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At least 271 records · Page 15Linked to original sources
PubMed2000

Effect of environmental pollution on the chromosomal variability of Chironomus riparius Meigen 1804 (Diptera, Chironomidae) larvae from two Piedmont stations.

Different frequencies of chromosomal alterations in salivary gland polytene chromosomes AB, CD and EF were described in larvae of Chironomus riparius (syn. Chironomus thummi) from the trace metal-polluted station of Santena on the river Banna, near Turin, and from the unpolluted station of Corio (40 Km from Turin) which was taken as a reference area. In a sample of 56 larvae from Santena, no specimen with the standard karyotype in all cells of the salivary glands was found. Different types of aberrations were found: 33 paracentric and five pericentric inversions, three deficiencies, four amplified sections and one chromatid break. Fifteen out of the 38 inversions and two amplified sections appeared to be inherited, while all the other aberrations were somatic. Most of the aberrations' breakpoints were located on both sides of the centromere regions, where constitutive heterochromatin is present. Also functional alterations were observed (mainly telomere and centromere decondensations and nine novel puffs). In a sample of 49 larvae of a population from the well-preserved area of Corio only six somatic and one inherited paracentric inversions were found. These results suggest that the strong destabilization of the genomes of C. riparius larvae from Santena could be a reaction to the activity of the toxic substances present in the polluted sediments of the river Banna.

Animals↗
PubMed2004

Topological estimation of electronic absorption bands of arene absorption spectra as a tool for modeling their toxicity and environmental pollution.

A novel application of distance-based topological indices : Wiener (W)-, Szeged (Sz)-, Padmakar-Ivan (PI)-, and Sadhana (Sd)-indices in modeling electronic absorption bands of arene absorption spectra has been described. It is demonstrated that all these indices correlate linearly with the logarithm of beta and para electronic absorption bands in several series of arene systems. The results have shown that our methodology is best suited for the estimation--lnlambda(beta), while comparatively less significant results are obtained in case of the estimation of lnlambda(p). The statistical analysis of the data have shown that PI index gives better results for modeling lnlambda(beta); while Sz index proved better for modeling lnlambda(p). The results are critically discussed on the basis of regression parameters and quality of correlation. Such a study will be useful as a tool for modeling toxicity of arene system as well as their environmental pollution.

Electrochemistry↗
PubMed2003

Reducing environmental pollution using animal feed enzymes.

The global livestock population is estimated to be close to 4 billion animals, and to produce around 500 million tons of manure annually (Baidoo, 2003). This is expected to increase in the future with the projected greater demand for meat for human consumption. The problem of manure disposal is exacerbated by the concentration of animal production in increasingly large units, to obtain economies of scale and keep up with the demand for cheap food. The primary environmentalfactors are manure volume, manure nitrogen and phosphorus contents, methane production and odour (Jongbloed and Lenis, 1998). Legislation in many regions now restricts the amount of manure that can be applied per hectare, to prevent environmental pollution (Centner, 2001; Pellini and Morris, 2001). There are a number of strategies the animal production industry can take to reduce environmental impact. These include taking steps to improve the efficiency of conversion of feed into edible products, reduce feed wastage and formulate diets that more closely satisfy animal requirements for specific nutrients. At present 50-80% of the nitrogen and phosphorus fed to animals are not utilized but are excreted via manure and urine to the environment (Baidoo, 2003). Biotechnology could play a very important role in reducing the environmental impact of animal production. Examples include the development of animals more efficient at converting nutrients into edible products, and of higher quality, more digestible feedstuffs. Biotechnology can also be used to produce a range of feed additives that can improve the efficiency of animal production, including for example recombinant somatrophin, amino acids and enzymes. This paper summarizes a series of four experiments looking at the effects of microbial xylanase or phytase supplementation on excretion in swine and poultry. This summary indicates that the inclusion of these enzymes in animal feeds can reduce manure volume by up to 14%, and nitrogen and phosphorus outputs by up to 13% and 70%, respectively.

6-Phytase↗
PubMed1995

Monitoring environmental pollution in Poland by chemical analysis of Scots pine (Pinus sylvestris L.) needles.

