Creazione di una banca dati delle concentrazioni occupazionali e ambientali di silice libera cristallina ai fini della valutazione delle esposizioni pregresse e attuali

BACKGROUND

Professional exposure to respirable dust containing crystalline silica is of great interest for the serious lung diseases resulting from exposure.

METHODS

During the period 1986-2019, 3611 exposure data to crystalline silica were collected from companies in central Italy. The data were divided and statistically analyzed based on the sampling system (Cyclone Dorr Oliver, CIP 10-R, Cyclone GS3, SKC plastic selector, Cyclone Higgins-Dewell and Cyclone Lippmann) and the ATECO code (code of economic activity, Italian acronym, used to classify companies when they interface with public institutions) of the companies in which they were collected. For each ATECO code, the division was made according to the type of sampling (personal or static) and the descriptive statistics of the data were calculated.

RESULTS

Overall, for personal samples, 8.8% of the data exceeds 0.1 mg/m3, 19.6% exceeds 0.05 mg/m3 and 33.8% exceeds 0.025 mg/m3, the limit values set by the EU Directive 2019/130, suggested by the SCOEL and published by ACGIH respectively. The ATECO codes with the highest worker exposure (geometric means 0.067 and 0.069 mg/m3) were 23.31.00 (manufacture of ceramic tiles for floors and walls) and 23.42.00 (manufacture of ceramic sanitary ware), while the lowest exposure is found in 81.29.91 (cleaning and washing of public areas, removal of snow and ice including shedding of sand) with a geometric mean of 0.002 mg/m3.

DISCUSSION

Despite the general reduction over time, there are still many sectors in which data are higher than the current occupational exposure limits; especially in these sectors it is necessary to implement the measures to fully assess worker exposure.

A Cross-Sectional Study on 3-(2-Deoxy-β-D-Erythro-Pentafuranosyl)Pyrimido[1,2-α]Purin-10(3H)-One Deoxyguanosine Adducts among Woodworkers in Tuscany, Italy

Occupational exposure to wood dust has been estimated to affect 3.6 million workers within the European Union (EU). The most serious health effect caused by wood dust is the nasal and sinonasal cancer (SNC), which has been observed predominantly among woodworkers. Free radicals produced by inflammatory reactions as a consequence of wood dust could play a major role in SNC development. Therefore, we investigated the association between wood dust and oxidative DNA damage in the cells of nasal epithelia, the target site of SNC. We have analyzed oxidative DNA damage by determining the levels of 3-(2-deoxy-β-D-erythro-pentafuranosyl)pyrimido[1,2-α]purin-10(3H)-one deoxyguanosine (M₁dG), a major-peroxidation-derived DNA adduct and a biomarker of cancer risk in 136 woodworkers compared to 87 controls in Tuscany, Italy. We then examined the association of M₁dG with co-exposure to volatile organic compounds (VOCs), exposure length, and urinary 15-F_2t isoprostane (15-F_2t-IsoP), a biomarker of oxidant status. Wood dust at the workplace was estimated by the Information System for Recording Occupational Exposures to Carcinogens. M₁dG was measured using ³²P-postlabeling and mass spectrometry. 15-F_2t-IsoP was analyzed using ELISA. Results show a significant excess of M₁dG in the woodworkers exposed to average levels of 1.48 mg/m³ relative to the controls. The overall mean ratio (MR) between the woodworkers and the controls was 1.28 (95% C.I. 1.03-1.58). After stratification for smoking habits and occupational status (exposure to wood dust alone and co-exposure to VOCs), the association of M₁dG with wood dust (alone) was even greater in non-smokers workers, MR of 1.43 (95% C.I. 1.09-1.87). Conversely, not consistent results were found in ex-smokers and current smokers. M₁dG was significantly associated with co-exposure to VOCs, MR of 1.95 (95% C.I. 1.46-2.61), and occupational history, MR of 2.47 (95% C.I. 1.67-3.62). Next, the frequency of M₁dG was significantly correlated to the urinary excretion of 15-F_2t-IsoP, regression coefficient (β) = 0.442 ± 0.172 (SE). Consistent with the hypothesis of a genotoxic mechanism, we observed an enhanced frequency of M₁dG adducts in woodworkers, even at the external levels below the regulatory limit. Our data implement the understanding of SNC and could be useful for the management of the adverse effects caused by this carcinogen.

