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Biomedical subjects

E De Rosa

Publications and source records attributed to E De Rosa.

At least 19 recordsLinked to original sources
PubMed1992

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↗
PubMed1987

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↗
PubMed1986

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↗
PubMed1986

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↗
PubMed1985

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↗
PubMed1978

[Colo-vesical fistulas in acute pathology of the colon].

A survey of the relevant literature and a statement of the acute diseases of the colon giving rise to urological complications are followed by a short account of the subjective and objective symptoms of colo-vesical fistulae. An assessment is also made of the advantages of careful diagnostic, clinical and instrumental appraisal. The classic management of such fistulae is described, and the main features of the surgical technique required are illustrated. Successful employment of total parenteral therapy in 13 cases of enteric fistula (including 2 colo-vesical cases) at the University of Genoa "R" Surgical Clinic is reported. The indications, contraindications and complications associated with this method are explained. The modalities whereby a gradual transition is made to feeding per os are described and the results obtained are evaluated.

Acute Disease↗
PubMed1978

[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↗
PubMed1978

[Risk of absorption of fluoride in electrode arc welding].

The AA. in order to investigate the risk of fluoride absorption examined two factories in which arc-welding electrodes were used. They measured: a) fluoride content in two most used electrodes; b) airborne fluoride concentrations and dustness in the presumed respiratory area of welders with or without fume and dust capture devices; d) airborne fluoride concentrations and dustness three meters away from the welding place during unprotected work with basic electrodes; e) concentrations of fluoride in urine during a workweek in welders (n = 63) and in a control group (n. = 25). The AA. conclude that, in spite of the high teoretical risk of breathing fluoride, the intake of this compound is very low if welders are protected by easy devices.

Air Pollutants↗
PubMed1978

[Industrial hygiene and improvement of the work environment].

The AA. report a series of practical experiments in the following industries: textiles, ceramics, graphics and heavy industry, in order to demonstrate the necessity and utility of industrial hygiene in which an occupational hazard is not simply identified, but rather an improvement of the work environment is undertaken and the results of such a programme are again controlled and evaluated. The data presented lend themselves to a discussion of a preventive nature since, from a comparison of the data before and after modification, the efficacy of the modification itself is evaluated. The efficacy may vary from simple maintenance of equipment to environmental purification procedures and necessity of applying corrective modifications directly by the raw materials.

Air Pollutants, Occupational↗
PubMed1975

[Urinary excretion of hippuric acid in workers exposed to toluene. Recommendation for a group biological standard (mac) (author's transl].

Four groups of workers of the rotogravure, shoe and plastic industries, all exposed to toluene, were studied by the authors. Hippuric acid was measured by a colorimetric method, on urines collected at the end of the work shift. From the obtained results, the authors believe that the biological standard (MAC) for an homogeneous working group could be 1100 mg/liter. Such a threshold, which could however be further revised, ought not to be exceeded; higher toluene concentrations will require technical changes of the working environment.

Adult↗