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Biomedical subjects

V Bencko

Publications and source records attributed to V Bencko.

At least 55 records · Page 3Linked to original sources
PubMed1995

[Modern ethical problems in environmental epidemiology].

The author presents a summary account on the session of the International workshop on ethical and philosophical issues in environmental epidemiology convened by the Rome Division of ECEH WHO and the International Society for Environmental Epidemiology (North Carolina, USA, Sept. 16-18, 1994). Twenty-one epidemiologists and workers concerned with ethics and philosophy from Europe, North America and other regions were invided. The subject of discussion was a definition of the discipline of environmental epidemiology and concurrently ethical and philosophical problems of the discipline. It was stated that it is essential to adopt ethical guidelines in the sphere of environmental epidemiology. It was recommended that, where reliable safeguards of processed personal data exist, access to the pertinent databases could be granted without previous informed consent of probands. Informed consent must be obtained only in later stages of research if direct contact with the individual subject is essential. Recommendations were adopted for practitioners, universities and training centres, professional organizations and institutions as well as sponsors interested in environmental epidemiology. It was emphasized that efforts to improve ethical awareness and practice must become and integral part of training and practical activities of all concerned.

Environmental Health↗
PubMed1995

Hospital waste--the current and future treatment and disposal trends.

Hospital wastes pose a serious public health problem. This is primarily caused by the diversity of the individual components of the waste which constitute a risk to health if inadequately handled. It is evident that economic and technical conditions for both a safe disposal, including environmentally sound manner incineration as well as efficient stem or microwave disinfection and a safe management practice based on legal regulations consequently will contribute to protections of both human health and the environment. There is no reason to assume there may be any universal, standard regulations to be used and accepted unianimously and consistently valid for all countries. It is necessary to honor the specific, social and economic background of every country. Nevertheless the European Community principles of hospital waste treatment and disposal will be eventually accepted by this country in principal, in the framework of a general economic and political integration of European countries.

Czech Republic↗
PubMed1994

Risk assessment of chemicals--a central European perspective.

During the last four decades in all the Central and East European countries it was intended that prevention of the adverse health effects of chemicals in occupational and environmental settings, including the drinking water and food basket of populations, be achieved by determination and compulsory observance of hygienic limit values (MAC, TLV, ADI). The authors have tried to demonstrate some specific features of risk assessment of exposure to chemicals in environmental and occupational settings. Although the approach to risk assessment and management was similar in many respects in the CMEA countries, implementation and hygienic practice was different in the individual countries in terms of many details and effectiveness. Due to long lasting experience with environmental pollution including health impact on humans, such as in the "Dirty Triangle of Europe" and other heavily contaminated areas a considerable knowledge has been gained. The authors recommend to analyse critically and evaluate the knowledge and experience and present it to the international scientific community and international institutions such as UNEP, ILO, IPCS, IRPTC and last but not least, OECD.

Environmental Exposure↗
PubMed1993

[Ultraviolet rays and their biological effects].

In conjunction with contamination of the atmosphere by freons interest in geophysical and health aspects of "ozone holes"--seasonal incidence of increased intensity of UV radiation--is increasing. Its biological effects depend on the intensity, period of exposure and wavelength. There is a wide range of different damage, local as well as general. In addition to pigmentation of the skin and symptoms produced by an elevated histamine blood level we find also changes which may have more serious and permanent consequences. These changes include the number and structure of Langerhans islets, changes of the peripheral capillary walls, dimerization of pyrimidine and thymine in DNA. These changes contribute to the development of malignancies of the skin. After exposure of the eye changes of pigmentation are found, and depending on the dose, also development of conjunctivitis or retinal damage. Recently interaction of UV radiation with arsenic was investigated. Conversely therapeutic effects of UV radiation in combination with chemotherapy are used in dermatology, such as inhibition of contact sensitization.

Eye↗
PubMed1993

Hospital waste management practice in the Czech Republic.

Hospital wastes pose a serious problem. This is primarily caused by the diversity of the individual components of the waste which constitute a risk to health if inadequately handled. It is evident that economic and technical conditions for both a safe disposal as well as efficient steam sterilization and management practice based on legal regulations consequently will contribute to protections of both human health and the environment.

Containment of Biohazards↗
PubMed1990

Immunological profiles in workers occupationally exposed to inorganic mercury.

