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At least 19 recordsLinked to original sources
PubMed2025

Birds of a feather flock together: social context exacerbates the effects of light pollution on circadian disruption.

Artificial light at night (ALAN), a growing pervasive pollutant, disrupts physiological and behavioural rhythms across organisms. Social interactions play a significant role in shaping individual and group biological rhythms, but they are often overlooked in the context of environmental stressors, such as ALAN. We explore how dim ALAN affects zebra finches (Taeniopygia guttata) in social and isolated environments, examining behavioural, physiological and molecular rhythms. We found that social birds under ALAN had an earlier activity onset and greater disruption in hypothalamic and liver circadian gene expression than control or isolated counterparts under ALAN. Additionally, we found that activity onset correlated negatively with hypothalamic bmal1 and cry1 expression in birds exposed to ALAN. Within ALAN-exposed birds, there was a larger disassociation between central and peripheral clock gene expression for social birds than in isolated birds. However, rhythmic melatonin concentrations did not differ among treatment groups. We show that social interactions may exacerbate the effects of ALAN, which highlights the impact of social interactions on circadian regulation at a molecular level and a critical need to consider social contexts in biological studies.

Animals↗
PubMed1992

Mutagenic activity of the leachate of municipal solid waste landfill.

Organic concentrates were recovered using XAD-2/8 resin adsorption from the leachates of municipal solid waste landfills and their mutagenic activities were tested for 8 months using the Ames Salmonella/microsome assay. Highly polluted leachates (COD and BOD > or = 40 mg/l) generally had equal or higher mutagenic activities than lightly polluted leachates (COD and BOD < 40 mg/l). But there was no clear difference in mutagenicity per amount of concentrate between the two leachates. These results suggest that the mutagenic activity of landfill leachate is decided to some degree by the organic concentration in the leachate. The mutagenic activities detected even in lightly polluted leachates were not so low as those of various kind of surface waters ever reported. It is suggested that it is important to investigate the mutagenic activity of the leachate for evaluation of the impact of landfill leachate on the environment.

Adsorption↗
PubMed2024

Microbial diversity and metabolic pathways linked to benzene degradation in petrochemical-polluted groundwater.

The rapid advance in shotgun metagenome sequencing has enabled us to identify uncultivated functional microorganisms in polluted environments. While aerobic petrochemical-degrading pathways have been extensively studied, the anaerobic mechanisms remain less explored. Here, we conducted a study at a petrochemical-polluted groundwater site in Henan Province, Central China. A total of twelve groundwater monitoring wells were installed to collect groundwater samples. Benzene appeared to be the predominant pollutant, detected in 10 out of 12 samples, with concentrations ranging from 1.4&#xa0;&#x3bc;g/L to 5,280&#xa0;&#x3bc;g/L. Due to the low aquifer permeability, pollutant migration occurred slowly, resulting in relatively low benzene concentrations downstream within the heavily polluted area. Deep metagenome sequencing revealed Proteobacteria as the dominant phylum, accounting for over 63&#xa0;% of total abundances. Microbial &#x3b1;-diversity was low in heavily polluted samples, with community compositions substantially differing from those in lightly polluted samples. dmpK encoding the phenol/toluene 2-monooxygenase was detected across all samples, while the dioxygenase bedC1 was not detected, suggesting that aerobic benzene degradation might occur through monooxygenation. Sequence assembly and binning yielded 350 high-quality metagenome-assembled genomes (MAGs), with 30 MAGs harboring functional genes associated with aerobic or anaerobic benzene degradation. About 80&#xa0;% of MAGs harboring functional genes associated with anaerobic benzene degradation remained taxonomically unclassified at the genus level, suggesting that our current database coverage of anaerobic benzene-degrading microorganisms is very limited. Furthermore, two genes integral to anaerobic benzene metabolism, i.e, benzoyl-CoA reductase (bamB) and glutaryl-CoA dehydrogenase (acd), were not annotated by metagenome functional analyses but were identified within the MAGs, signifying the importance of integrating both contig-based and MAG-based approaches. Together, our efforts of functional annotation and metagenome binning generate a robust blueprint of microbial functional potentials in petrochemical-polluted groundwater, which is crucial for designing proficient bioremediation strategies.

Groundwater↗
PubMed1976

Immunoglobulins under the influence of nonspecific factors. III. Immunoglobulins, pertussis antibodies and lysozyme in three child populations exposed to different air pollution.

