Lactate dehydrogenase activity in human placenta following exposure to environmental pollutants.

The impact of environmental pollution at the place of residence of pregnant women and of their smoking habits on the cellular energy metabolism of placental tissue was investigated. Samples of full-term placentas were randomly collected from two environmentally different regions of Slovakia (Bratislava, Stará Lubovna) and the activity of lactate dehydrogenase (LDH) was measured. Our results showed enhanced LDH activity in the placenta that was dependent on both the type of environmental pollutants at the place of residence and the smoking habits during pregnancy. The enhanced LDH activity may reflect hypoxic conditions due to the accumulation of heavy metals and toxic compounds of tobacco smoke in the placental tissue. A high content of heavy metal particles, found in placental samples from Stará Lubovna in our previous studies, might contribute to the increased LDH activity in placentas from this region. We hypothesize that fine metal particles deposited in the placental tissue might be phagocytozed by the syncytiotrophoblast, thus contributing to the decreased oxygen level in placental tissue.

Cord serum immunoglobulin E related to the environmental contamination of human placentas with organochlorine compounds.

Allergic diseases are on the rise in both prevalence and severity, especially in industrialized countries. The process of allergic sensitization needs an understanding of the role environmental factors play in its development. In addition to traditionally considered air pollutants, various persistent organochlorine pollutants, which accumulate in the human body over a lifetime via food intake, are toxic in humans. Placental contamination by chemicals may act as a biologic marker for the exposure of the mother or for the fetus via transplacental transfer. Placentas were collected from term deliveries in two Slovak regions. The samples were then analyzed for 21 selected organochlorine compounds. Specimens of cord blood from 2,050 neonates were gathered for the determination of levels of total immunoglobulin E (IgE). The regions were chosen according to their environmental characteristics: a city polluted with organic chemical industry versus a rural region devoid of industrial sources of pollution. In addition, data regarding the incidence rate of atopic eczema cases in the regions were considered. Comparisons between regions revealed that both the placental contamination with 16 of 21 organochlorine compounds and the cord serum IgE levels were significantly higher in the industrial region. The findings pointed to an association between organochlorine compounds and the higher levels of total IgE in newborns, signaling a higher allergic sensitization in the industrial region. This association was supported by the higher incidence rate of atopic eczema cases in the population registered in the industrial region.

Respiratory system response to ambient air magnesite particulates.

Ambient air particulates derived from a magnesite-processing plant contain magnesium oxide (85-90%), iron oxide (7-8%), calcium oxide (about 2.5-3%), Al- and Si oxides (0.1-0.5%) as well as additional elements in trace amounts as follows: Ni, Cr, Mn, Co, Hg, Cd, Pb, V, Ba, Ag, Cu and Sn. Magnesite clinker is manufactured from raw magnesite by baking in rotary furnaces using the Leseps-Polysius system, which represents the source of particulate pollutants entering the atmosphere. In the area heavily polluted by magnesite particles, the health impact using the data obtained from the exposed humans and animals was assessed. The reason for this study were the data on the increased frequency of respiratory diseases in children in the polluted area. In a group of children (9-10 years of age) residing in the area, the immune response to ambient air pollutants exposure in comparison to a non-exposed group living outside the polluted area was investigated. A statistically significant decrease in the amount of salivary lysozyme, SlgA, IgG and albumin in the exposed group was observed. Simultaneously, a 6-month respiratory exposure of a group of Chinchilla rabbits in that polluted area aimed at the simulation of the human exposure was conducted. In the exposed rabbits, enormously increased number of pulmonary alveolar macrophages (PAM) has been found. Using atomic absorption spectrometry, a statistically significant increase in magnesium content (e.g. a bioindicator of the exposure) in the body tissues of the exposed animals was found. The laboratory data obtained from the animal study contributed to the elucidation of the depressed immunity (especially in the respiratory system) in the children exposed to ambient air magnesite particulates.

Sites of lead and nickel accumulation in the placental tissue.