Maps of the distribution of environmental pollution by sulfur (S), zinc (Zn), cadmium (Cd), lead (Pb), copper (Cu), and arsenic (As) for the territory of Poland and the Warsaw (Warszawa) district were developed on the basis of chemical analysis of Scots pine (Pinus sylvestris L.) needles collected from randomly selected sampling points during 1983-1985. The maps show deposition zones for the studied elements and can help in identification of sources and directions of air pollution dispersion. This study indicated that vegetation in Poland is greatly endangered by sulfur dioxide (SO(2)) and other sulfurous air pollutants, whereas Zn, Cd, Pb, and As do not pose an immediate threat to vegetation in most of the country's territory. However, in the urban-industrial agglomeration of Katowice-Cracow, very high pollution with Z, Cd, Pb and As could limit growth and development of some sensitive plant species. Higher than normal levels of As in some areas of Poland (Upper Silesia, Glogow-Lubin Copper Region, and areas close to the Russian border near Braniewo) might affect the health of humans and animals. Results of this study indicated that Poland's environment was not contaminated with Cu.

Journal Article↗
PubMed1980

Interaction between environmental pollutants and respiratory infections.

The major aspects that must be considered in studies of the health effects of environmental pollutants are: the direct damage due to the exposure, the role of pre-existing disease, and effects of the exposure on the response to secondary stresses. In experimental studies at concentrations of air pollutants found in urban environments frank toxicological responses are rarely observed. However, exposure to a secondary stress, i.e. respiratory challenge with infectious bacteria, can exacerbate the response of the experimental host. Changes in the resistance to respiratory infections provide a highly sensitive experimental animal model system, which is increasingly used in studies of health effects of air pollutants. This model indicates the impairment of the basic defense mechanisms of the respiratory system by the combined exposure to low concentrations of pollutants and the superimposed bacterial infection. Changes in the resistance to respiratory infections were studied in various species of laboratory animals. S. pyogenes and K. pneumoniae are the bacteria of choice to induce the pulmonary infection. Included in the studies are short-term single and multiple exposures as well as long-term exposures to gaseous pollutants such as O3 and NO2 and particulate pollutants such as sulfates and nitrates. Changes in the resistance are measured as excess mortalities and reduced survival time as compared to those in infected animals not exposed to the pollutants. Other parameters measured ranged from changes in the immune response to changes in retention rates of bacteria in lungs.

Aerosols↗
PubMed2004

[Content of fluoride in hair and hoofs of wild boars and deer from Western Pomerania as a bioindicator of environmental pollution].

The aim of this study was to assess the fluoride content in hair and hoofs of wild boars and deer from Western Pomerania (Poland). Fluoride content was determined with the Orion 96-09 fluoroselective electrode. The highest content of fluoride (13.39 microg/g d.m.) was found in hair of wild boars from the city of Stargard Szczeciński. The lowest fluoride content was in the control group of boars from the city of Pyrzyce (8.41 microg/g d.m.) and Myślibórz (6.11 microg/g d.m.). It was concluded that biomonitoring of fluoride accumulation in hair and hoofs may be useful for the assessment of environmental pollution with fluorine compounds.

Animals↗
PubMed1999

Approaches to assessing combination effects of oestrogenic environmental pollutants.

Concerns about possible combination effects of environmental chemicals with estrogenic activity have motivated the search for synergisms between such agents. However, much published work has taken no account of the concepts and methods for analysing combination effects, which were developed in toxicology and pharmacology. In the present communication, we draw attention to conceptual frameworks relevant for a sound analysis of the effects of mixtures of oestrogenic compounds. A model calculation is presented demonstrating that it is conceivable that weakly oestrogenic compounds may be able to act together to produce significant effects, even when they are present at concentrations below their individual effect thresholds. Our results suggest that it may not be necessary to invoke synergisms in order to explain the discrepancy between the high concentrations of these agents required to produce effects in in vitro assay systems and their low concentrations in the environment.

Animals↗
PubMedDate not supplied

Effects of environmental pollutants on airways, allergic inflammation, and the immune response.

