Investigating Listening Effort in Classrooms for 5- to 7-Year-Old Children.

Purpose This study aims to investigate the listening effort made by young children in real classrooms during a prolonged speech reception task in the presence of background noise. Method The experiment was proposed to 117 typically developing kindergarten and primary school pupils, aged 5-7 years old. An ecological experimental approach was followed, and speech-in-noise tests were presented in the classrooms to groups made up of the whole class. The speech material of the Word Intelligibility by Picture Identification Test in the Italian language ( Arslan, Genovese, Orzan, & Turrini, 1997 ) was presented in 2 listening conditions (quiet classroom [no noise added] and working classroom [with stationary noise]) and was repeated twice during the experiment. Data on the number of correctly recognized words and the single-task response time (RT) were collected; the quantity of the latter was considered informative on listening effort. Results It was found that when background noise was present, the pupils' performance decreased, and greater RTs were required compared to the "quiet classroom" condition. When the RTs were analyzed over the course of the experiment, there were no changes in the quiet condition, whereas in the working classroom, a significant increase was found for the 6- and 7-year-old pupils. On the contrary, the youngest pupils (5-year-olds) showed a decrease in the RT results over the test repetitions. Conclusions The RT measured with a single-task paradigm was found to be a viable approach for investigating the listening effort in 6- to 7-year-old pupils. For this age range, the metric was sensitive to changes both in the listening conditions and within the same listening condition across the time of exposure. More research is needed to assess the feasibility of the experimental paradigm with the 5-year-old children.

How to improve performance and prevent burnout in safety representatives.

BACKGROUND: The present work is part of a greater research project, aimed to examine Safety Representatives' (SRs) role, twenty years after the appointment of this figure. OBJECTIVES: The study aims to investigate the role of some personal and organizational dimensions in the promotion of SRs' well-being, in terms of reducing burnout and improving performance. METHODS: The study involved 455 SRs operating in North East Italy. They completed a self-report questionnaire, regarding conflicts with co-workers, ethical conflict, training satisfaction, work engagement, performance, and burnout. RESULTS: Structural equation models show that work engagement partially mediates (γ=-0.52, p<0.001; ß=0.23, p<0.01) the relationship between conflict with co-workers and performance (γ=-0.26; p<0.01), as well as partially mediating (γ=0.14, p<0.05; ß=0.23; p<0.01) the relationship between training satisfaction and performance (γ=0.21, p<0.001). Moreover, it totally mediates the relationship between conflict with co-workers and burnout (γ=-0.52, p<0.001; ß=-0.40, p<0.001), as well as totally mediating the relationship between training satisfaction and burnout (γ=0.14, p<0.05; ß=-0.40, p<0.001). Finally, ethical conflict is positively associated with burnout (γ=0.047, p<0.001). CONCLUSIONS: This study provides useful information about the improvement of SRs' well-being, highlighting the importance of their involvement in this role.

Biological monitoring of low level exposure to benzene in an oil refinery: Effect of modulating factors.

The aim of the study was to investigate the effect of various factors that modulate the metabolism of benzene, including smoking habits, metabolic genotype of GST and co-exposure to toluene, on the levels of three biomarkers, i.e. urinary benzene (UB), S-phenylmercapturic acid (SPMA) and t,t-muconic acid (t,t-MA), in 146 refinery workers exposed to low levels of air benzene (AB) in the range <1.5-529.2 µg/m3 (mean value 32.6 µg/m3). The study confirmed the validity of SPMA as a good biomarker of benzene exposure even at low levels of exposure. It was also confirmed that cigarette smoking is the main confounding factor when assessing biological monitoring data of occupational exposure to AB. Our data indicate that the GSTT1, but not the GSTM1 genotype, significantly increases the urinary levels of SPMA, even at low levels of exposure. It is not known, though, whether subjects with a GSTT1 "null" genotype may be more susceptible to the effects of benzene. Finally, environmental toluene appears to inhibit the metabolism of benzene to SPMA even at low concentrations, also resulting in an underestimation by SPMA levels of the actual exposure of workers to benzene.

Aberrant promoter methylation in genes related to hematopoietic malignancy in workers exposed to a VOC mixture.