1. There is a variety of quantitative analytical data regarding the total concentrations of heavy metals in human placentae. However, little is known about sites of metal accumulation in the placental tissue structural zones in relation to the environment. In this study, the lead and the nickel particulate deposits in the placental chorionic plate, the chorionic villous tree and the basal plate, using tissue histochemical reactions for lead and nickel, have been estimated. The degree of metal contamination of placentae was assessed according to an arbitrary scale. Both metals have shown a common mode of accumulation in the placental tissue structural zones. Among the observed contaminated structures in the placental tissue, the syncytiotrophoblast was the most frequent site for lead and nickel particulate deposits. 2. The frequency distribution of both metals within the mentioned placental zones, using four metal contamination degrees, was determined. A heavily contaminated zone was found to be the chorionic villous tree, especially in samples from the industrial region. 3. A comparison between two Slovak regions (an industrial and a rural one) using statistical tests was performed. The frequency of samples without any lead occurrence in the chorionic villous tree was found to be 10% in the industrial region, and 16% in the rural region. Regarding the nickel deposits, the frequency of non-contaminated samples in the industrial region was 2%, whereas in the rural region 6%. A relationship between traffic related pollution and human placenta contamination was found in both investigated regions.

Different growth response of Euglena gracilis to Hg, Cd, Cr and Ni compounds.

The toxicity of inorganic mercury, nickel, chromium and cadmium on the unicellular photosynthetic flagellate Euglena gracilis, strain Z (E.g.) has been tested. Under the conditions used each metal impaired the growth rate of E.g., and had a very strong effect on cell motility. The degree of cytotoxicity and motility decreased from mercury iodide to cadmium chloride to cadmium nitrate to potassium dichromate to nickel sulfate. No mutagenic effects of the metals investigated have been observed. Adverse effects of metal compounds can be tested on the eukaryotic species of Euglena gracilis used as an intermediate model system between bacterial and animal model.

Immune response to exhaust gases derived from two-cycle combustion engine following experimental exposure.

Experimental exposures using laboratory Wistar rats inhaling the exhaust gases derived from a two-cycle combustion engine under the chamber conditions have been carried out. Immune response reflecting a burden of the respiratory system in the exposed animals following the respiratory exposure has been investigated. In variously designed exposure experiments, the dynamics of pulmonary alveolar macrophages (PAM) activity to phagocyte particular antigen (sheep red blood cells), the hemolysis production, the total serum complement level and the capacity of the pulmonary clearance from the inhaled silica dust have been examined. The findings revealed the depressed ability to produce antibodies against sheep red blood cells (SRBC) in case of prolonged animals exposure during the time-interval of antibodies production. PAM phagocytic activity decreased considerably as well, in the first phases of the SRBC phagocytosis. The total serum complement level was found to be decreased in consonance with the decreased hemolysins production. The pulmonary clearance from the inhaled silica particles was statistically significantly elevated in the animals exposed long-term before the dusting only. In case of the prolonged exposure during the lung clearance period of 25 days, the exposed animals did not show the difference anymore, if compared to the non-exposed group.

Exposure and impact assessment of emissions from mercury recycling using domestic rabbits.

A biomonitoring study using domestic rabbits (Chinchilla) aimed at the exposure and impact risks assessment of emissions released into the ambient air from a mercury-recycling plant has been carried out. Groups of rabbits were exposed to the emissions during 6 months at biomonitoring stations built up in two localities (Rudnany and Matejovce) in the distance of about 3 and 6 km around and downwind from the mercury-producing plant. The aim of the biomonitoring was to trace the translocation of inhaled inorganic Hg in body tissues and the immunotoxic impact of the emissions in the exposed mammalian organism in comparison to a non-exposed animals living outside the polluted area. The content of mercury (as a major pollutant in the ambient air in that area) in body tissues was done spectrometrically using a Trace Mercury Analyser TMA-254. Content of mercury and the other metals in the rabbits' hairs was determined by neutron activation analysis. A statistically significant increase of the inorganic Hg content in the specimens of kidneys, lungs, liver, thigh bone, heart muscle and brain was observed. Concerning the hairs, a statistically significant elevation of Hg and other elements (As, Cd, La, Zn, Na, K, W, Sr) has been found. The body tissue reaction to the increased accumulation of mercury has been investigated by a direct immunofluorescent method to search for body tissue immune complexes. The significant increase of Hg content determined in the organs (especially in kidneys and liver) of the exposed animals was also traced by the presence of immunofluorescent antibodies. In addition, the immunofluorescent antibodies in the myocardium have been proved.(ABSTRACT TRUNCATED AT 250 WORDS)

A non-traditional approach to risk assessment of respiratory exposure to outdoor air pollutants.

