Distribution of mesothelioma cases in different occupational groups and industries in Australia, 1979-1995

Asbestos Exposure and Malignant Mesothelioma in Construction Workers-Epidemiological Remarks by the Italian National Mesothelioma Registry (ReNaM)

Notwithstanding the ban in 1992, asbestos exposure for workers in the construction sector in Italy remains a concern. The purpose of this study is to describe the characteristics of malignant mesothelioma (MM) cases recorded by the Italian registry (ReNaM) among construction workers. Incident mesothelioma cases with a definite asbestos exposure have been analyzed. Characteristics of cases and territorial clusters of crude rates of MM in construction workers have been described, as well as the relation between asbestos use before the ban and the historical trend of workforce in the construction sector in Italy. ReNaM has collected 31,572 incident MM cases in the period from 1993 to 2018 and asbestos exposure has been assessed for 24,864 (78.2%) cases. An occupational exposure has been reported for 17,191 MM cases (69.1% of subjects with a definite asbestos exposure). Among them, 3574 had worked in the construction sector, with an increasing trend from 15.8% in the 1993–98 period to 23.9% in 2014–2018 and a ubiquitous territorial distribution. The large use of asbestos in construction sector before the ban makes probability of exposure for workers a real concern still today, particularly for those working in maintenance and removal of old buildings. There is a clear need to assess, inform, and prevent asbestos exposure in this sector.

Incidence of mesothelioma and asbestosis by occupation in a diverse workforce

OBJECTIVE

We sought to characterize detailed patterns of mesothelioma and asbestosis incidence in the workforce as part of an occupational disease surveillance program in Ontario, Canada.

METHODS

The Occupational Disease Surveillance System (ODSS) cohort was established using workers' compensation claims data and includes 2.18 million workers employed from 1983 to 2014. Workers were followed for mesothelioma and asbestosis diagnoses in Ontario Cancer Registry, physician, hospital, and ambulatory care records through 2016. Trends in incidence rates were estimated over the study period. Cox proportional hazard models were used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

A total of 854 mesothelioma and 737 asbestosis cases were diagnosed during follow-up. Compared with all other workers in the ODSS, those employed in construction trades occupations had the greatest adjusted incidence rate of both mesothelioma (223 cases; HR, 2.38; 95% CI: 2.03-2.78) and asbestosis (261 cases; HR, 3.64; 95% CI: 3.11-4.25). Rates were particularly elevated for insulators, pipefitters and plumbers, and carpenters. Workers in welding and flame cutting, boiler making, and mechanic and machinery repair occupations, as well as those in industrial chemical and primary metal manufacturing industries, had strongly elevated rates of both diseases. Rates were greater than anticipated for workers in electrical utility occupations and education and related services.

CONCLUSIONS

Results substantiate the risk of mesothelioma and asbestosis in occupation and industry groups in the Ontario workforce with known or suspected asbestos exposure. Sustained efforts to prevent the occurrence of additional cases of disease in high-risk groups are warranted.

Association between asbestos exposure and pericardial and tunica vaginalis testis malignant mesothelioma: a case-control study and epidemiological remarks

Objectives The purposes of this study are to describe the epidemiology of pericardial and tunica vaginalis testis mesothelioma and assess the role of asbestos exposure for these rare diseases. Methods Based on incident pericardial and tunica vaginalis testis mesothelioma cases collected from the Italian national mesothelioma registry (ReNaM) in the period 1993-2015, incidence rates, survival median period and prognostic factors have been evaluated. A case-control study has been performed to analyze the association with asbestos exposure (occupational and non-occupational) for these diseases. Results Between 1993 and 2015, 58 pericardial (20 women and 38 men) and 80 tunica vaginalis testis mesothelioma cases have been registered with a mean annual standardized (world standard population as reference) incidence rates of 0.049 (per million) in men and 0.023 in women for the pericardial site, and 0.095 for tunica vaginalis testis mesothelioma. Occupational exposure to asbestos was significantly associated with the risk of the diseases [odds ratio (OR) 3.68, 95% confidence interval (CI) 1.85-7.31 and OR 3.42, 95% CI 1.93-6.04 in pericardial and tunica vaginalis testis mesothelioma, respectively]. The median survival was 2.5 months for pericardial and 33.0 months for tunica vaginalis testis mesotheliomas. Age was the main predictive factor for survival for both anatomical sites. Conclusions For the first time in an analytical study, asbestos exposure was associated with pericardial and tunica vaginalis testis mesothelioma risk, supporting the causal role of asbestos for all anatomical sites. The extreme rarity of the diseases, the poor survival and the prognostic role of age have been confirmed based on population and nationwide mesothelioma registry data.

