Round-Robin Tests with Relocatable Coverslips Improve Asbestos Fibre Counting.

Asbestos fibre counting by phase-contrast microscope is subject to many sources of variation, including those dependent on the analyst. In this study, asbestos sample slides prepared with relocatable coverslips have been used for fibre counting among voluntary analysts to evaluate their proficiency. One slide of amosite and one of chrysotile were distributed to all the analysts, and three proficiency testing rounds were conducted for amosite and four for chrysotile. Each relocatable coverslip has a report in which are reported for each viewing field both the number of certified fibres (Verified Fibres) and a drawing representing the shape and position of the individual fibres. In the first round, the analysts were asked to report only the number of fibres counted in each of the predesignated fields of view. In the other rounds, subsequently developed, the analysts had to report the number and the position of the fibres for each field. The reported number of fibres and their position in each of the designed fields were evaluated against their respective verified fibres, to identify types of error. Discrepancies between reported fibres and verified fibres in each field of view have been used to evaluate the proficiency of the analysts. The discrepancies can be positive (D+) or negative (D-) depending on whether the analyst counts, for a specific field of view, more or less fibres compared to the verified fibres. The score is calculated using the following equation: Score = (1 - ∑D+ + ∑│D-│/VF) × 100. An analyst obtaining a score of ≥60, which corresponds to (∑D+ + ∑│D-│)/VF ≤ 0.40, is proficient. The number of laboratories that participating in this study varied from 13 to 17 depending on the rounds. For amosite fibre counts, the results were generally good compared to a proficiency score of 60. The major error made by analysts was the counting of fibres shorter than 5 µm, where this error was of 62% of extra fibres and accounted for 8% over-estimation of amosite fibres. For chrysotile, a score of ≥50 has been used to consider an analyst as proficient. The results of chrysotile fibres showed that in the first round all analysts counted less than fifty per cent of the verified fibres. In the second round 10 analysts out of 13 reached a score of ≥50, 8 of 16 in the third and 10 of 12 in the fourth. For chrysotile fibres, the error relating to the counting of fibres shorter than 5 µm was of 56% of extra fibres, but the error that most influenced the results was the number of oversight-missing fibres. This type of error accounted for 97% of the missing fibres and for the 29% under-estimation of the chrysotile fibres. For amosite fibre counting, results of this study show an improvement of the analyst's performance. For the chrysotile fibre count, although there is a significant improvement in the comparison between some rounds, this is not continuous over time.

[Asbestos exposure assessment in the first case of intrasplenic mesothelioma]. / Accertamento dell'esposizione ad amianto nel primo caso di mesothelioma splenico.

BACKGROUND: In 2013 the International Journal of Surgical Pathology published a case report of intrasplenic malignant mesothelioma (MM) in a 48-year-old man: it was the first report in literature describing a case of primitive intra-splenic MM, described without  a history of asbestos exposure. OBJECTIVE: To verify the possible past exposure to asbestos, ignored by the patient himself, by studying in depth his environmental and occupational history. METHODS: Information about the occupational and non-occupational history of the subject was collected by Experts of the Operational Unit of Occupational Health and Safety Control (UOC PSAL) of the Local Health Unit Umbria 1 - Perugia, using the Italian National Mesothelioma Register (ReNaM) questionnaire and guide lines; an inspection was  carried out at the past canning industry where the patient worked in the period 1982-1990 and material was taken to be analysed by MOCF and SEM. RESULTS: Samples showed the presence of asbestos  fibres belonging to the amphibole class (amosite and crocidolite) and to the serpentine class (chrysotile). CONCLUSIONS: The survey described the past occupational exposure to asbestos in a canning industry, where  the subject worked in the period 1982-1990,  unknown to the patient himself. The authors strongly confirm the  usefulness of standardized methods, such as the ReNaM Questionnaire, and the importance of technical expertise of the investigator to find and analyse the suspect materials and to demonstrate  possible past occupational exposure to asbestos.

[Levels of exposure to respirable fibres at worksites for abatement of compact and friable asbestos]. / Livelli di esposizione a fibre regolamentate in cantieri di bonifica di materiali contenenti amianto in matrice compatta e friabile.

