Thyroid hormones in male workers exposed to urban stressors.

BACKGROUND: The occupational exposure to urban pollution may induce adverse effects on the human health. METHODS: Plasma levels of thyrotropin stimulating hormone (TSH), free thyroxine (FT4) and free triiodothyronine (FT3) of 50 outdoor workers and 50 indoor workers were compared. RESULTS: In the outdoor workers the TSH levels were significantly higher than in the control subjects (p =0.02) while the average of FT3 and FT4 values, was not significantly different compared to the controls (p > 0.05). CONCLUSIONS: The differences found for TSH levels between outdoor and indoor workers, though not high, suggest that, due to greater exposure to environmental pollutants, the outdoor workers are more susceptible to the development of function abnormalities of the thyroid gland compared to indoor workers.

Workers exposed to urban stressors and the effects on antidiuretic hormone secretion.

BACKGROUND: The aim of this study was to evaluate whether urban pollutants can affect plasma levels of antidiuretic hormone (ADH) in outdoor workers. MATERIALS AND METHODS: We selected 208 subjects, 104 exposed to urban stressors and 104 non exposed to urban stressors. We divided these workers in 3 groups: Group 1 (non-smokers and non-drinkers), Group 2 (smokers and not drinkers) and Group 3 (drinkers and not smokers). The means and standard deviations of ADH were calculated, and a Student's t-test was used to compare means. The data were considered significant at p ≤ 0.05. RESULTS: The outdoor workers in Group 1 had significantly reduced plasma levels of ADH. In contrast, the outdoor workers in Groups 2 and 3 had increased plasma levels of ADH. These results were consistent in both men and women. CONCLUSIONS: The results suggest that urban pollutants may influence the secretion of ADH.

[Assessment of otoacustic emissions efficiency in diagnosis of hearing loss in workers exposed to airport stressors]. / [Valutazione della validità delle emissioni otoacustiche nella diagnostica del danno uditivo in lavoratori esposti a stressor aeroportuali].

OBJECTIVES: Otoacoustic emissions are signals that originate from the cochlea, measuring them can be considered an objective method in the assessment of auditory function. In our study we wanted to examine their efficiency among normal audiological exams. MATERIALS AND METHODS: We examined 14 workers exposed to continuous aircraft noise. They underwent ENT examination, metric eardrum test, hearing test tone audiometry system powered by 1 dB, spontaneous otoacoustic emissions and evoked otoacoustic emissions. For inclusion in the study the patients had to show bilateral normoacusia at the audiometry. RESULTS: The variation of the audiometric tracks was statistically significant (p <0.05) at a frequency of 4 kHz. As to SNR parameter (relationship between sound/noise) we noticed a tendency of the transient-evoked otoacustic emission (TEOAE) to shift their spectral content, in particular a decrease in the high frequency response and on the other hand an increase at low frequencies. A similar trend for shifting in latency of otoacoustic waves emissions after exposure to chronic noise. CONCLUSIONS: The measurement of evoked transient otoacoustic emissions is well tolerated by the workers and provides objective results, so it is a more effective and objective method then the tone audiometry.

[Working overseas and cardiovascular diseases: application of a screening method on Oil&Gas employees]. / Lavoro all'estero e malattie cardiovascolari: applicazione di un protocollo di screening su un gruppo di lavoratori del settore Oil&Gas.

Working overseas is a reality for decades in the Oil&Gas Industry and many noxae impact on the cardiovascular system. In fitness to work evaluation the physician should consider besides the conventional risk factors, the presence of cardiovascular diseases, and prevent their evolution. A cardiovascular screening and follow up after 2 years was carried out on 42 Oil&Gas employees, over 45 of age, during medical fitness to work. The main tests were ECG, exercise tolerance test (ETT) and echocardiocolordoppler, completed with other instrumental tests. Cardiovascular diseases causing unfitness to working overseas occurred in 7%, blood hypertension in 23%. The screening permitted to diagnose and correct acute cardiovascular diseases, that caused unfitness to work, and disease that can get worse related to occupational risk. Moreover it was fundamental for evaluation of fitness and timing of health surveillance.

