Lung fibre burden and risk of malignant mesothelioma in shipyard workers: a necropsy-based case-control study

OBJECTIVES

In Italy, the highest pleural cancer mortality and incidence have been observed among Italian regions where the 2 largest Italian shipyards were (and are) located. The objective of this study was to assess the exposure-response relationship for mesothelioma among male workers employed in the Monfalcone, Italy, shipyard.

METHODS

We conducted a necropsy-based case-control study. Cases (N = 102) were mesothelioma decedents and controls were those with lung cancer (N = 84). Complete job histories were available; the lung fibre content was measured using a scanning electron microscope with X-ray fluorescence, after sample preparation according to the European Respiratory Society guidelines. Odds ratios and 95% confidence intervals of mesothelioma by fibre type and lung fibre burden, as a categorical or continuous variable, were assessed by unconditional logistic regression, adjusted for age and time since exposure cessation. Analyses for the amphibole and chrysotile lung fibre burden were mutually adjusted. We calculated a cumulative exposure index by applying a job-exposure matrix to the job histories of study cases and assessed its correlation with the lung fibre burden.

RESULTS

We found an odds ratio of 22.0 (confidence intervals 5.66-85.7) for the highest lung fibre burden category (mean 43.8 million total asbestos fibres per gram of dry tissue) compared with the reference (mean 0.48). Using log10-transformed lung fibre burden, we found that the odds ratio was 3.71 (confidence intervals 2.03-6.79) for a 10-fold lung fibre burden increase. Results for the amphibole lung fibre burden were similar. Odds ratios increased over chrysotile lung fibre burden categories (P-trend = 0.025), and the odds ratio for a 10-fold increase was 4.73 (confidence intervals 0.32-70.4).

CONCLUSIONS

The cumulative exposure index was correlated with total and amphibole lung fibre burden, but not with chrysotile lung fibre burden. Mesothelioma risk was proportional to total, amphibole, and chrysotile lung fibre burden in shipyard workers.

Lung asbestos fiber burden analysis: effects of the counting rules for legal medicine evaluations

OBJECTIVES

The work shows the effect of counting rules, such as analysis magnification and asbestos fiber dimension to be count (with length ≥5 µm or also asbestos fibers with length <5 µm) in the lung asbestos fiber burden analysis for legal medicine evaluations.

METHODS

On the same lung tissue samples, two different analyses were carried out to count any asbestos fibers with length ≥1 µm and with length ≥5 µm. Results of the amphibole burden of the two analyses were compared by linear regression analysis on log10-transformed values.

RESULTS

The analysis should be carried out at an appropriate magnification and on samples prepared in such a way as they allow the counting of very fine fibers. If the analysis is limited to the asbestos fibers with length ≥5 µm, there is a high risk of not detecting possible residual chrysotile fiber burden and thinner crocidolite asbestos fibers.

CONCLUSIONS

On average we estimated that 1 amphibole fiber with length ≥5 µm corresponds to ∼8 amphibole fibers with length ≥1 µm in the lung. The values of the Helsinki criteria should be updated taking this into account.

[Pleural malignant mesotheliomas from environmental exposures to asbestos In Italy]

Pleural mesothelioma clusters from outdoor environmental exposure have been highlighted also in Italy and, on the basis of epidemiological surveillance coordinated by the Italian National Mesothelioma Register, their frequency has been estimated at about 4.5%. Epidemiological studies and evaluations of some regional mesothelioma registers have made it possible to highlight that the dispersion of asbestos fibers in the outdoor environment was the only ascertained cause of mesothelioma in subjects from asbestos-cement factories, from the Balangero mine (Piedmont Region), from some serpentine rock quarries with tremolite outcrops in the Southern Apennines and in Alta Val di Susa (Piedmont Region); from chrysotile and serpentine caves in Valmalenco (Lombardy Region). Furthermore, cases of pleural mesothelioma were clearly caused by environmental pollution from fluoroedenite fibers in Biancavilla (Sicily Region). On the other hand, regional mesothelioma registers have also reported other circumstances of environmental asbestos exposure, like in the case of steel industry, shipbuilding, chemical plants, railway lines, and repair/demolition of railway carriages. However, these reports have not found confirmation on the basis of ad-hoc studies and it is likely that there is a lack of homogeneity in the assessment of individual cases. Apart from the scenarios which have been the subject of ad-hoc studies, the assessment of the causal role of environmental exposure to "in place" asbestos in the onset of pleural mesothelioma is problematic without an effort to more carefully examine the circumstances of possible exposure, harmonization of the attribution criteria used in the individual regional registers, analytical assessment of the impact of such exposure on the risk of onset of mesothelioma.

[Biological risk from SARS-CoV-2 and respiratory protection device for health workers during the first pandemic phase: a scenario that had to be avoided]

In Italy, the SARS-CoV-2 pandemic showed the devastating consequences of a widespread biological risk not only for the general population, but also for healthcare workers that diagnose COVID-19 and treat patients. In the set of preventive measures taken to reduce this contagion, a fundamental role in personal protection is played by equipment suitable for preventing the contaminated air inhalation. Despite this severe biological risk during the first epidemic phase, some institutional operating protocols and recommendations have shown limitations and contradictions and, therefore, they must not be repeated. It was observed a widespread inadequate use of respiratory protections, such as surgical masks, which show a low efficacy for health workers; adequate respiratory protective devices are instead rarely used, while their use should have been guaranteed more extensively than it is recommended and noticed, according to the current work hygiene legislation.

[Death certification of pleural malignant mesothelioma from the Italian National Institute of Statistics: a comparison on 269 clinical diagnosis confirmed at autopsy (1997-2016)]

OBJECTIVES

To evaluate the agreement between pleural malignant mesothelioma diagnosis in life, with diagnoses confirmed at autopsy, and the certification of the cause of death in the form of the Italian National Institute of Statistics (Istat).

DESIGN

comparison between autopsic cases and cases from Istat.

SETTING AND PARTICIPANTS

two series of autopsy diagnoses of pleural malignant mesothelioma placed from 1997 to 2016; 185 in shipyard workers and 90 in Brescia province inhabitants, for whom the Istat death form was acquired for 180 and 89 subjects, respectively.

RESULTS

the general agreement between pleural malignant mesothelioma clinical diagnosis in life and death certification was about 91% for the first group and 92% for the second one. In the first group, the age at diagnosis does not affect the accuracy of the death certification, which instead increased over time to become total in the period 2010-2016.

CONCLUSIONS

the study suggests that the agreement between pleural malignant mesothelioma clinical diagnosis and certification of the cause of death appears to be very high.

Accuracy of pleural biopsy for the diagnosis of histologic subtype of malignant pleural mesothelioma: Necropsy-based study of 134 cases

BACKGROUND

Definition of histologic subtype of malignant pleural mesothelioma (MPM) is important for management of patients, because surgical treatment improves prognosis for patients with epithelioid but not biphasic or sarcomatoid MPM. In a series of necropsies performed in a hospital specialized for MPM diagnosis, we retrospectively investigated the accuracy of histologic diagnosis performed on pathologic specimens collected through pleural biopsies obtained at video-assisted thoracoscopic surgery (VATS) or surgery.

METHODS

We reviewed histologic records of an unselected series of autopsies performed in patients with MPM employed in the Monfalcone shipyards (Northeast Italy) or living with shipyard workers from 1999 through 2017. Using necropsy results as a gold standard, we calculated sensitivity, specificity, and positive and negative predictive values of histology from VATS or surgery after combining nonepithelioid subtypes.

RESULTS

We retrieved necropsy records for 134 patients: 62 (46.3%) with epithelioid, 51 (38.1%) with biphasic, and 21 (15.7%) with sarcomatoid MPM. We observed good sensitivity of VATS (0.94) and surgery (0.89) in diagnosing epithelioid MPM. Conversely, specificity was low (VATS: 0.46; surgery: 0.32). Therefore, positive predictive values were also low (VATS: 0.58; surgery: 0.60). Misclassification was particularly high for biphasic MPM (three-fourths of biphasic MPM at necropsy had been classified as epithelioid at VATS or surgery).

CONCLUSIONS

We observed a substantial degree of misclassification between epithelioid and biphasic MPM for pleural biopsies performed during VATS. Our results suggest caution should be taken in using histologic subtype obtained from VATS in selecting patients with MPM for surgical treatment. We also observed substantial misclassification of biospecimens collected during MPM surgery.

Lung Asbestos Fibre Burden and Pleural Mesothelioma in Women with Non-occupational Exposure

BACKGROUND

Malignant pleural mesothelioma (MPM) due to environmental and familial (domestic) asbestos exposure is well recognized. However, information on cumulative asbestos dose in subjects affected by MPM is limited.

OBJECTIVES

To evaluate the residual lung asbestos fibre and asbestos body burden in women with MPM with past environmental and/or familial asbestos exposure.

METHODS

We collected lung samples from autopsies regarding 15 non-occupationally asbestos-exposed MPM cases, divided in three groups: (i) familial exposure from the Fincantieri shipyards in Monfalcone (No. 7), (ii) environmental and familial asbestos exposure from the asbestos-cement plant Fibronit in Broni (No. 6), and (iii) environmental exposure from the Fibronit plant (No. 2). Asbestos body (AB) and fibres (AF) per gram of dry lung tissue were counted by optical and scanning electron microscopy, respectively, and expressed as geometric means and standard deviations (GM, GSD).

