Biomonitoring of industrial dusts on animals. II. Bioindication on alveolar macrophages

Rats and rabbits were exposed through the respiratory system to industrial dusts (magnesite emissions, solid wastes from nickel refinery dump, cement emissions) at biomonitory stations or in experimental chamber. Following exposure the animals were killed, the alveolar macrophages isolated and acid phosphatase and beta-glucuronidase estimated in the isolated cells. The activity of both enzymes was enhanced in the exposed animals in all cases. The enhancement was dependent on the length of exposure and amount of inhaled particles.     

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.     

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.     

An environmental nuisance: odor concentrated and transported by dust

Intensive swine production generates odorous emissions which flow from the buildings housing the animals. High ventilation rates bring in fresh air, remove heat and moisture and enhance pork productivity. Numerous compounds contribute to the uniquely offensive odors from swine facilities, including fatty acids, amines, aromatics and sulfur compounds. Dust particles, which originate predominantly from feces and feed, can adsorb and concentrate odorants in swine facilities. In addition, organic particles can decay and generate odorous compounds. Odorants can exist in much higher concentrations in the dust particles than in equivalent volumes of air. Thus, inhalation of odorous dust and deposition of the dust particles in the mucus overlying the olfactory mucosa are likely responsible for some odor-related complaints by swine farm neighbors. Accurate prediction of odor transport and dispersion downwind from swine farms may require models of dust dispersion and correlation between dust and odorant levels. Unfortunately, many approaches to estimating odor impact currently incorporate filtering of air to remove particulate matter before sensing by humans or electronic sensors. Accelerated progress in understanding this and other 'real world' odor control problems will require methodological innovations that allow quantification of odor in response to air streams containing vapor and particulate phases.     

Comparison of Microbial Contamination Levels Among Hospital Operating Rooms and Industrial Clean Rooms

Microbial contamination in industrial clean rooms was compared quantitatively and qualitatively with that of hospital operating rooms. The number of aerobic mesophilic microorganisms which accumulated on stainless-steel strips exposed for periods up to 21 weeks to the intramural air of four operating rooms was at least 1 log higher than the accumulation on strips exposed in four clean rooms, and was essentially the same as that found in two factory areas. Volumetric air samplings showed that there were significantly higher numbers of airborne viable particles per cubic foot of air in operating rooms than in industrial clean rooms. In contrast to clean rooms, where most of the airborne contaminants were those associated with human hair, skin, and respiratory tract, the hospital operating rooms showed a very high level of microorganisms associated with dust and soil.     

Mechanical damage to rabbit tracheal epithelium from inhaling inert pyrite dust of needle - like structure. Part I.

The effect of pyrite dust inhalation on the ultrastructure of rabbit tracheal epithelium was studied as a model of mechanic damage of the epithelium from a chemically practically inert aerosol of needle-like structure. Rabbits were eposed to a mean pyrite dust concentration of 49.7 mg/m3 in a solid-aerosol inhalation chamber for intervals of 1/2,2 or 8 h. At each interval, tissue from three animals was examined. Dust particles were found to penetrate gradually into and affect epithelial cells but were not transported further by the cells or phagocytized. Dust particles especially cumulated in the secretory goblet cells. The ciliary border was also deranged and consequently the vital self-cleaning function of the respiratory passages epithelium was impaired.     

Electron microscopic study of the tissue reaction of lungs exposed to quartz dust of varying dispersity

The tissue reaction of the lungs exposed to quartz dust of varying dispersity was studied by light, transmission and scanning electron microscopy. It is suggested that specific clinical manifestations of dust pathology are related to dispersity of silica. The largest quartz-containing dust particles give rise chiefly to the development of dust bronchitis. The most cytotoxic "medium" fractions lead to appearance of nodular forms of silicosis, whereas highly dispersed dust particles of quartz give rise to the development of diffusive sclerotic changes in the lungs.     

近20年来京津冀地区土壤风蚀扬尘颗粒物排放变化

京津冀地区是我国大气污染严重区域,土壤扬尘颗粒物排放变化研究对于改善京津冀地区空气质量具有重要意义。收集2000-2019年京津冀地区气候、土壤、植被覆盖数据,分析近20年来京津冀地区土壤扬尘颗粒物排放变化,揭示其变化的影响因素。结果显示2000-2019年京津冀地区土壤扬尘源总悬浮颗粒物（TSP）排放系数均值为1.79 t km^-2 a^-1,其中PM10占8.99%,PM2.5占0.25%。近20年土壤扬尘源TSP排放系数具有下降趋势,PM10和PM2.5排放系数变化过程与TSP一致。上述变化主要受气候因子变化影响,其次受植被覆盖度影响。分析发现近20年来京津冀地区土壤扬尘源TSP排放系数变化主要受年降水量影响。沧州市、天津市和石家庄市土壤扬尘源TSP、PM10和PM2.5排放系数均值较高,张家口市、保定市和沧州市土壤扬尘源TSP排放量占京津冀地区总量的19.18%、12.98%和11.63%。耕地土壤扬尘排放量最大占京津冀地区总量的59.83%,是抑制土壤扬尘源颗粒物排放的重点关注对象,其次为草地占15.66%。2019年邢台市土壤扬尘源PM10排放占观测值比例最高为12.66%,石家庄市和天津市占比也较高分别为11.09%和10.30%,沧州市和邯郸市占比分别为8.63%和8.02%。上述地区环境管理部门均应关注土壤扬尘源颗粒物排放对空气质量的影响。     

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.     

