Sergio Iavicoli

Comparative cyto-genotoxicity assessment of functionalized and pristine multiwalled carbon nanotubes on human lung epithelial cells.

Chemical functionalization extends CNT applications conferring them new functions, but could modify their toxicity. We compared cytotoxicity and genotoxic/oxidative effects of -OH functionalized and pristine MWCNTs to evaluated the influence of the functionalization exposing A549 cells to 1-40μg/ml of both MWCNTs for 2, 4 and 24h. Cytotoxicity was evaluated by MTT and LDH tests and apoptosis induction, direct/oxidative DNA damage by Fpg-modified comet assay. After 24h we found viability reduction significant at 20 and 40μg/ml for both the MWCNTs with a detectable viability reduction already at lower concentrations for MWCNTs. A significant LDH release was found only for MWCNTs. Significant apoptosis induction was found from 10μg/ml of MWCNT-OH. A concentration-dependent increase of direct DNA damage, significant at 40μg/ml of MWCNTs and beginning from 5μg/ml of MWCNT-OH was detected at all exposure times. Oxidative DNA damage was not observed for both CNTs. The results indicate a different cytotoxic mechanism, by membrane damage for MWCNTs and apoptosis for MWCNT-OH, that could be explained by a different cellular uptake. Moreover, we found an earlier genotoxic effect for MWCNT-OH. The findings suggest that further studies on functionalized CNTs are necessary before using them in several applications particularly in biomedical field.

Evaluation of oxidative damage and inhibition of DNA repair in an in vitro study of nickel exposure

It has been suggested that Nickel is involved in oxidative damage and inhibition of DNA repair. We studied the effects of NiSO4 on oxidative stress and DNA repair in Jurkat cells to elucidate its mechanism of action. Cells were treated with H2O2 and ROS generation (by flow cytometry), and oxidative DNA damage (as tail moment by Fpg-enzyme comet test), were evaluated immediately and after 4 and 24 h of DNA damage recovery occurred in presence or absence of NiSO4 (0.017 and 0.17 microM) to clarify possible interactions of Ni with DNA repair processes. Moreover, cells were exposed to the same doses of NiSO4 for 4 and 24 hours to evaluate its direct oxidative effect. The results of the comet test showed high tail moment immediately after oxidative burst with a decreasing after 4 h of DNA recovery, and a slight increase after 24 h of recovery. The decreases were more limited for cells treated with NiSO4 0.17 microM indicating an inhibition of oxidative DNA damage repair by this substance. An induction of ROS was observed after 4 h of incubation with higher dose of NiSO4. Cells treated with H2O2 showed the highest level of ROS after 4 h of recovery in presence of NiSO4 0.17 microM that remained at elevated levels also after 24 h of recovery suggesting a synergistic action of Ni with H2O2 in the reduction of cellular anti-oxidative defence activities.

Pleural malignant mesothelioma epidemic: incidence, modalities of asbestos exposure and occupations involved from the Italian National Register.

Due to the large scale use of asbestos (more than 3.5 million tons produced or imported until its definitive banning in 1992), a specific national surveillance system of mesothelioma incident cases is active in Italy, with direct and individual anamnestic etiological investigation. In the period between 1993 and 2004, a case‐list of 8,868 pleural MM was recorded by the Italian National Register (ReNaM) and the modalities of exposure to asbestos fibres have been investigated for 6,603 of them. Standardized incidence rates are 3.49 (per 100,000 inhabitants) for men and 1.25 for women, with a wide regional variability. Occupational asbestos exposure was in 69.3% of interviewed subjects (N = 4,577 cases), while 4.4% was due to cohabitation with someone (generally, the husband) occupationally exposed, 4.7% by environmental exposure from living near a contamination source and 1.6% during a leisure activity. In the male group, 81.5% of interviewed subjects exhibit an occupational exposure. In the exposed workers, the median year of first exposure was 1957, and mean latency was 43.7 years. The analysis of exposures by industrial sector focuses on a decreasing trend for those traditionally signaled as “at risk” (asbestos‐cement industry, shipbuilding and repair and railway carriages maintenance) and an increasing trend for the building construction sector. The systematic mesothelioma surveillance system is relevant for the prevention of the disease and for supporting an efficient compensation system. The existing experience on all‐too‐predictable asbestos effects should be transferred to developing countries where asbestos use is spreading.

Multi‐walled carbon nanotubes induce cytotoxicity and genotoxicity in human lung epithelial cells

