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Biomedical subjects

J Kangas

Publications and source records attributed to J Kangas.

51 records · Page 3Linked to original sources

Ammonia, hydrogen sulphide and methyl mercaptides in Finnish municipal sewage plants and pumping stations.

Ammonia, methane, hydrogen sulphide and methyl mercaptides were analyzed in the atmospheres of 16 Finnish municipal waste water treatment plants and in 18 pumping stations. The sulphides were analyzed on site as it was found that, with the standard 0.5-l laminated plastic bags, significant amounts of the vapours were lost from the gas phase. The relative humidity of the sampled air was the most likely cause. Under normal operating conditions, sulphides varied from less than 0.07 to 53 micrograms l-1, with highest concentrations found at the sludge presses. Pumping stations had sulphide vapours from 0.07 to 0.5 microgram l-1. The presence of ammonia (0.007-3.5 micrograms l-1) and methane (0.7-18 micrograms l-1) confirmed the hypothesis of the anaerobic origin of the offensive gases. Although more effective ventilation without scrubbing the emission gases would reduce the health hazard in the plants it would burden the environment.

Ammonia↗

Effects of phenoxyacetic acids on the induction of chromosome aberrations in vitro and in vivo.

The effects of phenoxyacetic acid herbicides were investigated on the induction of chromosome aberrations in human peripheral lymphocyte cultures in vitro and in lymphocytes of exposed workers in vivo. Pure 2,4-dichlorophenoxyacetic acid (2,4-D; 0.125, 0.150, 0.200 and 0.350 mM) did not increase the number of aberrations, whereas the commercial 2,4-D formulation (0.125, 0.250, 0.500, 1.000 and 1.250 mM, with respect to phenoxyacetic acid concentration) significantly increased the number of chromosome aberrations in vitro (without exogenous metabolic activation). The phenoxy acid levels in the breathing zone of the workers varied between 0.3 and 0.4 mg/m3, and the concentrations of phenoxyacetic acids in the urine of the workers after exposure varied from 0.000 to 0.055 mmol/l. There were no increases in chromosome aberrations in peripheral lymphocytes of the exposed subjects.

2,4-Dichlorophenoxyacetic Acid↗

Exposure to hydrogen sulfide, mercaptans and sulfur dioxide in pulp industry.

An hygienic survey for hydrogen sulfide, methyl mercaptan and its derivatives and sulfur dioxide in kraft mills and in sulfite mills revealed concentrations varying from 0 to 20 ppm hydrogen sulfide, 0 to 15 ppm methyl mercaptan and comparable amounts of dimethyl sulfide with dimethyl disulfide up to 1.5 ppm. The greatest emissions were detected at chip chutes and evaporation vacuum pumps. Batch operations yielded clearly higher sulfur dioxide concentrations (up to 20 ppm) as compared to a continuous ammonia-base digester. Furthermore, there was a strong correlation with the season in the sulfite mills where higher concentrations were found in the winter when natural ventilation was poorer. As to the health effects, the exposed workers complained of headaches and a decrease in concentration capacity more often than matched controls. The number of sick leaves was greater in the exposed workers than among the controls.

Attention↗

Canine parvovirus infection in housed raccoon dogs and foxes in Finland.

An outbreaks of severe enteritis occurred among young raccoon dogs on fur farms in eastern Finland. Post mortem examinations revealed gross and microscopic lesions which were typical of parvovirus infections described in cats, mink and dogs. The intestine was dilatated, oedematous and the normal villi were significantly reduced. A parvovirus was isolated from faeces and found to resemble canine parvovirus by its ability to haemagglutinate pig erythrocytes at pH 7.2 and its antigenic properties. Experimental inoculations showed that both housed raccoon dogs and foxes are susceptible.

Animals↗

Comparison of dextranomer and streptokinase-streptodornase in the treatment of venous leg ulcers and other infected wounds.

The clinical efficacy of dextranomer (Debrisan) and streptokinase-streptodornase (Varidase) was compared in a controlled randomized in-patient study. There were two patient groups: Group A consisting of 28 patients with a total of 31 venous leg ulcers and Group B consisting of 56 patients with other infected wounds (posttraumatic and postoperative wounds, amputation stumps, burn wounds, arteriosclerotic ulcers, decubital ulcers, ulcers due to bone disease, rheumatic ulcers, ulcers due to erysipelas and wounds of mixed aetiology). Both agents have a good cleansing effect as well as a good effect on infection and wet necrosis. Dextranomer stimulates the formation of granulation tissue faster than streptokinase-streptodornase.

Bacterial Infections↗

Effect of in situ composting on reducing offensive odors and volatile organic compounds in swineries.

Seven swine farms were studied to find out how the in situ composting system, compared to the slatted floor pit system, influences the concentration and occurrence of malodorous compounds. Ammonia concentrations were measured with diffusion tubes. Small molecular sulfur compounds were analyzed using laminated bags and a gas chromatograph with a FP-detector. All other volatile organic compounds were analyzed by gas chromatography/mass spectrometry with simultaneous sniffing of the eluted compounds. About 400 organic compounds were identified from the air samples, and 94 suspect odorous compounds are listed in the present article. The most intense and unpleasant odors were caused by p-cresol, carboxylic acids (C2-C7), and some ketones such as 3-hydroxy-2-butanone, 2,3-butanedione, and 2-butanone. Terpenes (alpha-pinene, beta-pinene, 3-carene, and limonene), which originate from sawdust, caused the main peaks in the chromatograms of compost swineries. In swine confinement buildings where the composting system was functioning properly, the concentration of sulfur compounds, and especially of carboxylic acids, ketones, and p-cresol, fell effectively. The use of sawdust as composting material caused elevated concentrations of terpenes in the ambient air. There was clearly less airborne ammonia and hydrogen sulfide in the well-functioning compost swineries than in the poorly functioning ones. Elevated hydrogen sulfide levels were measured during turning work, however. In one composting swinery, the hydrogen sulfide level was as high as 15 mg/m3 during turning work. All the other concentrations of odorous compounds did not exceed occupational exposure limit values, but several compounds exceeded the respective threshold odor concentrations.

Air Pollutants, Occupational↗