[Influence of non-occupational sources on the levels of biomarkers of internal dose for use in biological monitoring of occupational exposure to extremely low concentrations of benzene]. / Ruolo dei fattori non occupazionali nel condizionare i livelli di indicatori di dose interna utilizzati per monitorare l'esposizione occupazionale a concentrazioni molto molto basse di benzene.

OBJECTIVES: To study how traditional (t,t-muconic acid--t,t-MA and S-phenylmercapturic--SPMA) and new (urinary benzene) urinary biomarkers of internal dose can contribute to exclude an occupational source of exposure to extremely low concentrations of benzene, also analyzing the influence that non-occupational sources of exposure, such as cigarette smoking and urban pollution, can have on the levels of these biomarkers. MATERIALS AND METHODS: Assessment was made of 6 workers employed at a groundwater purification plant polluted by benzene (exposed) and 6 administrative clerks employed at the same plant (controls); both groups included smokers and non-smokers. Environmental monitoring (fixed and personal samplings lasting 8 hours) and biological monitoring (determinations of t,t-MA, SPMA, urinary benzene, and urinary creatinine so as to apply suitable adjustments) were performed in exposed workers on 10 successive days, including also rest days (background exposure), and in controls only once. RESULTS: Airborne benzene always resulted lower than the limit of detection of the analytical method in both fixed and personal samplings done on exposed workers and controls during working days, while personal samplings done on exposed workers during rest days showed benzene concentrations even higher than 5 microg/m3, that is the limit value for ambient air quality. Concentrations of t,t-MA, SPMA and urinary benzene did not show differences between exposed workers, regardless of whether they were studied on working or rest days, and controls and appeared to be largely within the reference value range for the Italian population. All biomarkers of internal dose examined in the study showed significantly higher values in smokers than non-smokers. In the latter, SPMA was always below the limit of detection, while urinary benzene resulted higher than the limit of detection in 60.0% and 87.5% of the determinations done on working and on rest days, respectively. CONCLUSIONS: In situations of occupational exposure to extremely low doses of benzene or of absence of exposure, the application of an integrated environmental--biological monitoring approach, involving the determination of SPMA and/or urinary benzene, together with a careful evaluation of those factors determining non-occupational exposure to the toxicant, seems indispensable in order to be able to exclude the presence of occupational exposure. In these particular situations of occupational exposure to benzene, the interpretation of the results of environmental and biological monitoring should not only consider the TLV or BEI, but also the limit value for ambient air quality and the reference value for the general population, since benzene is able to determine genotoxic carcinogenic effects even at exposure to extremely low concentrations of the toxicant.

[Industrial noise and presbyacusia in the determination of hearing damage: studies in chemical industry workers]. / Rumore industriale e presbisociacusia nel determinismo del danno uditivo: indagine in lavoratori dell'industria chimica.

An audiometric investigation was carried out on 710 workers of a chemical plant in order to ascertain the role of industrial noise and presbysocio-acusia in causing hearing loss. The workers underwent an audiometric test both aerial and via bone, in a sound-proof chamber, after a 16-hour rest from noise. The subjects also answered a questionnaire on nonoccupational noise exposure and previous hearing and dysmetabolic disorders. Noise exposure was assessed on the basis of a cumulative exposure index obtained for each subject by multiplying the mean daily exposure level by seniority in the job. The results showed that in workers not exposed to high noise levels, industrial noise and presbysocio-acusia induce, via a direct mechanism, either separately or together, only slight damage to social hearing frequencies, i.e., those of normal conversation. At frequencies of 4 and 6 kHz, however, presbysocio-acusia seems to play a more important role than industrial noise in causing hearing loss. The practical implications arising from this study concern the frequencies that should be used for a medicolegal assessment of industrial noise induced hearing loss and the the threshold for these frequencies above which assessment of hearing loss should begin. As regards the first point, the results obtained in this study suggest the use of medicolegal methods based on normal conversation frequencies since presbysocio-acusia should not in any case be taken from these frequencies as it affects them only marginally. As regards the second point, the results show that assessment of hearing loss should begin when the hearing threshold at the above frequencies exceeds 25 dB. The study also showed that in epidemiological investigations on subjects exposed to industrial noise, the cumulative exposure index is better correlated with the rise in hearing threshold at the various frequencies than with seniority.