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Biomedical subjects

G B Bartolucci

Publications and source records attributed to G B Bartolucci.

At least 19 recordsLinked to original sources

Chromosome aberrations and micronuclei in lymphocytes of workers exposed to low and medium levels of styrene.

In the present study we analysed 19 workers exposed to styrene in two factories where polyester resins were used. Because of the different sizes of the pieces undergoing resin processing, the environmental styrene concentrations and urinary mandelic acid (MA) levels of the analysed subjects were quite different in the two plants examined. Cytogenetic monitoring was performed by analysis of chromosome aberrations (CAs) and micronuclei (Mn) in peripheral blood lymphocytes. Cytogenetic analysis revealed a significant increase in the percentage of aberrant cells and total aberrations in the group with higher styrene exposure (group 2) and no increase in the group with lower exposure (group 1), as compared with matched controls. Mn frequencies were not significantly increased in the two exposed populations. No correlations between length of exposure and CA or Mn frequency were found, and a weak correlation was found between exposure levels, measured as urinary MA, and Mn frequencies. Only 5 of the 12 exposed workers examined in group 2 had urinary MA levels higher than the limit recommended by the ACGIH in 1990-91 [1]. Significant increases in DNA damage are therefore already found at urinary MA levels lower than the internationally suggested exposure limits.

Adult

Micronucleated cells in nasal mucosa of formaldehyde-exposed workers.

The frequency of micronuclei (MN) and cytology of respiratory nasal mucosa cells were evaluated in 15 non-smokers exposed to formaldehyde in a plywood factory. Each subject was paired with a control matched for age and sex. Mean levels of exposure to formaldehyde ranged from about 0.1 mg/m3 in the sawmill and shearing-press departments to 0.39 mg/m3 in the warehouse area. There was a contemporary exposure to low levels of wood dust (inspirable mass ranged from 0.23 mg/m3 in the warehouse to 0.73 mg/m3 during sawing operations). Nasal respiratory cell samples were collected by an otorhinolaryngologist near the inner turbinate using a brush for endocervical cytology. After staining (Feulgen plus Fast Green and Papanicolaou's method for MN analysis and cytology, respectively), about 6000 cells were screened for micronuclei and scored in parallel for cytology according to a histopathological scale. A higher frequency of micronucleated cells was observed in the exposed group than in the controls (0.90 +/- 0.47 vs. 0.25 +/- 0.22, Mann-Whitney U test: p less than 0.01). Cytological examination indicated chronic phlogosis in the nasal respiratory mucosa of plywood factory workers, with a high frequency of squamous metaplasia cells (mean score 2.3 +/- 0.5 vs. 1.6 +/- 0.5 in the control group, Mann-Whitney U test: p less than 0.01).

Adult

Pulmonary impairment in workers exposed to silicon carbide.

Two hundred and sixty seven workers employed in the manufacture of silicon carbide (SiC) were examined to determine the effects of exposure to contaminants (SiC, quartz, and SO2) in the workplace on pulmonary function. No exposure concentrations exceeded the current permissible limits. Ten subjects (3.7%) showed rounded opacities (profusion greater than or equal to 1/0). Two subjects employed only in the final stages of the production process and not exposed to crystalline silica showed opacities (profusion q1/0 and q2/1) on x ray film suggesting a role of SiC in the genesis of interstitial lung disease. Chest abnormalities on x ray film were correlated with cumulative exposure to dust and pulmonary function was affected by cumulative dust exposure, profusion of opacities, and smoking. It is concluded that the current standards do not provide adequate protection against pneumoconiosis and chronic pulmonary disease in this industry.

Carbon

Studies of biological and chemical monitoring of low-level exposure to ethylene oxide.

