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Biomedical subjects

A Mutti

Publications and source records attributed to A Mutti.

At least 109 records · Page 6Linked to original sources
PubMed1984

Biological monitoring of occupational exposure to different chromium compounds at various valency states.

Chromium concentrations in the air were measured in seven different workroom environments, where exposure to water soluble hexavalent or trivalent compounds was expected. Urinary excretion of chromium was measured before and after the same arbitrarily chosen working day. End-of-shift urinary chromium and its increase above pre-exposure levels were closely related to the concentration of water soluble chromium (VI) in the air. The values corresponding to 50 micrograms m-3 in the air, which is the current threshold limit value in most countries, were 29.8 and 12.2 micrograms g-1 of creatinine, respectively. Urinary chromium in workers exposed to water insoluble chromates or to water soluble chromic (III) sulphate was definitely higher than that observed in subjects not occupationally exposed to chromium compounds, but it cannot be recommended as short-term exposure test for evaluation of the job-related hazard.

Absorption↗
PubMed1984

n-Hexane metabolism in occupationally exposed workers.

Lung uptake and excretion of n-hexane were studied in ten workers in a shoe factory. Simultaneous samples of inhaled and alveolar air were collected with the aid of a Rhan-Otis valve, personal samplers, and charcoal tubes. Alveolar excretion was monitored during a six hour postexposure period. Uptake was calculated from lung ventilation, the retention coefficient, and environmental concentrations. The amount of exhaled n-hexane was calculated from the decay curve. According to the experimental data, alveolar retention was about 25% of the inhaled n-hexane, corresponding to a lung uptake of about 17%. The postexposure alveolar excretion was about 10% of the total uptake. The main metabolites of n-hexane were identified and measured by capillary GC/MS in spot urine samples collected before, at the end, and 15 hours after the same working shift. Urinary concentrations were low, though related to n-hexane in the air. 2,5-Hexanedione in the end of shift samples gave the best estimate of overall exposure. About 3 mg/g creatinine of 2,5-hexanedione would correspond to about 50 ppm of n-hexane in the air (mean daily exposure).

Absorption↗
PubMed1984

Neuroendocrine effects of styrene on occupationally exposed workers.

The serum levels of prolactin (PRL), human growth hormone (HGH), thyroid-stimulating hormone (TSH), and the gonadotropins follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were measured in 30 females exposed to about 130 (range 65-300) ppm of styrene in the air and in 30 age-matched referents to show whether styrene exposure influences the dopaminergic tuberoinfundibular system (TIDA). The exposed subjects' serum levels of PRL were more than double the reference values and were significantly related to the urinary excretion of styrene metabolites, ie, to the sum of mandelic acid (MA) and phenylglyoxylic acid (PGA) in the "next-morning" urine spot sample. Such a relationship still proved to be statistically significant after the removal of the effects of age and duration of exposure with the method of partial correlation. The serum concentrations of HGH in the exposed workers were also higher than in the reference group. Though within the reference levels, the TSH values of the exposed subjects were significantly related to the urinary excretion of MA and PGA. These results are consistent with the dose-dependent depletion in tuberoinfundibular dopamine after experimental styrene exposure of rabbits.

Adult↗
PubMed1984

Enzyme-linked immunosorbent assay of retinol-binding protein in serum and urine.

This highly sensitive method for determining retinol-binding protein in human serum and urine is based on a double-antibody "sandwich"-type enzyme-linked immunosorbent assay. The assayable concentration range is 0.8-48 micrograms/L, the detection limit 0.2 micrograms/L. Within-assay coefficients of variation for 10 determinations at two different concentrations were 5.5 and 5.8%. The corresponding between-assay CVs were 7.9 and 9.2%. We saw no interference from any components of urine or serum. The mean urinary excretion by 30 healthy subjects, as determined by this method, was 101 micrograms/g of creatinine (SD 38.8). The concentration in serum averaged 43 mg/L (SD 12.1).

Adult↗
PubMed1983

Early indicators of renal damage in workers exposed to organic solvents.