Circadian rhythm of air-borne bacteria and dust particles in a mouse breeding room

The circadian rhythm of air-borne bacteria and dust particles in a mice breeding room was studied at 1-hour intervals on the first, third and fifth day after accommodation of the animals. The numbers of air-borne bacteria in the room increased day by day after accommodation, and showed a circadian rhythm which went down at about noon and rose with three peaks at about 20:00, 1:00 and 8:00. The numbers of dust particles tended to decrease from day to day, and they showed almost the same circadian rhythm as the air-borne bacteria. Correlations between air-borne bacteria and dust particles were not significant for each particle level on the first day, but were significant for all the particle levels of 0.3, 1, 2, and 5 microns at the third day, and were also significant at particles levels of 0.5 micron or more on the fifth day.     

Allergenic and immunogenic properties of industrial dust of the cotton factory

The results of the determination of the allergenic and immunogenic properties of industrial dust of the cotton factory complex are presented. The antigen of industrial dust consists of, at least, 5 antigenic components. The presence of common antigenic determinants in the antigen of industrial dust and in cotton pollen antigen has been established. The administration of relatively large doses of the allergen according to a shortened schedule has been experimentally shown to enhance the curative effectiveness of specific therapy.     

Lung Changes in Woodworkers

Pathological changes were observed in the lungs of two workers who had been exposed to wood dust for many years. The cause of death in each case was unrelated to the lung condition. The histopathological changes in the lung were: (1) centrilobular fibrosis and emphysema, (2) the presence of intra-alveolar basophilic particles which had excited a histiocytic and foreign body reaction. Special studies of these bodies tended to confirm the suspicion that they were particles of wood dust. Studies have shown that woodworkers are in an environment heavily saturated with wood dust. The present study suggests that the wood dust is inhaled into the alveoli and may lead to changes in the lungs.     

Air-borne dust and its protein in laboratory animal facilities

Atopic individuals who were exposed to dust in animal rooms for a long time were more likely than non-atopics to have animal-related symptoms. Standard skin prick tests were performed using crude antigens from dander and urine, and 75 to 100% of atopic persons had positive skin reactions. It seems that allergens in animal rooms result from air-borne dust and the dust originates in animal urine and dander. The protein content occurs as dust particles both below and above 10 micron in diameter. The dust particles above 10 micron cannot pass through face masks, so half of the dust protein is arrested under the mask, but smaller particles pass through. In order to minimize the symptoms, we need to improve the design of cages, animal rooms, experimental rooms, ventilation systems and other protective equipment.     

The interaction of surface and dust particle size on the pick-up and grooming behaviour of the German cockroachBlattella germanica

The relationship between the particle size of an inert silica dust, its up-take from different surfaces and the grooming behaviour of males, gravid females, and fifth and sixth instar nymphs of the German cockroachBlattella germanica (Dictyoptera: Blattellidae) (L.) was investigated. The normal grooming behaviour of gravid females, nymphs and males differed according to sex and age. The gravid females and nymphs exhibited greater grooming activity than the males, especially of the antennae and the legs. Gravid females, nymphs, and adult males exhibited increased grooming activity after exposure to dust in the size range 0.5–63 μm, but there was no significant difference in grooming behaviour from the control when cockroaches were exposed to dust sizes greater than 70 μm. Antennal grooming by males was greater than leg grooming when exposed to all dust sizes, except size particles ranging 4.5–7.5 μm. A dust pick-up experiment indicated that the average amount of dust transferred toB. germanica is affected by particle size, the porosity of the treated surface, and the sex and age of the cockroaches. Gravid females picked up greater amounts of dust than fifth and sixth instar nymphs, which in turn picked up more dust than males. Silica dust particles (0.5–7.5 μm) were picked up more effectively than larger particle sizes, by all three categories, males, females and fifth and sixth instar nymphs of cockroach on all three test surfaces plastic, ceramic and unpainted plywood. Plywood was the least effective surface for transfer of dust, of all sizes, to males, females and nymphs.     

