[Sleep disorders in cement workers]. / I disturbi del sonno nei lavoratori dell'industria del cemento.

Obstructive Sleep Apnea Syndrome (OSAS) and Excessive Daytime Sleepiness (EDS) are sleep disorders which can increase cardiovascular risk. An health survey was performed on the cement workers to estimate the prevalence of sleep disorders and to investigate occupational, personal and health risk factors that could influence it. A total of 761 male workers, employed at 10 different cement plants of South Italy and Sicily, were examined. All subjects gave informed consent to take part in the survey. The following questionnaires were administered: Berlin Questionnaire to estimate the high risk of OSAS, Epworth Sleepiness Scale for EDS, a questionnaire posing questions about working conditions, personal characteristic, lifestyle, past history of disease and present illness. Statistical analysis was performed with the statistical package SPSS. The prevalence of high risk of OSAS and of EDS resulted respectively in 24.2% and 3.4% of workers. Sleep disorders detected with the two questionnaires were significantly associated. A positive and significant association between OSAS and respectively age, time of employment, BMI, ex-smoker status, neck, waist or hip circumferences, chronic fatigue and arterial hypertension was observed. Subjective variables regarding working conditions (job interest, evaluation oforganization of work and job satisfaction) and alcohol consumption were not associated with the high risk of OSAS. Shift work (2 and 3 shifts) was not associated with the high risk of OSAS. An healthy worker effect was observed for workers who changed from shift work (2 or 3 shifts) to fixed daytime work. For them, this change to fixed daytime work was conditioned by chronic disease like hypertension and obesity. EDS was not dependent, associated or correlated with any of the occupational, personal or pathologic variables investigated in the study. In conclusion the research showed no relationship between working conditions, particularly shift work, and the high risk of OSAS, and the influence of obesity in determining the high risk of OSAS, itself a potential cardiovascular risk factor. The interest of occupational physician has been focused on introducing in health surveillance also measures of health promotion regarding sleep disorders with the aim of preserving health condition in workers.

[Validity of urinary 2-thiothiazolidine-4-carboxylic acid (TTCA) as biomarker of exposure to very low concentrations of carbon disulphide: preliminary results]. / Validiti dell'acido 2-tiotiazolidin-4-carbossilico (TTCA) urinario quale indicatore biologico dell'esposizione a concentrazioni molto basse di solfuro di carbonio: risultati preliminori.

The possibility to use urinary 2-thiothiazolidine-4-carboxylic acid (TTCA) as biomarker of occupational exposure to very low doses of carbon disulphide (CS2) was evaluated preliminarily in 10 workers employed in a chemical plant where rubber vulcanization accelerators are produced, and in 10 workers, residents in the same geographical area and not occupationally exposed to CS2 and dithiocarbamates (DTC). Exposure to airborne CS2 was assessed, only for exposed workers, by both personal and area samplers. For the determination of TTCA, a spot urine sample was collected for each worker, exposed and non exposed, at the end of work-shift. A questionnaire probing lifestyle and dietary habits and non occupational exposure to CS2 and DTC was administered to all workers involved in the study. Environmental exposure to CS2 in 2007 ranged between 0.21 mg/m3 and 0.73 mg/m3 for personal sampling, and between 0.23 mg/m3 and 0.41 mg/m3 for area sampling. Urinary TTCA levels resulted very low and did not show any significant difference between exposed (Median: 10.8 microg/g creat; Range: 6.1-26.4 microg/g creat) and non exposed workers (Median: 9.3 microg/g creat; Range: 3.0-33.0 microg/g creat), while higher, but not significant concentrations of TTCA were observed in smokers than in non smokers (p = 0.09). No correlation was found between urinary TTCA levels and environmental exposure to CS2, age, body mass index, smoking and dietary habits. In conclusion, the low sensibility and specificity in the assessment of occupational exposure to low doses of CS2 in workers compared to general population subjects, makes urinary TTCA a biomarker with a low usefulness in biological monitoring. ACGIH, besides, should also introduce "B" (background) notation, at present not considered for the BEI indicated for urinary TTCA.

[Significance and limitation of creatinine adjustment for urinary chromium and arsenic in biological monitoring of occupational exposure to these metallic elements]. / Significato e limiti della correzione per creatinina del cromo e dell'arsenico urinari nel monitoraggio biologico dell'esposizione professionale ai due elementi metallici.

