[Dust and microorganism count at delivery, sorting and composting of home refuse and home refuse-like industrial waste]. / Staub- und Keimzahlmessungen bei der Anlieferung, Sortierung und Kompostierung von Hausmüll und hausmüllähnlichem Gewerbeabfall.

The exposure of employees to airborne dust and microorganisms was assessed in a waste processing plant established to recover reusable materials from unsorted domestic and industrial waste. Exposure criteria considered relevant were the quantity of the individual size-selected particle fractions, the morphological properties of the particles, their heavy metal content, and the degree of their contamination with various microorganisms and mold. In addition, separate microbiological analyses to determine potential pathogen concentrations in the air were made. The highest concentrations of total and fine dust were measured in the waste delivery area. A close correlation between the frequency of deliveries and the level of dust exposure was observed. In this area, fine dust concentrations exceeded the threshold limit value of 6 mg/m3 repeatedly for shorter periods. The average fine dust concentration during an entire work-shift, however, was considerably lower than this value. Particles with an aerodynamic diameter of 2 to 7 microns predominated both in the waste delivery and the processing areas. Fibrous dust particles were present in smaller numbers than spherical particles and consisted mainly of organic materials. Natural and artificial inorganic fibers were found only occasionally. The concentrations of lead, cadmium, nickel and mercury were considerably lower than the corresponding MAK and TRK values, and were--with the exception of lead--in the range of the respective metal concentrations in the atmosphere of urban areas. Microscopical examinations of used protective masks (protection category P2) revealed that dust particles were deposited even on the inner side of the masks. Most of the particles on this side were very small and carried nickel or titanium. Microorganism concentrations measured in air from the highly dust-exposed areas of the plant showed values up to 6.9 x 10(5) cfu/m3, with a mold content of 6.6 x 10(4) cfu/m3. Approximately 90% of the microorganisms were deposited on particles of the fine dust fraction (particle size < 7 microns), and more than 50% contaminated particles with an aerodynamic diameter of 2 to 4.7 microns. In the compost facility, mold concentrations of up to 8.4 x 10(5) cfu/m3 were measured. In contrast, the level of microbial contamination in the filtered air from the compost facility did not exceed the concentration measured in air outside the plant. The data which were obtained during the winter months are probably at the lower end of the average exposure range over the entire year. In regard to exposure assessment, it should be mentioned that particles with a size of 4 to 7 microns are not really "inert" particles, since they are preferential carriers for heavy metals and microorganisms. More studies in the future should be performed to establish, whether the level of exposure to microorganisms can be estimated indirectly by the determination of dust exposure.

Stereometabolism of styrene in man. Urinary excretion of chiral styrene metabolites.

Chiral styrene metabolites obtained during initial styrene exposure of test persons were determined in urine samples using capillary gas chromatography. A typical time-dependent urinary concentration profile of one person over a 49-h period is presented and compared with the results of a previous study of occupationally exposed workers and an unexposed control group. Maximum levels of excretion of all styrene metabolites were observed at about the end of a 9-h workshift. Forty hours after exposure, the L/D-ratio of mandelic acid had subsided to the initial value, and the L/D-ratio of phenylethylene glycol to a value equal or slightly above the initial value.

Stereometabolism of styrene in man: gas chromatographic determination of phenylethyleneglycol enantiomers and phenylethanol isomers in the urine of occupationally-exposed persons.

A gas chromatographic procedure for the determination of phenylethyleneglycol enantiomers and phenylethanol isomers is described and applied to the investigation of urine samples from occupationally styrene-exposed workers (11 males, six females) and an unexposed control group. Phenylethyleneglycol enantiomers and 2-phenylethanol were present in the urine samples of exposed and unexposed individuals whereas 1-DL-phenylethanol was not found in control urine. The L/D enantiomer ratio of phenylethyleneglycol was found to be approximately 3 in the exposed group and 1.5 in the control group. Because of the close structural relation of these metabolites to the primarily formed epoxide, the results give further insight into the stereotoxicity of styrene in man.

The determination of amino-acid enantiomers in human saliva with Chirasil-Val.