Geographic study of mortality due to mesothelioma in Peru and its evolution

BACKGROUND

Peru has a public health problem because of asbestos imports. We analyzed the mortality trends for mesothelioma in Peru and its provinces from 2005 to 2014 and estimated their relationship with the amount of asbestos imported previously.

METHODS

We computed age-standardized mortality rates (ASMRs) per 100,000 population (direct method and SEGI world standard population reference), and the standardized mortality ratio (SMR). The relationship between the amount of asbestos imported annually along the period 1965-2010 and the number of mesothelioma deaths per year from 2005 to 2014 was estimated by log-linear Poisson regression models and Pearson correlation calculations.

RESULTS

After correcting the number of deaths, Peru registered 428 cases (or 430 when corrected cases are rounded by sex) between 2005 and 2014. The highest ASMRs were in Arequipa and Callao (range: 0.40-0.41/100,000 population), followed by Huancavelica (0.36/100,000 population). This translates into approximately one death per each 68-111 of asbestos tons imported. The latency period for the higher level of positive correlation found was 8 years (r = 0.8). Male female sex ratio was lower in provinces such as Junin and Hunacavelica with geological asbestos risk.

CONCLUSIONS

Two patterns of mesothelioma risk have been detected, occupational and environmental. During the 2002-2006 years, Peru increased the asbestos use. If crocidolite imports were also increased, this could be behind the 8 years latency period detected. Peru should boost strategies towards the total ban of all forms of asbestos.

Incidence of mesothelioma in Lombardy, Italy: exposure to asbestos, time patterns and future projections

OBJECTIVES

In Italy, asbestos has been extensively used from 1945 to 1992. We evaluated the impact of exposure to asbestos on occurrence of malignant mesothelioma (MM) in the Lombardy Region, Northwest Italy, the most populated and industrialised Italian region.

METHODS

From the Lombardy Mesothelioma Registry, we selected all incident cases of MM diagnosed between 2000 and 2012. We described sources of exposure to asbestos and examined time trends of MM rates. Using Poisson age-cohort models, we derived projections of burden of MM in the Lombardy population for the period 2013-2029.

RESULTS

In 2000-2012, we recorded 4442 cases of MM (2850 men, 1592 women). Occupational exposure to asbestos was more frequent in men (73.6%) than in women (38.2%). Non-occupational exposure was found for 13.6% of women and 3.6% of men. The average number of cases of MM per year was still increasing (+3.6% in men, +3.3% in women). Incidence rates were still increasing in individuals aged 65+ years and declining in younger people. A maximum of 417 cases of MM (267 men, 150 women) are expected in 2019. We forecast there will be 6832 more cases (4397 in men, 2435 in women) in the period 2013-2029, for a total of 11 274 cases of MM (7247 in men, 4027 in women) in 30 years.

CONCLUSIONS

This study documented a high burden of MM in both genders in the Lombardy Region, reflecting extensive occupational (mainly in men) and non-occupational (mainly in women) exposure to asbestos in the past. Incidence rates are still increasing; a downturn in occurrence of MM is expected to occur after 2019.