Ten sanitary workers exposed to concentrations of ethylene oxide below 1 ppm were studied to determine whether effects could be observed at low exposure levels. A significant increase in the number of sister chromatid exchanges in cultured lymphocytes was found only for five subjects with relatively high exposure in the sterilization area. However, it was not possible to separate clearly the effect of smoking from that of ethylene oxide exposure. No increase in the frequencies of micronuclei in lymphocytes and buccal cells was found. The level of 2-hydroxyethyl adducts to the N-terminal valines in hemoglobin responded in a reliable fashion to chronic ethylene oxide exposure and smoking. Furthermore, measurement of levels of 2-hydroxyethyl adducts to the N-terminal valines in hemoglobin made it possible to reconstruct the dynamics of a leakage of ethylene oxide which involved three workers.

Adult

Hippuric acid and ortho-cresol as biological indicators of occupational exposure to toluene.

Industrial exposure to toluene was studied in a group of 18 subjects working in a printing plant, exposed only to this solvent. Environmental monitoring was carried out using personal samplers for the whole work-shift. Urine samples were collected for the determination of hippuric acid and ortho(o)-cresol before toluene exposure, at the end of the work-shift, and 5, 9, and 17 h after the end of the work-shift. The values of two metabolites in all the urinary samples were corrected for g creatinine and specific gravity (1.024). Toluene time weighted average (TWA) concentrations ranged from 51 to 221 mg/m3 (7-h samples; two samplings lasting 3.5 h each). Urinary hippuric acid and o-cresol values at the end of the work-shift were significantly higher than the prework-shift values. Both hippuricuria and o-cresoluria end-of-work-shift values, corrected for creatinine and specific gravity, were significantly related to the mean daily environmental concentration of toluene, the correlation being weaker for o-cresol. Correlation coefficients were 0.88 and 0.84 for hippuric acid and 0.63 and 0.62 for o-cresol after correction for creatinine and specific gravity, respectively. No significant relationship was observed between environmental exposure and the values of the two urinary metabolites 5, 9, and 17 h after the end of the work-shift. Extrapolated values from the linear regression analysis at 375 mg/m3 were in good agreement with the biological exposure index (BEI) suggested by ACGIH for hippuric acid.(ABSTRACT TRUNCATED AT 250 WORDS)

Cresols

Sister chromatid exchanges and DNA repair capability in sanitary workers exposed to ethylene oxide: evaluation of the dose-effect relationship.

Determination of ethylene oxide (EtO) in the working environment and induction of sister chromatid exchanges (SCE) and unscheduled DNA synthesis (UDS) in peripheral lymphocytes of 10 exposed sanitary workers and 10 control subjects matched for sex, age, and smoking habits are reported. The relationship between the external dose of EtO and the frequency of SCE was determined in the above group and in a group of 41 sanitary workers previously studied. The 10 newly examined workers were exposed to EtO concentrations (1.84 ppm as time-weighted average) intermediate between the high (10.7 ppm) and low (0.35 ppm) levels of exposure of the two previously examined groups (19 and 22 workers, respectively). A statistically significant (p less than 0.002) increase of SCE frequency was observed between the present control and exposed groups. The inducibility of unscheduled DNA synthesis by gamma rays was lower in the lymphocytes of the exposed workers than in controls, but the difference was not statistically significant. A significant relationship between the frequency of SCE and the level of EtO exposure for the three exposed groups was demonstrated by two different statistical methods. It is suggested that the present Italian threshold limit value for EtO (3 ppm) may not protect the exposed workers against possible genotoxic effects and that even a chronic exposure to 1 ppm may not be devoid of genotoxic risk.

Chromosome Aberrations

Identification of the n-heptane metabolites in rat and human urine.