Occupational exposure to volatile organic compounds (VOCs) may cause hematopoietic malignancy, either by single exposure to benzene or possibly due to a concomitant exposure to several VOCs. Since oxidative stress, inflammation and DNA repair pathways are closely involved in cancer development, the effect of VOC exposure on expression of proteins involved in these pathways has been studied, but epigenetic changes have not been well described. Here, DNA methylation status following occupational exposure to a VOC mixture was assessed by bisulfite sequencing of the promoter regions of seven genes involved in the mentioned pathways. Peripheral blood samples and individual-level VOC exposure data were obtained from healthy leather shoe factory workers (LS, n=40) and gas station attendants (GS, n=36), as well as a reference group of university employees (C, n=66). Exposure levels for acetone, ethylbenzene, methyl ethyl ketone, n-hexane, toluene and xylene were higher in LS (p<0.001); benzene and methyl acetate levels were higher in GS (p<0.001). TOP2A, SOD1, and TNF-α promoter methylation status was increased in LS (p<0.05). In LS, we also found significant correlations between GSTP1 promoter methylation and both iNOS (r=0.37, p=0.008) and COX-2 (r=-0.38, p=0.007) methylation. In exposed groups, ethylbenzene exposure levels showed a significant correlation with TOP2A methylation (ß=0.33). Our results show early, toxic effects at the epigenetic level caused by occupational exposure to high levels of a VOC mixture. These subcellular modifications may represent the initial mechanism of toxicity leading to hematopoietic malignancy, possibly due to a synergistic, hematotoxic effect of VOC mixtures.

Promoter methylation status in genes related with inflammation, nitrosative stress and xenobiotic metabolism in low-level benzene exposure: Searching for biomarkers of oncogenesis.

Exposure to low levels of benzene may cause acute myeloid leukemia in humans. Epigenetic effects in benzene exposure have been studied for tumor suppressor genes and oxidative stress-related genes, but other cellular pathways must be explored. Here, we studied promoter DNA methylation of IL6, CYP2E1 and iNOS in blood cells from three groups of workers: a) gas station attendants (GS) exposed to low levels of benzene; b) plastic shoe factory workers (PS) exposed to other solvents different to benzene and c) administrative workers as a reference group with no solvent exposure (C). RESULTS: IL6 promoter methylation was higher in GS workers (p < 0.05). Also in GS, CYP2E1 promoter methylation negatively correlated with benzene levels (r = -0.47, p < 0.05); iNOS promoter methylation positively correlated with CYP2E1 promoter methylation (r = 0.29, p < 0.05), cumulative time of exposure (r = 0.31, p < 0.05) as well as with urinary levels of S- Phenyl mercapturic acid (SPMA), (r = 0.55, p < 0.05). Our results demonstrate alterations in the inflammation pathway at the epigenetic level associated with exposure to benzene. Correlations between iNOS methylation with both CYP2E1 methylation and urinary SPMA levels represent novel evidence about CYP2E1 epigenetic regulation and activity related with nitrosative stress, making promoter methylation status of these genes a potential biomarker in early stages of oncogenesis.

Woodworkers and the inflammatory effects of softwood/hardwood dust: evidence from nasal cytology.

Our primary aim was to use nasal cytology to compare a group of woodworkers with a group of unexposed subjects to see whether wood dust exposure correlates with specific patterns of inflammatory or infectious rhinitis. A secondary aim was to seek any differences in nasal symptoms or nasal cytology between workers exposed to softwood vs hardwood dust, thereby comparing the inflammatory harmful potential of the two woods. Among 117 woodworkers at factories in the Veneto region (Italy), 40 exposed to either softwood or hardwood dust were assessed by means of a questionnaire, nasal cytology, and personal wood dust sampling, and compared with 40 unexposed controls. Woodworkers reported significantly more nasal symptoms than controls (p = 0.0007). The woodworker group's nasal smears contained significantly more neutrophils (p < 0.00001) and lymphocytes (p = 0.02) than the control group's. The softwood workers had significantly lower levels of personal exposure to wood dust than the hardwood workers (p = 0.04); there were no significant differences in age, history of cigarette smoking, or period of exposure between these two sub-cohorts of woodworkers. A statistical trend indicated that softwood workers had more eosinophils (p = 0.05) and lymphocytes (p = 0.05) in their rhinocytograms. Nasal cytology revealed chronic inflammatory rhinitis in a significant proportion of woodworkers' enroled in this study. It also suggested a different harmful potential for softwood and hardwood dust. Nasal cytology could prove useful in screening woodworkers for chronic inflammatory rhinitis. Further investigations are needed to examine the role of different types of wood dust in nasal inflammation.

