[Vitiligo appearing after contact with mud containing solvents: an occupational cause?].

The authors describe one case of Vitiligo in a worker employed in a firm for the exploitation of underground energetic products. The disease occurred after contact with the mud used for the drilling containing aromatic, aliphatic and chlorinated hydrocarbons. The possible occupational cause of the disease, as more solvents in the mud have the structure of aromatic hydrocarbons is discussed.

Evaluation of exposure to isoflurane (Forane): environmental and biological measurements in operating room personnel.

The concentration of isoflurane (Forane) in the ambient atmosphere was determined in 11 operating theaters of 5 hospitals in Italy. The concentration of isoflurane in the ambient air exceeds the recommended time-weighted average exposure levels (median value: 113 mumol/m3). Isoflurane was detected in the urine of 45 exposed subjects (anesthetists, surgeons, and nurses).

The urinary concentration of solvents as a biological indicator of exposure: proposal for the biological equivalent exposure limit for nine solvents.

Organic solvents are generally volatile substances that are absorbed mainly through the lungs; they are eliminated chiefly through the lungs and kidneys. In urine they are present as metabolites and, in very little part, as parent compound. The urinary concentration of solvent (Cu) can be used for the biological monitoring of exposed subjects to evaluate their exposure and correlate with the Threshold Limit Value (TLV) during the working day.

[Proposal of the biological monitoring of inhalation anesthetics].

The long-term occupational exposure to inhalation anaesthetics might represent a health hazard; mainly it may have an adverse effect on the reproductive outcome. Nitrous oxide is the anaesthetic employed in the largest amount during general anaesthesia and it can be used as an indicator of occupational exposure to all the components the mixture; but if the pattern of dispersion of them (when leaking into the operating theater) are not the same, two indicators should be used: N2O (gas) + another component the mixture (vapour). Our results concern practically 5 points: --Analysis of N2O by means of a diffusive personal sampler (comparison with a conventional sampling method) --Analysis of N2O in urine collected after 4 hours of exposure during routine anaesthetic work (headspace method) --Comparison of environmental and biological data concerning N2O --Comparison of environmental and biological data concerning a component of the anaesthetic mixture, forane --Proposal of biological exposure indices for nitrous oxide and forane.

[Use of gas chromatography with flame ionization (GC-FID) in the measurement of solvents in the urine].

The urinary concentration of some solvents (acetone, cyclohexane, 1,2 dichloropropane, n-hexane, methyl ethyl ketone, perchloroethylene, styrene, toluene, 1,1,1, trichloroethane) was measured by means of a gas chromatography Hewlett-Packard 5890 supplied with a flame ionization detector (GC-FID, DANI HS 3950). The coefficient of variation of the method was lower than 5%. The sensitivity of the GC-FID was very similar to what of mass spectrometer detector (GC-MSD, HP 5970 A).

Methemoglobin and carboxyhemoglobin levels in smokers and non smokers.

The authors examined the blood of 856 subjects (377 smokers and 479 non smokers) in order to evaluate the levels of Methemoglobin (MetHb) in relationship to tobacco smoke. The Methemoglobin, Carboxyhemoglobin, Percent Oxyhemoglobin and Total Hemoglobin were measured using an automated spectrometer (IL 282 CO - Oximeter). The authors found that the levels of MetHb in the smokers exceed that in the non smokers: in fact the level of MetHb in the smokers (% MetHb = 0.

Urinary elimination of acetone in experimental and occupational exposure.

Fifteen volunteers were exposed to an acetone vapor concentration of 964-8, 610 mumol/m3 (56-500 mg/m3) for 2-4 h in an exposure chamber. Ten subjects were at rest during the exposure, and five were exposed at alternate rest and light physical exercise. Subsequently 104 workers occupationally exposed to acetone were studied.

[Relationship of environmental levels, respiratory absorption and urinary concentrations of various solvents: effects of work load].

The physical demand in the workplaces can be different depending on each specific job. This involves that workers exposed to the same environmental level of an airborne can absorb different amounts of it depending on their pulmonary ventilation. Starting from the relationship between the uptake (U) and the urinary concentration (Cu) of 6 solvents (Acetone, Styrene, Xylenes, Toluene, Methylchloroform, Tetrachloroethylene) and from the equation expressing their lung uptake the expected values of a biological index after a given time of exposure can be derived.

Effects of dimethylformamide (DMF) on coagulation and platelet activity.

The effects of dimethylformamide (DMF) on hemostatic functions, especially on platelet activity, were examined both in vitro and in vivo in 15 workers exposed to DMF (27 mg/m3, median value). Twenty-eight control subjects who were not exposed to DMF, but comparable for age, anthropometric data, and smoking habits, were also studied. Workers exposed to DMF showed a decrease in the number of platelets and had longer coagulation times, probably due to a change caused by DMF on the membrane receptor of platelets and on the phospholipid components of the clotting system.

Urinary elimination of styrene in experimental and occupational exposure.

Twenty human volunteers were exposed to styrene vapor at 273-1 654 mumol/m3 (28.4-172.3 mg/m3) for a period of 1 to 3 h at rest (15 cases) and during light physical exercise (5 cases).