Forty-one male mercury-exposed workers were examined for the serum concentration levels of immunoglobulins (IgG, IgA, IgM), alpha-1-antitrypsin (A1AT), alpha-2-macroglobulin (A2M), ceruloplasmin (CPL) and orosomucoid (ORO). In the period preceding this investigation the mercury concentrations in workplace air ranged from 0.106 to 0.783 mg.m-3, the range of urinary mercury concentrations was from 0.029 to 0.545 mg.1(-1). All but two (IgG and A1AT) of the immune parameters tested were at the levels that were evidently higher than those found in a control group of 55 workers matched by age who lived in a relatively clean area. The percentage of individuals with no value out of the range of normal physiological limits was in the controls almost 80%, in the exposed 36.6% only. These findings confirm the literature data which show that an inhalation exposure to inorganic mercury may evidently have a stimulating effect on some serum proteins in humans.

Analysis of Variance↗
PubMed1990

Bioaccumulation of metals from nickel smelter waste in P and F1 generation of exposed animals. Part III. Morphological responses.

Inhalation exposure experiments were conducted on a group of female adult Chinchilla rabbits placed in a field biomonitoring station located downwind from dumped nickel refinery wastes. Their F1 generation offsprings were exposed prenatally and 6 weeks postnatally. After termination of exposure, both P and F1 generation rabbits were sacrificed, their organs removed and subjected to a histologic examination using light and electron microscopy techniques. The histological responses were most marked in P generation female rabbits, namely hypertrophy of the muscle layer of pulmonary artery walls and foci of atelactasis. Electron microscopic examinations of the myocardium of chamber-exposed rats revealed evidence of muscle fibre lesions at sites of intercalary discs and changes in mitochondrial structure as a result of accumulated Ni, Cr and/or other metals. Histologically remarkable was interstitial accumulation of an unidentified electron-dense crystalloid substance situated near blood capillaries and between myofibrils and collagenous fibres; this substance is believed to be a result of metal-protein interaction. The rats injected intravenously with a suspension of metal waste displayed mitochondrial lesions analogous to those observed after inhalation exposure, but no presence of the electron-dence substance could be noted. It is concluded that chronic exposure to metal waste may give rise to cardiovascular lesions.

Animals↗
PubMed1990

Biological monitoring of human exposure to metals.

Biological monitoring of exposure to metals and metalloids involves not only determination of these elements in selected body fluids and tissues but, in some cases, also determination of a certain biochemical indicator which signalises the presence of the monitored element in the organism. Biological monitoring of occupational exposure to metals has a long tradition whereas biological monitoring of exposure in general environment has developed more intensively only in the past two decades. New information about the toxic effect of some metals and metalloids and about their kinetics of absorption, distribution and excretion in experimental animals, and particularly in man, is necessary for elaborating suitable biological exposure tests. Of current interest is also the movement of persistent noxae in the environment, seen from the ecologic view point. This report outlines the present state of the problem in Czechoslovakia.

Adult↗
PubMed1989

Mercury-selenium interaction: distribution and excretion of 203Hg2+ in rats after simultaneous administration of selenite or selenate.

In female rats intravenously injected with 203HgCl2 (0.6 mg Hg2+ per kg body wt.) the effect of intraperitoneal administration of selenite or selenate (0.525 mg Se per kg body wt.) on distribution and excretion of 203Hg was studied. The content of 203Hg was lower in kidney and higher in liver and blood in the groups treated with selenate or selenite when compared with rats which received only mercury. The brain content of 203Hg was significantly increased in rats injected with selenite. Both selenium compounds injected immediately after mercury significantly decreased urinary as well as biliary excretion of 203Hg. A transient increase in the rate of biliary excretion of 203Hg during the first 2 h after administration was observed in rats treated with selenate. This finding seems to support the idea that the reduction of selenate to selenite in the body is not rapid but takes at least several hours.

Animals↗
PubMed1989

[Air pollution emissions and changes in lung function].