Assessment of exposure to oak wood dust using gallic acid as a chemical marker.

OBJECTIVES: The American Conference of Governmental Industrial Hygienists (ACGIH) has classified oak dust as a human carcinogen (A1), based on increased sinus and nasal cancer rates among exposed workers. The aims of this study were to investigate the use of gallic acid (GA) as a chemical marker of occupational exposure to oak dusts, to develop a high-performance liquid chromatography-diode array detector method to quantify GA and to apply the method in the analysis of oak dust samples collected in several factories. METHODS: A high-performance liquid chromatography method was developed to detect GA in oak wood dust. The method was tested in the field, and GA was extracted from inhalable oak wood dust collected using the Institute of Occupational Medicine inhalable dust sampler in the air of five woodworking plants where only oak wood is used. RESULTS: A total of 57 samples with dust concentrations in the range of 0.27-11.14 mg/m(3) were collected. Five of these samples exceeded the Italian threshold limit value of 5 mg/m(3), and 30 samples exceeded the ACGIH TLV of 1 mg/m(3). The GA concentrations were in the range 0.02-4.18 µg/m(3). The total oak dust sampled was correlated with the GA content with a correlation coefficient (r) of 0.95. CONCLUSIONS: The GA in the tannic extracts of oak wood may be considered a good marker for this type of wood, and its concentration in wood dust sampled in the work environment is useful in assessing the true exposure to carcinogenic oak dust.

[The teaching of occupational medicine in the Master of Science in Medicine in the twenty years since the introduction of Table XVIII]. / L'insegnamento della Medicina del lavoro nel corso di laurea magistrale in Medicina e Chirurgia a vent'anni dall'introduzione della Tabella XVIII.

In 1991, the implementation of the new programme for education and training in Medicine and Surgery has introduced the teaching of Occupational Medicine (OM) as a compulsory subject for all medical students. After two decades from that event and in conjunction with the implementation of the new academic departments introduced by the law 240/2010, the aim of the present study was to address the current status and the main characteristics of education and training, including clinical activities, in OM in Italian Universities and to update the information on the related academic human resources available. A questionnaire was developed to investigate the different features of the academic staff belonging to the area of OM (SSD MED/44), and to evaluate the organization of teaching and the clinical activities performed by the Occupational Medicine sections. The results showed that among the 40 Italian universities with a degree course in Medicine and Surgery, 67% of them have at least one full professor, 72% one associate professor and 78% one assistant professor belonging to the area of OM. Nevertheless, a steady decrease in the number of academic staff is observed with time, which caused a lack of presence of the discipline in some universities. In most degree courses in Medicine and Surgery the teaching of OM is usually included in an integrated course together with other disciplines such as General and Applied Hygiene and/or Forensic and Legal Medicine. Within the integrated course the number of University Education & Training Credits (CFU, corresponding to approx. 25 hrs of teaching overall) assigned to OM is generally between 2 and 3 (61% of cases). The teaching of OM is also present in eight different master degree courses (MSc) and in 33 different triennial degree courses (BSc). To support the teaching clinical activities, such as workers' health surveillance, laboratories, ambulatories, and DH or inpatient activities are performed, in one or more of these forms, by almost all of the OM institutions. The findings of this study, despite being subject to change rapidly with time, still provide an invaluable set of information and should represent, therefore, a rational basis for planning the future recruitment of academic staff and for updating the contents and methodologies of graduate education and training in Occupational Medicine in Italian universities.

The mediating role of interpersonal conflict at work in the relationship between negative affectivity and biomarkers of stress.