The aim of this study was to verify a non-traditional assessment of respiratory exposure to outdoor air pollutants in industrial areas. The technique involved environmental biological monitoring' using domestic rabbits in the neighborhood of a mercury-producing plant. Rabbits were exposed whole-body to mercury emissions for 6 months in special cages near the plant. Control rabbits were kept using the same schedule outside the polluted area. Potential toxicity was assessed by: (a) measurement of Hg-accumulation in lungs and other body tissues by atomic absorption spectroscopy (AAS); (b) scanning electron microscopy (SEM) of the tracheal surface; and (c) measurement of toxic effects on pulmonary alveolar macrophages (PAM) by a rossette assay (Fc immunoglobulin binding). We found increased Hg concentrations in the lungs, kidneys, liver, heart, brain and bone; changes in the mucosal relief of the trachea, and depression of PAM Fc receptor (FcR) activity to IgG. A 6-month chamber exposure of Wistar rats to the aerosol created from solid particles of the mercury-producing plant revealed the increase of Hg-content in the same body tissues except the brain, and, less intense morphologic changes on the tracheal relief. Biomonitoring using environmental exposure of domestic rabbits might be useful in screening for possible health hazards to the respiratory system from complex outdoor aerosols.

Issues related to dust aerosols in the magnesite industry. II. Environmental exposure.

Magnesite waste containing largely magnesium oxide (MgO) and a mixture of other metals forms aerosols with a considerable portion of respirable particles when released into the atmosphere. Several animal species (domestic rabbits, Wistar rats, cattle) were used to biologically monitor the accumulation and effects of inhaled magnesite aerosol in two actual locations of the magnesite industry. The study revealed the biological accumulation of magnesium, iron and other metals in the bodies of exposed animals (and F1 animals) as well as specific lesions on tracheal relief, morphological changes in organ microstructure (especially in the lungs, spleen, liver and myocardium), alternations in the reproductive capacity of females, distorted Mg:Ca:P ratio as well as changes in the immune profile. The findings of biological monitoring of animals are consistent with the conclusions of epidemiological studies.

Issues related to dust aerosols in the magnesite industry. I. Chamber exposure.

The present paper is an overview of the experimental research into the effects of flue magnesite dust in the magnesite industry in which the raw material (magnesite) is processed into refractory magnesite clinker. The issues related to dust are divided into two problem areas: a) dust aerosol arising in the process of ore mining and consisting largely of magnesite (MgCO3) and b) dust aerosol originating during ore baking in rotatory furnaces and made up mostly of MgO. Thus, larger groups of people become exposed to these aerosols as a result of solid particles escaping into the atmosphere than in the case of occupational exposure. Experimental research carried out on laboratory animals after chamber exposure provided findings on the deposition, retention and elimination of magnesite dust, on impaired balance between magnesium and calcium leading to damage of biological membranes, on how the immune profile or reproduction and embryogenesis is impacted as well as on the possible interaction with sodium salicylate as a result of an impaired acid base balance. These findings are followed up by evidence produced in the course of biological monitoring (Part II).

[The effect of magnesite emission into the environment on the respiratory tract in rabbits studies with scanning electron microscopy with additional equipment]. / Vplyv magnezitových emisií v ovzdusí na dýchacie cesty králika studované rastrovacím elektrónovým mikroskopom s prídavným zariadením.

Changes induced by magnesite dusts on the mucosa relief of the airways of rabbits are described. X-ray microanalysis and examination by raster electron microscopy were used to determine and verify the changes.

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.

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.

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.

Biomonitoring of industrial dusts on animals. I. Bioaccumulation of dust components.

The bioaccumulation of industrial dust components in laboratory animals exposed by inhalation was studied under environmental conditions. Three types of industrial emissions were investigated: magnesite emissions, wastes from nickel refinery and cement emissions, respectively. The findings revealed that the chemical components of the industrial dust particles inhaled by animals are accumulated not only in the lungs, but also in the other organs, bone and hair of the exposed animals. In addition, the dust components were found in the organs of the F1 generation as well. This suggests a new aspect for the assessment of the biohazard of industrial dust particles in the environment.