RESULTS

GM/GSD of AB counts were 6123/9.6 (Group 1), 13 800/10.4 (Group 2), and 8400/1.1 (Group 3); GM/GSD of AF were 0.6/2.1 (Group 1), 7.9/2.1 (Group 2), and 6.0/2.3 (Group 3) million. Pleural plaques were observed in 12 cases.

CONCLUSIONS

Exclusive familial exposure to asbestos determined cumulative doses close to those observed in moderate occupational exposure circumstances. Our results also suggest that combined environmental and familial exposures may cause unexpectedly high cumulative fibre doses.

[Asbestos exposure and related diseases among friction products workers (1971-2016)]

Worldwide studies have been published on the mortality of workers employed in asbestos-based materials for the production of clutches and brakes. However no one of these studies is related to Italian cases. Furthermore, not even surveys have been conducted in Italy to characterize the correlation between asbestos exposures and the possible occurring of asbestos-related disease. Our objectives are the following: i) to assess and quantify the asbestos exposure cases, ii) to describe the nature and the frequency of asbestos-related diseases among blue collar employees of an important factory producing brakes and clutches with chrysotile asbestos content from 1971 to 1993 and iii) to provide preliminary data on cumulative asbestos exposure estimated using lung fibre burden analysis. Critical appraisal of airborne asbestos fibre measurements and identification of cases of asbestos-related diseases between the blue collar employees, either notified to the local health authority or recovered from the Italian national Mesothelioma registry was investigated. Lung fibre burden analysis using the lung tissue samples from two deceased blue collar employees was also performed. Airborne asbestos fibre measurements (carried out in 1982) suggested asbestos fibres average concentrations of about 0.3 f/ml, while all 1992 measurements showed results below 0.1 f/ml. Furthermore, since 1988, we identified four cases of pleural plaques, three cases of asbestosis and seven cases of lung cancer. No case of malignant mesothelioma was found. In both lung cancer cases, analysed to measure the lung fibre burden, commercial amphiboles were absent or in limited concentration but chrysotile and, especially, tremolite asbestos were present in noticeable amount. In conclusion, since 1971 and up to early 1980s, exposure to chrysotile asbestos and talc, likely contaminated by tremolite, had been significant and comparable to levels causing asbestosis long-term risk. No case of malignant mesothelioma was found, that is consistent with the absence of amphiboles and with the lower risk of mesothelioma associated with the chrysotile asbestos. However a subset of the blue collar employees, the ones employed later on, could still have not reached the full risk condition, and so being still at risk of developing malignant mesothelioma. In the two lung cancer cases studied, the lung fibre burden was essentially made of chrysotile and tremolite. Lastly, lung cancer occurrence in the population of blue collar employees has been likely underestimated and the correct determination of lung cancer risk should be done through the mortality analysis of this population.

Diagnosis of lung cancer: a necropsy-based study of 128 cases (1997-2016)

BACKGROUND

The diagnosis of lung cancer (LC) may be difficult to make in the elderly. We report on the diagnostic elements available in life in an LC necropsy case series of asbestos-exposed workers and describe the frequency of non-neoplastic asbestos-related diseases as biological exposure indices.

METHODS

We reviewed pathologic and clinical records of an unselected series of autopsies (1997-2016) in patients with LC employed in the Monfalcone shipyards. We assessed the consistency with autopsy results of diagnoses based on, respectively, radiologic, cytologic, and histologic findings.

RESULTS

Data on 128 autopsy-confirmed LC cases were available; in life, 119 had been diagnosed as LC. Among these, 49 had histologic confirmation of diagnosis (17 with immunophenotyping); histology had been negative in 4. Cytology had been the main positive finding and the basis for diagnosis in 24 cases, but had been negative in 13. Chest computed tomography had been the basis for diagnosis in 45; in 18 cases, it had been negative. Nine patients had received a diagnosis different from LC, among whom 4 had been suspected to have malignant pleural mesothelioma by chest computed tomography. Pleural plaques were found in 124 and histologic asbestosis in 46 cases.

CONCLUSIONS

Autopsies confirmed all LC diagnoses received in life, including 46 that would have been considered only possible LC based on clinical workup. The overall survival in this case series was poor. The high prevalence of pleural plaques and asbestosis suggest severity of asbestos exposures.

Silicosi severa da terre di diatomee nella produzione di alginato ad uso odontoiatrico: uno studio necroscopico

BACKGROUND

Severe silicosis from occupational exposure to calcined diatomaceous earth has been observed in the past, due to the high-temperature transformation of amorphous silica in crystalline phases, mainly cristobalite. In dental alginate production and use a silica exposure may be underestimated.

OBJECTIVES

To describe the clinical picture, the scenario and pattern of occupational exposure to silica and the corresponding necroscopic findings of a case of silicosis in a worker engaged in the production of alginates for dental use.

METHODS

A commercial sample of calcinated diatomaceous earth and necroscopic lung samples were analysed by scanning electron microscopy (SEM-EDS) and X-ray diffraction (XRD) for the quali-quantitative determination of crystalline silica. Material safety data sheets (MSDSs) of diatomaceous earth produced in 2002 and 2018 were examined to assess the information content on silicosis risk. Clinical findings and post-mortem examinations of the worker are evaluated.

RESULTS

A cristobalite concentration of 36% (wt/wt) was determined in the diatomaceous earth sample and a large amount of diatom fragments were observed in lung samples. The DRX spectra indicated the presence of cristobalite either in the bulk sample or in the lung tissues. The MSDS dated 2002 reported the presence of SLC up to 63% with cristobalite concentrations minor of 60%, and the resulting risk of silicosis, while the MSDS dated 2018 and referred to a commercial product currently on the market indicated a concentration of cristobalite minor of 1% and no risk of silicosis. The worker was suffering from a severe silicosis, histologically confirmed by necropsy.

CONCLUSION

The present case-study revealed that the risk of silicosis from calcined diatomaceous earths used to produce dental alginates has been ignored. The lack of engineering controls and personal protection measures led to a high cristobalite lung burden, consistent with the development of a severe silicosis that were a contributing factor of death. A MSDS of a commercial product currently on the market does not report this serious hazard.

[About the asbestos and the Position Paper on asbestos of the Italian Society of Occupational Medicine]

The SIML Position Paper dedicated to asbestos (PPA) is addressed (mainly) to competent practitioners (CP) for the purposes to provide a guidance about a set of items classified as markedly interesting: the actuality of asbestos exposure and the evaluation of the related risk; the diagnosis of the asbestos related diseases; the shape of the risk functions (namely about mesotheliomas); the causal relationship between exposure and disease; the medical surveillance of the workers currently and previously exposed. The scientific literature doesn't acknowledge the idea that nowadays in Italy the frequency of pleural mesotheliomas deriving from environmental asbestos from outdoor sources exposures is really a relevant item. Inside the SIML PPA the chapter concerning industrial hygiene and environmental monitoring themes shows inaccuracies and deficiencies, so resulting of scarce utility for the CPs that should be called for a more cooperative role in front of the employers. The arguments of the diagnosis of the asbestos related diseases is developed with an undue emphasis upon the differential histological diagnosis of asbestosis and, especially, of pleural mesothelioma: nosographic aspects that hardly are posed to the attention of the CP. A similar emphasis is posed towards the shape of the risk function for pleural mesothelioma, a theme absent from the current practice of the CP such as of other occupational practitioners. In conclusion, next to themes of undoubted interest for the PC, the SIML PPA dwells on the scrutiny of some topics representing critical elements of the current contrast between consultants and valuers in the context of criminal prosecutions: subjects having forensic relevance but far from the "application actuality" for the CP invoked in the PPA. A greater transparency, last but not least, was to have been posed, inside the SIML PPA, in the disclosure of the conflict of interests (COIs) of some Authors, declaring their consultancy in favour of companies.

Relationship between pleural plaques and biomarkers of cumulative asbestos dose. A necropsy study

BACKGROUND

The relationship between pleural plaques and cumulative asbestos exposure is controversial.

OBJECTIVES

To evaluate the relationship between lung asbestos bodies (AB) and fibres (AF) and plaques presence and extension.

METHODS

In a necropsy series of shipyard workers with asbestos-related diseases, we measured counts (per g of dry lung tissue) of AB (thousands) and AF>1 µm (millions). Pleural plaques were classified into three extension grades. We fitted univariate and multivariable linear (dependent variables: AB and AF, log10 transformed) and multinomial (dependent variable: plaques grade) regression models.

RESULTS

We analysed 124 subjects, 13 without plaques 20 with grade 1, 69 with grade 2, and 22 with grade 3 plaques. Geometric means (GM) of AB were 10.6, 23.3, 126, and 140 in the four groups respectively (P=0.0001). GMs for AF (mostly amphiboles) were 1.2, 1.4, 7.3, and 12.9 (P=0.0001). AB and AF were strongly correlated (r=0.81). The likelihood of no plaques and grade 1 plaques decreased with increasing AB and AF doses, with a corresponding increase of grade 2 and 3 plaques. Plaque presence and extension was also associated with histologically verified asbestosis (P<0.001).

CONCLUSIONS

Our study showed a strong positive relationship between pleural plaque presence and extension and both lung asbestos burden and asbestosis.

On the diagnosis of malignant pleural mesothelioma: A necropsy-based study of 171 cases (1997–2016)

Background:

Malignant pleural mesothelioma (MPM) diagnosis is known to be difficult. We report on the diagnostic elements available in life in an MPM necropsy case series and describe the frequency of non-neoplastic asbestos-related diseases as biological exposure indices.

