Problemi na khigienata最新文献

The use of lubricated oils in industry is related to processes of dispersing, evaporation and thermo-oxidizing destruction. As a result, in the air is eliminated a complex vaporous-gas aerosol mixture, consisting of lubricated aerosols, vapours and volatile products of evaporation and products of thermo-oxidizing destruction. In the vapour-gas phase are identified hydrocarbons [saturated, unsaturated, aromatic and cyclic] oxygen- containing hydrocarbon derivatives-aldehydes, ketones, esters, alcohols] in some cases CO. HCL. The composition of the mixture depends on the type of the lubricated oils and on the specific technological operation. The detailed study of the components of the mixture is a prerequisite for determining the leading toxic substances and for correct evaluation of the exposure and professional risk in industries, allowing a course of destructive processes with the lubricated oils.

During an annual toxicological experiment on white male rats, receiving orally vanadium (V) and nickel (Ni) in doses, equivalent to the accepted in Bulgaria, maximum allowable norms for ist category surface waters (respectively 0.005 mg/kg and 0.0025 mg/kg), 2 and 6 times and 20 and 60 times higher, is studied the atherogenic effect of the latter after the indices: total cholesterol, beta-lipoproteins, phospholipids, lecithin, total lipids, total protein and hexoses of glycoproteins in the serum; oxyproline, hexauranium acids and hexoses, hexosamines, connected with the proteins in the aorta. It is established that V and Ni in chronic combined effect in doses, equivalent to those accepted in Bulgaria, in maximum allowable concentrations for Ist category waters and surpassing them 2 and 6 time respectively, lead to no changes in the biochemical composition of the connective tissue of the aorta and to disorders in the lipidic and protein metabolism, while in higher doses is registered an increase of the glucoproteins and decrease in the glucosaminglycans in the aorta and decrease of the total lipids in the serum. The results point out, that V and Ni in the conditions of the experiment don't accelerate the processes of the natural ageing of the vessels and have no atherogenic effect. Juxtaposing the data for V and Ni concentrations in drinking waters in Bulgaria with our results give grounds to reckon, that their raised content in drinking waters in some regions do not represent a risk factor for the development of atherosclerosis.

The results from the investigation of the threshold of discomfort in 385 operators from firm "Kremikovtsi" are discussed. The most expressed changes are found in operators with increased tonal auditory threshold up to 45 and above 50 dB, in high confidential probability. The observed changes in the threshold of discomfort are classified into 3 groups: 1). Raised tonal auditory threshold (up to 30 dB) without decrease in the threshold of discomfort; 2). Decreased threshold of discomfort (with about 15-20 dB) in raised tonal auditory threshold (up to 45 dB); 3). Decreased threshold of discomfort on the background of raised (above 50 dB) tonal auditory threshold. On 4 figures are represented audiograms, illustrating the state of tonal auditory threshold, the field of hearing and the threshold of discomfort. The field of hearing of the operators from the III and IV groups is narrowed, and in the latter also deformed. The explanation of this pathophysiological phenomenon is related to the increased effect of the sound irritation and the presence of recruitment phenomenon with possible engagement of the central end of the auditory analyser. It is underlined, that the threshold of discomfort is sensitive index for the state of the individual norms of each operator for the speech-sound-noise discomfort.(ABSTRACT TRUNCATED AT 250 WORDS)

Oscillographic examinations on the temporal arteries of creative and technical specialists from the Bulgarian television are performed, who ensure direct transmission of the TV programs. The results point out to considerable increase in the level of the maximal temporal blood pressure and spastic oscillatory indices more strongly expressed in the creative specialists, which could be related to the nervous and psychic as well as emotional strain and high professional responsibility during the direct transmission of the TV programs. The data of the examinations confirm the significance of the functional oscillographic studies of the temporal arteries for revealing the early unfavourable changes in the cardiovascular system, in view of timely prevention of hypertension diseases.