Perspectives on refractory ceramic fiber (RCF) carcinogenicity: comparisons with other fibers

In 2011, SCOEL classified RCF as a secondary genotoxic carcinogen and supported a practical threshold. Inflammation was considered the predominant manifestation of RCF toxicity. Intrapleural and intraperitoneal implantation induced mesotheliomas and sarcomas in laboratory animals. Chronic nose-only inhalation bioassays indicated that RCF exposure in rats increased the incidence of lung cancer and similar exposures resulted in mesothelioma in hamsters, but these studies may have been compromised by overload. Epidemiological studies in the US and Europe showed an association between exposure and prevalence of respiratory symptoms and pleural plaques, but no interstitial fibrosis, mesotheliomas, or increased numbers of lung tumors were observed. As the latency of asbestos induced mesotheliomas can be up to 50 years, the relationship between RCF exposure and respiratory malignances has not been fully determined. Nonetheless, it is possible to offer useful perspectives. RCF and rock wool have similar airborne fiber dimensions and biopersistence. Therefore, it is likely that these fibers have similar toxicology. Traditional rock wool has been the subject of numerous cohort and case control studies. For rock wool, IARC (2002) concluded that the epidemiological studies did not provide evidence of carcinogenicity. Based on analogies with rock wool (read across), it is reasonable to believe that increases in lung cancer or any mesotheliomas are unlikely to be found in the RCF-exposed cohort. RCF producers have developed a product stewardship program to measure and control fiber concentrations and to further understand the health status of their workers.

The latency period of mesothelioma among a cohort of British asbestos workers (1978-2005)

Background:

The Great Britain (GB) Asbestos Survey is a prospective cohort of asbestos workers in GB. The objective of this study was to investigate determinants of mesothelioma latency, paying particular attention to indicators of intensity of asbestos exposure such as occupation, sex, and presence of asbestosis.

Methods:

The analysis included members of the cohort who died with mesothelioma between 1978 and 2005. The primary outcome was the latency period defined as the time from first occupational exposure to asbestos to death with mesothelioma. Generalised gamma accelerated failure-time models were used to estimate time ratios (TRs).

Results:

After excluding missing data, there were 614 workers who died with mesothelioma between 1978 and 2005. Total follow-up time was 9280 person-years, with a median latency of 22.8 years (95% confidence interval (CI) 16.0–27.2 years). In the fully adjusted model, latency was around 29% longer for females compared with males (TR=1.29, 95% CI=1.18–1.42), and 5% shorter for those who died with asbestosis compared with those who did not (TR=0.95, 95% CI=0.91–0.99). There was no evidence of an association between latency and occupation.

Conclusion:

This study did not find sufficient evidence that greater intensity asbestos exposures would lead to shorter mesothelioma latencies.

OccIDEAS: An Innovative Tool to Assess Past Asbestos Exposure in the Australian Mesothelioma Registry

Malignant mesothelioma is an uncommon but rapidly fatal disease for which the principal aetiological agent is exposure to asbestos. Mesothelioma is of particular significance in Australia where asbestos use was very widespread from the 1950s until the 1980s. Exposure to asbestos includes occupational exposure associated with working with asbestos or in workplaces where asbestos is used and also 'take-home' exposure of family members of asbestos exposed workers. Asbestos exposure may also be non-occupational, occurring as a consequence of using asbestos products in non-occupational contexts and passive exposure is also possible, such as exposure to asbestos products in the built environment or proximity to an environmental source of exposure, for example an asbestos production plant. The extremely long latency period for this disease makes exposure assessment problematic in the context of a mesothelioma registry. OccIDEAS, a recently developed online tool for retrospective exposure assessment, has been adapted for use in the Australian Mesothelioma Registry (AMR) to enable systematic retrospective exposure assessment of consenting cases. Twelve occupational questionnaire modules and one non-occupational module have been developed for the AMR, which form the basis of structured interviews using OccIDEAS, which also stores collected data and provides a framework for generating metrics of exposure.