Methods:

We reviewed pathologic and clinical records of an unselected series of autopsies (1977–2016) in patients with MPM employed in the Monfalcone shipyards or living with shipyard workers. We assessed the consistency with autopsy results of diagnoses based on, respectively, radiologic, cytologic, and histologic findings, with and without immunophenotyping.

Results:

Data on 171 cases were available: for 169, autopsy confirmed the MPM diagnosis. In life, 119 cases had histologic confirmation of diagnosis, whereas 7 were negative; all cases without immunophenotypization were autoptic MPMs. Cytology alone had been positive in 18 autoptic MPM cases, negative in 14. Radiologic imaging alone had been positive in another 16, negative in 11. In the 2 cases not confirmed at autopsy, MPM had been suspected by chest computed tomography only. Bilateral pleural plaques were found in 144 and histologic evidence of asbestosis in 62 cases.

Conclusions:

Autopsies confirmed 169/171 cases, including cases that would not be considered as certain based on diagnosis in life. Radiologic imaging, cytologic examination of pleural effusions, or both combined had low sensitivity but high positive predictive value: when they are positive, proceeding to thoracoscopy should be justified. MPM has been correctly diagnosed even without immunohistochemistry. The prevalence of pleural plaques and asbestosis was high due to severity of asbestos exposures in these cases.

Effects of Combined Therapies on the Survival of Pleural Mesothelioma Patients Treated in Brescia, 1982–2006

Aims and background

During the 1990's, the traditional unimodal treatments (surgery, radiotherapy, chemotherapy, immunotherapy) for malignant pleural mesothelioma started to be combined in bimodal or multimodal strategies. However, recent population-based analyses of the survival of patients with malignant pleural mesothelioma indicate that even these treatments have not led to significant improvements in prognosis, which remains very poor. The present study assessed the survival of patients given combined treatments and multimodal therapies in a specialized hospital department.

Methods

The study population comprised 530 patients diagnosed with malignant pleural mesothelioma from 1982 to 2006: 343 of them were residents in the province of Brescia (Lombardy, Northern Italy) and 187 were residents outside the province, with a follow-up to 31 December 2009. Kaplan-Meier survival analyses and Cox proportional risks model were used to test sex, age at diagnosis, histological type and treatments, as prognostic factors.

Results

The estimated median survival for the whole group of patients was 317 days (257 for residents and 398 for non-residents), and respectively 310 and 340 days in the groups diagnosed in the periods 1982–2000 and 2001–2006. Multivariate analysis confirmed that the prognosis was better for younger patients and cases of epithelioid type malignant pleural mesothelioma, whereas for patients receiving any single treatment the prognosis was not significantly better than for those given palliative care alone. However, patients receiving combined treatments or the multimodality approach had significantly longer median survival and the relative risk of death was respectively 0.57 and 0.61 compared to untreated patients (or those only given symptomatic therapy).

Conclusions

This is the first study in Italy to assess the effectiveness of different treatment approaches in a significant number of patients treated in one hospital. Further studies are needed to confirm the improvement in prognosis – even if modest – on larger numbers of patients and taking into account the different stages of the disease.

Pleural mesothelioma in doll manufacture: possible asbestos exposure

BACKGROUND

The occurrence of malignant mesothelioma is almost always causally associated to asbestos exposure but, considering women occurrences, this association is often difficult to demonstrate and consequently the asbestos exposure is defined as 'unknown'.

OBJECTIVES

To describe the working activity and to give occupational asbestos exposure probability estimation related to an uncommon and poorly investigated productive sector: doll manufacture.

METHODS

From the Province of Brescia Mesothelioma Registry, established in 1993 on population-based criteria, we have extracted the certified mesothelioma diagnosis cases, related to patients who were employed for some time in doll manufacture.

RESULTS

Among the 757 total cases of malignant mesothelioma registered and studied up to 2016, we found 3 cases of pleural epithelial mesothelioma histologically diagnosed in young women who had worked in two doll manufacturing companies and whose asbestos exposure had been initially defined as 'unknown', because an environmental, family or extra-professional asbestos exposure was considered unlikely. However, the judicial autopsy performed on one of the 3 women had allowed examining lung tissue samples with Scanning Electron Microscopy. This technique showed a concentration of amphiboles fibers of about 12,000,000 per gram of dry lung tissue, with a consequent re-classification of asbestos exposure from 'unknown' to 'occupational certified'.

DISCUSSION

Mesotheliomas in women with no apparent occupational asbestos exposure are normally referred to life or family environmental exposure. Moreover, it is known that occupational asbestos exposure in women is difficult to recognize. Previously, only one publication had reported two cases of mesothelioma in cloth doll manufacture. The occurrence of two mesothelioma cases in the same company out of the three here presented was suggesting an occupational exposure. The finding of a high amphibole fibers lung concentration confirmed the previous hypothesis, despite the impossibility to determine the circumstances with good evidence.

CONCLUSION

The three cases of mesothelioma in doll production workers suggest that also in this restricted manufacturing sector had occurred an occupational asbestos exposure, which is up to now unknown and isn't due only to the use of sewing or ironing machines. The lung asbestos fibers burden analysis is confirmed to be a decisive factor in the assessment of mesothelioma cases with 'unknown' exposure.

Occupational exposure to PCDDs, PCDFs, and DL-PCBs in metallurgical plants of the Brescia (Lombardy Region, northern Italy) area

The concentration values of polychlorodibenzodioxins (PCDDs), polychlorodibenzofurans (PCDFs), and dioxin-like polychlorobiphenyls (DL-PCBs) in blood serum samples (pools) of metallurgical workers in the area of the city of Brescia (northern Italy) were statistically processed. As to workers' exposure characteristics, pools were divided into 34 professionally exposed (PE) and 11 non-professionally exposed (NPE). A further subdivision of PE pools was according to workplaces in which ferrous (N = 24) and non-ferrous (N = 10) materials were handled. To evaluate the aforesaid differences we applied the age-adjusted Generalized Linear Models. We identified significant (P ≤ 0.05) exposure models of the classification groups. The first subdivision was confirmed by the concentrations of 1,2,3,4,6,7,8-H₇CDF, DL-PCB 105, and DL-PCB 189; the second was confirmed by the concentrations of PCDF TEQ₉₇, PCDD + PCDF + DL-PCB (TEQ_TOT) TEQ₉₇, 2,3,4,7,8-P₅CDF, 1,2,3,6,7,8-H₆CDD, 1,2,3,4,6,7,8-H₇CDD, and PCB 189. Based on the literature, all mentioned congeners have been found in stack gas and fly ash samples of metallurgical plants: therefore, these indicators indicate the exposure to such work environments. Specifically, the concentrations measured in the workers' blood serum appear to depend on the type of material processed during work.

Residual fibre lung burden among patients with pleural mesothelioma who have been occupationally exposed to asbestos

OBJECTIVES

To evaluate the lungs asbestos fibres concentration in participants with malignant pleural mesothelioma (MPM) who have been occupationally exposed.

METHODS

The lung samples were obtained from pleuropneumonectomies or autopsies of 271 male MPMs. The lung samples were examined through scanning electron microscopy. Retrospective assessment was used to assess for asbestos exposure. This study includes 248 MPMs with an occupational exposure defined as either 'definite' or 'probable' or 'possible'.

RESULTS

The participants had finished working in asbestos exposure conditions more than 20 years ago (on average 26.1±11.0 years). The fibre burden resulted with a geometric mean equal to 2.0 (95% CI 1.6 to 2.4) million fibres per gram of dry lung tissue. The burden was higher among participants employed in asbestos textiles industry and in shipyards with insulation material, if compared with construction workers or non-asbestos textile workers or participants working in chemicals or as auto mechanics. 91.3% of MPMs had a detectable amount of amphibole fibres. A strong lung clearance capability was evident among workers exposed to chrysotile fibres. Owing to that, the 1997 Helsinki Criteria for occupational exposure were reached in <35% of cases among participant working in construction, in metallurgical industry, in chemical or textile industry and among those performing brake repair activities.

CONCLUSIONS

The MPM cases are now occurring in Italy in participants who ceased occupational asbestos exposure decades before the analysis. A large majority still shows a residual content of amphibole fibres, but given the lung clearance capability, attribution to occupational exposure cannot rely only on fibres detection.

[Not Available]

BACKGROUND

Asbestos-related diseases among shipyard workers are well known in Italy but descriptive long-term studies are limited; asbestos has been extensively used but the past exposure intensity has never been estimated because data from environmental and biological monitoring are almost absent.

OBJECTIVES

To describe the asbestos-related dis-eases (1996-2015) diagnosed among shipbuilding workers from a very important shipyard in Northern Italy, and to assess past asbestos exposure levels by cumulative dose indices, fibres and asbestos bodies.

METHODS

The cases of workers suffering from asbestos-related diseases diagnosed from 1996 to 2015 were collected on the occasion of some legal trials; the diagnosis, and the asbestos occupational and non-occupational exposure, were carefully evaluated.Lung samples were obtained from subjects, taking advantage of the autopsies; asbestos fibers were counted by means of a Scanning Electron Microscope, equipped with x-ray fluorescence microanalyses at 12.0000 amplification, and asbestos bodies by means of an Optical Microscope at 500 amplification.

