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Biomedical subjects

F Brugnone

Publications and source records attributed to F Brugnone.

90 records · Page 5Linked to original sources
PubMedDate not supplied

Biological monitoring of fluctuating occupational exposures to styrene.

Nine workers occupationally exposed to styrene producing refrigerator lorries were analyzed. The styrene exposure was monitored 8 hours a day, for 5 days a week, for 1 week. We collected from workers a urine sample before and after each work shift. Moreover, alveolar air samples were obtained at the end of all work shifts. On Thursday afternoon and on Friday morning blood samples were taken from workers. The relationship between styrene exposure and biological data is reported and discussed. Alveolar, urinary and blood concentrations of styrene were comparable, suggesting similar kinetics. Biological styrene concentrations were significantly correlated with the mean daily environmental concentrations, but higher correlation coefficients were found with afternoon exposures. A narrow linear relationship between alveolar (Y) and urinary (X) styrene concentrations was found (Y = 0.359; r = 0.8579; n = 45; p less than 0.001). Urinary concentrations of mandelic acid (Y) confirmed a good relationship with the mean styrene exposure (X) (Y = 2.7 x +169; r = 0.4677 n = 45; p less than 0.01).

Air Pollutants, Occupational↗
PubMedDate not supplied

[Effects of cigarette smoking on blood and alveolar air levels of benzene].

Benzene was measured in blood and alveolar air of a group of 168 subjects, consisting of 34 chemical industry workers exposed to benzene and 134 definitely not occupationally exposed to benzene. A gas chromatographic method was used with mass spectrometry and cryogenic trap. The results of the biological measurements were compared with the environmental levels of benzene in the room where samples were taken and at the worksite during the previous day's shift. All environmental air samples showed measurable levels of benzene, which agrees with the observations of many authors, according to which benzene is a common pollutant also of the living and external environments. Benzene in blood measured on morning samples was correlated with the previous day's exposure. In the group of non-exposed, both blood and alveolar concentrations of benzene were significantly higher in the 68 smokers than in the 66 non-smokers and the biological levels of benzene were inversely correlated with the time that had elapsed since the last cigarette smoked. In the chemical workers, the high biological levels of benzene due to occupational exposure largely exceeded the variations in concentration due to cigarette smoking and cancelled out the differences between smokers and non-smokers. It can therefore be assumed that smoking was not influential and did not interfere with the interpretation of the results in the occupationally exposed workers. Lastly, cigarette smoking, as a cyclical and additional factors of exposure, seems to be responsible for the disturbance in the relationships between biological benzene levels and ubiquitous environmental pollution, a relationship that was only observable in non-smoking subjects not occupationally exposed, but not in the group of smokers.

Benzene↗
PubMedDate not supplied

Monitoring of industrial exposure to dimethylformamide by analysis of alveolar air.

The occupational exposure to Dimethylformamide was studied by testing the environmental and alveolar air of 8 workers, at hourly intervals, during the workshift. The correlations between alveolar and environmental concentrations of Dimethylformamide turned out to be statistically significant at all the intervals studied, except at the 4th hour when the correlation was not significant. In six out of the eight workers studied, the correlation between alveolar and environmental concentrations was statistically significant. Only in two workers was the correlation not significant. On the basis of the slope of the regression line between all the data, the alveolar concentration of Dimethylformamide turned out to correspond to 27,8% of the environmental concentration.

Air Pollutants, Occupational↗
PubMedDate not supplied

Blood and urine concentrations of chemical pollutants in the general population.

The concentration of 9 environmental chemical pollutants in the general population was measured in blood and urine. For the 9 different pollutants, the blood samples tested varied from 88 for acetone to 431 for benzene. Urine samples varied from 48 for styrene to 213 for n-hexane. Six of these agents (benzene, toluene, styrene, n-hexane, acetone and carbon disulphide) were present in all or almost all (100-94%) blood samples. The three chlorides (chloroform, trichloroethylene and tetrachloroethylene) were present only in 60-85% of samples. After acetone, with blood concentrations in microgram/1 (mean 840 microgram/l), the highest mean blood levels were those of toluene (1097 ng/l), chloroform (955 ng/l) and n-hexane (642 ng/l). Trichloroethylene and free carbon disulphide showed similar values (458 and 438 ng/l, respectively). Finally, benzene, styrene and tetrachloroethylene showed the lowest values (262, 217 and 149 ng/l, respectively). There was generally a significant difference between rural and urban workers in terms of blood benzene (200 ng/l vs 264 ng/l), trichloroethylene (180 ng/l vs 763 ng/l) and tetrachloroethylene (62 ng/l vs 263 ng/l). In a group of subjects potentially exposed to industrial solvents, classed as chemical workers, blood benzene, toluene, chloroform and n-hexane were significantly higher than in rural and urban workers. Smokers showed a significantly higher blood concentration than non-smokers for benzene (381 ng/l vs 205 ng/1), toluene (1431 ng/l vs 977 ng/l), and n-hexane (838 ng/l vs 532 ng/l). All or almost all urine samples (100-92%) contained all the compounds except trichloroethylene and tetrachloroethylene, present in 79% and 76% of samples, respectively (table 2). Urinary concentrations of all compounds did not differ significantly between rural and urban workers. Benzene and toluene were significantly higher in in urine of smokers than of non-smokers. Chloroform and n-hexane showed significantly higher urinary than blood values. Excluding acetone, with urinary and blood concentrations in pg/l, chloroform, toluene and n-hexane showed the highest mean concentrations both in blood and in urine.