BACKGROUND: Starting from a project aimed at assessing the carcinogenic risk in some industrial sectors covered by Local Health Authority No.1 (LHA) in Perugia (USL Umbria1, Italian acronym), worksites for abatement of materials containing asbestos (MCA) were examined in order to estimate respirable fibres exposure levels in workers. Abatement work is, indeed, a fast developing sector, but is not free from asbestos risks in the long-term, particularly carcinogenic risks; this kind of work therefore requires maximum effort in respecting prevention standards prescribed in the relative legislation. OBJECTIVES: The aim of the research was to define the personal levels of exposure to respirable fibres and to create a reliable database for the interpretation of possible asbestos-related cases of neoplasms that may occur in the future in workers of this important occupational sector. METHODS: The authors took in consideration operations both on compact MCA and on friable MCA. In the case of compact MCA, exposure values measured by the LHA via their own sampling were compared to those measured by the companies involved in the project. In the case of friable MCA, however, sampling was only performed by the LHA and the assessment covered not only workers' exposure levels but also the pollution levels in the areas in the vicinity of the work site. RESULTS: In the case of compact MCA, results showed moderate average values of personal fibre exposure, and always considerably lower than the limit values (100 fibres/litre) prescribed by law (Legislative Decree 81/08); however, the average values detected by the LHA (15,8 fibres/litre) were significantly higher (p < 0.001) than those detected by companies (4,9 fibres/litre). In the case of friable MCA, however, average personal exposure values of workers (106,8 fibres/litre) were even higher than the limit values prescribed by current regulations, while in areas near the work sites, average fibre pollution levels (1,04 fibres/litre) were always very low and lacked significant variations (p > 0.05) during the different phases of work. CONCLUSIONS: According to the authors, the data collected show how in MCA abatement operations a carcinogenic risk in the long-term is in any case present, and this both in compact MCA work, where not all the prevention measures were accurately observed, and even more so, in friable MCA work, where average exposure levels of workers showed a heavy trend to exceed the above mentioned limit values. Considering the different evolution of the results of sampling carried out by the LHA and by the companies, the authors also highlight the need to provide mandatory technical guidelines for industrial hygiene laboratories so that sampling and analysis methods are as homogeneous as possible, thus making the results of research easily comparable.

Occupational exposure to styrene in the fibreglass reinforced plastic industry: comparison between two different manufacturing processes.

BACKGROUND: Styrene is used in manufacturing fiberglass reinforced plastics: and occupational exposure was related to neurotoxicology and genotoxicity. The sum of the metabolites mandelic and phenylglyoxylic acids is the ACGIH biomarker for occupational exposure with a BEI of 400 mg/g of creatinine in end shift urine corresponding to a airborne styrene concentration of 85 mg/m3. There are two main molding processes, open and closed, the last more effective at controlling worker's styrene exposure. OBJECTIVES: To compare the open molding process to the compression of fiber reinforced resin foils, a kind of closed molding, monitoring the styrene exposure of workers in two production sites (A and B). METHODS: Environmental Monitoring was carried out by Radiello samplers and Biological Monitoring by means of the determination of MA and PGA with HPLC/MS/MS in 10 workers at Site A and 14 at Site B. RESULTS: The median values for styrene exposure resulted 31.1 mg/m3 for Site A and 24.4 mg/m for Site B, while the medians for the sum of the two metabolites in the end shift urine were 86.7 e 33.8 mg/g creatinine respectively. There is a significant linear correlation between personal styrene exposure and the excretion of styrene metabolites (R = 0.74). CONCLUSIONS: As expected the exposure markers of the workers of the two production sites resulted higher in the open process. The analytical results of both environmental and biological monitoring were all below the occupational exposure limits, confirming the efficacy of the protective devices.

[A survey on workers' individual exposure to crystalline silica in the building industry]. / Indagine conoscitiva sull'esposizione personale dei lavoratori a silice libera cristallina in edilizia.

BACKGROUND: The wide-spread presence of silica in nature and the variety of materials containing it cause crystalline silica exposure of workers in various industrial activities. Moreover crystalline silica is classified as carcinogenic to humans (Group 1) by IARC, in relation to its possible lung carcinogenicity. OBJECTIVES AND METHODS: The purpose of this paper was to assess respirable particles and crystalline silica exposure of workers in a number of some building sites located in the area of a Local Health Unit in the Umbria region. The study examined differences in four types of building sites: "construction of new buildings", "renovation of old buildings", "road construction" and "transport of aggregates by loaders in crushing plants". According to the strategy suggested by European Standard EN 689/1997, personal air samples were collected during work in jobs characterized by elevated amounts of widespread dust. RESULTS AND CONCLUSIONS: Analysis of data showed that levels of exposure to crystalline silica were lower than the limits recommended by ACGIH/2010 in almost all samples except one. The percentages of crystalline silica in respirable particles were in the range 0.4%-21%. Crystalline silica exposure levels were different in the various jobs and comparison between the mean values of exposure levels in each one showed statistically significant differences (p < 0.01, variance analysis). Work with the highest exposure to crystalline silica were: brick cutting, plaster brushing, "Serena stone" cutting, as they use tools operating at high speed and often in dry conditions (grinder, power drill, pneumatic hammer), producing low-size airborne particles (respirable fraction). During work in these jobs levels of worker exposure to crystalline silica showed high variability, so that it was impossible to establish if in the medium-long term, they were lower than the Threshold Limit Values with a set probabilistic certainty (OTL test, confidence level 95%). In the remaining jobs the assessment of occupational exposures to crystalline silica showed a low probability of exceeding the Threshold Limit Values.

