Environmental and biological monitoring of occupational exposure to polynuclear aromatic hydrocarbons during highway pavement construction in Italy.

OBJECTIVES: We performed a cross-sectional study with the main aim of evaluating occupational exposure to polycyclic aromatic hydrocarbons (PAHs) in workers involved in the pavement construction of a new highway in Northern Italy, where modified bitumen was used as binder for Hot Mix Asphalt. METHODS: We applied a combined approach of air and biological monitoring. Both the aerosol and vapour phases of bitumen were collected applying the NIOSH 5506 method. The 16 PAHs listed as high priority by EPA were determined by HPLC-UV. End-of-shift urine samples were collected from 144 workers to determine 1-hydroxypyrene (1-OHP) and 2-naphthol (2-NAP) concentrations after enzyme digestion and HPLC-UV analysis. Socio-demographic and lifestyle information was collected by a questionnaire. RESULTS: Paving workers were actually exposed to PAHs, including carcinogenic compounds, that were measurable only in the aerosol phase. Higher exposure as well as dose levels were measured for the paver group. Biological monitoring confirmed that 1-OHP was less affected by smoking habits as compared to 2-NAP and showed a higher association with occupational exposure. CONCLUSION: Carcinogenic PAH compounds were detectable only in the aerosol phase and this must be taken into account in the adoption of preventive measures. Biomonitoring supported the superiority of 1-OHP as compared to 2-NAP in assessing the internal dose in such workers.

Pleural mesothelioma in doll manufacture: possible asbestos exposure. / Mesoteliomi pleurici in addette alla fabbricazione di bambole: esposizione ad amianto?

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.

[Pleural mesothelioma in a school teacher: asbestos exposure due to DAS paste]. / Mesotelioma pleurico in maestro elementare: esposizione ad amianto dovuta alla pasta DAS.

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.

[PAH exposure in asphalt workers]. / Monitoraggio biologico dell'esposizione ad idrocarburi policiclici aromatici in un gruppo di asfaltatori.

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.

Biological monitoring of tungsten (and cobalt) in workers of a hard metal alloy industry.

OBJECTIVES: To evaluate a combined biomonitoring approach based on both cobalt and tungsten determination in workers of the hard metal alloy sector. METHODS: We enrolled 55 workers from a factory producing cutting tools for carpentry. Combined workroom air and biological monitoring of both cobalt and tungsten relied on inductively coupled plasma mass spectrometry determinations. Metals were determined on plasma, blood and urine samples. Urine samples from 34 unexposed subjects were also analyzed. RESULTS: Tungsten was determined in every collected sample. Workers showed significantly higher urinary tungsten levels than controls (pre-shift values of 4.12 vs. 0.06 microg/l on average; P < 0.0005). Both airborne and biological levels of tungsten prevailed among workers involved in wet-grinding activities. The element was excreted at higher urinary levels than cobalt and showed lower circulating (blood, plasma) concentrations. Exposure-dose relationships were apparent for tungsten biomarkers. CONCLUSIONS: Obtained results may contribute to the development of biomarkers of exposure to tungsten. The association of such biomarkers to traditional determinations of cobalt in blood and/or urine may substantially improve the exposure assessment of workers employed in cemented carbide industries.

Low levels of occupational exposure to arsenic and antimony: effects on lysosomal glycohydrolase levels in plasma of exposed workers and in lymphocyte cultures.

BACKGROUND: Heavy metals have been shown to alter the mechanism and release of lysosomal enzymes. In the present study, the activities of lysosomal glycohydrolases were determined in order to evaluate the asymptomatic toxic effects of low levels of exposure to arsenic (As) and antimony (Sb) in art glass workers. METHODS: N-acetyl-beta-D-glucosaminidase (NAG), beta-D-glucuronidase (GCR), alpha- and beta-D-galactosidase, alpha-D-glucosidase, and alpha-D-mannosidase were determined by a fluorimetric assay in the plasma of 26 art glass workers. Lymphocytes cultured in the presence of different species of As and Sb served as an in vitro model for the study of the protective action of selenium and zinc. RESULTS: No significant difference in the plasma levels of the various enzymes was detected in art glass workers or control subjects. The in vitro experiments demonstrated that secretion of lysosomal glycohydrolases was increased by Sb (225%) and decreased by As (57%) at the same concentration of elements (200 microg/L). The addition of bivalent selenium to the culture neutralized the effects of both metals, while zinc chloride did not show any protective effect. CONCLUSIONS: As for the plasma glycohydrolases, no praecox signs of toxicity related to a low concentration of As and Sb was evident in art glass workers. This may be due to the antagonistic effects demonstrated by these two metals in vitro. Their different mechanism of action on release of glycohydrolases is being discussed.