[Exposure to acetone: experimental study of absorption and pulmonary elimination in normal subjects].

Alveolar (CA) and mixed expired air (CE) acetone concentrations were measured in 15 healthy volunteer subjects, exposed to acetone (CI) in an exposure chamber (exposure range: 48-565 mg/m3) both at rest and during exercise (50 W). The Relative Uptake (R = 1-CE/CI) was 0.54 at rest (120' and 240') and 0.

[Evaluation of oxygen consumption and other cardiorespiratory parameters measured during the execution of 3 types of muscular exercises used in respiratory kinesitherapy].

Oxygen consumption (VO2) and other cardiorespiratory parameters (pulmonary ventilation, tidal volume, respiratory rate, alveolar ventilation, heart rate) have been measured in 10 healthy subjects (20-40 years old) while performing 3 respiratory exercise (abdominal muscles reinforcement, scapulo-humeral articulation movements and chest expansion). The performance of the abdominal muscles reinforcement exercises requires the highest oxygen consumption. The 3 exercises decrease the "Dead space/Tidal volume" ratio and increase the alveolar ventilation.

Urine/air partition coefficients for some industrially important substances.

The urine/air and blood/urine partition coefficients (lambda) of 43 commonly employed organic solvents (Aliphatic, Cyclic, Aromatic and Halogenated Hydrocarbons, Ketones, Alcohols and Esters) are reported. The analyses were performed by the multiple equilibration method (constant pressure method) using a Hewlett-Packard 5880 gas chromatograph. The lambda values proposed can be employed in the field of biological monitoring of subjects occupationally exposed to solvents vapors.

Urinary elimination of p-dichlorobenzene (p-DCB) and weighted exposure concentration.

The aim of the present work is to determine p-DCB concentration in the urine of exposed workers and to verify a possible correlation with the environmental exposure. The authors studied four subjects exposed to different p-DCB environmental concentrations during a working week. The measurement of the substances was performed by means of a Hewlett-Packard 5880 A gas-chromatograph supplied with a Hewlett-Packard 5970 A Mass Selective Detector.

Respiratory measurements of occupational exposure to industrial solvents.

The authors report the parameters which rule the absorption and elimination of polluting solvent vapours in exposed subjects (Ventilation, Pulmonary Capillary Flow, Solubility Coefficients, Environmental Concentrations, Exposure Times). These parameters are included in the equations showing the absorption and elimination indexes and lung clearances. Some methods to measure the Solubility Coefficients of inert gases in biological media and the values referring to 51 industrial solvents, commonly employed or important from the toxicological point of view, are described.

[Stability of esters in the blood in vitro].

The aim of this paper was to evaluate the lambda values of this group of solvents experimentally, by means of an analytical method which has already been used for other solvents. During our experiments we found that most acetates we tested (n-butyl-acetate; sec.butyl-acetate; ter-butyl-acetate; ethyl-acetate; amyl-acetate; methyl-acetate; n-propyl-acetate) were particularly unstable and hydrolyzed rapidly in alcohol and in the corresponding acid.

[Changes induced by dimethylformamide on platelet function and coagulation activity].

The effect of Dimethylformamide on platelet function and on clotting system has been studied on eight workers exposed to the product, widely used in industry as a solvent of acrylic resins. A significant reduction of the number of the platelets and a drawing out of PTT and PT has been noticed. Such informations has been explained as chronical peripheral use or as modification of phospholipid components induced by DMF instead of synthesis defect, as no significant variation of the fibrinogen and of AT III values, proteins synthetized by liver, has been observed.

[N-hexane and toluene in the urine of occupationally exposed subjects. Measurement and significance of its presence].

N-hexane and toluene in the urine of occupationally exposed subjects. Measurement and significance of their presence. The determination of n-hexane and toluene in urine was performed in 23 subjects who were occupationally exposed to n-hexane and in 8 subjects exposed to toluene, by means of the head space technique.

Determination of plasmatic copper and zinc in uncomplicated pregnancies.

The copper and zinc plasmatic concentrations were determined in a group of 50 pregnant women and in a control group. We found higher copper and lower zinc plasmatic levels in pregnancy than in control group. No correlation was found between the copper and zinc plasmatic levels and the weeks of pregnancy.

n-Hexane urine elimination and weighted exposure concentration.

The concentration of n-hexane in urine was determined in 30 subjects occupationally exposed to n-hexane (median value 59.6 mg/m3) in a shoe factory. The measurement of the substance was performed by means of a Hewlett-Packard 5880 gas chromatograph supplied with a Hewlett-Packard 5970 Mass Selective Detector.

[An open system for exposure to noted and controlled concentrations of aeriform substances].

The AA describe the realise of an open circuit exposure chamber: it enables to reach solvent concentration levels that are continuously monitored and kept within the limits of acceptability. The room can be employed in studies and experimental researches on the respiratory absorption levels of airborne pollutants in man. The following data are reported: on microclimatic parameters, on the monitoring of CO2 concentration in the room when someone is inside, on the solvent concentration measures in different points of the room, on the monitoring of the quickness to reach the steady-state and wash-out in the room, on the available concentration ranges.