Numerous n-heptane metabolites have been identified and quantified by gas chromatography and mass spectrometry in some tissues and in the urine of Sprague Dawley rats exposed for 6 h to 1800 ppm n-heptane. 2-Heptanol and 3-heptanol were the main biotransformation products of the solvent. 2-Heptanone, 3-heptanone, 4-heptanol, 2,5-heptanedione, gamma-valerolactone, 2-ethyl-5-methyl-2,3-dihydrofuran and 2,6-dimethyl-2,5-dihydropyran were also found as metabolites of n-heptane. In five shoe factory workers and in three rubber factory workers the mean exposure to technical heptane was measured (n-heptane ranged between 5 and 196 mg/m3). In the urine collected at the end of their work shift some n-heptane biotransformation products were found: 2-heptanol, 3-heptanol, 2-heptanone, 4-heptanone and 2,5-heptanedione. 2-Heptanol was the main n-heptane metabolite and its urinary concentrations ranged between 0.1 and 1.9 mg/l. Urinary 2,5-heptanedione was detectable only in some samples and at very low concentration (0.1-0.4 mg/l). These data suggest that n-heptane can be considered as a neurotoxic product, since it gives rise to 2,5-heptanedione, but the small amount of the urinary metabolite is very unlikely to cause clinical damage to the peripheral nervous system.

Animals

Ethylene oxide exposure. Biological monitoring by analysis of alveolar air and blood.

Occupational exposure to ethylene oxide (ETO) was studied in ten workers employed in a hospital sterilizer unit by testing environmental air, alveolar air and blood during and at the end of the workshift. Alveolar (Ca) and blood (Cb) ETO concentrations were correlated with each other (r = 0.744, n = 36, P less than 0.001) and both with the environmental (Ci) concentrations (r = 0.947, n = 144, P less than 0.001; r = 0.827, n = 36, P less than 0.001). The alveolar retention of ETO (1-Ca/Ci) was equal to 75-80% of the inhaled ETO. In comparison with a blood/air partition coefficient equal in vitro to 90 (SD = 20), the mean Cb/Ca ratio found in the exposed workers was equal to 12-17. During work the blood ETO concentration was, on average, three times the environmental ETO concentration.

Air

Toluene concentrations in the blood and alveolar air of workers during the workshift and the morning after.

Occupational toluene exposure was studied during the workshift and the morning after by the analysis of environmental air, alveolar air, and blood. Environmental toluene exposure was measured by both continuous and instantaneous sampling. Instantaneous environmental toluene concentrations correlated better with alveolar toluene concentrations (r = 0.94; n = 155) than with blood toluene concentrations (r = 0.71; n = 52). Continuous environmental toluene concentrations correlated better with blood toluene concentrations (r = 0.84; n = 65) than with alveolar toluene concentrations (r = 0.52; n = 46). During the workshift and the morning after, blood and alveolar toluene concentrations correlated significantly with each other (r = 0.75; n = 66 and r = 0.67; n = 52). In a group of workers who were exposed to a mean environmental toluene concentration of 146 micromilligrams the concentrations of toluene in the alveolar air and blood the morning after were 3.2 micromilligrams (SD = 1.7) and 27.5 micromilligrams (SD = 12.7) respectively. With regard to the morning after toluene determinations, blood concentrations correlated (r = 0.52; n = 52; p less than 0.001) better than the alveolar concentrations with the corresponding afternoon values (r = 0.36; n = 52; p less than 0.01). The decline of the toluene concentrations from the end of one workshift to the start of the next exposure indicated a mean toluene half life of 3.8 hours in the alveolar air and of 4.5 hours in blood and therefore the 17 hour interval between two consecutive workshifts was insufficient for the complete elimination of absorbed toluene.

Air Pollutants, Occupational

The validity of urinary metabolites as indicators of low exposures to toluene.