Occupational, domestic and environmental mesothelioma risks in the British population: a case-control study

We obtained lifetime occupational and residential histories by telephone interview with 622 mesothelioma patients (512 men, 110 women) and 1420 population controls. Odds ratios (ORs) were converted to lifetime risk (LR) estimates for Britons born in the 1940s. Male ORs (95% confidence interval (CI)) relative to low-risk occupations for >10 years of exposure before the age of 30 years were 50.0 (25.8–96.8) for carpenters (LR 1 in 17), 17.1 (10.3–28.3) for plumbers, electricians and painters, 7.0 (3.2–15.2) for other construction workers, 15.3 (9.0–26.2) for other recognised high-risk occupations and 5.2 (3.1–8.5) in other industries where asbestos may be encountered. The LR was similar in apparently unexposed men and women (∼1 in 1000), and this was approximately doubled in exposed workers’ relatives (OR 2.0, 95% CI 1.3–3.2). No other environmental hazards were identified. In all, 14% of male and 62% of female cases were not attributable to occupational or domestic asbestos exposure. Approximately half of the male cases were construction workers, and only four had worked for more than 5 years in asbestos product manufacture.

Évaluation quantitative du risque de cancer du poumon et de mésothéliome pleural chez les mécaniciens de véhicules automobiles

BACKGROUND

A quantitative assessment of the risk of lung cancer and pleural mesothelioma among mechanics exposed to dust released from automobile asbestos-containing parts was performed.

METHODS

The population of automobile mechanics in France, according to profession and industrial sectors codes, was estimated from the data of the 1999 census. Risks were computed for a total male population of 242,360 automobile mechanics aged 16 to 60 years. Exposure to asbestos among these workers comes from maintenance tasks involving asbestos-containing parts produced before 1997 (date of the asbestos ban in France). Airborne asbestos concentration data available from the literature were highly variable. No data reporting the distribution of time spent for such tasks over a typical week of work were available. Therefore, different weekly exposure profiles were simulated, based on data from the 1994 SUMER survey. Risk models were those used for assessing asbestos health effects by all national and international agencies. Exposure scenarios mixed different levels of exposure, periods of time, proportions of exposed workers and dates of the "natural" disappearance of the automobile fleet built before asbestos was banned in brakes and other parts. The most realistic scenario hypothesizes that all automobile mechanics were exposed to asbestos, that the exposure levels ranged from 0.06 and 0.25 fibers/liter per week for the period before 1997, and between 0.01 and 0.06 fibers/liter per week afterwards until 2010.

RESULTS

According to this scenario, the number of lifelong cancer deaths (lung and pleura) induced by asbestos exposure in this population is estimated at 602 "unavoidable" cases, due to exposure experienced before 2003; 43 other cases will occur if asbestos is not removed from existing automobiles.

Residential proximity to naturally occurring asbestos and mesothelioma risk in California

RATIONALE

Little is known about environmental exposure to low levels of naturally occurring asbestos (NOA) and malignant mesothelioma (MM) risk.

OBJECTIVES

To conduct a cancer registry-based case control study of residential proximity to NOA with MM in California.

METHODS

Incident MM cases (n = 2,908) aged 35 yr or more, diagnosed between 1988 and 1997, were selected from the California Cancer Registry and frequency matched to control subjects with pancreatic cancer (n = 2,908) by 5-yr age group and sex. Control subjects were selected by stratified random sampling from 28,123 incident pancreatic cancers in the same time period. We located 93.7% of subjects at the house or street level at initial diagnosis. Individual occupational exposure to asbestos was derived from the longest held occupation, available for 74% of MM cases and 63% of pancreatic cancers. Occupational exposure to asbestos was determined by a priori classification and confirmed by association with mesothelioma.