Electromagnetic fields from mobile phones do not affect the inner auditory system of Sprague-Dawley rats

The auditory system is the first biological structure facing the electromagnetic fields emitted by mobile phones. The aim of this study was to evaluate the cochlear functionality of Sprague-Dawley rats exposed to electromagnetic fields at the typical frequencies of GSM mobile phones (900 and 1800 MHz) by distortion product otoacoustic emissions, which are a well-known indicator of the status of the cochlea's outer hair cells. A population of 48 rats was divided into exposed and sham-exposed groups. Three sets of four loop antennas, one for sham-exposed animals and two for exposed animals, were used for the local exposures. Rats were exposed 2 h/day, 5 days/week for 4 weeks at a local SAR of 2 W/kg in the ear. Distortion product otoacoustic emissions tests were carried out before, during and after the exposure. The analysis of the data shows no statistically significant differences between the audiological signals recorded for the different groups.     

Determination of heavy metals in the fruit of date palm growing at different locations of Riyadh

Exposure of heavy metals to human beings has risen dramatically in the last 50 years. In today’s urban and industrial society, there is no escaping from exposure to toxic chemicals and heavy metals. Humans are more likely to be exposed to heavy metal contamination from the dust that adheres to edible plants than from bioaccumulation. This is because it is very difficult to wash off all the dust particles from the plant material before ingesting them. The objectives of this experiment were to determine the concentrations of lead (Pb) and cadmium (Cd) in washing residues and in the tissues of fruits of date palm growing in 14 sites of Riyadh and also to assess whether the fruits were safe for human consumption. The washing residues and tissue of date palm fruits collected from different sites showed the presence of significant amounts of the Pb and Cd. The concentration of Pb in the dust and fruit tissue increased with increasing anthropogenic sources. Therefore, fruits of date palm might be used as a pollution indicator; it might be recommend that fruits of date palm could be safe for human consumption after washing. The mean concentration of Pb and Cd in all the samples collected from different sites is within the safe limits recommended by FAO/WHO.     

Soil dust as a factor which changes the histochemical picture of the rat lung

White Wistar female rats only once were administered intratracheally a suspension of the soil dust in the physiologic saline. The respirable fraction of the soil dust was used for preparing the suspension of the latter. The experiment was carried out in 2 groups of rats. The animals of the 1st group received the soil dust suspension which was the mixture of the soil samples from 3 different places in Poland, the animals of the 2nd group from 3 other places in Poland. The control animals were once administered the physiologic saline. 9 months after the application of dust, the specimen of the left lung were taken for histochemical examinations. The reactions to the activity of succinic and lactate dehydrogenase, of tetrazole reductase NADP, and of acid phosphatase and ATP-ase were performed. The changes in the activity of the studied respiratory enzymes and the increase of the reaction to the acid phosphatase were observed. The results reveal the disorders of the oxidation-reduction processes and the intensification of the lytic processes in the pulmonary parenchyma of the animals exposed to the action of the soil dust.     

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).     

Abiotic formation of bioorganic compounds in space--preliminary experiments on ground and future exobiology experiments in space.

Simulation experiments on ground have shown that "amino acid precursors", which give amino acids after acid-hydrolysis, can be formed when an ice mixture simulating ice mantles of interstellar dust particles (lSDs) is irradiated with high energy particles or UV light. It is strongly suggested that such bioorganic compounds were delivered by comets for the first biosphere on the Earth. It is of great interest to confirm this hypothesis in actual space conditions, such as in an exposed facility of JEM. Fundamental designs for such exobiology experiments in earth orbit (EEEO) will be discussed.     

Influence of colchicine on pulmonary silicotic fibrogenesis in rats

With an aim to evaluate the antifibrotic action of colchicine in experimental model of pulmonary silicosis, the effect of colchicine on developing and developed pulmonary silicosis induced by quartz was studied in rats in vivo and on alveolar macrophages exposed to quartz particulates in vitro. A progressive increase in wet and dry weight of lungs exposed to quartz dust alone, and quartz dust and colchicine injected orally was investigated. An increase in collagen contents, with lapse in time, in animals exposed intratracheally to quartz dust, or exposed similarly to quartz dust but receiving colchicine simultaneously through oral route was observed. A blindfold evaluation of histological sections of lungs of silicotic animals with or without colchicine administration during development of lesions did not reveal any difference between two groups of silicotic rats. Administration of colchicine for 4 weeks after the lesions were developed neither inhibited nor retarded the laying down of collagen. The studies were extended to investigate the effect of colchicine on quartz-induced alveolar macrophage cytotoxicity. The presence of varying concentrations of colchicine in the culture medium did not significantly alter cytotoxic potential of quartz. The results reveal that colchicine administration during the development of and on developed silicosis does not significantly alter pathogenesis of silicotic lesions. At the cellular level colchicine does not modulate quartz-induced alveolar macrophage cytotoxicity, believed to be a significant event for the onset of pulmonary silicotic fibrogenesis.