RESULTS

192 malignant mesotheliomas (6 in women), 196 lung cancers and 14 asbestosis (without cancer) were observed (1996-2015); autopsies were carried out on 80% of all subjects and 98% of mesotheliomas were confirmed by autopsies. Pleural plaques occurred on 90% of mesotheliomas and 87% of lung cancers; histologically mild asbestosis were diagnosed on 28% of mesotheliomas and 48% of lung cancers. In malignant mesothelioma and lung cancer cases respectively, the duration of occupational exposure was on average 24 and 23 ys, the latency time 48 and 46 ys, hiring at the shipyard before 1970 24 and 23 ys. Out of 114 lung analysis, the burden of asbestos fibres was >10 million for 33.3% of subjects and out of 99 lung analysis asbestos bodies was >10.000 for 71.7%; the average time since last exposure was 31 ys. Both asbestos fibres and asbestos bodies concentrations were significantly higher (GMR 2,5) among mesothelioma vs lung cancer.

CONCLUSION

A relevant number of asbestos-related diseases among shipbuilding workers, mainly mesothelioma and lung cancer, exposed in shipyard until the 1980's were identified by an active search. Thanks to several autopsies, the diagnoses of cancer are confirmed as a cause of death, and a high frequency of histological asbestosis, previously ignored,was shown. The lung burden analysis of asbestos bodies and asbestos fibres, the largest ever performed among ship-building workers, confirms the spread and relevance of asbestos exposure. The best estimate of past exposure intensity was provided by both biological indices.

[Pleural mesothelioma in a school teacher: asbestos exposure due to DAS paste]

BACKGROUND

Malignant mesothelioma cases among primary school teachers are usually linked with asbestos exposure due to the mineral contained in the building structure. Among the approximately 12,000 cases of mesothelioma described in the fourth report of the National Mesothelioma Register, 11 cases of primary school teachers are reported, in spite of the fact that the "catalogue of asbestos use" does not describe circumstances of asbestos exposure other than or different to that due to asbestos contained in the buildings. Four cases in the Brescia Provincial Mesothelioma Register are identified as teachers, without this circumstance of exposure.

OBJECTIVES

To characterize the asbestos concentration and fibre type retained in the lungs of a teacher reported as a new mesothelioma case and preliminarily classified as of unknown asbestos exposure.

METHODS

The mesothelioma case presented here was diagnosed at age 78 and malignant mesothelioma was confirmed at autopsy; the patient was interviewed directly for occupational history. Samples of lung parenchyma from necropsies were collected, stored and analyzed by scanning electron microscope (SEM) and samples of DAS paste were analyzed by SEM to detect asbestos fibre content.

RESULTS

It was possible to confirm past exposure to DAS paste in forming and finishing dry items and toys during school recreational activity almost every day from the mid-60s to about the mid-70s. Subsequent SEM analysis showed: i) chrysotile fibres were found in an old and unused pack of DAS paste; ii) a lung burden of 1,400 asbestos bodies, 310.000 total asbestos fibres (33% chrysotile, 67% amphibole) and 210.000 talc fibre per gr/dry lung tissue was detected from necropsies performed on the subject. These results seem to be in agreement with an occupational exposure to asbestos due to past use of DAS paste. After the investigation, this case was reclassified from "unknowun" to " sure" occupational asbestos exposure. The occupational origin of the tumour was recognized by the Italian Workers' Compensation Authority (INAIL).

CONCLUSION

This case suggests i) the need to carry out any possible detailed studies of the circumstances and exposure sources whenever any mesothelioma case is classified as "asbestos exposure unknown", according to the guidelines of the National Mesothelioma Register, ii) handling of DAS paste can be considered as sure asbestos exposure and iii) it should be borne in mind that mesothelioma cases can occur even after cumulative low, occupational exposure, even only to chrysotile.

[Symptoms and upper limb work-related musculo-skeletal disorders among 173 supermarket cashiers]

BACKGROUND

Cashiers in supermarket chains have long been considered at risk for the development of work related musculo-skeletal disorders of the upper limbs (UL-WMSDs). The aim of this study was to assess the prevalence of UL-WMSDs among workers operating supermarket cash tills and, after clinical tests, their frequency.

METHODS

A standardized questionnaire was given to a random group of 173 workers in order to collect information regarding symptoms in the upper limbs (pain and parasthesia). Among the 111 workers who reached a "positive clinical history threshold" we selected a random sample of subjects to undergo clinical tests (professional medical care, ultrasound examination, electro-neurographic examination).

RESULTS

64% of the workers had a positive clinical history for UL-WMSDs. The most frequently reported disorder was pain, especially in the shoulder, while 37% of workers suffered from one or more disorders of the upper limbs. Clinical tests were performed on 51 workers (47 women) whose average length of service was 20 years and 2/3 were part-time workers; a total of 43 UL-WMSDs (59%) were diagnosed in 30 workers, including 13 (30.2%) cases of compressive neuropathies, 13 cases of hand/elbow tendinitis (30.2%) and 17 cases of shoulder tendinitis (39.5%). The average age of these 30 subjects was 47 years, with a length of service of 23 years, mostly part-time workers.

CONCLUSIONS

We found a high prevalence of general disorders and cases of UL-WMSDs among the workers investigated, including part-time workers and workers who were not working exclusively as cashiers. The study also revealed a poor health surveillance programme to identify/ UL-WMSDs that should be the responsibility of the occupational physician and a consequent underestimation of risk and lack of the information needed to adopt preventive measures.

Occupational exposure to PCDDs, PCDFs, and PCBs of metallurgical workers in some industrial plants of the Brescia area, northern Italy

BACKGROUND

The study was carried out in order to respond to public concern on the occupational exposure of metallurgical workers to highly toxic PCDDs, PCDFs, and PCBs in the area of the city of Brescia, northern Italy.

OBJECTIVES

The study investigated the effects on the haematic burden of occupational exposures to the aforesaid contaminants in different work environments, attempting to establish causal relationships and providing indications for occupational health preventive measures.

METHODS

Chemical concentrations were measured in blood serum of "professionally exposed" (PE) and "not professionally exposed" (NPE) subjects. NPE subjects included industrial administrative employees, Brescia inhabitants, and remote rural people.

RESULTS

The central tendency indexes of contaminant cumulative concentrations were higher in PE than in NPE samples (for the mean values: PCDDs+PCDFs, 22.9 vs. 19.5 pgWHO-TEQ(1997)/g lb; DL-PCBs, 26.0 vs. 23.6 pgWHO-TEQ(1997)/g lb; PCDDs+PCDFs+DL-PCBs (TEQ(TOT)), 48.9 vs. 43.1 pgWHO-TEQ(1997)/g lb; Σ(6)[NDL-PCBs], 427 vs. 401 ng g(-1)lb); however, no statistical differences were detected at P=0.05. A significant difference for PCDDs+PCDFs and TEQ(TOT) was observed as the NPE data were progressively reduced to those of the remote rural people. The existence of a differential occupational exposure due to different environments was detected by applying the factor analysis to congener-specific data (analytical profiles).

CONCLUSIONS

Findings indicate that metallurgical workers may be exposed to PCDD, PCDF, and PCB more than the general population, in particular due to non-negligible contributions to exposure from workplace ambient air. Findings also suggest that an improvement of preventive measures may be required to avoid chemical overexposure in certain metallurgical workplaces. To identify exposure groups, the DL- and NDL-PCB analytical profiles seemed to be more sensitive to environmental exposure sources/pathways than those of PCDDs and PCDFs.

Effects of combined therapies on the survival of pleural mesothelioma patients treated in Brescia, 1982-2006

AIMS AND BACKGROUND

During the 1990's, the traditional unimodal treatments (surgery, radiotherapy, chemotherapy, immunotherapy) for malignant pleural mesothelioma started to be combined in bimodal or multimodal strategies. However, recent population-based analyses of the survival of patients with malignant pleural mesothelioma indicate that even these treatments have not led to significant improvements in prognosis, which remains very poor. The present study assessed the survival of patients given combined treatments and multimodal therapies in a specialized hospital department.

METHODS

The study population comprised 530 patients diagnosed with malignant pleural mesothelioma from 1982 to 2006: 343 of them were residents in the province of Brescia (Lombardy, Northern Italy) and 187 were residents outside the province, with a follow-up to 31 December 2009. Kaplan-Meier survival analyses and Cox proportional risks model were used to test sex, age at diagnosis, histological type and treatments, as prognostic factors.

RESULTS

The estimated median survival for the whole group of patients was 317 days (257 for residents and 398 for non-residents), and respectively 310 and 340 days in the groups diagnosed in the periods 1982-2000 and 2001-2006. Multivariate analysis confirmed that the prognosis was better for younger patients and cases of epithelioid type malignant pleural mesothelioma, whereas for patients receiving any single treatment the prognosis was not significantly better than for those given palliative care alone. However, patients receiving combined treatments or the multimodality approach had significantly longer median survival and the relative risk of death was respectively 0.57 and 0.61 compared to untreated patients (or those only given symptomatic therapy).

CONCLUSIONS

This is the first study in Italy to assess the effectiveness of different treatment approaches in a significant number of patients treated in one hospital. Further studies are needed to confirm the improvement in prognosis - even if modest--on larger numbers of patients and taking into account the different stages of the disease.

[Dust and silica exposure on metallurgical furnace maintenance using refractory materials]

In the metallurgical industries the silica risk has long been known, particularly for the refractoryes maintenance workers. The maintenance of furnaces, ladles and tundisches refractory linings, on the current organization of production, is provided by companies under contract. The information available about the characterization of risk for this group of workers are at present inadequate. The study investigates the exposure to dust, also containing free crystalline silica (SLC), through the analysis of samples of commercial products used in the reconstruction of refractory linings of furnaces, ladles and tundisches, materials from the demolition of refractory articles and dust from work areas. It also presents the results of an environmental investigation conducted during the demolition and reconstruction of the refractory in three steel mills. The Authors, by the numerous inspections and the systematic survey of working conditions, have formulated a SLC risk profile and some proposals for prevention.