This study examined the association between interpersonal conflict at work (ICW) and serum levels of three possible biomarkers of stress, namely the pro-inflammatory cytokines Interleukin 1 beta (IL-1ß), Interleukin 12 (IL-12), and Interleukin 17 (IL-17). Additionally, this study investigated the role of negative affectivity (NA) in the relationship between ICW and the pro-inflammatory cytokines. Data from 121 employees in an Italian healthcare organization were analyzed using structural equation modeling. Results showed that ICW was positively associated with IL-1ß, IL-12, and IL-17, after controlling for the effect of gender. Moreover, ICW completely mediated the relationship between NA and the pro-inflammatory cytokines IL-1ß, IL-12, and IL-17. This mediating effect was significant after controlling for the effect of gender. Overall, this study suggests that work-related stress may be associated with biomarkers of inflammation, and that negative affectivity may influence the stress process affecting the exposure to psychosocial stressors.

Investigating nasal cytology as a potential tool for diagnosing occupational rhinitis in woodworkers.

BACKGROUND: Our primary endpoint was to use nasal cytology to compare woodworkers with unexposed subjects to see if wood dust exposure correlates with specific patterns of inflammatory or infectious rhinitis. A secondary endpoint was to identify any differences in the exposed group's nasal symptoms or nasal cytology by years of exposure or personal exposure levels. METHODS: Ninety-two woodworkers and 90 controls were assessed using a questionnaire and nasal cytology (on nasal mucosa obtained by scraping). Wood dust exposure was investigated using personal sampling methods. RESULTS: Woodworkers reported significantly more nasal symptoms than controls (p < 0.00001). The woodworkers' nasal smears revealed more neutrophils (p = 0.001) and significantly higher mean neutrophil scores (p = 0.001) than control smears. Lymphocytes were also found more often in the woodworkers' rhinocytograms (statistical trend, p = 0.06). Neutrophilic rhinitis was diagnosed more frequently in the exposed workers than in controls (chi-square = 5.97, p < 0.05). Woodworkers with lymphocytes in their nasal smears had been exposed to wood dust for longer periods of time (statistical trend; p = 0.06). No differences in nasal symptoms or cell counts emerged when woodworkers were stratified by levels of personal exposure. CONCLUSION: Nasal cytology should be further investigated in woodworkers before considering it a screening method for identifying woodworkers with chronic inflammatory rhinitis.

Micronuclei and chromosome aberrations in subjects occupationally exposed to antineoplastic drugs: a multicentric approach.

OBJECTIVES: Recently published works showed that occupational exposure to antineoplastic drugs (ANPD) is still frequent in hospital settings, despite significant safety policy improvements. The aim of this study was to assess the current level of occupational exposure to ANPD and any potentially associated cytogenetic damages in hospital nurses routinely handling ANPD. METHODS: Occupationally ANPD-exposed (n = 71) and ANPD-unexposed (n = 77; control) nurses were recruited on a voluntary basis from five hospitals in Northern and Central Italy. Evaluation of surface contamination and dermal exposure to ANPD was assessed by determining cyclophosphamide (CP) on selected surfaces (wipes) and on exposed nurses' clothes (pads). The concentration of unmetabolized CP­as a biomarker of internal dose­was measured in end-shift urine samples. Biomonitoring of genotoxic effects (i.e., biological effect monitoring) was conducted by analyzing micronuclei (MN) and chromosome aberrations (CA) in peripheral blood lymphocytes. Genetic polymorphisms for enzymes involved in metabolic detoxification (i.e., glutathione S-transferases) were analyzed as well. RESULTS: We observed a significant increase in MN frequency (5.30 ± 2.99 and 3.29 ± 1.97; mean values ± standard deviation; p < 0.0001) in exposed nurses versus controls, as well as in CA detection (3.30 ± 2.05 and 1.84 ± 1.67; p < 0.0001), exposed subjects versus controls. Our results provide evidence that, despite safety controlled conditions, ANPD handling still represents a considerable genotoxic risk for occupationally exposed personnel. CONCLUSIONS: Because both MN and CA have been described as being predictive of group-increased cancer risk, our findings point to a need for improving specific safety procedures in handling and administering ANPD.

High-frequency hearing thresholds: effects of age, occupational ultrasound and noise exposure.