In order to investigate the renal function, a cross-sectional study was carried out on four groups of workers significantly exposed to a mixture of alicyclic and aliphatic C5-C7 hydrocarbons, to styrene, to a mixture mostly composed of toluene and xylenes and to chlorinated hydrocarbons, respectively. The study involved 438 workers. Exposure was characterized by means of urinary metabolites, or by means of environmental measures, when biological indicators were not available. The renal function impairment indicators included total proteinuria, albuminuria and urinary excretion of muramidase (E.C. 3.2.1.17) and beta-glucuronidase (E.C. 3.2.1.31). The trend of these parameters provides some evidence of renal damage due to occupational exposure to organic solvents and suggests that the lesions are mild and tubular rather than glomerular.

Adult↗
PubMed1983

Mortality experience among chromeplating workers. Initial findings.

A retrospective cohort study was conducted in nine chromeplating plants to examine the mortality of workers employed for at least one year during the period January 1951-December 1981. The study group totaled 178 individuals, 116 of whom were from "hard" and 62 from "bright" chromeplating plants. Vital status ascertainment was 97% complete. The total number of deaths was fairly close to the expected figure (15 observed, 15.2 expected), whereas deaths from tumors exceeded the expected number (8 observed, 4.2 expected). Individuals were distinguished into two subcohorts depending on the exposure intensity, which was much higher in hard than in bright chromeplating. Most deaths from cancer occurred among hard chromium platers, the excess against the expected rate being statistically significant (7 observed, 2.7 expected, p = 0.02). All deaths from lung cancer occurred in this subcohort (3 observed, 0.7 expected, p = 0.03). The increased mortality from cancer among chromium platers seems to be related to exposure intensity and strongly suggests the need for further studies on larger cohorts to confirm the carcinogenicity of chromic acid in man.

Chromium↗
PubMed1982

Neurophysiological effects of long-term exposure to hydrocarbon mixtures.

Motor nerve conduction velocity (MCV) was measured on median, ulnar and peroneal nerves in a reference group of 52 workers and a group of 95 workers exposed to hydrocarbon mixtures in a shoe factory. Exposure-related changes were found in motor action potential (MAP) amplitudes of the three nerves and in median and peroneal MCVs. Electroneurographic abnormalities were also present in a subgroup of workers exposed to air concentrations near the current ACGIH (1979) recommended threshold limit value (TLV) for the mixture. Our results suggest the need for lowering the TLV for the main components n-hexane and cyclohexane. A synergistic effect of the two hexacarbon solvent might also be considered in the hygienic evaluation of the workplace.

Action Potentials↗
PubMed1982

n-Hexane-induced changes in nerve conduction velocities and somatosensory evoked potentials.

Fifteen women from a shoe factory were examined clinically and their cerebral evoked responses to 256 electrical stimulations of the median nerve were averaged. Neurophysiological investigations included maximal motor (MCV) and distal sensory (dSCV) nerve conduction velocity measurement on ulnar, median, and peroneal nerves. A referent group was composed of 15 age-matched women without exposure to neurotoxic chemicals. MCVs and dSCVs of the exposed workers were significantly reduced vs referents, while P15 and N20 components of the somatosensory evoked potentials (SEP) showed an increased latency. A negative linear relationship was found between dSCV and P15 latency. However, two subjects with an abnormally low dSCV showed normal SEP latency, and two other subjects displayed abnormal SEP latency, while their dSCV was in the normal range. Therefore, SEP investigation may give additional information on nervous system function, even in subjects with peripheral neuropathy. The later SEP components were much flatter in the exposed than in the referent group, suggesting some neurotoxic effects of n-hexane on the central nervous system too.

Adult↗
PubMed1982

Neurophysiological changes in workers exposed to organic solvents in a shoe factory.

Motor conduction velocity (MCV) was measured in the median, ulnar, and peroneal nerves of 52 referents and 95 workers from a shoe factory, in a search for dose-effect and dose-response relationships between exposure to organic solvents and subclinical impairment of the peripheral nervous system (PNS). According to the environmental concentrations, the exposure was expressed as the sum of the products between the median hygienic effect (ranging from 0.08 to 2.89) and worktime (from 1 to 29 a) in every job. The motor action potential (MAP) amplitudes, durations and shapes of the exposed workers were significantly affected even if to a different extent and significance level when compared to those of the MCVs of the referents. The MCVs of the median (t = 3.17, p less than 0.01) and peroneal (t = 2.11, p less than 0.05) nerves were reduced as compared to reference values. In the exposed group, the MCV of the median nerve was negatively correlated with exposure score (r = 0.45, p less than 0.01) but not with age. No relationship was found between MVCs of the ulnar and peroneal nerves and exposure. The MCV of the median nerve was particularly slow in a subgroup of workers with an exposure score of greater than 20 (t = 2.30, p less than 0.05 vs the other exposed workers; t = 5.56, p less than 0.01 vs the referents). This exposure score represents only 50% of the maximum allowable score for a worktime of 40 a. Even if none of the examined workers showed clinical signs of polyneuropathy, evidence of subclinical effects on the PNS were found among subjects with long-term exposure to hexacarbon mixtures. Therefore, our results suggest the need for a lowering of current threshold limit values at least for n-hexane.