[Cumulative exposure to polychlorodibenzo-p-dioxins (PCDDS), polychlorodibenzofurans (PCDFS) and polychlorobiphenyls (PCB) in the metallurgic workers and the general population in Brescia province, northern Italy]

High temperature metallurgical processes may significantly contribute to the release of polychlorodibenzo-p-dioxins (PCDDs) and polychlorodibenzofurans (PCDFs) into the environment. Aim of this study was to evaluate the exposure to PCDDs, PCDFs, dioxin-like PCBs (DL-PCBs) and non dioxin-like PCBs (NDL-PCBs) in a sample of 300 workers of metallurgical plants operating in the Brescia area and in a control group of 113 men. Serum samples were grouped in pools of 10 and analyzed for their concentration of PCDDs and PCDFs, DL- and NDL-PCBs. Metallurgical workers show serum concentrations of NDL-PCBs similar to those observed in non-occupationally exposed living in Brescia, except in the case of some congeners, such as PCBs 28, 52, 101 which result to be significantly higher in metallurgical workers. Their concentrations range of "dioxins" was of 32.5 - 84.8 pgTEQ g(-1) lb. No significant difference was found between metallurgical workers and the control group on the whole, but the difference became significant when comparing metallurgical workers with the group of the 47 subjects living in remote non industrialised areas. In conclusion, concentrations of total PCBs observed in metallurgy workers are comparable with those observed in the control group, with the exception of a few, more volatile, congeners which resulted to be higher in metallurgy workers. Concentrations of PCDDs and PCDFs showed a range of values similar to that observed in the general population of Brescia not professionally exposed. However, concentrations of PCDDs and PCDFs observed in subjects resident in "remote" areas were significantly lower than those assessed in metallurgy workers and subjects living in the town of Brescia. On the whole, men living in the town of Brescia show levels of PCBs, PCDDs and PCDFs higher than those observed in other groups of the Italian general population, this reflecting the intense industrial activity of the town.

[Critical in demolition and removal of asbestos cement materials]

Those involved in the asbestos removal is the main category of workers currently exposed to asbestos in the province of Brescia. Although Italy, since 1991, has special rules for the protection of workers exposed to asbestos, improved further by D. Lgs. n. 81 of 2008, the working conditions found in shipyards are still far from a satisfactory degree of protection of workers. Sanitary facilities are largely lacking, management of work clothing is left to chance, use of filtering face masks is often incorrect, wetting of surfaces with encapsulant is frequently inadequate, daily cleaning of work areas and areas of construction that may have been contaminated by asbestos fibers with extractors absolute filters is shortly implemented. Little attention is also paid to the protection of workers from the premises concerned to the replacement of the cover, as well as to the dispersion in the external environment of asbestos fibers that contaminate the gutters removed and sent for disposal. Finally, it is still very high risk of falling from, documented by the tribute of serious and fatal accidents that occur in these sites. Increased surveillance of Health Prevention Services of ASL is required to achieve higher levels of prevention.

[Occupational risk and work-related diseases on steel foundries]

The iron foundries are still well represented in the area of Brescia and, despite having been involved in a major technological developments, have still risks to the health of workers. In order to verify the state of the art and effectiveness of prevention measures implemented by various companies, in recent years have carried out numerous inspections, environmental monitoring and biological. Furthermore, there were in the regional information system diseases reported and/or by the reported health. In particular it is shown that, in addition to chemical and physical risk factors, although in a much reduced compared to the 80s, are still present in our workplace pollutants (PAHs, silica, metal fumes, formaldehyde) at the base of classification of iron foundries in group 1, carcinogenic to humans, IARC, 1987 e 2012.

[Lung asbestos fibre burden in textile workers with malignant mesothelioma]

BACKGROUND

Lung burden of amphibole fibres is a good biological index of occupational cumulative asbestos exposure. Malignant mesothelioma (MM) has been amply documented in textile industry workers, dealing either with mineral fibres or with vegetable and animal fibres. So far the concentration of asbestos fibres in lung tissue among textile workers has not been reported in Italy. We analysed asbestos burden in the lung tissue of eleven textile-workers with malignant mesothelioma, mainly employed in industries near Brescia, in the North of Italy.

OBJECTIVES

To characterize lung asbestos concentration and fibre type retained in the lung of asbestos and non-asbestos textile workers.

METHODS

Sample of lung parenchyma from necropsies and extrapleural pneumonectomy were collected, stored and analysed by scanning electron microscope, according to the methods recommended in the current scientific literature. Nine patients were interviewed directly for occupational history.

RESULTS

Eleven cases of MM (10 primary pleural, 1 primary peritoneal) were collected, 9 women and 2 men, aged between 51 and 87 years, 4 asbestos-textile workers and 7 non-asbestos textile workers. The highest values of asbestos fibres were detected in all the workers of the former group and in 3 non-asbestos workers (jute recycling employees), with concentrations between 9.1 and 397 million/g of dried lung tissue. The total fibre concentration in the other 4 non-asbestos textile workers (silk and cotton production workers) ranged from 0.33 to 1.2 million/g of dried lung tissue. In only one of these subjects, did lung amphibole burden exceed 1,000,000 amphibole fibres longer than 1 microm per g of dried tissue. Eight cases out of eleven, showed a higher concentration of amphiboles than chrysotile. We detected amphibole fibres in all the "non-asbestos" textile workers and for two of them a higher concentration of tremolite.

CONCLUSION

i) Among textile workers using asbestos or jute recycling, the asbestos fibre burden is as high as that found in other high risk jobs (e.g. asbestos-cement workers); ii) among non-asbestos textile workers, employed in cotton and silk production, the fibre content in lung tissue was much lower and it was nonetheless above the occupational cut-off for one of them; iii) tremolite found in lung tissue of non-asbestos textile workers with MM could be a contaminant of chrysotile friction materials or originate, with other amphiboles, from some other source as yet to be investigated.

[Pulmonary concentration of asbestos fibers in steel workers with pleural mesothelioma]

The asbestos fibre burden of the lung has been used in the past as a biological indicator of cumulative exposure to the mineral so much so that in 1997 reference limits even for non-occupationally exposed people have been proposed. This kind of analysis was performed on groups of workers of different type of industries and allowed to achieve a qualitative-quantitative estimate of past exposure to asbestos, even in absence of exposure estimates by environmental monitoring. An important example is the steel industry where asbestos was widely used in the past, but for which there are not available exposure estimates of workers. Among the mesothelioma cases collected by the Mesothelioma Registry of the Province of Brescia from 1980 to present there are 55 workers who spent at least 5 years in steel industry, on a total of 289 cases classified as asbestos exposed (19%). For 8 subjects who worked in steel mills and production of electrical steel pipes, of which 4 in the same plant, lung tissue samples were available for the asbestos fibres burden analysis (7 samples coming from autopsies and 1 from extra-pleural pneumonectomy). In all cases the diagnosis was given with histological analyses supplemented with immunohistochemistry. In 7 cases autopsied the diagnosis was confirmed. The work histories have been reconstructed in detail through the interview process, inclusive of details of duties performed. The asbestos fibre burden analyses showed a range of concentrations between 260,000 and 11,000,000 ff per grams of dry tissue; the concentration of amphiboles was much higher than that of chrysotile. The highest body burden was detected in the maintenance workers of the same plant in witch a cluster of malignant mesothelioma was observed. In conclusion, this study illustrates the results of asbestos fibres burden analyses in subjects where exposure to asbestos is sure but not quantifiable. The results showed also that these concentrations can reach values that overlap with those found in asbestos-cement workers and in asbestos-textile workers. These data suggest to consider the cases of mesothelioma occurred in the steel workers at least as "possible" exposure, even in the absence of adequate information on the circumstances of contact with asbestos. This study, although based on a small number of cases, is the only one ever held in Italy on workers in this sector.

Serum concentrations of beta-hexachlorocyclohexane in groups of the Italian general population: a human biomonitoring study

Because of its persistence and toxicological profile, beta-hexachlorocyclohexane (beta-HCH) has been proposed for inclusion in the Stockholm Convention on persistent organic pollutants (POPs). Although the use of technical HCH, which is the primary source of beta-HCH in the environment, has been banned in the EU in 1978 and progressively at a global level, beta-HCH is still detectable in the general environment worldwide. Human exposure mostly occurs via food and may be of concern in areas where illegal use and/or improper disposal of stockpiles occurred and locally grown food is consumed. Exposure of the Italian general population to beta-HCH has been poorly characterised. Lack of human biomonitoring data severely hinders the ability to interpret potential increases in exposure related to situations of environmental risk. We carried out a human biomonitoring study aimed to provide baseline information on background exposure of the Italian general population to this pollutant. For this purpose, we analysed 116 serum samples from groups of subjects of both sex from the general population residing in three Italian towns at different latitudes. Serum concentrations of beta-HCH resulted to be comprised between 1.64 and 300 ng/g fat, with a median value of 18.0 ng/g fat and a 90th percentile of 65.9 ng/g fat. The serum concentrations detected are in line with those detected in most Western European countries.

[PAH exposure in asphalt workers]

BACKGROUND

There has been interest in evaluating the potential carcinogenicity of bitumen fumes in asphalt workers since the 1960's. The IARC classified air-refined bitumens as possible human carcinogens, while coal-tar fumes were classified as known carcinogens. Occupational/environmental PAH exposure can be measured by several urinary markers. Urinary 1-OHP has become the most commonly used biological marker of PAH exposure in asphalt workers.