Wood dust and urinary 15-F2t isoprostane in Italian industry workers

Wood dust is one of the most common occupational exposures, with about 3.6 million of workers in the wood industry in Europe. Wood particles can deposit in the nose and the respiratory tract and cause adverse health effects. Occupational exposure to wood dust has been associated with malignant tumors of the nasal cavity and paranasal sinuses. The induction of oxidative stress and the generation of reactive oxygen species through activation of inflammatory cells could have a role in the carcinogenicity of respirable wood dust. Therefore, we conducted a cross-sectional study to evaluate the prevalence of urinary 15-F_2t isoprostane (15-F_2t-IsoP), a biomarker of oxidative stress and peroxidation of lipids, in 123 wood workers compared to 57 unexposed controls living in Tuscany region, Italy. 15-F_2t-IsoP generation was measured by ELISA. The main result of the present study showed that a statistically significant excess of this biomarker occurred in the workers exposed to 1.48 mg/m³ of airborne wood dust with respect to the unexposed controls. The overall mean ratio (MR) between the workers exposed to wood dust and the controls was 1.36, 95% Confidence Interval (C.I.) 1.18-1.57, after correction for age and smoking habits. A significant increment of 15-F_2t-IsoP (43%) was observed in the smokers as compared to the non-smokers. The urinary excretion of 15-F_2t-IsoP was significantly associated with co-exposure to organic solvents, i.e., MR of 1.41, 95% C.I. 1.17-1.70, after adjustment for age and smoking habits. A 41% excess was observed in long-term wood workers, 95% C.I. 1.14-1.75. Multivariate regression analysis showed that the level of 15-F_2t-IsoP was linearly correlated to the length of exposure, regression coefficient (β) = 0.244 ± 0.002 (SE). The overall increment by exposure group persisted after stratification for smoking habits. For instance, in smokers, a 53% excess was detected in the wood workers as compared to the controls, 95% C.I. 1.23-1.91. Our data support the hypothesis that oxidative stress and lipid peroxidation can have a role in the toxicity of wood dust F₂-IsoP measure can be a tool for the evaluation of the effectiveness of targeted interventions aimed to reduce exposures to environmental carcinogens.

Chemical variability of artificial stone powders in relation to their health effects

The occurrence of highly severe silica-related diseases among the resin- and silica-based artificial stone workers was claimed, associated to an extremely short latency. High levels of exposure and intrinsic properties of AS are thought to modulate the development of silicosis and auto-immune diseases. This study compares parent materials and processed dusts, to shed light on changes of AS occurring in the manufacturing process, through an XRF, EPR and XAS investigation. We point out the extremely wide variability of the materials, the occurrence of chemical signatures impressed by the processing techniques, and the unprecedented generation of stable radicals associated to the lysis of the Si-O chemical bond inside the resin coated respirable crystalline silica. These results suggest that the AS processing in industrial stone workshops can create respirable dusts with peculiar physical and chemical properties, to be correlated to the observed clinical evidences.

Identificazione dei lavoratori ex-esposti ad amianto in Toscana da inserire nel programma di sorveglianza sanitaria

BACKGROUND

In 2016 the Administration of the Tuscany Region, Italy, established a health surveillance programme for workers with past asbestos exposure. The programme includes two levels of activities, a local basic health evaluation, and a centralized in-depth evaluation of specific cases.

OBJECTIVES

To estimate the number and identify the workers with past exposure to asbestos in Tuscan industrial settings entitled to participate in the health surveillance programme.

METHODS

The number of formerly-exposed workers was estimated from the records of the working population of 15,441 workers of thirteen Tuscan asbestos industrial plants and from the existing data bases of the Local Health Administrations (USLs) and the Institute for Study, Prevention and Cancer Network (ISPRO), and from national data bases such as Social Security Administration (INPS) and National Institute for Insurance against Accidents at Work (INAIL). The expected number of medical examinations per year was estimated from the adhesion rates seen in previous comparable programmes.