PURPOSE: It has been suggested that high-frequency audiometry (HFA) could represent a useful preventive measure in exposed workers. The aim was to investigate the effects of age, ultrasound and noise on high-frequency hearing thresholds. METHODS: We tested 24 industrial ultrasound-exposed subjects, 113 industrial noise-exposed subjects and 148 non-exposed subjects. Each subject was tested with both conventional-frequency (0.125-8 kHz) and high-frequency (9-18 kHz) audiometry. RESULTS: The hearing threshold at high frequency deteriorated as a function of age, especially in subjects more than 30 years old. The ultrasound-exposed subjects had significantly higher hearing thresholds than the non-exposed ones at the high frequencies, being greatest from 10 to 14 kHz. This hearing loss was already significantly evident in subjects with exposure <5 years and increased with years of exposure and advancing age. The noise exposure group had significantly higher hearing thresholds than the non-exposed group at the conventional frequencies 4 and 6 kHz and at the high frequency of 14 kHz. After stratification for age, there was a significant difference between the two groups at 9-10 and 14-15 kHz only for those under 30 years of age. CONCLUSION: Multivariate analysis indicated that age was the primary predictor, and noise and ultrasound exposure the secondary predictors of hearing thresholds in the high-frequency range. The results suggest that HFA could be useful in the early diagnosis of noise-induced hearing loss in younger groups of workers (under 30 years of age).

Biomonitoring occupational sevoflurane exposure at low levels by urinary sevoflurane and hexafluoroisopropanol.

This study aimed to correlate environmental sevoflurane levels with urinary concentrations of sevoflurane (Sev-U) or its metabolite hexafluoroisopropanol (HFIP) in order to assess and discuss the main issues relating to which biomarker of sevoflurane exposure is best, and possibly suggest the corresponding biological equivalent exposure limit values. Individual sevoflurane exposure was measured in 100 healthcare operators at five hospitals in north-east Italy using the passive air sampling device Radiello(®), and assaying Sev-U and HFIP concentrations in their urine collected at the end of the operating room session. All analyses were performed by gas chromatography-mass spectrometry. Environmental sevoflurane levels in the operating rooms were also monitored continuously using an infrared photoacoustic analyzer. Our results showed very low individual sevoflurane exposure levels, generally below 0.5 ppm (mean 0.116 ppm; range 0.007-0.940 ppm). Sev-U and HFIP concentrations were in the range of 0.1-17.28 µg/L and 5-550 µg/L, respectively. Both biomarkers showed a statistically significant correlation with the environmental exposure levels (Sev-U, r=0.49; HFIP, r=0.52), albeit showing fairly scattered values. Sev-U values seem to be influenced by peaks of exposure, especially at the end of the operating-room session, whereas HFIP levels by exposure on the previous day, the data being consistent with the biomarkers' very different half-lives (2.8 and 19 h, respectively). According to our results, both Sev-U and HFIP are appropriate biomarkers for assessing sevoflurane exposure at low levels, although with some differences in times/patterns of exposure. More work is needed to identify the best biomarker of sevoflurane exposure and the corresponding biological equivalent exposure limit values.

[The role of occupational physician in the risk assessment]. / II ruolo del medico competente nella valutazione del rischio.

Occupational Physician has a marginal role in the Risk Assessment (RA). He is rarely involved and generally he only reads the documentation of RA made by other specialists in the prevention and safety. The law obliges him to work with the Employer, not only for the planning of health surveillance but also for the preparation of measures for the protection of the health and psycho-physical integrity of workers. But it is mainly for the content and methodology of the RA that it is necessary the contribution of the occupational physician. The RA is in fact a multi-stage and multi-disciplinary activity carried out in close collaboration with industrial hygienists, ergonomists, safety experts, psychologists. The occupational physician for his studies and education is the most appropriate professional to evaluate the quality of the data and to make an integration between indicators of environmental contamination and biological indicators of internal dose and effect or damage. We agree with the Italian Society of Occupational Health and Industrial Hygiene that is necessary to proceed to the recognition of the role of occupational physician as a "consultant" of the company about health and safety in the workplace and involved in RA even when it is not necessary the health surveillance.

Reliability of urinary excretion rate adjustment in measurements of hippuric acid in urine.