Creatinine adjustment has been used to remove the influence of the effect of urine dilution on exposure biomarkers measured in spot samples. This research aimed to determine the reliability of creatinine adjustment for urinary chromium and arsenic in subjects from general population considering interferences able to influence creatinine excretion. 444 male subjects were examined and each participant was administered an anamnestic questionnaire. Chromium and arsenic were determined on second morning void urine samples by atomic absorption spectrophotometry and creatinine by Jaffè method. Urinary creatinine showed a significant negative decrease with age increasing (p < 0.001). Chromium concentrations resulted higher in subjects with renal disease, particularly after creatinine adjustment (p = 0.014). Age was negatively correlated with urinary creatinine (rho = -0.23; p < 0.001), and positively with chromium (rho = 0.13; p = 0.007) and arsenic (rho = 0.17; p = 0.004), only after creatinine adjustment. A positive correlation was also found between unadjusted chromium and arsenic (rho = 0.10; p = 0.039) and between urinary creatinine and both unadjusted chromium (rho = 0.32; p < 0.001) and arsenic (rho = 0.18; p < 0.001). An high coefficient of correlation was observed between unadjusted chromium (rho = 0.88; p < 0.001) and arsenic (rho = 0.90; p < 0.001) and the respective adjusted values. Multiple regression showed a dependence of urinary creatinine and adjusted chromium and arsenic concentrations on age. In conclusion, although chromium and arsenic seem to have a renal kinetics of excretion comparable to the creatinine one, the influence of age on creatinine elimination suggests that the expression of urinary values of these metallic elements as microg/L is more reliable.

[Influence of cigarette smoking on the excretion of urinary benzene in filling-station attendants]. / Influenza del fumo di sigaretta sulla concentrazione di benzene urinario negli addetti alla distribuzione di carburante.

The influence of cigarette smoking on concentrations of urinary benzene, a sensitive and specific biomarker proposed for biological monitoring of exposure to very low doses of benzene, was investigated in 24 filling-station attendants and 31 workers non occupationally exposed to benzene. Environmental monitoring was performed by personal passive samplers "Radiello", and a spot urine sample was collected at the end of the work shift, from all subjects, for the determination of urinary benzene. Exposure to benzene resulted significantly higher in filling-station attendants (mean 23.3 +/- 17.0 microg/m3; range 4.5-66.3 microg/m3) than in controls (mean 4.6 +/- 2.6 microg/m3; range < 3-11.5 microg/m3), while concentrations of urinary benzene did not show any significant difference between the two groups. Considering all subjects as a single group, it was observed that urinary benzene concentrations were positively correlated with the number of cigarettes smoked during the sampling time (rho = 0.38; p = 0.047) and with airborne benzene levels (rho = 0.32; p = 0.019), and negatively correlated with the time elapsed between the last smoked cigarette and urine collecting (rho = -0.40; p = 0.045). Multiple regression analysis confirmed the influence of cigarette smoking on urinary benzene concentrations. In conclusion, our study showed the validity of urinary benzene as a biomarker for biological monitoring of exposure to very low doses of benzene, although cigarette smoking determined a prevalent etiological role at the low environmental benzene concentrations observed.

[In vitro effects of hexavalent and tetravalent tellurium on immune functions]. / Effetti "in vitro" del tellurio esavalente e tetravalente su funzioni immunitarie.

The "in vitro" immune effects of K2TeO3xH2O (Te IV) and K2TeO4x2H2O (Te VI) on peripheral blood mononuclear cells (PBMC) was determined. Te(IV) inhibited PBMC proliferation and IFN-gamma, IL-5 and TNF-alpha release from PBMC more than Te (VI).

[Comparative in vitro study of various titanium compounds on the immune system]. / Studio "in vitro" sugli effetti comparati di differenti composti del titanio sul sistema immunitario.

The "in vitro" immune effects of different Ti compounds on peripheral blood mononuclear cells (PBMC) were determined. The results show that Ti dioxide is not immunotoxic; Ti oxalate is strongly immunotoxic; titanocene inhibits cytokine release but not PBMC proliferation, while Ti ascorbate inhibits TNF-alpha release from PBMC but not that of IFN-gamma. The results show that Ti toxicity depends on speciation.