The use of polysiloxanes as stationary phase in glass-capillary gas-chromatography carrying chiral groups enables the separation and quantitation of most amino-acid enantiomers and a variety of other compounds in a much shorter time than previously. This phase exhibits low volatility and high thermal stability and may be used in routine analysis with open tubular columns at temperatures of at least 175 degrees C. Most protein amino acids are separated in a temperature programme between 90 and 175 degrees C, thus obviating the need for multiple injections. Resolution factors are lower than those of other diamide phases containing the L-valine-t. butyl-amide group, but are sufficient for resolution of almost all protein amino-acid enantiomers. Incomplete recovery from the sample, incomplete derivatization, hydrolysis and thermal decomposition of the derivative and shifting response factors can be compensated for by adding the unnatural enantiomer. The accuracy of amino-acid analysis by enantiomer labelling is equal or superior to that of known methods and permits complete analysis of peptides with respect to both amino-acid composition and the optical purity of each amino acid. The application of this method to human saliva provided information concerning enzymic and bacterial process in the mouth.

Effects of gabexate mesilate on the reactions of lipid metabolism in endotoxic shock.

Endotoxic shock was induced in rabbits of either sex by IV injection of 50 micrograms/kg endotoxin (ET) extracted from E coli O-55 by Boivin's method. A polyvinyl catheter was introduced into the superior vena cava under local anesthesia 1 day prior to the experiments. We observed a rise of plasma-free fatty acids (FFA) from an initial mean value of 190 muEq/liter to a level of 290 muEq/liter within 6 h after injection of endotoxin. The increase of FFA was followed by a rise of plasma triglycerides (TG) and an increase of very low-density lipoproteins (VLDL), beginning 1-2 h later. The rise of FFA and the following increase of TG and VLDL were significantly reduced by infusion of 14 micrograms/kg X min gabexate mesilate (GM). Our results indicate that GM--in addition to its well-known proteinase inhibitory action--effects fatty acid metabolism.

Experimental exposure to toluene: further consideration of cresol formation in man.

In two separate experiments 10 healthy men each were exposed at rest in an exposure chamber to about 200 ppm toluene in the air. Hippuric acid, o-, m-, p-cresol, and phenol in urine were detected by capillary gas chromatography at the beginning and at the end of exposure, and at variable times after the cessation of exposure. In addition toluene in blood was determined at the same intervals. The results indicate that in addition to hippuric acid, o-, m-, p-cresol are metabolites of toluene; the detoxication lasting 24 hours at least.

[Infrared spectrometry and gas chromatography for determination of halothane in operation rooms (author's transl)]. / Kontinuierlicher infrarotspektrometrischer und intermittierender gaschromatographischer Nachweis (Personal-Air-Monitoring) des Halothans in der Luft von Operationsräumen.

Chronic halothane intoxication is a health hazard to anaesthetic personnel and requires permanent control of the degree of exposure. Two different methods are described: a continuous infrared spectrometric and an intermittent gas chromatographic determination of airborne halothane. An elaborate instruction for the measuring procedure is given; calibration techniques and detection limits are discussed. Data from operating rooms with different security equipment are listed. For determining the total burden gas chromatography is the method of choice, as the concentration range to be detected is rather low in general. In addition infrared spectrometric concentration monitoring gives valuable information about concentration peaks caused by typical handling in an operation room.

Metabolism of toluene in man: gas-chromatographic determination of o-, m- and p-cresol in urine.

Complete separation of phenol, o-, m- and p-cresol was achieved by capillary gas-chromatography. Urinary concentrations of cresols were determined quantitatively in samples from 10 male workers exposed to toluene. Besides p-cresol, o- and m-cresol were found to be urinary compounds in the case of the exposed group in contrast to normal persons. This finding was proved by gas-chromatography/mass spectrometry. The difference between both groups is significant. It is concluded that beside hippuric acid o-, m- and p-cresol are metabolites of toluene.

[Psychomotor responses under standardized trichloroethylene load (author's transl)]. / Psychomotorische Reaktionen unter definierter Trichloräthylenbelastung

20 volunteers were exposed for 4 hrs to a concentration of trichloroethylene in room air of 95 ppm. Before and after exposure the Wiener Determinationsgerät, the Wiener Reaktionsgerät, and the motorische Leistungsserie (Schoppe) were used to perform 6 tests, each of which gave 15 measurements. A comparison with the results of a blank test which had been obtained 1 week before with the same volunteers under the same conditions, but without the use of trichloroethylene, yielded no statistically significant impairment of the psychomotorial function by trichloroethylene. Further investigations are being carried out.