The urinary excretion rate is calculated based on short-term, defined time sample collections with a known sample mass, and this measurement can be used to remove the variability in urine concentrations due to urine dilution. Adjustment to the urinary excretion rate of hippuric acid was evaluated in 31 healthy volunteers (14 males and 17 females). Urine was collected as short-term or spot samples and tested for specific gravity, creatinine and hippuric acid. Hippuric acid values were unadjusted or adjusted to measurements of specific gravity, creatinine or urinary excretion rate. Hippuric acid levels were partially independent of urinary volume and urinary flow rate, in contrast to specific gravity and creatinine, which were both highly dependent on the hippuric acid level. Accordingly, hippuric acid was independent on urinary specific gravity and creatinine excretion. Unadjusted and adjusted values for specific gravity or creatinine were generally closely correlated, especially in spot samples. Values adjusted to the urinary excretion rate appeared well correlated to those unadjusted and adjusted to specific gravity or creatinine values. Thus, adjustment of crude hippuric acid values to the urinary excretion rate is a valid procedure but is difficult to apply in the field of occupational medicine and does not improve the information derived from values determined in spot urine samples, either unadjusted or adjusted to specific gravity and creatinine.

Chemical markers of occupational exposure to teak wood dust.

A novel high-performance liquid chromatographic/ultraviolet method was developed to detect lapachol (LP) and deoxylapachol (DLP) in wood dust as chemical markers of teak wood (a suspected human carcinogen). The specificity of this analysis was determined by noting the absence of LP and DLP in 12 other specimens of different woods belonging to the angiosperm family. The consistency was examined by analyzing teak from three different sources, where the percentages (wt/wt) of the chemicals ranged from 0.006 to 0.261 for LP and from 0.038 to 0.497 for DLP, respectively. Although the LP and DLP components of teak varied according to source, a very high correlation coefficient (r (2) > 0.98 always) was found between the content of the two markers in the bulk specimens and in bulk dust derived from them. The method was then applied to teak dust collected on polyvinylchloride filters from aerosol in an exposure chamber in the range of mass loadings between 0.03 and 3.65 mg, which corresponds to a dust exposure between 0.124 and 8.703 mg m(-3) for a sampling time of 2h. A field test was also carried out in a small factory where teak was used. A good correlation was confirmed between LP and DLP versus the dust collected on the filter in both cases. LP and DLP can be markers to estimate the true quantities of teak dust inhaled in a workplace with mixed wood dust, provided the results are matched to the content of LP and DLP in the bulk wood. LP and DLP have also been proposed as the agents responsible for allergic reaction to teak dust. Therefore, it would be useful to evaluate the exposure to these two substances even without a relationship to teak dust exposure.

[Monitoring of the occupational and environmental exposure to low doses of benzene]. / Il monitoraggio dell'esposizione occupazionale ed ambientale a basse dosi di benzene.

AIM: To verify which of the various biomarkers of internal dose of benzene can be considered reliable for biological monitoring of exposure to the low concentrations present nowadays in working and living environments. MATERIALS AND METHODS: The specific literature was analyzed to assess the reliability of the different biomarkers of internal dose. RESULTS AND CONCLUSIONS: T,t-muconic acid is a non specific biomarker for benzene, valid for exposure to concentrations up to one order of magnitude less than the threshold limit of 3250 microg/m3. S-phenylmercapturic acid (SPMA) is a reliable marker even for exposure to concentrations up to two orders below the threshold value of 3250 microg/m3, and can be considered the biomarker of choice for biological monitoring of workers exposed to benzene. Urinary benzene does not seem to have any real advantages over SPMA for monitoring occupational exposure to benzene, but it does seem to be more reliable than SPMA to assess exposure to concentrations like those present in living environments. A smoking habit influences the urinary excretion of all the described biomarkers, and for the current low levels of occupational and environmental exposure to benzene, must be taken into account when interpreting the results of biological monitoring.

[Considerations on the limit values for benzene]. / Considerazioni sui valori limite per il benzene.

Occupational exposure limits and guideline values for the general population proposed for benzene by several international bodies are discussed and compared with the Italian and EU occupational limit values, taking also into account the criteria used for their derivation. Benzene is an environmental pollutant, and the EU guideline value for ambient air is 5 microg/m3, based on carcinogenic risk. Presently, occupational exposures are greatly reduced, and in many instances close to those of the general population. Consequently, it does not seem to be appropriate to maintain the Italian and the EU occupational exposure limits of 1 ppm (3.2 mg/m3), which are inconsistent with the ALARA principle and not justified by technological constraints. It should be pointed out that, in any case, preventive interventions should be carried out, beyond the compliance with the established limit values, in order to ensure the lowest exposure and by carrying out biological monitoring as a tool to verify the appropriateness of risk management measures.