Among the environmental hazards in a modern industrial society, air pollutants are of major significance. They can directly affect the cells of the bronchopulmonary system and lead to an irritation of the epithelial and immunocompetent cells. This results in a decreased secretion of immunoglobulin A, and, consequently, a decreased resistance against infections. Thereby pathogens, especially bacteria, may lead to an inflammation of the respiratory tract. Apart from the direct toxic effect of their pollutants, recurrent inflammations eventually lead to small airway obstruction. The spirometric parameters FVC, FEV1 and MEF50 were reduced. IgA concentration in the saliva was determined by means of immunodiffusion and was found to be reduced when compared to a less exposed group. A series of pathogenic germs were isolated from various mucous membranes (conjunctiva, nose/throat). The median immissions for the children examined were 1.345 mg/m3 SO2 and 0.189 mg/m3 HCl.

Air Pollutants↗
PubMed1989

Environmental protection and its trends in developing countries.

On instances of some worldwide problems of environmental protection, the authors refer to the fact, that a target of industrial countries is to help to the developing countries. Mainly it means an aim in such sense, that the dangerous failures and faults which happened in the past, should not be repeated as a consequence of temporaneous economical problems in the Third World. In the long run it is a common interest of all and certainly a sufficient motivation of a commonly coordinated effort in this field. It is at most desirable, that all developing projects, from a simple water supply to the integrated developing concepts, for example eco-agriculture projects, correspond with the national interests as well as with the specific requirements of environmental control.

Developing Countries↗
PubMed1989

[Water studies of inhabitants of refuse disposal sites in Cairo. 1].

In two waste disposal sites in Cairo, drinking water samples from springs, drinking vessels and kitchens were investigated. Total germ count lay seldom below one thousand and ten million pro ml. Apart from various faecal germs, Aeromonas hydrophila was also found. The high occurrence of diarrhoeal diseases among the inhabitants of the waste disposal sites can be traced with certainty to the extremely bad drinking water quality.

Colony Count, Microbial↗
PubMed1989

[The pathogen spectrum of the conjunctiva of inhabitants of refuse disposal sites in Cairo. I].

In Cairo's waste disposal sites conjunctivitis is frequently found resulting from the burning process of plastic, paper, etc.. Recurrent secondary contamination of the conjunctiva by pathogenic and non-pathogenic microorganisms often takes place; however, in certain germ species, the differentiation between pathogenic or non-pathogenic organisms within a damaged mucous membrane cannot be made. Furthermore, in this study, we have attempted to investigate germ reproduction during the application of PVP-eyedrops. However, our results cannot be conclusive because of the high environmental contamination, very low personal hygiene resulting from contaminated water and the constant exposure of samples to environmental contamination. Studies will be continued.

Air Microbiology↗
PubMed1989

Bioaccumulation of metals from nickel smelter waste in P and F1 generations of exposed animals. I. Dynamics of metal distribution in the organs and AM activity.

A group of female Chinchilla rabbits was exposed respiratory to metal aerosol originating from dumped wastes of a nickel smelter. The experiment was carried out in a biomonitoring station situated 4 km away from the dump in the direction of prevailing winds. Metals (Fe, Cr, Ni) introduced by inhaled waste particles were found in the increased amount in the body organs of exposed (P and F1) animals. Following a 3-months exposure of female rabbits (P), the elevated level of Cr in liver and kidneys was found, and after 6-month exposure also in the heart and thigh muscles. The Ni content proved to be increased in the lungs, heart and thigh muscles following 3-month period and in the liver after the 6-month exposure. Concerning the Fe content, it was already elevated in all the organs investigated except the lungs after 3-month exposure. The alveolar macrophage (AM) count was increased significantly in the exposed female rabbits (P) only after 6 months (P less than 0.05) and rose continually till the end of 9-month exposure (P less than 0.01). The enzyme activity of lysosomes was enhanced after 9-month exposure. In F1 rabbits 6 weeks of age elevated levels of chromium were found in the liver, kidneys, heart and thigh muscles. The Fe content was increased in the liver and thigh muscle, while the Ni content was enhanced only in the brain. The increased mucus secretion was observed on the tracheal mucous relief of F1 rabbits in response to the noxious effect of needle-shaped metal particles using an electron scanning microscope, despite the short duration (6 weeks) of postnatal exposure. The reported findings emphasize the effects of metal particles originating from the waste of a nickel smelter in an environment where the mean value of the dust fallout was only 4 g.m-2.30 days-1.

Air Pollutants, Occupational↗
PubMed1989

Bioaccumulation of metals from a nickel smelter waste in P and F1 generations of exposed animals. II. Modulation of immune processes.