The devitrification of artificial fibers: a multimethodic approach to quantify the temperature-time onset of cancerogenic crystalline phases.

A variety of artificial fibers extensively employed as lining in high-temperature apparatus may undergo a devitrification process that leads to significant changes in the chemical-physical properties of the materials. Among them, the crystallization of carcinogenic minerals, such as cristobalite, has already been documented for alumino-silicate ceramic fibers. Five fibrous samples with different compositions were treated over a wide range of temperatures (20-1500°C) and times (24-336 h) to investigate the rate and the crystalline phases that are formed as well their onset temperatures. The new phases were characterized by using a multimethodic approach: phase transformations were monitored together with thermal analysis and the new phases were investigated by using X-ray powder diffraction analysis. The crystalline:amorphous ratio was monitored by Rietveld refinement of X-ray diffraction data. Scanning electron microscopy was used to study the effect of heat treatments on the morphology of fibers, and the nanostructures were investigated by transmission electron microscopy (TEM). The results show that the main crystalline phases are cristobalite, diopside, mullite, and zirconia. The onset of cristobalite was observed at temperature lower than that thermodynamically expected. The TEM analysis showed that protostructures were present in the material vitrified from sol-gel-derived products, which can act as crystallization nuclei. The study shows that the devitrification leads to health hazard due to the formation of inhalable powder of cancerogenic crystalline phases.

[Comparison between two granulometric selectors--Dorr-Oliver and GS3--in respirable particles sampling for analytical measurement of quartz content]. / Confronto fra due selettori granulometrici: Dorr-Oliver e GS3 nel campionamento di polveri respirabili per la determinazione di quarzo.

BACKGROUND: A Local Health Unit in the Umbria Region of Italy carried out environmental investigations to estimate exposure to respirable particles among workers in a number of companies belonging to the ceramics and brick industries manufacturing categories. OBJECTIVES: The purpose of this paper was to estimate the degree of agreement of two sampling methods, Dorr-Oliver and GS3 selectors. Both selectors are deemed to comply with the respirable particles sampling reported in European Standard EN 481/1993. METHODS: For each worker, respirable particles and the quartz contained therein were collected using Dorr-Oliver and GS3 selectors simultaneously, so that quartz exposure was also measured. CONCLUSIONS: The comparison between the two series of airborne concentrations of respirable particles (collected with the two selectors), showed statistically significant differences (p < 0.05 with Student's t test). Moreover, Pearson's coefficient showed a low correlation between the two series of data. A similar conclusion was obtained analysing quartz airborne concentrations. The results seem to confirm that the two sampling methods possess a different capture power ofparticles as a function of their size.

[Carcinogens project in a Local Health Unit in Umbria: updating of risk so as to estimate worker exposure levels]. / Progetto cancerogeni in una ASL dell'Umbria: aggiornamento della mappa di rischio ai fini della stima dei livelli di esposizione dei lavoratori.

BACKGROUND: The gradual increase of substances coming onto the market, many of which are still not classified in terms of hazard for worker's health, in addition to those classified as carcinogens by the European Economic Community, imposes a review of the implementation of protective measures foreseen in specific regulations, also with the aim of assessing worker exposure. OBJECTIVES AND METHOD: For this purpose, the SPSAL (Prevention and Safety at the Workplace Service) of ASL (Local Health Unit) No. 2, Umbria Region, in 1996, when Law No. 626/94 came into force, started a project aimed at identifying the companies located in the Unit's territory that used and/or produced carcinogens in their production cycle. In a sample of these companies, divided by category (wood,fuel distributors, engineering, galvanization,foundries, brickworks, ceramics processing, tobacco industries, and companies specializing in removal and recovery of asbestos-containing materials) environmental investigations were carried out to verify the levels of worker exposure to the carcinogens thus identified. In some cases, sampling was repeated even after the implementation ofspecific remedial measures in order to verify their effectiveness in terms of reducing risk. RESULTS AND CONCLUSIONS: The production cycle, the use or production of carcinogenic substances was investigated in 811 companies, where the number of exposed workers was 3821. The environmental sampling carried out showed levels of exposure to various carcinogens that were below the limits specified by law or recommended by the major industrial hygiene associations. Checks carried out after the improvements confirmed their effectiveness and a significant reduction in risk. The exposed workers were identified for the purposes of entry in a special register that could, in the long term, facilitate the reconstruction of occupational exposure to carcinogens. This will also facilitate correct insurance and pension benefits and any legal action that might be taken.