RESULTS

The estimated number of workers with past asbestos exposure eligible to the programme was 5,446. The estimated number of health examinations in the first and second phases of the surveillance programme during 2016-24 was 7,275 and 7,155, respectively, follow-up examinations included. The number of workers identified from local data bases was 4,713: They had been operating in 129 plants that had been using asbestos in the past. Further 1,395 workers were identified from previous health surveillance activities.

CONCLUSIONS

The use of several sources of information and the cooperation between occupational health services made it possible to identify a high proportion of former asbestos workers and plants., It is, nevertheless, still necessary to complete the list of eligible workers, and to facilitate their participation by making the programme more widely known.

Physico-chemical properties of quartz from industrial manufacturing and its cytotoxic effects on alveolar macrophages: The case of green sand mould casting for iron production

Industrial processing of materials containing quartz induces physico-chemical modifications that contribute to the variability of quartz hazard in different plants. Here, modifications affecting a quartz-rich sand during cast iron production, have been investigated. Composition, morphology, presence of radicals associated to quartz and reactivity in free radical generation were studied on a raw sand and on a dust recovered after mould dismantling. Additionally, cytotoxicity of the processed dust and ROS and NO generation were evaluated on MH-S macrophages. Particle morphology and size were marginally affected by casting processing, which caused only a slight increase of the amount of respirable fraction. The raw sand was able to catalyze OH and CO2(-) generation in cell-free test, even if in a lesser extent than the reference quartz (Min-U-Sil), and shows hAl radicals, conventionally found in any quartz-bearing raw materials. Enrichment in iron and extensive coverage with amorphous carbon were observed during processing. They likely contributed, respectively, to increasing the ability of processed dust to release CO2- and to suppressing OH generation respect to the raw sand. Carbon coverage and repeated thermal treatments during industrial processing also caused annealing of radiogenic hAl defects. Finally, no cellular responses were observed with the respirable fraction of the processed powder.

Oxidatively damaged DNA in the nasal epithelium of workers occupationally exposed to silica dust in Tuscany region, Italy

Chronic silica exposure has been associated to cancer and silicosis. Furthermore, the induction of oxidative stress and the generation of reactive oxygen species have been indicated to play a main role in the carcinogenicity of respirable silica. Therefore, we conducted a cross-sectional study to evaluate the prevalence of 3-(2-deoxy-β-D-erythro-pentafuranosyl)pyrimido[1,2-α]purin-10(3H)-one deoxyguanosine (M1dG) adducts, a biomarker of oxidative stress and peroxidation of lipids, in the nasal epithelium of 135 silica-exposed workers, employed in pottery, ceramic and marble manufacturing plants as well as in a stone quarry, in respect to 118 controls living in Tuscany region, Italy. The M1dG generation was measured by the (32)P-postlabelling assay. Significant higher levels of M1dG adducts per 10(8) normal nucleotides were observed in the nasal epithelium of smokers, 77.9±9.8 (SE), and in those of former smokers, 80.7±9.7 (SE), as compared to non-smokers, 57.1±6.2 (SE), P = 0.001 and P = 0.004, respectively. Significant increments of M1dG adducts were found in the nasal epithelium of workers that handle artificial marble conglomerates, 184±36.4 (SE), and in those of quarry workers, 120±34.7 (SE), with respect to controls, 50.6±2.7 (SE), P = 0.014 and P < 0.001, respectively. Null increments were observed in association with the pottery and the ceramic factories. After stratification for different exposures, silica-exposed workers that were co-exposed to organic solvents, and welding and exhaust fumes have significantly higher M1dG levels, 90.4±13.4 (SE), P = 0.014 vs.

CONTROL

Our data suggested that silica exposure might be associated with genotoxicity in the nasal epithelial cells of silica-exposed workers that handle of artificial marble conglomerates and quarry workers. Importantly, we observed that co-exposures to other respiratory carcinogens may have contributed to enhance the burden of M1dG adducts in the nasal epithelium of silica-exposed workers.