OBJECTIVES

The aim of this study was to assess asphalt workers' exposure levels by monitoring 1-OHP urinary excretion and compare this data with those of non-occupationally exposed subjects.

METHODS

We investigated three groups of asphalt workers: 100 in summer 2007, 29 in winter 2007, and 148 during summer 2008 and compared 1-OHP urinary concentrations using Kruskall-Wallis test.

RESULTS

Median 1-OHP urinary concentrations during the three biomonitoring sampling periods were 0.65, 0.17 and 0.53 microg/g creatinine respectively. There was a significant difference in 1-OHP values between the three groups (p < 0.001).

CONCLUSIONS

our study showed that PAH exposure of asphalt workers' is higher than that observed in the general population and in workers in urban areas. Our results suggest that PAH exposure in the three groups studied is not sufficiently kept under control by the use of personal protective equipment and that biomonitoring is useful in evaluating PAH exposure and for risk assessment. Regulations need to be enforced for workers exposed to cancer risk, such as the register of workers exposed to carcinogens.

[To-day exposure to occupational carcinogens and their effects. The experience of the rubber industry, iron metallurgy, asphalt work and aviculture]

While the progressive improvement of hygiene situations in the workplaces has taken to a reduction of chemical carcinogens exposure, in recent years in Italy the number of compensated occupational cancer resulting from carcinogens exposures of distant decades, has been increasing. Nevertheless, several experiences suggest that the proportion of occupational cancers unrecognised and not notified, as required by law, still remains important. This contribution concerns some experiences, performed between 2004-2008 by the Local Occupational Health Service (SPSAL) located in a highly industrialised province, on the working sector of rubber, iron and steel industry, the asphalt working and the poultry stock-breeders. This work concerns the following issues: - the evaluation of carcinogens exposure; - technical preventive measures and personal protection; - the level of workers' information and formation and the registration of exposed workers; - the characterization of work-related cancer. The results of the 5 years of activity allow us to underline that, in the most of 49 plants involved in the study, the carcinogens exposure evaluation and the prevention and protection measures were lacking. Information of workers was largely deficient and the registration of exposed workers was absent. A major attention to detect and to evaluate the work-related cancer has allowed us to recognize 50 new cases in the iron-steel industries and 21 new cases in a rubber industry. Although this experience concerns only few occupational fields, it provides the basis to call for a greater commitment of SPSAL addressed to companies and general practitioners to both, the promotion and surveillance of the correct procedures of carcinogens exposure evaluation and his prevention, and the active detection of occupational cancer, still missing.

[Work-related carpal tunnel syndrome. Motivations and results of a surveillance system]

BACKGROUND

Current statistics show that work-related carpal tunnel syndrome (CTS) has been increasing constantly over the last ten years. Nevertheless, available data on the incidence of CTS in the general population and on the occupational proportion of the aetiology of this disease suggest considerable underreporting of work-related cases, which reflects on the number of cases reported to INAIL (National Insurance Institute for Industrial Accidents) and does not give an accurate epidemiological picture of their origin and distribution. For this reason, in the course of a prevention programme of upper limb disorders due to biomechanical overload, a second experiment concerning CTS surveillance system was carried out by collecting self-reported information via postal questionnaires. The aim of this study was to estimate the prevalence of work-related cases in the selected group of the general population and to identify work tasks and factories with significant risk of CTS clusters.

METHODS

From the hospital discharge lists of the Province of Brescia for 2001 and 2005, 1558 surgical cases were selected, aged 18-65 years, excluding housewives (nearly 25% of the total); thus 637 surgical cases were included in the study (68.6% female and 31.4% male).

RESULTS AND CONCLUSIONS

Obesity frequency was observed to be higher in the sample than in the general population. This was not the case for diabetes. The probability of surgical CTS cases attributable to occupational exposure was estimated by dividing the 637 cases into three exposure categories:probable, possible and improbable with results of respectively 44.4%, 36.6% and 19%; in the first category, the frequency among females was 78.8%. The CTS cases among females less than 40 years old was 40% in the probable exposure category versus 10% into the improbable exposure category. In the latter category, the prevalence of concomitant hand tendinitis was 11% versus 22% in the probable exposure category. Obese patients fell into the three occupational risk groups in the same proportion. Among the 283 STC cases considered as probable occupational exposure cases, only 11 were reported as required by law to the Occupational Health Service. Whereas a number of work tasks and work sectors with high risk factors were confirmed, there were relatively few factories with a possible presence of clusters, probably due to the small sample size compared to the general population and to the density of the factories potentially at risk. The epidemiological surveillance thus carried out provided more evidence confirming the serious underreporting of the work-related STC cases in a highly industrialised province and also provided useful information on the local situation regarding high-risk occupations, which need to be addressed via interventions of primary prevention should, possibly with greater involvement of the occupational physicians.

Survival of pleural malignant mesothelioma in Italy: a population-based study

A median survival time of about 9 months is generally reported among malignant pleural mesothelioma cases. Recently, better results in terms of survival and performance status have been reported in clinical trials that included highly selected patients. We describe the survival of pleural mesothelioma patients and the factors predictive of survival in an unselected, population-based setting. Pleural mesothelioma cases (4,100) registered from 1990 to 2001 by 9 Italian regional mesothelioma registries contributing to the network of the National Mesothelioma Registry were followed until December 31, 2005. Univariate (Kaplan-Meier) and multivariate (Cox proportional hazards regression) analyses of survival were carried out according to selected individual characteristics, including limited information on treatment in a subset of 578 cases. The median survival time was 9.8 months (95% confidence interval: 9.4-10.1). In multivariate analysis, younger age at diagnosis and epithelioid histotype were associated with significantly reduced hazard ratios. Positive effects of gender (women) and being diagnosed in a hospital with a thoracic surgery unit were of border-line statistical significance. No association with calendar period of diagnosis or asbestos exposure was present. Treatment was not associated with a statistically significant improvement in survival. This is the largest population-based study on survival in patients with pleural mesothelioma to date. Age and morphology were the main prognostic factors. Results regarding the effect of treatment were disappointing but may be useful to assess the future impact, at the population level, of recently introduced therapies.

[Asbestos fibre lung burden and exposure indices in asbestos-cement workers]

BACKGROUND

In many previous studies, the asbestos fibres retained in the lung were regarded as a good index of cumulative occupational asbestos exposure. Twelve workers suffering from asbestos-related diseases and had been employed in an asbestos-cement factory operating from 1961 to 1994 underwent post mortem investigations in the course of a criminal law suit.

OBJECTIVES

Samples of lung tissues were collected for electron microscopy analysis to measure the asbestos fibre burden of the lungs in workers with high exposure, and assess the possible correlation between asbestos fibre lung burden and the estimated levels of cumulative exposure.

METHODS

Samples of lung parenchyma obtained from a consecutive series of 12 post-mortem examinations that were performed between 1994 and 2007and included 5 cases of malignant pleural mesothelioma, 4 lung cancers, 1 case of asbestosis and2 ofpleuralplagues, were collected, stored and analysed by SEM electron microscopy, according to the methods suggested by the current scientific literature. For each worker, all males, a detailed occupational history was reconstructed by means ofpersonal interviews; both the measurements of airborne asbestos fibresperformed by the factory in the 1970's and the duration of each single job in the plant were taken into account to estimate an individual cumulative exposure index.

RESULTS

A wide variation of total asbestos fibre concentrations in the lung (1,320-118 million) was observed; in all 12 workers, the lung amphibole fibre burden exceeded 1,000,000 fibres per g/dry tissue, The highest values were detected in the mesothelioma cases, in which the mean fibre concentrations differed statistically (t=2.29, p=0.045) from the mean calculated for the other asbestos-related diseases; in 9 subjects only amphibole fibres were detected. There was a good correlation between total asbestos fibre concentration and cumulative exposure index (r=0.91, p<0.0001).

CONCLUSION

This study, which was numerically the biggest ever performed in Italy for this category of workers, confirms a wide range of total asbestos fibre burden in heavily occupationally exposed workers and showed that of the asbestos-related diseases, the highest lung concentrations of asbestos fibres were reached in cases of mesothelioma. It was also observed that almost the entire lung burden consists of only amphibole fibres, all exceeding 1 million per gramme of dry tissue. This study tested a synthetic cumulative occupational exposure index, which appears to be well correlated to the level of exposure established by biological analysis.

[Recycle of jute bags; asbestos in agriculture, exposure and pathology ]

During the last four years, a deeper examination of malignant mesothelioma (MM) cases occurred within non asbestos textile industry highlighted asbestos past exposure in several textile industrial divisions. In spite of that, poor information about recycled textile bags previously containing asbestos fibres is available to the National Mesothelioma Registry, although holding a remarkable data bank on more than 3500 work histories and sources of asbestos exposures. Besides the analysis of the exposure circumstances and the registered health effects of the past exposure within the recycling activity, the aim of this research was to relate the possible involvement of the agricultural sector, where the use of recycled jute bags was very diffused. The MM cases were collected from the Mesothelioma Registry of Brescia, asbestosis, pleural plaques and lung cancer cases were collected from the Occupational Diseases Archive of the Local Public Occupational Health Service of the Province of Brescia. During the 1977-2006 period, 8 cases of MM, 4 cases of pulmonary asbestosis, 4 of isolated bilateral pleural plaques and I of lung cancer in pulmonary asbestosis, were observed among workers employed in bags recycling activity in 4 small companies, one of them still operating, employing about 50 workers. Even more, among the 65 MM cases classified by the Registry with "unknown asbestos exposure" (UAE), the most relevant frequency of working histories concerned the agriculture sector. Confirming a past signalling, the investigations underlined the cross linkage between this working activity and the diffusion of recycled bags in the agriculture sector. In the Province of Brescia, the activities of these small jute bags recycling plants were linked, even geographically, to the asbestos cement manufacture plant using a huge number of bags, roughly until mid seventies. Therefore, a large number of these recycled bags, previously containing asbestos, were generally used for harvesting and trading agricultural typical products of northern Italy. According to the 2003 National Mesothelioma Registry Guide Lines, MM in agricultural workers are still classified as UAE due to poor information available. In the light of these new findings, it looks reasonable to review the UAE within agriculturalists attributing a new classification of "possible" occupational asbestos exposure, although other exposure circumstances might have occurred in the past.

