PubMed HealthSearch

SEARCH · PubMed Health

Results for “Environmental pollution”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources

[Salmonella typhimurium--test system for detecting the mutagenic activity of environmental pollutants. II. Mutagenic effect of heavy metal salts in an in vitro system with metabolic activation].

Mutagenic effect of zinc chloride on Salmonella typhimurium strain was detected using in vitro metabolic activation system. Cadmium chloride showed no significant mutagenic activity in the same system. It is recommended to use both in vitro and in vivo metabolic activation systems in mutagenicity testing of chemicals.

Animals

Microbial catabolism, the carbon cycle and environmental pollution.

The establishment of a carbon cycle was a necessary prerequisite for the evolution of higher forms of life. This could not have been achieved without the direct participation of oxygen gas in certain metabolic reactions. The controlled activation of oxygen is catalyzed by microbial oxygenases; in principle, activated oxygen is hazardous to all living forms but without it, the degradative segment of the carbon cycle could not operate. The degradation of aromatic compounds is not an esoteric activity of a few specialized microorganisms. It occurs continuously, accompanied by fixation and cycling of oxygen on a massive scale; but like other global biochemical processes it tends to be neglected in general biological curricula. However, knowledge of the scope and limitations of microbial catabolic enzymes is central to the development of rational approaches to many of society's environmental concerns.

Acinetobacter

[Salmonella typhimurium as a test system for detecting the mutagenic activity of environmental pollutants. I. The mutagenic action of heavy metal salts in in vivo and in vitro systems without metabolic activation].

The work presents the data on mutagenic effects of heavy metal salts (Zn and Cd) on Salmonella typhimurium test strains using mutagenicity test in vitro without metabolic activation and host-mediated assay. The techniques used enabled to determine also the types of mutations arising from the exposure to ZnCl2 and CdCl2.

Animals

CHEMFILE: an in-house information system for the chemical indexing of Abstracts on Health Effects of Environmental Pollutants (HEEP).

The inclusion of a Chemical Abstracts Service (CAS) Registry Number index in HEEP has led to the need for a special database designed to link substance names with their appropriate CAS chemical compound Registry Numbers. Begun in 1968 as a tape record with batch mode updates and few record modification capabilities, the information system, which we call CHEMFILE, has evolved to its current form of disk storage with on-line access for file maintenance.

Abstracting and Indexing

[Relationship between environmental pollution and genetic monitoring of human populations].

The basis of genetic monitoring is the knowledge of laws of the spontaneous mutation process. These laws are determined for human chromosome and genome mutations by cytogenetic examination of newborns, infants with congenital defects, and the material of spontaneous abortions. Confidence intervals and all the necessary sample sizes were calculated when registering the mutagenic effects of different intensity in the general population as well as to the groups of closer contact with mutagens. Such calculations were made for controlling the spontaneous mutation process in lymphocytes of human peripheral blood on the basis of registering chromosome aberrations.

Abortion, Spontaneous

Variation of corneal glycosaminoglycan values of hares in relation to environmental pollution by industrial emissions.

In localities contaminated by industrial emissions a significant decrease in keratan sulfate and chondroitin 4-sulfate occurs in the cornea of the hare. The changes also occur in hares living near small emission sources with a local emission zone; therefore they should not be neglected, especially if the area is used for recreation, as in the case reported here. The decrease in glycosaminoglycan values is more pronounced in adults than in juveniles, because of the length of exposure. Relatively large amounts of keratan sulfate in the glycosaminoglycan fraction correspond to changes expected in a prematurely senescent tissue. Because of the painstaking laboratory work required, assessment of glycosaminoglycans could be used for special bioindication purposes but would not be suitable for routine monitoring.

Animals

The regulative role of food consumption in the induction of rat liver cell proliferation by drugs and environmental pollutants.

alpha-hexachlorocyclohexane (alpha-HCH) was used to stimulate cell proliferation in rat liver. Food consumption at two different stages of the replicative cycle was found to be required for the enhancement of DNA synthesis by this agent: (1) Before or at the time of alpha-HCH administration (G0), (2) 12--15 hours later, i.e. 5--8 hours before initiation of DNA synthesis ("R"-point). Other alpha-HCH mediated changes in the liver i.e. organ enlargement and the induction of drug-metabolising enzymes, remained unaffected by the absence of food. This suggests that the nutritional control is specific for induction of DNA synthesis. It is concluded that food consumption, in addition to specific stimuli of liver growth, is an exogenous regulator of liver cell proliferation.

Animals

Polychlorinated terphenyls as an environmental pollutant in Japan.

This paper summarizes the results of the studies made by our group and other investigators in Japan on the residue levels of polychlorinated terphenyls (PCTs) in a variety of items in the environment including the human body. In contrast to widespread distribution of PCBs in the environment, PCT residues were seldom found in samples from aquatic environments such as water and sludge and waterfowl and fish, and, if found, the levels of PCTs were so low as to be practically negligible. Similarly, no significant levels of PCTs were detectable in foodstuffs such as edible oils, vegetables, dairy products and meat and in prepared diets. These findings may be explained by the fact that PCTs are much less volatile and soluble than PCBs and the total industrial output of PCTs was as small as 2700 tonnes which is 1/20 of PCBs produced in Japan. However, the levels of PCTs in human fat and blood were shown to be almost equivalent to PCBs, despite a negligible amount of PCTs being found in food. No clear explanation of human contamination by PCTs has been proposed so far.

Adipose Tissue

[Nutritive antibiotic additives in animal feeding stuffs--a further form of environmental pollution (author's transl)].

Feeding domestic animals with mycelia, a by-product of vitamine production, gave rise to the side effect of markedly improved utilization of the fodder. This effect is not due to the vitamine and protein content but to the antibiotic content of this waste product. The nutritive effect was brought about by a larger number of different antibiotics in concentrations which were considerably lower than the therapeutically required doses. Therefore we speak, in this connection, of a nutritive addition of antibiotics to animal fodder. Since at the time of introducing this feeding method only the mutational resistance to antibiotics of pathogens was known and since the nutritive dosaging cannot select such therapeutically relevant degrees of resistance of the germs, no importance was attached to the development of the resistance and its effect on human medicine. However, during the last decade it has been found that the feeding of antibiotics is indeed capable of selecting the plasmidic resistance to antibiotics of the gram-negative intestinal bacteria in the faeces of the animals. For pigs, calves and hens--to quote only the most important animals--now contain a coliflora almost completely studded with R-factors. Owing to the transmissibility of the plasmids and the epidemiologically short path from animal to man, dangers emerge for the human medicine from this nutritive selection. Therefore the use of all antibiotics which select resistance plasmids, should be avoided in animal feed stuffs. It would be best, if antibiotics used in human medicine were not used in veterinary practice.

Animal Feed