The increasing use of nanomaterials in consumer products highlights the importance of understanding their potential toxic effects. We evaluated cytotoxic and genotoxic/oxidative effects induced by commercial multi‐walled carbon nanotubes (MWCNTs) on human lung epithelial (A549) cells treated with 5, 10, 40 and 100 µg ml−1 for different exposure times. Scanning electron microscopy (SEM) analysis, MTT [3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide] and lactate dehydrogenase (LDH) assays were performed to evaluate cytotoxicity. Fpg‐modified comet assay was used to evaluate direct‐oxidative DNA damage. LDH leakage was detected after 2, 4 and 24 h of exposure and viability reduction was revealed after 24 h. SEM analysis, performed after 4 and 24 h exposure, showed cell surface changes such as lower microvilli density, microvilli structure modifications and the presence of holes in plasma membrane. We found an induction of direct DNA damage after each exposure time and at all concentrations, statistically significant at 10 and 40 µg ml−1 after 2 h, at 5, 10, 100 µg ml−1 after 4 h and at 10 µg ml−1 after 24 h exposure. However, oxidative DNA damage was not found. The results showed an induction of early cytotoxic effects such as loss of membrane integrity, surface morphological changes and MWCNT agglomerate entrance at all concentrations. We also demonstrated the ability of MWCNTs to induce early genotoxicity. This study emphasizes the suitability of our approach to evaluating simultaneously the early response of the cell membrane and DNA to different MWCNT concentrations and exposure times in cells of target organ. The findings contribute to elucidation of the mechanism by which MWCNTs cause toxic effects in an in vitro experimental model. Copyright

Indoor formaldehyde and acetaldehyde levels in the province of Bari, South Italy, and estimated health risk

Indoor and outdoor formaldehyde and acetaldehyde levels were assessed to characterize pollution in dwellings in the city and the Province of Bari, also taking into account seasonal variability, and to investigate health effects of aldehyde exposure on the general population. In 2007, passive environmental monitoring was performed, for 24 hours, in the kitchen of 59 dwellings, as well as outdoors for 27 of them. A questionnaire probing personal and home characteristics was administered to all 182 subjects habitually resident in the homes. During the period January-June 2008, formaldehyde and acetaldehyde levels were monitored monthly in 20 of the investigated dwellings inhabited only by non smokers. Indoor formaldehyde and acetaldehyde concentrations were significantly higher (16.0 +/- 8.0 and 10.7 +/- 8.8 microg m(-3)) than outdoor concentrations (4.4 +/- 1.7 and 3.4 +/- 2.0 microg m(-3)), showing a correlation between indoor levels of the two aldehydes (r = 0.41; p = 0.001). In dwellings inhabited only by non smokers, formaldehyde concentrations were higher in the presence of furniture bought new or restored less than one year before (p = 0.03). Formaldehyde and acetaldehyde levels were significantly higher in winter months than in spring-summer months (F = 2.86, p = 0.02; F = 5.39, p < 0.001) and seemed to be influenced by the time that kitchen windows were kept open. As regards the effects on human health, a low prevalence of allergic disease and no association between any irritant or allergic complaints and indoor levels of the two aldehydes was observed. In conclusion, the results showed low indoor and outdoor concentrations of formaldehyde and acetaldehyde, not generally posing a risk for human health.

Evaluation of a suitable DNA damage biomarker for human biomonitoring of exposed workers

The objective of this study was to identify a sensitive and noninvasive biomarker of early genotoxic effects, for health risk assessment of workers exposed to mixtures of low doses of xenobiotics. We studied 30 workers exposed to antineoplastic drugs, 57 workers exposed to different mixtures of polycyclic aromatic hydrocarbons (PAHs) (41 airport workers and 16 paving workers) and 76 controls. Comet and micronucleus (MN) tests were performed on lymphocytes and exfoliated buccal cells. The MN assay on lymphocytes did not show significant differences between exposed and controls, while the MN assay on exfoliated buccal cells showed higher values in workers exposed to antineoplastics as compared with controls (0.85 vs. 0.48, P = 0.042). The comet assay on lymphocytes showed a higher comet percentage value (18.11 vs. 11.24 in controls, P = 0.001) and mean tail moment (TM) value (21.84 vs. 16.72 in controls, P = 0.003) in individuals exposed to PAHs as compared with controls; no significant differences were found in exposed to antineoplastics. The comet assay on exfoliated buccal cells did not show significant differences between exposed and control groups for comet percentages, whereas the TM value was higher in workers exposed to PAHs (55.1 vs. 32.31 for controls, P < 0.001). These results show that exfoliated buccal cells, obtained by a noninvasive procedure, represent robust target cells to assess the occupational exposure to inhalable mixture of chemicals at low doses. The comet assay seems to be suitable to promptly evaluate the genotoxic effects of PAHs mixtures that also contain volatile substances. The MN test is suitable to evaluate the effects of antineoplastics. Environ. Mol. Mutagen. 2009.

Oxidative and pro-inflammatory effects of cobalt and titanium oxide nanoparticles on aortic and venous endothelial cells

Ultra-fine particles have recently been included among the risk factors for the development of endothelium inflammation and atherosclerosis, and cobalt (CoNPs) and titanium oxide nanoparticles (TiNPs) have attracted attention because of their wide range of applications. We investigated their toxicity profiles in two primary endothelial cell lines derived from human aorta (HAECs) and human umbilical vein (HUVECs) by comparing cell viability, oxidative stress, the expression of adhesion molecules and the release of chemokines during NP exposure. Both NPs were very rapidly internalised, and significantly increased adhesion molecule (ICAM-1, VCAM-1, E-selectin) mRNA and protein levels and the release of monocyte chemoattractant protein-1 (MCP-1) and interleukin 8 (IL-8). However, unlike the TiNPs, the CoNPs also induced time- and concentration-dependent metabolic impairment and oxidative stress without any evident signs of cell death or the induction of apoptosis. There were differences between the HAECs and HUVECs in terms of the extent of oxidative stress-related enzyme and vascular adhesion molecule expression, ROS production, and pro-inflammatory cytokine release despite the similar rate of NP internalisation, thus indicating endothelium heterogeneity in response to exogenous stimuli. Our data indicate that NPs can induce endothelial inflammatory responses via various pathways not involving only oxidative stress.