Acetone↗
PubMedDate not supplied

Carbon disulfide in blood: a method for storing and analysing samples.

Concentrations of free and acid-labile carbon disulfide in human blood were determined by gas chromatography mass-spectrometry. Carbon disulfide was measured in the blood of 62 subjects not occupationally exposed to the solvent, and in 27 subjects treated with disulfiram (which is partially biotransformed into carbon disulfide). In blood, a small part of carbon disulfide is free (it can be analysed without any blood treatment); most carbon disulfide is bound ("acid labile" carbon disulfide), and requires acid hydrolysis to become free and detectable. During the first phase of our study, stored samples of blood (storage at 4 degrees C for 15-40 days) were used. Later, we analysed fresh blood samples. A significant decrease in carbon disulfide was found in stored samples in comparison to fresh samples. During storage, free and acid-labile carbon disulfide in blood decreased respectively to 26% and 27% of the initial concentration within a month. In fresh samples, free carbon disulfide concentrations in blood showed a median of 139 ng/l in normal subjects. Acid-labile carbon disulfide concentrations were much higher (median 2743 ng/l). Free and acid-labile carbon disulfide in blood were closely correlated (r = 0.9358). Blood samples stored at -80 degrees C maintained a constant concentration of carbon disulfide over almost three weeks.

Alcoholism↗
PubMedDate not supplied

[Blood interface in environmental and occupational exposure to industrial chemical pollutants].

The concentration of 12 environmental chemical pollutants was measured in the blood of the general population. With reference to the 12 different pollutants, the blood samples tested varied from 88 for acetone to 431 for benzene. Nine of these agents (benzene, toluene, styrene, cumene, xilene, n-hexane, nitrous oxide (N20), acetone and carbon disulphide) were present in all or almost all (100-94%) blood samples. The three chlorides (chloroform, trichloroethylene and tetrachloroethylene) were present only in 60-85% of samples. After acetone and carbon disulphide, with blood concentrations in microgram/l (mean 840 micrograms/l and 2.4 micrograms/l respectively), the highest mean blood levels were those of toluene (1097 ng/l), chloroform (955 ng/l), N2O (915 ng/l), and n-hexane (642 ng/l). Trichloroethylene and free carbon disulphide had similar values (458 and 438 ng/l, respectively). Finally, benzene, styrene and tetrachloroethylene had the lowest values (262, 217 and 149 ng/l, respectively). There was generally a significant difference between rural and urban workers in terms of blood benzene (200 ng/l vs. 264 ng/l), trichloroethylene (180 ng/l vs 763 ng/l) and tetrachloroethylene (62 ng/l vs. 263 ng/l). In a group of subjects potentially exposed to industrial solvents, classed as chemical workers, blood benzene, toluene, chloroform and n-hexane were significantly higher than in rural and urban workers. Smokers showed a significantly higher blood concentration than non-smokers for benzene (381 ng/l vs. 205 ng/l), toluene (1431 ng/l vs. 976 ng/l) and n-hexane (803 ng/l vs. 505 ng/l).

Acetone↗
PubMedDate not supplied

[Urban air pollutant exposure among traffic policemen].