Particulate and gaseous air pollutants are capable of damaging the airway epithelial lining and of shifting the local immune balance, thereby facilitating the induction of persistent inflammation. Epidemiological studies are inconclusive regarding whether air pollution increases the incidence of asthma and chronic bronchitis in the population. Clearly, environmental pollution can, however, precipitate attacks and emergency-room admissions in those already suffering from such conditions. The catastrophic potential of airborne pollution was demonstrated in the 1960s and 1970s, when inverted atmospheric pressure conditions trapped smog over cities on the Eastern coast of the United States and over Europe. This smog resulted in thousands of hospital admissions and dozens of deaths. With the general rise in the incidence of atopy and asthma in the Western population, it is of major public health interest to reduce, as much as possible, the exposure of such populations to anthropogenic and natural sources of pollution.

Acrolein↗
PubMed2006

Environmental pollutants in gallbladder carcinogenesis.

Gallbladder cancer is a common malignancy of the gastrointestinal tract that shows wide geographical variation in its distribution. Cause of gallbladder cancer is still obscure; however, various etiological factors have been proposed. Of these gallstones and inflammation of the gallbladder is commonest. Despite three decades of active research no conclusive evidence is available as to what causes gallbladder cancer? In this article we reviewed the evidence on the role of environmental pollutants on gallbladder carcinogenesis. A detailed search of Medline was carried out which revealed only 12 articles. A number of heavy metals like nickel, cadmium, etc. have been implicated; however, the evidence is not robust enough to conclude its association. Role of radiation and pesticides in river water have also been evaluated without any conclusive evidence of its association with gallbladder cancer. Better designed case-control studies or cohort studies looking at exposure are required before it could be accepted as one of the causes of GBC.

Cadmium↗
PubMed2002

Metabolism of 2-nitrofluorene, an environmental pollutant, by liver preparations of sea bream, Pagrus major.

1. The in vitro metabolism of 2-nitrofluorene (NF), an environmental pollutant, was examined in fish, focusing on nitro-reduction followed by N-acylation and hydroxylation. 2. When NF was incubated with liver microsomes or cytosol of sea bream, Pagrus major, in the presence of NADPH or 2-hydroxypyrimidine, 2-aminofluorene (AF) was formed. 3. When AF was incubated with liver cytosol in the presence of acetyl-CoA or N-formyl-L-kynurenine, 2-acetylaminofluorene (AAF) or 2-formylaminofluorene (FAF) was formed, respectively. AAF and FAF thus formed were deacylated to the parent AF by the liver preparations. 4. AF, AAF and FAF were oxidized to 7-hydroxy or 5-hydroxy derivatives by the liver microsomes. 5. Nitro-reduction, N-acylation and ring-hydroxylation of NF and the metabolites were also observed in rat liver preparations. These activities in sea bream livers were lower than those of rat liver. However, the order of magnitude of these activities in fish was the same as in rat. 6. It is suggested that NF is effectively reduced to AF by the cytochrome P450 system or aldehyde oxidase, and the acylated metabolites, AAF and FAF, generated by arylamine acetyltransferase and formamidase were hydroxylated by the cytochrome P450 system in fish in the same way as in rat. Further, the acetylamino and formylamino derivatives were interconverted via amino derivatives in the fish.

Air Pollutants↗
PubMed2004

Factors affecting the sorption of model environmental pollutants onto silver polydimethylsiloxane nanocomposite Raman substrates.

The presence of aromatic compounds in water is an important topic in environmental sciences. Silver-polydimethylsiloxane nanocomposites (Ag-PDMS) have recently been demonstrated as promising substrates for the detection of model environmental pollutants via surface-enhanced Raman spectroscopy (SERS). This work discusses how different variables such as pH and matrix composition can affect the sorption and SERS activity of these chemicals. The results show that the conjugate base of weak acids can interact more efficiently with the substrate, leading to an increased signal at higher pH, while amino-aromatic compounds interact more efficiently at a lower pH. The sorption of these chemicals is an essential step in the process and has been attributed to the absorption of the analyte into the PDMS followed by its adsorption to the metallic surface. In addition, the presence of moderate concentrations (1 x 10(-4) M) of a supporting electrolyte such as nitrate or fluoride can improve the sorption of 4-hydroxybenzoic acid to the Ag-PDMS nanoparticles. Other ions such as phosphate and chloride cause rapid oxidation of the substrates even at concentrations as low as 1 x 10(-5) M. The effect of these variables in the analysis of real samples is presented. The potential use of liquid chromatography for isolating the model pollutants from detrimental matrix components in nat- ural waters is also shown.

Adsorption↗
PubMed1993

Development of screening tests for aneuploidy induction by environmental pollutants.