MAIN RESULTS

The adjusted odds ratios and 95% confidence interval for low, medium, and high probabilities of occupational exposures to asbestos were 1.71 (1.32-2.21), 2.51 (1.91-3.30), and 14.94 (8.37-26.67), respectively. Logistic regression analysis from a subset of 1,133 mesothelioma cases and 890 control subjects with pancreatic cancer showed that the odds of mesothelioma decreased approximately 6.3% for every 10 km farther from the nearest asbestos source, an odds ratio of 0.937 (95% confidence interval = 0.895-0.982), adjusted for age, sex, and occupational exposure to asbestos.

CONCLUSIONS

These data support the hypothesis that residential proximity to NOA is significantly associated with increased risk of MM in California.

Predictions of mortality from pleural mesothelioma in Italy: a model based on asbestos consumption figures supports results from age-period-cohort models

Italy was the second main asbestos producer in Europe, after the Soviet Union, until the end of the 1980s, and raw asbestos was imported on a large scale until 1992. The Italian pattern of asbestos consumption lags on average about 10 years behind the United States, Australia, the United Kingdom and the Nordic countries. Measures to reduce exposure were introduced in the mid-1970s in some workplaces. In 1986, limitations were imposed on the use of crocidolite and in 1992 asbestos was definitively banned. We have used primary pleural cancer mortality figures (1970-1999) to predict mortality from mesothelioma among Italian men in the next 30 years by age-cohort-period models and by a model based on asbestos consumption figures. The pleural cancer/mesothelioma ratio and mesothelioma misdiagnosis in the past were taken into account in the analysis. Estimated risks of birth cohorts born after 1945 decrease less quickly in Italy than in other Western countries. The findings predict a peak with about 800 mesothelioma annual deaths in the period 2012-2024. Results estimated using age-period-cohort models were similar to those obtained from the asbestos consumption model.

Asbestos, asbestos-related diseases, and compensation claims in The Netherlands

In The Netherlands the number of asbestos-related diseases is increasing. An age-cohort model predicts a steep rise in pleural mesothelioma deaths up to 490 cases per year among men, with a total death toll close over 12,000 cases during 2000-2028. In the past decade the number of compensation claims for asbestos-related diseases has more than doubled, with increasingly verdicts in favor of claimants. In addition to the medical information, information about the state of the art of preventive measures in different periods of time plays a decisive role in these claims. The use of asbestos in The Netherlands, the occurrence of asbestos-related diseases, the national asbestos regulations, and the position of the claimants in asbestos lawsuits in The Netherlands are reviewed.

Malignant mesothelioma in Italy, 1997

BACKGROUND

The Italian National Mesothelioma Register (ReNaM) was set up at the Istituto Superiore Prevenzione e Sicurezza Lavoro (ISPESL), in Rome, in accordance with Art. 36 of Italian Legislative Decree No. 277 [1991].

METHODS

Five Italian regions, Piedmont, Liguria, Emilia-Romagna, Tuscany, and Apulia, agreed to record mesothelioma cases according to guidelines established by ISPESL, to define exposure to asbestos and transmit the data systematically to ISPESL.

RESULTS

Four hundred and twenty-nine mesothelioma cases, diagnosed in 1997, are recorded. The standardized annual incidence rate for definite pleural mesothelioma is 1.51 per 100,000 inhabitants (2.26 for males and 0.79 for females). Exposure was defined for 198 mesotheliomas with a histological diagnosis: 125 (63%) refer to occupational exposure, 10 (5%) to environmental exposure, and 5 (2.5%) to household exposure.

CONCLUSIONS

Despite the ReNaM's work, many limitations still have to be overcome. Clear-cut information on asbestos exposure is available for a limited number of cases; and differing regional procedures in collecting and evaluating mesotheloma cases exist. At this stage the identification and evaluation of a large number of cases of mesothelioma is a worthwhile result. This epidemiological surveillance, currently being extended to other regions, will enable us to better assess the impact and diffusion of this disease in future, and to monitor more closely the effects of ceasing asbestos use in 1992, and the efficacy of preventive measures since mid '70s. Am. J. Ind. Med. 45:55-62, 2004.