Exposure to dusts and benzene was studied in 65 traffic policemen. Samples of total dusts showed that mean personal exposure was 0.44 (SD = 0.30) mg/m3, with peaks of about 2 mg/m3. Exposure to 1-nitropyrene (1-NP), the main compound occurring in emissions from diesel engines, which was estimated from concentrations in dusts collected with high-flow samplers, was 0.28 (SD = 0.19) ng/m3 (range: 0.06-1.24 ng/m3). The mean concentration of benzene in the breathing zone was 41 (SD = 20) micrograms/m3, although a level of 100 micrograms/m3 was slightly exceeded in one subject. In urine samples collected before and after workshifts, two biological indicators of exposure to benzene were measured, urinary benzene and urinary trans, trans-muconic acid (MA). The mean values of urinary benzene before and after workshift were similar (98, SD = 81 and 83, SD = 55 ng/l; n = 63; Wilcoxon's T-test = not significant), while a moderate increase in the metabolite was observed (MA = 0.08, SD = 0.11; 0.11, SD = 0.09 mg/g creatinine, in pre- and post-shift samples respectively; Wilcoxon's T-test, z = 3.00; p < 0.01). The levels of exposure to dusts and 1-NP deriving from diesel engine emissions were comparable to those of other occupational groups with this type of risk (garage mechanics, workers operating diesel engine machinery, etc.). Traffic police exposure to benzene was similar to that of the whole population of Padova (40 micrograms/m3, mean annual 24-hour value). However, the values of urinary MA, like those reported by other authors for non-smoker controls, increased after the workshift, indicating low occupational exposure to this pollutant. It should be noted that traffic police exposure to benzene is much lower than that of other occupational categories, e.g., fuel pump distributors.

Air Pollutants↗
PubMedDate not supplied

[Environmental exposure and blood levels of benzene in gas station attendants. Comparison with the general population].

Environmental benzene levels were measured in 26 petrol stations using both active and passive stationary and personal samplers. Simultaneously, benzene levels were measured in the petrol station operators on blood samples collected at the end of the work shift and the following morning before starting work. The petrol stations belonged to various different oil companies and were studied both during the winter (9 stations) and in the summer (17 stations). The environmental levels measured with active samplers in the 26 stations were on average 256 ng/l, were significantly lower (98 ng/l) in winter and higher (326 ng/l) in summer. The blood levels of benzene in 77 workers at the end of the work shift were on average 548 ng/l, were significantly lower (306 ng/l) in winter and higher (651 ng/l) in summer. The following morning, blood levels of benzene were lower than those found at the end of the work shift, on average 249 ng/l in winter and 427 ng/l in summer. Smokers had higher benzene levels than non-smokers, both in winter at the end of the work shift (617/170 ng/l) and the following morning (506/137 ng/l), and in summer at the end of the shift (742/517 ng/l) and the following morning (535/233 ng/l). A comparison with a sample of 243 "normal" subjects of the general population showed that their mean blood level of benzene of 165 ng/l was significantly lower than the level found in petrol station workers the morning after the work shift (364 ng/l).

Adolescent↗
PubMedDate not supplied

Biological monitoring of acrylonitrile exposure.

This study reports the results obtained with the environmental and biological monitoring of 34 workers exposed to acrylonitrile (ACN). Occupational exposure was monitored during 8-h work shifts with both active and diffusive personal samplers which yielded comparable results. The median exposure was 78 micrograms/m3. The ACN concentration in urine collected at the end of the work shifts correlated significantly with the environmental exposure. The ACN concentration in the pre-shift urine samples (median 3.6 micrograms/l) was lower than that found in the post-shift samples (median 10.9 micrograms/l), but higher than in the urine of non-exposed people (median 0.45 microgram/l). Smoking is an important confounding factor in monitoring exposure to ACN. The ACN concentration in urine provides reliable information about occupational and non-occupational exposure to ACN. Aspects of the mechanism of ACN excretion in urine are also discussed.

Acrylonitrile↗
PubMedDate not supplied

[Chrono-thermometry in the diagnosis of Raynaud-like vasculopathies caused by prolonged use of vibrating tools].

Raynaud's phenomenon may be secondary to several different pathological conditions. In some cases it is favoured by occupational exposure to vibration of the upper arms. The diagnosis of Raynaud's phenomenon requires clinical information together with specific technical investigations. This report presents the results of 232 chrono-thermometric tests performed on 157 workers exposed to vibrations during the use of different kinds of tools. Seventy-five subjects not exposed to vibrations of the upper arms but with suspected Raynaud's syndrome were also tested. Chrono-thermometry enabled us to distinguish between three different subgroups of subjects exposed to vibrations: 61 workers with "normal" chrono-thermometry, 33 subjects with "pathological" vascular reactivity to cold in some fingers and 63 workers with such reactivity in all fingers. Similarly the 75 patients not exposed to vibration could also be divided into three groups. No statistical difference was found between the chrono-thermometric results obtained from the exposed and non-exposed subjects when divided into the three subgroups. The overall analysis of the combined results of the different kinds of tests (capillaroscopy plus a vascular reactivity test) is discussed.

Adolescent↗