Biomonitoring of environmental pollution hazards from a nickel smelter waste dump.

Longterm field exposure study was carried out on 10 rabbits placed for 6 months in a bioindication station located about 3 km downwind of a disposal site of nickel smelter waste dump. As revealed by the method of atomic absorption spectrophotometry, all of these animals showed elevated nickel and chromium levels in their body organs and hair. These findings were paralleled by histologic abnormalities in the lungs and liver tissues. Average dustfall values at the site of exposure did not exceed 5.5 g X m-2 X 30 d-1 during the period of observation. Dustfall deposits in this location contained nickel and chromium in amounts that were higher than in control locality. Analogous experiments on Wistar rats were carried out in a laboratory exposure chamber (exposure 4 h/day, 5 days/week, for a period of 6 months). After exposures to 50 mg X m-3 of metallic dust, lung parenchyma of rats was characterized by the presence of dust particles in various phases of phagocytosis as well as the presence of badly damaged or disintegrated alveolar macrophage cells, which pointed to metallic aerosol toxicity for biomembranes. The technique of air pollution biomonitoring on animals, correlated with the data on ambient air concentrations of the suspended particulate matter and its content of trace metals, appears to be a well suitable tool in establishing the potential air pollution hazards to the exposed populations living in the area of concern.

Immuno-biochemical findings in groups of individuals occupationally and non-occupationally exposed to emissions containing nickel and cobalt.

Immune reactions elicited in the sera of individuals exposed to nickel and cobalt were assessed by changes in the concentration of serum immunoglobulins IgG, IgA and IgM and serum proteins alpha 2 macroglobulin (A2M), transferrin (TRF), alpha 1-antitrypsin (A1AT), ceruloplasmin (CPL) and lysozyme (LYS). Examinations were carried out in workers occupationally exposed to Ni (38 individuals) or Co (35 individuals) and in groups of non-occupationally exposed children living in areas with a different degree of air pollution from a nearby source of Ni and Co emissions (one group was made up of 54 exposed children, the other one of 64 "less exposed" children of the same age). Groups of non-exposed controls were represented by a group of 42 male adults matched by age and by a group of 48 children from a non-polluted area. Significantly increased average values were obtained for IgG, IgA and IgM in group of workers exposed to Ni, for IgA in workers exposed to Co and for A1AT, A2M, CPL and LYS in both groups of occupationally exposed adults (p less than 0.001 - p less than 0.005). Among non-occupationally exposed children the group of the most exposed had significantly elevated average values for A2M and A1AT which were higher than those recorded in groups of "less exposed" and control children (p less than 0.02 and p less than 0.05, respectively). The biomedical importance of these findings is discussed in detail.

Modulation of peripheral lymphocyte and alveolar macrophage activity by magnesite emissions.

Modulation of alveolar macrophage and peripheral lymphocyte activities in rats exposed to magnesite emissions was tested under field and laboratory conditions. The field exposure test were conducted in a locality near a magnesite ore processing plant, the time observation was 18 weeks. The laboratory exposure tests were performed in an inhalation chamber at a constant magnesite dust aerosol concentration of 50 mg . m-3; the animals were exposed 4 hours a day, 5 days a week for a period of 70 days. Eighteen weeks of exposure to magnesium-polluted ambient air was found to increase the number of alveolar macrophages, to stimulate acid phosphatase activity in these cells, and to enhance activity of peripheral B lymphocytes to form EAC rosettes. The inhalation chamber experiments, evaluated after 46 and 70 days of exposure, resulted in an enhanced acid phosphatase activity of alveolar macrophages, enhanced lactate dehydrogenase activity of peripheral lymphocytes and in an increased percentage of B lymphocytes in blood, depending on exposure time. The activation of peripheral lymphocytes and alveolar macrophages observed in rats exposed under field and laboratory (here in dependence on exposure time) conditions clearly suggest that the cells participating in the induction and expression of the immune response are distinctly modulated in their activity by in vivo exposure to magnesite dust.