Prevention of silica health effects in Italy: current challenges for the Occupational Health and Safety Unit of the Italian National Health Service

BACKGROUND

Since its foundation in 2002, the Italian Silica Network (NIS), a collaborative network of professionals and public authorities, has been engaged in several aspects of research, control, and prevention of silica exposure and effects, and also in support for compensation claims for silica-related occupational health effects in Italy.

METHODS

We start with a report on the NIS point of view concerning the recent scientific results (from epidemiology and laboratory studies), including those carried out by NIS in cooperation with Italian universities and other public agencies. This is followed by a description of the data on silica exposure in different Italian workplaces and guidelines for the management of occupational exposure to silica, as developed by two model regional programmes for the ceramics industry, metal foundries and tunnel excavation.

RESULTS

The NIS initiatives highlighted the persistence of workplace conditions posing a significant risk for silica-related health effects, particularly in small industries and workshops. Experimental work has also shown that a number of physical and chemical factors affect the bioreactivity of silica particles.

CONCLUSION

Based on NIS experience, it appears clear that currently conditions exist in Italy so as to positively contribute to the WHO Programme for the eradication of silicosis and the other diseases related to silica exposure. In order to achieve this goal, a coordinated and wide-ranging effort is required to reduce the wide gap in specific prevention activities, particularly in small industries and workshops, where high levels of silica exposure sometimes occur.

[The occupational carcinogenic risk at present time in Italy. Continuity and discontinuity with the past: emerging issues and perspectives]

Here are recalled the most interesting elements in order to outline a history of cultural representation and application of the criteria to fight and control the effects and, eventually, the risks from carcinogens in the workplace in Italy in a period longer than a century. The roles of the actors of this process, such as social partners and institutions, are illustrated, and consequently the critical aspects of risks management and control at present starting from the description of two different scientific and ideological policies, the <<MAC 0>> (TLV null) and the criteria required by current legislation, although in conflict between them but, at least in some cases, able to interact and, in some aspects, completing themselves. The critical points and some contradiction of the system are described and emphasis is placed on the imperative need to promote the risks primary prevention from carcinogens rather than possible other interests on the insurance and welfare fields.

The health of foreign workers in Italy

At the beginning of 2002, there were 1,600,000 foreign-born persons living in Italy; the majority from countries outside Europe. Those residing in the country for working purposes were 800,680. Italy's shift to a tertiary and service-oriented economy has considerably modified the working market, concentrating demand at two extremes: on one hand, a highly specialized workforce, and on the other, a totally unqualified, mobile, and flexible one, which includes most immigrants.

[Male breast tumors in railway engine drivers: investigation of 5 cases]

The paper describes the results of the investigation carried out on five cases of male breast tumours in railway engine drivers notified to the public Occupational Health Service of Florence in 1999. The aim was to evaluate the possibility of professional extremely low frequency electromagnetic fields (ELF) exposure etiology. The extent of this exposure is described with particular care to engine drivers, comparing the one measured in Italy with those reported in other countries.

[Activities of the industrial physician in a state preventive health service. The case of Italy]

We analyzed the occupational health activities of physicians in a public occupational health service using the Method of Organizational Congruences (MOC). Occupational health activities are changing in Italy with the application of the European Community Directives (Decreto Legislativo 626/94). We identified four major organizational constraints: a lack and difficult in interdisciplinary work, absence of worker control on the activities, limitations in planning specific industrial area studies, increased conflict between prevention and control activities. We predict for the future an increase of these constraints with a reduction in the professional level of the physicians employed in the state system of local occupational health units.

Circadian rhythms in dynamic electrocardiography

A group of ten healthy subjects aged 32-58 years was studied by dynamic electrocardiography. An electrocardiogram (ECG) was recorded on CM 5 lead for 14 seconds every 15 minutes during the 24 hours. All the subjects were under a similar nyctohemeral schedule, sleeping between 23.30 and 06.45, and all followed their spontaneous diet without any restriction. "Mean Cosinor" analysis of the data revealed statistically significant circadian rhythms of heart rate (HR), R and T-wave voltages, duration of the QT interval and ST segment displacement, but not of the duration of the corrected QT (QTc).