[Malignant mesothelioma in garment sewing-machine workers]

BACKGROUND

Due to poor information collected through patient interviews, a considerable number of malignant mesothelioma (MM) cases still remain classified as "unknown" asbestos exposure in the Italian Mesotelioma Registry (Re.Na.M). At the same time, some occupational asbestos exposures, which were previously unknown, have been demonstrated in certain types of work, i.e., in agriculture and in the textile industry.

OBJECTIVES

The aim of this research was to investigate the possible past occupational exposure to asbestos in clothing workers using sewing-machines.

METHODS

The MM cases were collected from the Mesothelioma Registry of Brescia. Work histories were obtained via a standardized questionnaire. Investigations were conducted in sewing-machine maintenance workshop in order to collect information regarding the possible use of asbestos parts. In addition, the use of asbestos friction materials and the use of insulated asbestos materials was checked in the clothing divisions by interviewing the management and maintenance workers of two companies where cases of MM were observed.

RESULTS

The Mesothelioma Registry of Brescia identified and collected 10 MM cases with past work in the clothing industry: 6 used sewing-machines and 4 were self-employed tailors. The search for asbestos materials gave positive results as the use of friction materials had been widespread since the 1950's in all types of sewing-machines; in addition, asbestos materials were used to insulate some parts of the ironing equipment and the steam pipelines.

CONCLUSION

The results of this investigation suggest assigning at least "possible occupational asbestos exposure" to those cases employed in clothing manufacture since the 1950's, who used sewing-machines or pressing machines, according to the Re.Na.M guidelines. Other possible occupational exposures to asbestos in this working sector cannot be excluded; when the simple interview of patients does not reveal such exposures further investigations are needed in order to demonstrate all the possible circumstances of exposure.

[The epidemiologic surveillance of malignant mesothelioma in the Lower Iseo Lake area]

Starting from an hospital observation of the mesotheliomas cluster in women living in a lakeside area (Iseo lake, Northern Italy), an epidemiological surveillance of this tumour was performed by the local occupational health service. This cluster wasn't notified, in spite of the relevant number of factories producing asbestos textile materials in this area. From 1977 to august 2006, 45 cases of mesothelioma were detected among the workers of 3 textile industries located in 3 little villages: 14 cases occurred working crocidolite and chrysotile rope and gasket; 20 cases in a textile factory producing cotton garments, that was adjacent to and polluted by the farmer and were asbestos insulation and blankets used for fireproofing are present; 11 cases occurred among women working in silk factories. The mesothelioma cases occurred in the same period in this area, which constituted the recruitment area of the people working in the 3 textile plants (11 villages, about 43,000 inhabitants), are 55.93% of which had been occupationally exposed to asbestos. Out of the dockyard and the asbestos-cement industries, this frequency of occupational exposed workers is the highest never observed in Italy. The majority of the cases (66%) occurred among women working in the textile factories. In a women, producing asbestos textile materials and suffered form peritoneal mesothelioma and pleural plaques, the analysis (by SEM) of asbestos fibre lung burden show 286 million fibres x gr. of dry tissue. Between the 42 mesothelioma cases occurring in the population of the 3 villages where the textile plants was located, we observed only one case with possible environmental exposure to asbestos: a gardener of the village where the manufacturing asbestos ropes and gasket plant is present. In the silk factories, asbestos exposure was probable because of the presence of asbestos insulated pipes. The female pleural mesothelioma standard incidence observed in this area (6.8 x 100,000, 1977-2005) is the highest never estimate in Italy. The epidemiological surveillance of the mesothelioma appear essential to identify cases unreported and allow the collection of information useful to understand clearly the asbestos exposure effects on health's workers and to estimate the tumour incidence in the population.

Mesothelioma in blood related subjects: report of 11 clusters among 1954 Italy cases and review of the literature

BACKGROUND

Malignant mesothelioma is a sporadic tumor related to asbestos. Its occurrence in blood relatives raises the question of potential contribution of predisposing factors.

METHODS

The study analyses the features of mesothelioma in blood relatives that might explain the disease clustering. Data sources of familial clusters were three population-based Mesothelioma Registries in Italy (Veneto and Apulia Regions, Brescia province; 1978-2005) and Medline, Toxline, and Oshline/Hseline databases for a review of the literature (1968-2006).

RESULTS

Eleven clusters (22 cases) were identified among 1954 Italy mesothelioma cases, and 51 clusters (120 cases) were extracted from 33 studies. The proportion of Italy familial cases was 1.4 per 100 mesothelioma cases; the ratio between the number of familial clusters and the number of non-familial mesothelioma cases was 1:148. The mesothelioma profile in consanguineous is the same as in non-consanguineous subjects (male prevalence; pleural site; age at diagnosis >50 years; asbestos exposure). Most clusters occurred in asbestos workers (shipyard, asbestos-cement production/processing, and insulation) and household-exposed blood relatives. Others were related to asbestos-cement factory pollution, asbestos-in-place, and handling asbestos-contaminated textiles. Two clusters were without any known exposure. Cancer family history revealed lung cancer cases in eight clusters.

CONCLUSIONS

Available data support asbestos exposure as the main risk factor in mesothelioma cases among blood relatives. Our finding of a low proportion of familial cases would not suggest the influence of a large genetic component for mesothelioma in blood relatives.

[Cancer of the nasal cavity and paranasal sinuses in poultry breeders. An unsuspected occupation at risk]

BACKGROUND

Wood dust exposure is strongly associated with the induction of cancer of the nasal cavity and paranasal sinuses (NSC), mainly among furniture production workers. Only limited information is available on wood dust exposure in other industrial sectors, including agriculture. NSC's are defined as "high occupational aetiology fraction" neoplasms, and are therefore indicated as sentinel tumours in occupational medicine.

OBJECTIVES

The report concerns two cases of NSC that occurred in two poultry breeders and the investigations performed in order to define their occupational exposure.

METHODS AND RESULTS

Epidemiological surveillance of NSC within the framework of routine activity of the Cancer Registry of the Province of Brescia (one million inhabitants) identified the two cases. Initially the first NSC case was considered as "probably exposed to formaldehyde" during shed tile disinfecting operations. After discovery of a similar case and further investigation in the sector formaldehyde exposure was found to be at a very low level. However, the observation that hard and soft wood dust was present, followed by dust monitoring, revealed a high level of exposure. The 23 personal and area air samples, performed in a turkey breeding shed, gave concentrations of between 1.3 and 2.3 mg/mc during low dust exposure jobs and concentrations of between 4 and 43.2 mg/mc during litter replacement (100% exceeded the ACGH TLV limit of 1 mg/cm and 25% were even above the legal limits (5 mg/mc according to Italian D.Lgs. 66/2000)). Since breeders are not aware of this type of risk and the use ofpersonal protection is not scrupulous, the local health and safety unit has started an information campaign for the entire work category as regards the necessity of controlling this cancer risk. The two cases of NSC described here were reported to the National Labour Insurance Institute (INAIL) for compensation.

CONCLUSION

NSC epidemiological surveillance performed through a population registry proved to be of great use in the identification of cases among employees in similar sectors, and thus the identification of previously unknown wood dust exposures with consequent implementation of preventive measures.

[Pleural mesothelioma in cotton spinning workers]

BACKGROUND

Cases of malignant mesothelioma (MM) in the non-asbestos textile industry have recently been described, but asbestos exposure in spinning and looming has seldom been reported. Nevertheless, on a national level the Italian Mesothelioma Registry (Re.Na.M) contains numerous cases of MM with past non-asbestos textile work but classified as "unknown" exposure due to poor information.

OBJECTIVES

The aim of this research was to investigate possible past occupational exposure to asbestos in this specific industrial sector.

METHODS

The MM cases were collected from the Mesothelioma Registry of Brescia. Work histories were obtained via a standardized questionnaire. Investigations were conducted in textile machinery manufacturing plants in order to collect information regarding the possible use of asbestos parts; at the same time, the use of asbestos friction materials and the use of sprayed asbestos for noise abatement purposes or thermal insulation was checked in the cotton industry by interviewing the management of two companies where a cluster of MM was observed.

RESULTS

The Mesothelioma Registry of Brescia retrieved and collected 15 MM cases with past work in the cotton spinning industry, 4 of them employed in the same company. Further search of asbestos use gave positive results as the use of friction materials has been widespread since the fifties, while sprayed asbestos was not found anywhere in the cotton industry. On the other hand, half of the cases were employed during the thirties and forties, when friction materials appear to have been asbestos-free. Therefore the other hypothesis of exposure could be direct manufacture of asbestos yarn.