The levels of IgG, IgA, IgM, lysozyme, agglutinins against B. pertussis and B. parapertussis were followed in the blood serum of 306 children 9--10 years old in 3 areas of Central Bohemian region. In children dwelling in areas with more polluted air significantly higher levels of serum lysozyme and of parapertussis antibodies were found by the t-test. The distribution of these values shows significant differences between more polluted areas in comparison with lower-pollution area also in Kolmogorov-Smirnov test. The average levels of Ig approached statistically critical values but did not reach them, but significant differences in the distribution of values of IgG and IgA were shown by the F-test and chi2-test between lightly and heavily polluted areas. The values of immunological reactions in polluted areas were always higher than in the non-polluted group. This provides evidence for a hypothesis about a stimulatory effect of polluted air on immunological mechanisms in child population. The higher values of IgM observed recently by other authors in women were shown in girls of 9--10 years.

Agglutinins↗
PubMed1976

Morphometric study of trout gills: a light-microscopic method suitable for the evaluation of pollutant action.

1. Methods are described for the morphometric estimation of parameters of the gill system of trout which are relevant to its function in gas exchange. The methods have been used with 1 mum sections viewed under the light microscope. 2. In particular the diffusion distances between water and blood are measured, which together with determinations of gill area, provide figures for the morphometrically estimated diffusing capacity. 3. The methods have been used to compare the diffusing capacity of gills from control fish and those treated in polluted waters. The concept of relative diffusing capacity (Drel) is introduced which enables comparisons to be made without the need to determine the absolute diffusing capacity. 4. Quantitative estimation of changes in relative volumes and surface areas of components of the secondary lamellae were determined, and employed to explain the possible anatomical causes of changes in Drel. 5. It is suggested that these methods can be of value in the comparison of the gills of fish treated in different waters.

Animals↗
PubMed1976

Presence of certain enteroviruses (Coxsackie) in sewage effluents and in river waters of Roumania.

The paper presents the results of research studies conducted during a lo-year period (1962-1971) with the view to detect certain enteroviruses (Coxsackie) from sewage, river and drinking water samples, and from the filter sand of drinking water-works supplied with river water. The method consisted first in preconcentrating the samples collected on immersed gauze pads, secondly in the concentration of the virus samples by the following methods-used either separately or in parallel: the Amberlite method, the yeast cell and the aluminum hydroxide concentration method. The isolation of A and B Coxasackie viruses averaged 29.12% in the sewage samples and 14.66% in the river water samples. Lower values were found both in aqueduct water and in the filter sand (2 positive samples out of 65 and 3 positive samples out of 39, respectively). A seasonal distribution of the viral incidence was evidenced in the sewage samples with lower value in the river water, while the frequency decreased with the distance from the pollution source. For the lightly contamined waters (river and aqueduct waters) the yeast cell concentration method gave the best results, this method being also the single reliable method for Coxsackie virus isolation from the filter sand samples.

Animals↗
PubMed1975

Dust counting. Critical review and presentation of Vermont practice.

Counting respirable dust particles using bright field microscopy has been the classic approach for rapid practical evaluation of the dustiness of workplace atmospheres. The technique has been beset with difficulties arising out of variations in the optical systems and the counting cells used by various laboratories. This papar reviews the history of the technique and some of the problems which have been encountered. It also details the method used by the Vermont Division of Occupational Health for the past 20 years to count dust, describing the easily reproducible optical system and the use of a "thin" hemocytometer cell employed.

Air Pollution↗
PubMed1976

Presence of certain enteroviruses (Coxsackie) in sewage effluents and in river waters of Roumania.

The paper presents the results of research studies conducted during a 10-year period (1962-1971) with the view to detect certain enteroviruses (Coxsackie) from sewage, river and drinking water samples, and from the filter sand of drinking water-works supplied with river water. The method consisted first in preconcentrating the samples collected on immersed gauze pads, secondly in the concentration of the virus samples by the following methods-used either separately or in parallel: the Amberlite method, the yeast cell and the aluminium bydroxide concentration method. The isolation of A and B Coxackie viruses averaged 29.12% in the sewage samples and 14.66% in the river water samples. Lower values were found both in aqueduct water and in the filter sand (2 positive samples out of 65 and 3 positive samples out of 39, respectively). A seasonal distribution of the viral incidence was evidenced in the sewage samples with lower value in the river water, while the frequency decreased with the distance from the pollution source. For the lightly contaminated water (river and aqueduct waters) the yeast cell concentration method gave the best results, this method being also the single reliable method for Coxsackie virus isolation from the filter sand samples.