When legally required mutagenicity testing of chemicals is undertaken, the important genetic end point of aneuploidy is not included because validated test methods are lacking. Therefore, the Commission of the European Communities (CEC) has funded a research program to develop and validate tests for aneuploidy induction. Ten chemicals, selected on the basis of their ability to interact with cell organelles relevant for aneuploidy induction, were tested in 11 laboratories. The assays ranged from in vitro tubulin assembly studies to in vivo germ-cell tests. The results allow several conclusions: a) Fungal aneuploidy tests are not capable of detecting inhibitors of mammalian tubulin polymerization such as colchicine and vinblastine. Therefore, they will not play a role in screening for aneuploidy but are of value for studying the relationship between induced aneuploidy and recombination. b) Chemicals that induce aneuploidy in mammalian germ cells are readily detected in the in vitro mammalian cell systems. Some chemicals such as thiabendazole and thimerosal induce aneuploidy in vitro but do not appear to be very effective in vivo. c) Cell division aberrations induced in mammalian cells in vitro seem to be predictive for aneuploidy induction in the same cell type. Likewise, c-mitotic effects and cell cycle delay in vivo in mitotic and meiotic cells correlate with aneuploidy induction in the respective tissue. A second CEC Aneuploidy Program has started recently to refine the most promising test protocols, to provide understanding of variety of mechanisms by which chemicals induce aneuploidy, and to establish a data base for aneugens among environmental pollutants.

Aneuploidy↗
PubMed1993

[Cytogenetic examinations in biomonitoring residents residing closest to the area near the Sendzimir metallurgy plant in Krakow exposed to environmental pollution].

There are many studies done to identify the genetic hazard from occupational exposure of workers, but rather little is known about genetic effects in inhabitants of polluted areas. The aim of the study was to examine chromosome aberrations, sister chromatid exchanges and number of micronuclei in lymphocytes of persons living in the close vicinity of a large metallurgical plant. The results were compared with those obtained for the inhabitants of a village located 40 km from the city of Cracow and from the plant. An increased incidence of chromosome aberrations (0.66-4.66%, control 0.78%), sister chromatid exchanges (mean 9.73, control: 6.0) was found in the group living near the steel foundry. The paper also includes some data on measurements of the air pollution in the Nowa Huta region as well as on the amounts of heavy metals in vegetables in this region. Environmental pollution is worsening.

Aged↗
PubMedDate not supplied

[The erosion of asbestos cement roofs: an important source of environmental pollution].

A microscopic investigation on samples of asbestos cement roofs weathered from 2 months to 15 years or more was carried out. Surface alterations begin as early as 2 months, are well visible after a few years and become very severe after 5-10 years. The deterioration of the cement structure, due mainly to the chemical attack of the acid rains produces a release of fibres that is more evident with increasing duration of the exposure. The surface of the "old" roofs must be considered as important source of environmental pollution, that increases the total carcinogenic potential of the polluted atmosphere in a non-negligible way, considering also the enormous extension of the surfaces. Instead of replacing the roofs, adequate primers and sealants can be applied after careful preparatory cleaning: gross contamination of water and/or surrounding areas must be avoided by appropriate work procedures. The deteriorated materials containing amphiboles must be considered with priority.

Asbestos↗
PubMed2000

Roe deer antlers as monitoring units for assessing temporal changes in environmental pollution by fluoride and lead in a German forest area over a 67-year period.

Fluoride and lead concentrations were analyzed in antlers of adult roe bucks (Capreolus capreolus) collected between 1932 and 1998 in a forest area of 800 ha, that directly borders on the eastern suburbs of Cologne (Germany). Values ranged between 158 and 3,713 mg/kg dry weight for fluoride and from 0.4 to 12.0 mg/kg dry weight for lead, and varied significantly between periods (1932-49, 1950-59, 1960-69, 1970-79, 1980-89, 1990-98). Antler bone levels of both contaminants decreased markedly during the 1980s and 1990s. As a consequence, mean fluoride and lead concentrations in antlers collected in the 1990s were significantly lower than those from all preceding periods. These findings indicate a pronounced decline in fluoride and lead pollution of the study area, which is attributed to reduced emissions from stationary sources and, in the case of lead, to the introduction of unleaded gasoline and the subsequent phasing out of leaded gasoline in Germany. Because antlers are replaced annually, grow during a seasonally fixed period of some months, and are regularly collected and kept by hunters, they are useful monitoring units for recording past and present environmental pollution by "bone-seeking" pollutants in a cost-effective way. Due to its relative abundance and its rather narrow home range, the roe deer is well suited as a monitoring species for assessing changes in ambient contaminant levels on a local scale.