CONCLUSION

The results of this investigation indicate the attribution, at least, of possible asbestos exposure"for those cases employed in textile industries since the fifties, according to the Re.Na.M guidelines; for those cases employed before that period the same classification can be attributed on an epidemiological basis. Previous work periods need further investigation in order to demonstrate the circumstances of the occupational asbestos exposure, given the heterogeneity of work processes and machinery characteristic of this industrial sector.

[Sino-nasal inverted papillomas and occupational etiology]

The sino-nasal inverted papilloma is a rare benign tumour with certain aggressive features because of frequent relapses and the high probability of malignant degeneration. For these reasons, several studies have been made to evaluate the efficacy of the different courses of treatment, but only afew studies have been carried out to establish the etiology of this tumour, which is still uncertain. Although it is believed that viral infection, chronic inflammation and cigarette smoking can play an important etiological role, it has recently been suggested that occupational risk factors, such as those involved in malignant epithelial sino-nasal cancer (SNC), can also be involved in causing sino-nasal inverted papilloma. A group of 70 patients was examined who have been diagnosed with inverted papilloma from 1991 to 2003; the occupational history, collected via the standardized questionnaire, showed that risk factors like wood and leather dusts, chromium and nickel vapours or fumes and formaldehyde were associated with only 5% of all cases. This proportion is much lower than that established for SNC in several epidemiological studies. Although occupational environmental pollution can be a source of chronic sino-nasal mucosa irritation, on the basis of our results we believe that a causal relationship between exposure to occupational risk factors and inverted papilloma is not likely, differently from the suggestions made in other studies. Consequently, an epidemiological surveillance of inverted papilloma as a "sentinel" tumour, as has been proposed in Italy for SNC, is not considered necessary. Among the possible non-occupational risk factors we observed that 75% of the male patients were smokers and 40% of all patients suffered from chronic sinusitis and sino-nasal polyps. Lastly, among the 70 cases of inverted papilloma, we observed 5 with malignant degeneration.

[Two cases of pleural mesothelioma following unusual and unrecognized exposure to asbestos. The role of Occupational Health and Safety Service in identifying past occupational exposure]

BACKGROUND

In Italy there was a wide use of asbestos in various manufacturing sectors and for many different uses, some of which are still partly or completely unknown. A detailed reconstruction of the work histories of mesothelioma patients made it possible, in some cases, to identify ignored circumstances of asbestos exposure. Moreover, the identification of cluster of cases takes on special significance in suggesting a possible previous asbestos exposure, where the information collected on single cases do not imply as much.

OBJECTIVES

This report concerns two cases of malignant mesothelioma that occurred in two workers employed in the same processes in a small factory that manufactured and repaired electric motors for hand tools.

METHODS AND RESULTS

In the Province of Brescia (one million inhabitants) a Mesothelioma Register is in operation. The first case was classified, according to Re.Na.M.1996 criteria (National Mesothelioma Register) as "unknown" occupational exposure. The identification of a second case, that was discovered thanks to the surveillance system of the Mesothelioma Register, encouraged the local Occupational Health and Safety Service to perform a more detailed investigation that revealed, for both subjects, previously unknown occupational exposure. This consisted of grinding, in a damp setting, electric motor parts bushed with phenolic thermosetting resins reinforced with chrysotile asbestos. Moreover, weekly cleaning of the plants could have been an occasion for dust dispersion. It is likely that this exposure did not last long and was limited in extent. Other similar reports of such circumstances of occupational exposure were not available in the literature.

CONCLUSIONS

The results confirm the high information value of systematic collection of incidental cases in the population, which is feasible thanks to the disease register, and the significant role of the local Occupational Health Services in demonstrating past asbestos exposure.

Malignant mesothelioma and the working environment: the viewpoint of the occupational physician

BACKGROUND

Firm scientific evidence supports the causal association between malignant mesothelioma (MM) and occupational exposure to asbestos. Risk attributable to occupation varies from 30 to 80% across different populations. The existence of a threshold level below which there is no risk of MM is still debated. A prompt and thorough assessment of exposure is essential to evaluate and manage MM cases, from diagnostic and epidemiological points of view.

OBJECTIVES AND METHODS

To highlight the multiple areas of intervention by Occupational Physicians (OP) in MM evaluation and management, to describe an experience of OP in the province of Brescia.

RESULTS

The main areas of interest of the OP are exposure assessment, diagnosis (clinical, etiological), medico-legal issues, social consequences, preventive strategies, risk communication, scientific dispute/uncertainties. By means of an active search, the Brescia MM registry, managed by OP belonging to the local health authority observed 309 MM from 1977 to 2003; the local Institute of Occupational Health, hosted in a hospital of national relevance, evaluated about 200 MM in the last decade. The main outcomes of OP activity are the high percentage of direct interviews, individual case management, expert exposure assessment, etiological diagnosis, counselling, medico-legal assistance, better knowledge of occupational risks, enhanced cooperation among health professionals (oncologists, pathologists, surgeons, pneumologists, general practitioners and OP), important contribution to Registries and to epidemiology (estimates of attributable risks, incidence, survival rates), with positive social and scientific consequences (insurance agencies, trade union organizations, public events, teaching opportunities).

CONCLUSIONS

This experience highlights the multifaceted role of OP in active research and evaluation of MM cases, in the context of a multidisciplinary approach.

[Epithelial naso-sinusal cancer incidence and the role of work in 100 cases diagnosed in the Province of Brescia (northern Italy), in the period 1978-2002]

BACKGROUND

Naso-sinusal cancers (NSC) cover a group of rare tumours in Italy for which the role of occupational risk has been established. The systematic survey of NSC in the province of Brescia made it possible to analyse the jobs of the cases occurring in the area.

OBJECTIVES

The aims of the research were: estimation of epithelial NSC incidence both in the general population and among wood and leather workers, description of the frequency and type of occupational exposure to substances or manufacturing processes.

METHODS

The epithelial type cases were obtained from the Naso-sinusal Cancer Register (population-based) operating in the Province of Brescia since 1994. Work histories were obtained via a standardized questionnaire.

RESULTS

The annual incidence ofepithelial NSC (for 100,000) in the entire population (1,090,000 inhabitants, ISTAT census 1991) from 1993 to 1997 and from 1998 to 2002 was nearly the same, 0.82 and 0.90 for men, 0.37 and 0.37 for women, respectively. The nasal cavity was the most affected anatomic site (45%) and squamous cell carcinoma was the most frequent histotype (44%) among the first 100 cases whose case histories were appropriate; in the ethmoidal sinus adenocarcinoma represented 62% of the cases; 25% of all cases were exposed to occupational carcinogens (list A) and particularly to wood dust (17%), even if only of softwood species (30%), and leather dusts (7%) especially in the shoe repair. The average latency period was 47 years (SD 7.4) and 44 years (SD 5.6) respectively; 71% of these epithelial NSC cases involved the ethmoid and 85% were adenocarcinomas. Only 1% of the cases was exposed to chromium and nickel and occurred in galvanization processes. Among the exposures to occupational risks with limited epidemiological evidence (list B) there was one case exposed to formaldehyde and 42 cases occurring in the building, agricultural, metallurgic and textile sectors. Thus all the exposures to occupational risks, both certain and probable (lists A and B) reached 84% among men and 17% among women. Epithelial NSC annual incidence rates (for 100,000) estimated among the wood and leather workers for the period 1985-2002 were 13 and 6.5 respectively.

CONCLUSION

The results confirm the meaning of sentinel event for these tumours in occupational health and justify maintaining an active surveillance programme for the cases occurring in the area.

[Survival analysis of malignant mesothelioma treated in Brescia, northern Italy, 1982-2000]

OBJECTIVE

To study the survival for malignant mesothelioma on general population cases over the 1982-2000 period and to evaluate the effectiveness of the new therapeutic protocols (intrapleural immunotherapy and mulitmodality therapy) to improve the prognosis on the group of selected hospital patients treated from 1996 to 2000.

DESIGN

Survival analysis of malignant mesothelioma on the general population cases and survival analysis for the 1996-2000 period on the selected group of hospital patients.

SETTING

The Malignant Mesothelioma Register of the Brescia Province (northern Italy) and Pulmonology Dept. of the General hospital of Brescia.

PARTICIPANTS

353 mesothelioma cases observed in the province of Brescia from 1982 to 2000, 215 of which are residents in the province and 138 from other provinces, 324 are pleural and 29 peritoneal mesothelioma, 141 of all diagnosed between 1982 and 1995 and 212 between 1996 and 2000.

MAIN OUTCOME MEASURES

Observed survival (%) at one, three, five-year and median survival by gender, site and residence on the general population cases treated with conventional therapy and on selected hospital patients group treated with intrapleural immunotherapy and mulimodality therapy.

RESULTS

Median survival for pleural mesothelioma is of 233 days for the men and 291 days for the women in the group of incident cases; median survival is higher for cases from other provinces (388 and 496 days respectively). From 1996 the number of cases treated with new therapic protocols is steadily increasing, patients without therapy (or only talcaggio) passed from 87% in the period between 1982-1995 to 43% in the period 1996-2000. Nevertheless, multivariate analysis by the Cox model based on incident cases proved that histological subtype and age are the only most important prognostic factors (cases with fibrous morphology and older age are associated with lower survival).

CONCLUSION

In the incident case group the increase of survival for pleural mesothelioma of cases treated with recent therapeutic protocols doesn't reach statistical significance. These results are similar to those of previous studies conducted to identify prognostic factors for mesothelioma survival; they don't permit confirmation of the efficacy of the recent therapy on the population base cases and only allow one to suppose them in the cases of the non resident population. The efficacy of the recent therapy has to be further investigated with regard to the stage of the disease.