Enterovirus↗
PubMed1979

Should the concept of the recommended dietary allowance be altered to incorporate interactive effects of ubiquitous pollutants?

Using ascorbic acid as a model, this paper proposes that the concept of the RDA should be broadened to take into account the effects of ubiquitous pollutants on human health, a factor presently not incorporated in RDA derivations. It is now widely accepted that ascorbic acid nutritional status markedly affects the toxicity and/or carcinogenicity of greater than 50 pollutants, many of which are ubiquitous in the air, water, and food environments. At the present time, the data do not warrant changing the ascorbic acid RDA in light of the knowledge of pollutant interactions.

Animals↗
PubMed1992

Photoactivation of 2-nitrofluorene in vitro and in the rat in vivo. UVA-induced formation of reactive intermediates that bind covalently to RNA and protein.

2-Nitrofluorene (2-NF), an environmental pollutant, can be activated by UV light to reactive intermediates that bind covalently to RNA and protein in vitro: high levels of covalent binding were obtained. This covalent binding was not dependent on the presence of oxygen in the solution and could be decreased by glutathione. Hydrolysis of the in vitro modified RNA and subsequent analysis of the liberated bases by HPLC revealed that approximately 15% of the covalent binding of 2-NF to RNA could be attributed to the formation of a guanosine adduct of nitroreduced 2-NF, N-(deoxyguanosin-8-yl)-2-aminofluorene. Many other adducts are formed of which the structure and mechanism of formation are as yet unknown. The possibility of photoactivation of 2-NF in the rat in vivo was also investigated. Photoactivation increased covalent binding of 2-NF in the skin but not in other organs. The mechanism of the photoactivation of 2-NF is discussed.

Animals↗
PubMed1975

Prevalence of respiratory symptoms in towns with different air pollution.

An epidemiologic study was carried out for the estimation of air pollution as a risk factor for chronic obstructive lung disease. The whole male population aged 40 to 60 years was investigated in a polluted and a non-polluted control town. The subjects with occupational exposure to dusts, gases and irritant vapours were discarded from the study. The prevalence of respiratory symptoms and of chronic bronchitis in the polluted town was twice that in the control (non-polluted) one. These results are discussed in the light of some previous investigations of the authors and of the available data in the literature.

Adult↗
PubMed1976

[On the interaction of polycyclic aromatic hydrocarbons and light with regard to its syncarcinogenic effects (author's transl)].

The rapidly growing pollution of the human biosphaere with potentially carcinogenic agents gives increased relevance to questions concerning the interaction of both chemical and physical agents in carcinogenesis. One such combination of environmental agents - that between polycyclic aromatic hydrocarbons and light - which heretofore has received little attention from workers in the field of environmental research, was investigated in the present paper. The phototoxic (cytotoxic) effects of carcinogenic aromatic hydrocarbons was demonstrated using ciliates of the species Tetrahymena pyriformis as the sensitive substrate. The experiments were conducted both with the chemically pure compounds and with native soot containing the adsorbed hydrocarbons. The following results were obtained: 1. Phototoxicity for ciliates of the highly carcinogenic benzo(a)pyrene may still be demonstrated in dilutions containing but 2 ppb (mug/l) of the substance, while the non-carcinogenic benzo(e)pyrene and fluorenthene are only weakly toxic in much higher concentrations. 2. The combination of benzo(a)pyrene and fluoranthene produced neither an additive nor a quenching effect, i.e., the resulting phototoxicity merely reflected the action of benzo(a)pyrene. 3. No phototoxic effect was observed in case of the fluorescent carcinogen, aflatoxin B1, in concentrations up to 200 ppb. This is taken to indicate that the property of fluorescence of carcinogenic substances by itself does not account for the phototoxic phenomenon. 4. The intense phototoxic activity of native soot ingested by the ciliates was shown to be dependent on the amount of polycyclic hydrocarbons contained. 5. Removal of polycyclic aromatic hydrocarbons from the soot particles by extraction with benzene resulted in the loss of phototoxic activity.

Aflatoxins↗