A group of female Chinchilla rabbits was exposed through inhalation to the metal aerosol derived from dumped waste of a nickel smelter. The experiments were carried out in a field exposure station. Increased levels of tissue immune complexes were found in the myocardium and lungs of P females, whereas F1 rabbits (exposed both prenatally and 6 weeks postnatally) from the same group of P females had significantly elevated serum circulating immune complexes as compared to controls. In P rabbits, nonspecific serum tumoricidal activity was increased by 8.2%, while in F1 animals the increase was by 14%. Transplantation immunity was examined in a group of inbred Lewis rats following the transplantation of a skin allograft from the ear of inbred Berlin-Druckrey rats. The mean time of allograft survival in animals following i.v. administration metal dust suspension 2 days prior to transplantation, was prolonged as compared to controls. On day 22 after allograft transplantation, lactate dehydrogenase activity was found to be reduced in peripheral lymphocytes, and the liver and spleen weight proved to be diminished. These findings suggest a modulating effect of the metal dust from a nickel smelter regarding nonspecific serum tumoricidal activity and transplantation immunity as well as immune complex formation.

Air Pollutants↗
PubMed1988

Immunological profiles in workers of a power plant burning coal rich in arsenic content.

A group of 47 male adults working in a thermal power plant burning coal containing 900 to 1,500 g of arsenic per ton dry weight was examined on the blood serum immunoglobulins IgG, IgA and IgM content and levels of acute reactants alpha-1-antitrypsin (A1AT), alpha-2-macroglobulin (A2M), transferrin (TRF), orosomucoid (ORO) ceruloplasmin (CPL), and lysozyme (LYS). Investigations in the control group comprising 27 workers from another power plant in the same district where the coal content of arsenic was more than 10 times lower were analogous. The inter-group differences in means were evaluated by t-test, differences in the association of values by F-test, and the correlations with age and the length of exposure were assessed using the regression analysis method. The differences in mean IgG, IgA, IgM, LYS and A2M levels between the exposed and control groups of workers were insignificant or of borderline significance only. In contrast, differences in TRF, ORO and particularly CPL levels were statistically highly significant, in all instances P less than 0.001. In the control group, persons with abnormal values in at least two immunobiochemical tests used accounted for 3.7%, in the group of the exposed for 51% (P less than 0.002). All these findings, especially the rise in CPL concentration levels in the exposed group are discussed on the background of the rise in cancer mortality rates found previously in this group of power plant workers.

Acute-Phase Proteins↗
PubMed1988

Immunobiochemical profiles of workers differing in the degree of occupational exposure to vinyl chloride.

The immunobiochemical studies were conducted in a group of 98 production workers engaged in polyvinyl chloride manufacture from ethylene (group A workers) and in a group of 59 vinyl chloride workers from a chemical plant employing classic production technology from acetylene (group B workers). Both groups of workers were matched by age (group A workers: 37.7 +/- 8.66 years; group B workers: 34.9 +/- 11.2 years) and average exposure length (group A workers: 8.6 +/- 3.0 years; group B workers: 10.7 +/- 8.4 years). All workers were examined for the serum concentrations of immunoglobulins IgG, IgA and IgM and acute reactants lysozyme (LYS), transferrin (TRF), ceruloplasmin (CPL), alpha-l-antitrypsin (AlAT), alpha-2-macroglobulin (A2M) and orosomucoid (ORO). The statistical analysis included calculations of means, standard deviations and 95% confidence intervals. Differences in means were evaluated by t-test, differences in the distribution pattern of values by F-test. Abnormality of values was assessed by comparisons to normal values valid in Czechoslovakia. Group A worked in conditions meeting the MAC 10 mg VC.m-3 comparing with group B workers had elevated levels of IgG (P less than 0.005), IgA and IgM (P less than 0.001 both). Group B workers differed from group A workers by exhibiting significantly elevated levels of AlAT, and CPL. (P less than 0.001). The differences in the frequency of abnormal values between group A and group B worked in substantially less favourable hygienic conditions were significant for immunoglobulins elevated in group A and for ORO (P less than 0.01) and CPL (P less than 0.001) elevated in group B. The possible relationship of these immunobiochemical findings with the degree of vinyl chloride exposure are critically analyzed.

Adult↗