Animals↗
PubMed1995

The improved Allium/Vicia root tip micronucleus assay for clastogenicity of environmental pollutants.

The meristematic mitotic cells of plant roots are appropriate and efficient cytogenetic materials for the detection of clastogenicity of environmental pollutants, especially for in situ monitoring of water contaminants. Among several cytological endpoints in these fast dividing cells, such as chromosome/chromatid aberrations, sister-chromatid exchanges and micronuclei, the most effective and simplest indicator of cytological damage is micronucleus formation. Although the Allium cepa and Vicia faba root meristem micronucleus assays (Allium/Vicia root MCN) have been used in clastogenicity studies about 12 times by various authors in the last 25 years, there is no report on the comparison of the efficiency of these two plant systems and in different cell populations (meristem and F1) of the root tip as well as under adequate recovery duration. In order to maximize the efficiency of these bioassays, the current study was designed to compare the Allium and the Vicia root MCN assays on the basis of chromosome length, peak sensitivity of the mitotic cells, and the regions of the root tip where the MCN are formed. The total length of the 2n complement of Allium chromosomes is 14.4 microns and the total length of the 2n complement of Vicia is 9.32 microns. The peak sensitivity determined by serial fixation at 12-h intervals after 100 R of X-irradiation is 44 h. The slope of the X-ray dose-response curve of Allium roots derived from the meristematic regions was lower than that derived from cells in the F1 region. Higher efficiency was also demonstrated when the MCN frequencies were scored from the F1 cells in both Allium and Vicia treated with formaldehyde (FA), mitomycin C (MMC), and maleic hydrazide (MH). The results indicated that scoring of MCN frequencies from the F1 cell region of the root tip was more efficient than scoring from the meristematic region. The X-ray linear regression dose-response curves were established in both Allium and Vicia cell systems and the coefficients of correlations, slope values were used to verify the reliability and efficiency of these two plant cell systems. Based on the dose-response slope value of 0.894 for Allium and 0.643 for Vicia, the Allium root MCN was a more efficient test system. The greater sensitivity of the Allium roots is probably due to the greater total length of the diploid complement and the higher number of metacentric chromosomes.(ABSTRACT TRUNCATED AT 400 WORDS)

Allium↗
PubMed1998

Public health in central and eastern Europe and the role of environmental pollution.

The central and eastern European countries that composed the former Eastern Bloc have experienced an alarming decline in public health since the dissolution of the Soviet Union. Death rates have increased in most age groups. Life expectancy, especially among males, has decreased in many countries; in Russia, male life expectancy dropped by six years between 1989 and 1994. By 2020, these countries are projected to have smaller increases in life expectancy than any other geographic region. The conditions responsible for the excess mortality are cardiovascular disease, cancer, and injuries among adults. The major factors in the sharp increase are poverty, social disintegration, and crime, overlaid on historically high rates of smoking, alcohol use, and psychosocial stress. Environmental pollution, although common and sometimes severe in the former Eastern Bloc, is another, albeit not the chief, cause of the sharp decline in public health since 1989.

Environmental Pollution↗
PubMedDate not supplied

[The use of nucleolar morphological characteristics of birch seedlings for the assessment of environmental pollution].

Micronucleus frequency in buccal mucosa from the oral cavity of children as well as nucleolar structural characteristics (surface area of single nucleoli as well as their number and type) in the root meristem of seed progeny of birch (Betula pendula Roth) were studied in some districts of Voronezh City and Voronezh Region (Novovoronezh Town, Zemlyansk Village). Similar trends of changes in cytogenetic parameters have been revealed for both subjects. Regression analysis allowed us to generate an equation relating the cytogenetic parameters of birch seed progeny (surface area of single nucleoli) and humans (frequency of micronuclei in buccal mucosa of children). This study can be considered as a result of cytogenetic monitoring of environmental pollution in some areas of Voronezh City and Voronezh Region.

Betula↗