CI 1.30-2.24) vs. machinery operators. Construction of inverted arch turns out to have an incidence rate ratio three times higher than digging out (IRR "all-events" = 2.79; 95% CI 2.27-3.43; IRR "firsts-event = 2.98; 95% CI 2.33-3.81). The probability of "serious" injuries (>30 days) is higher for miners (IRR=2.45; 95% CI 1.65-3.64) and for carpenters (IRR=2.31; 95% CI 1.53-3.49). CONCLUSION: this study pointed out to indicate some determinants (age, task and work phase) of injuries in tunneling about which little had been published previously. These results are useful for addressing preventive measures, for control and prevention activities and point to the need to explore the effect of experience and to study, through a case crossover design, transient working and individual risk factors for traumatic injury within these working sites.