European social dialogue on psychosocial risks at work: Benefits and challenges

In many European countries, psychosocial risks such as work-related stress, violence, bullying and harassment have become major concerns for occupational safety and health. Has the development of instruments and approaches to meet these challenges kept pace? This article examines the role of European social dialogue as a relatively novel mode of regulation (‘soft law’) in the field of psychosocial risks, considering also the changing political and economic context of the enlarged EU. Although some progress has been achieved, diverging stakeholder perspectives and structural weaknesses still pose serious challenges to effective social dialogue in this area. We draw on the results of a recently completed project on psychosocial risk management, including the findings of a European stakeholder survey among experts in occupational safety and health.

Prevalence and incidence of antibodies to Borrelia burgdorferi and to tick-borne encephalitis virus in agricultural and forestry workers from Tuscany, Italy.

The ticks Ixodes persulcatus and Ixodes ricinus are the main vectors of both Borrelia burgdorferi sensu lato and tick-borne encephalitis (TBE) virus in Eurasia. Borrelia burgdorferi is the cause of Lyme borreliosis, and TBE is a biphasic meningoencephalitis induced by an arbovirus belonging to the flavivirus family. The principal aims of the current investigation were (i) to determine the frequency of serological evidence of Borrelia burgdorferi sensu lato and TBE infections in healthy agricultural and forestry workers, (ii) to determine the incidence of seroconversion for antibodies against Borrelia burgdorferi sensu lato and TBE virus in Tuscan workers during a 1-year survey; and (iii) to assess the occupational risk for agricultural and forestry activities in a defined area (Tuscany, Italy). A total of 412 blood samples were taken from agricultural and forestry workers, and information on age, duration of employment, and history of tick bites was collected in a questionnaire to establish the risk factors for the diseases. Three hundred sixty-five blood donors from the same region served as controls. To estimate the rate of seroconversion, 176 of the agricultural and forestry workers were tested 1 year later. IgG and IgM antibodies against Borrelia burgdorferi sensu lato and TBE virus were detected in serum by an enzyme-linked immunosorbent assay and confirmed by Western blot analysis for Borrelia burgdorferi and by a test for inhibition of hemagglutination for TBE. Antibodies against Borrelia burgdorferi were more frequent among the workers than in the control group (7.8% vs. 4.9% in the IgG-IgM enzyme-linked immunosorbent assay and 7.03% vs. 3.56% in the confirmatory test). No seropositivity was observed for TBE virus. Eighteen of 176 subjects who underwent a second blood test developed specific antibodies against Borrelia burgdorferi within 1 year.

Evaluation of cytotoxic, genotoxic and inflammatory response in human alveolar and bronchial epithelial cells exposed to titanium dioxide nanoparticles

The toxicity of titanium dioxide nanoparticles (TiO2‐NPs), used in several applications, seems to be influenced by their specific physicochemical characteristics. Cyto‐genotoxic and inflammatory effects induced by a mixture of 79% anatase/21% rutile TiO2‐NPs were investigated in human alveolar (A549) and bronchial (BEAS‐2B) cells exposed to 1–40 µg ml–1 30 min, 2 and 24 h to assess potential pulmonary toxicity. The specific physicochemical properties such as crystallinity, NP size and shape, agglomerate size, surface charge and specific surface area (SSA) were analysed. Cytotoxic effects were studied by evaluating cell viability using the WST1 assay and membrane damage using LDH analysis. Direct/oxidative DNA damage was assessed by the Fpg‐comet assay and the inflammatory potential was evaluated as interleukin (IL)‐6, IL‐8 and tumour necrosis factor (TNF)‐α release by enzyme‐linked immunosorbant assay (ELISA). In A549 cells no significant viability reduction and moderate membrane damage, only at the highest concentration, were detected, whereas BEAS‐2B cells showed a significant viability reduction and early membrane damage starting from 10 µg ml–1. Direct/oxidative DNA damage at 40 µg ml–1 and increased IL‐6 release at 5 µg ml–1 were found only in A549 cells after 2 h. The secretion of pro‐inflammatory cytokine IL‐6, involved in the early acute inflammatory response, and oxidative DNA damage indicate the promotion of early and transient oxidative‐inflammatory effects of tested TiO2‐NPs on human alveolar cells. The findings show a higher susceptibility of normal bronchial cells to cytotoxic effects and higher responsiveness of transformed alveolar cells to genotoxic, oxidative and early inflammatory effects induced by tested TiO2‐NPs. This different cell behaviour after TiO2‐NPs exposure suggests the use of both cell lines and multiple end‐points to elucidate NP toxicity on the respiratory system. Copyright