Exposure to toluene was studied in a group of 14 subjects working in a printing industry, who were exposed to this solvent only. Environmental monitoring was carried out using personal samplers for the whole workshift over three consecutive days. Toluene TWA concentrations ranged from 37 to 229 mg/m3. At the end of the workshift on each day of investigation, urine samples were collected for the determination of hippuric acid and ortho-cresol. Hippuric acid was also determined for urine before the workshift and on the Saturday and Monday mornings after the end of exposure; hippuric acid was also determined in 16 controls over the same five-day period. At the end of the workshift, hippuricuria levels in exposed workers always turned out to be statistically different from pre-workshift levels and those of the controls. The end-of-workshift hippuricuria levels of exposed workers were significantly correlated with the mean daily environmental concentration (TWA): in the three days of comparative study, we found r = 0.63 (P less than 0.05) on Day 1, r = 0.90 (P less than 0.001) on Day 2, and r = 0.87 (P less than 0.001) on Day 3. Ortho-cresol turned out to be correlated with daily exposure less significantly than hippuric acid: r = 0.49 (n.s.) on Day 1; r = 0.78 (P less than 0.001) on Day 2, and r = 0.65 (P less than 0.05) on Day 3. Using all available data (41 observations), a very significant correlation (P less than 0.001) was found between the TWA and both metabolites (r = 0.80 for hippuric acid; r = 0.68 for o-cresol). The values of the two metabolites in the end-of-workshift urine samples (41 observations) also turned out to be well correlated (r = 0.70; P less than 0.001). The authors conclude that hippuric acid is a valid test for evaluating even low exposures to toluene.

Air Pollutants, Occupational

Effects of tricresylphosphate on esterase activity of rat serum and tissues.

The effect of tricresylphosphate (TCP) was studied in vitro and in vivo on the rat liver and brain enzymes acetylcholinesterase (ACC), butyrylcholinesterase (CHE), arylesterase (ARE), aliesterase (ALI), and the microsomal nicotinamide-adenine dinucleotide phosphate oxidase (NADPH2-oxidase) system. The results show that, in the male rat, TCP given intraperitoneally induces an increase in liver microsomal ARE AND NADPH2-oxidase and a decrease in ALI and cholinesterase; no activation of ARE and NADPH2-oxidase is observed in female rats.

Animals

Polyvinyl chloride pneumoconiosis: epidemiological study of exposed workers.

Among 1216 workers who were employed in a polyvinyl chloride production factory and who had had no previous dust exposure elsewhere, 20 cases of pneumoconiosis were found. Chest x-ray abnormalities were characterized by limited profusion, irregular type and low gravity. All 20 workers had been exposed to high PVC dust levels. The chest x-ray changes were observed after a minimum exposure of five years and, in a small percentage of cases, were associated with slight restrictive respiratory function impairments. Moreover, in the whole group of workers 388 cases (31.9%) were found with non-specific x-ray abnormalities mainly related to age and smoking.

Adult

[Industrial pollution by solvents with special reference to limited values for mixtures].

The report concerns the AA. experience in the field of pollution due to solvents, particularly in the following industries: shoe manufacturing, graphics and the production and application of paints. The exposure risk in these 3 indutries is quantitatively and qualitatively defined based on data obtained from the gas--chromatographic analysis of 238 work environment samples. The data are evaluated with reference to limit values established by the ACGIH, the Italian Society of Occupational Medicine and the Italian Society of Industrial Hygiene. In additon to the evaluation with respect to the TLV and VLP, the hygiene parameter of TLVs for mixtures is evaluated in the field of industrial hygiene.

Air Pollutants

[The occupational risks in a company producing aluminum alloy wheels].

An environmental hygiene study was carried out in a factory making aluminium alloy wheels via pressure moulding. Physical risk factors (noise and microclimate) and chemical risk factors (respirable dust, mineral oils, solvents, fluorides, formaldehyde, CO) were assessed. Analysis of the data showed that physical risk factors were prevalent, whereas chemical pollution was insignificant due to technical improvements made by the management in the course of several redesigns of the plants.

Air Pollutants, Occupational

[Pollution by nitrous dioxide during diagnostic laparoscopy interventions].

Here we have outlined the data relative to an environmental survey carried out in a laparoscopy clinic at the hospital of Padua, to determine the environmental concentration of nitrous dioxide (N2O) used for intra-abdominal inflation during diagnostic laparoscopy interventions. The data obtained have revealed cases of considerable N2O environmental pollution. This above all, due to spontaneous loss of gas during the intervention and to the lack of adequate ventilation systems.

Air Pollutants, Occupational