Adolescent↗
PubMed1981

Absorption and alveolar excretion of cyclohexane in workers in a shoe factory.

The lung uptake and excretion of cyclohexane were studied in five workers and three volunteers in a shoe factory. Air samples were collected from the breathing zones with personal samplers, and simultaneous samples of inhaled and alveolar air were collected with the aid of a Rhan-Otis valve. Cyclohexane was absorbed on activated NIOSH approved charcoal tubes. The uptake was calculated from the pulmonary ventilation, the retention coefficient and environmental concentration. Alveolar excretion was monitored during a 6 h post-exposure period. The amount of exhaled cyclohexane was calculated from the decay curve. According to experimental data, the alveolar retention of cyclohexane is about 34% of the inhaled dose. This corresponds to a lung uptake of 23%. The post-exposure alveolar excretion does not exceed 10% of the total uptake. The difference between respiratory uptake and excretion indicates that the amount metabolized may be very large. Nevertheless, the urinary excretion of the main metabolites, cyclohexanol and cyclohexanone, was only about 1% of the absorbed dose.

Absorption↗
PubMed1981

Organic solvents and chronic glomerulonephritis: a cross-sectional study with negative findings for aliphatic and alicyclic C5-C7 hydrocarbons.

Proteinuria, albuminuria, urinary beta-glucuronidase and serum creatinine were estimated in 182 workers exposed to organic solvents in four shoe factories, as well as 30 workers with past exposure and 80 control subjects. Ambient air concentrations at each workplace were also measured. In most of these samples, the concentration of organic solvents exceeded the ACGIH recommended threshold limit value for the mixture. Total protein excretion was significantly elevated in exposed workers, although none of the workers had abnormal albuminuria or serum creatinine. Four had increased lysozymuria. There was also a simultaneous elevation of beta-glucuronidase. These findings suggest that a mild and presumably reversible tubular lesion, but not glomerular damage, may occur in workers occupationally exposed to C5-C7 hydrocarbon mixtures.

Adult↗
PubMed1980

[Chronic non-specific disease of the respiratory system and measurable alterations in workers in the chromium-plating industry (author's transl)].

Lung function test performed on 26 chromium plating workers showed a high prevalence of obstructive disease and of change in DLCO. The connection between lung function impairment and occupational exposure to chromium is suggested by the relationship between respiratory changes and biological indices of chromium absorption. The prevalence and the severity of ventilatory impairment also show an increasing trend with the duration of the exposure, while the smoking habitus seems not to be important.

Adult↗
PubMed1980

[Spirometric alterations in chromium-exposed welders (author's transl)].

Lung function tests were examined on 28 welders using high chromium alloyed electrode for two years. Respiratory function change seem to be related to the duration of employment as welders. On the contrary, obstructive disease and alveolo-capillary impairment were found with same prevalence in groups of workers differently exposed to chromium. It presumably occurs because the exposure to chromium is quite short.

Adult↗
PubMed1978

Nephrotoxicity of chromium. Remarks on an experimental and epidemiological investigation.

Observations conducted on a group of workers exposed to chromium (who showed a rapid urinary excretion of the metal and progressive increase of clearance with cumulative years of exposure), induced the authors to evaluate the nephrotoxic action of chromium in rats exposed to acute and chronic intoxication. The progressive Cr accumulation in the renal cortex during the course of testing explains the increase of the excreted fraction of filtered Cr, and therefore, the clearance, of the metal through the reduction of the tubular lumen-epithelium gradient. Paralleling the anatomical lesions (demonstrated only at the level of the proximal tubular cells), are the increasing modifications of the cellular lesion or altered reabsorption registered by several urinary indicators. Similar changes were found in subjects chronically exposed to the metal; their reversibility is linked to the possibility of repairing the epithelial damage by stopping exposure.

Animals↗