A study of ambient air pollution differences over the residential areas in Sofia and the effect of the morbidity of the population has been carried out. Correlation analysis between the average concentrations of particulates, SO2, NO2, H2S, phenol and lead, and the incidence of several groups of diseases among adults and children has been performed. It has been found out that air pollution is more intensive in the centre of the city as a consequence of the heavy motor vehicle traffic and the old way of town planning. The results point out also that diseases of the lung, eye and skin are more frequent among the residents of city areas situated next to industrial zones, while diseases of the cardiovascular, hemopoietic and endocrine systems are more typical in the city centre as compared to a control residential areas. Although ambient air pollution has been found to the moderate, the correlation analysis suggests an influence of air pollution on the incidence of chronic diseases and immune imbalance. It is supposed that each pollutant possesses an individual risk potential.

Nitrous oxide and halothane are one of the most widely used anesthetics in the surgical practice. A spectrophotometric method in the infrared area is worked out for direct determination in gas phase simultaneously on nitrous oxide at 2236 cm-1 and on halothane at 813 cm-1 by means of 20 m gas cuvette. The sensitivity of the method for nitrous oxide is 20 mg/m3 and for halothane 5 mg/m3. The reproducibility of the method expressed as coefficient of variation is +/- 1-6%. The method is specific in the presence of other anesthesiological means. The air samples are taken in bags of Tedlar and depending on the sampling velocity the method can be used for recording the moment and average shift concentrations of nitrous oxide and halothane.

A study is carried out on the microclimate, physiological reaction of patients, chemical and bacteriological composition of the air in rooms of different location in the ward for cardiovascular pathology during the heating period of the year, according to some basic and integral indices. The characteristics of the interhospital environment in the rooms of the investigated ward is determined mainly by the irrational regime of heating, location, size of the glazed transparent area. In the hospital rooms are formed unsatisfactory hygienic norm parameters of the microclimate and the chemical composition of the air. The specific thermal environment affects the physiological reactions of the patients and leads to creation of conditions of discomfort and loading of the thermoregulation in direction of overheating.

Rapid and cheap test is developed on the basis of colorimetric tubes "Hygitest", produced in Bulgaria, which could substitute, in a number of cases, the more expensive chromatographic procedure. The method of gas extraction of the examined material is used in the test, and as measuring instrument are used colorimetric tubes "Hygitest" type "Vinylchloride-1-A", which are supplied with reinforced filter for humidity and with special scale. A specially constructed flask is used for thermal desorption. The test has reproducibility and sensitivity significant for performing screening and routine control on the raw materials for production of packings from polyvinylchloride for nutrition purposes. The method "Vinyl-test" is standardized for control on the free monomer content in the packings for nutrition purposes with branch normal of the Ministry of Health and the State firm "Polychim" OH 02 77051-84 (Change No 1 of 8.07.1991).

Examinations are performed on 120 workers from the plant for nitrogen and 253 workers from the plant for phosphorous fertilizers. For comparison is used a control group of 103 persons having no professional contact with chemical noxa. The measuring of the arterial pressure and assessment of the arterial hypertension rate is performed after the standardised method of the World Health Organization (1984). The probability of ischemic disease of the heart is determined on the basis of the electrocardiographic changes (Minnesota code) and the data of the questionnaire of G. A. Rose (WHO, 1984). The results point out, that the arterial hypertension incidence and that of the ischemic disease of the heart in the exposed workers in both plants is insignificantly higher than that of the controls. There is no effect of the specialized length of service on the dissemination of the registered cardio-vascular diseases. The data of the carried out investigation show no presence of heightened risk of arterial hypertension and ischemic heart disease in workers from the nitrogen and phosphorous fertilizers production.

The present work is part of a complex study of the health problems concerning the training of schoolchildren from the musical school--Sofia in specialty violin and piano. In order to examine the changes in the activity of the sympathetic-adrenal system for tracing the concentrations of sodium, potassium and index sodium/potassium in saliva of schoolchildren from the musical school during the general education program and also during individual training. The changes established during the experiment show the dynamics in the functional state of the sympathetic-adrenal system. We have to mention, that during the individual training an increased activity of the adrenal is observed, in connection with the emotional adjustment and emotional expenditure of schoolchildren.