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PubMedDate not supplied

Toxicological investigations in the semiconductor industry: IV. Studies on the subchronic oral toxicity and genotoxicity of vacuum pump oils contaminated by waste products from aluminum plasma etching processes.

Dry etching processes in semiconductor manufacturing use ionized gases in closed reactors at pressures below 1 torr. Vacuum pump systems that service the reaction chambers are potential sources of exposure to complex mixtures of inorganic and organic compounds. These mixtures consist of unused process gases and process by-products that condense and accumulate in the vacuum pump oils. To evaluate potential hazards of dry etch vacuum equipment, a contaminated vacuum pump oil sample from a BCl3/Cl2 etching process was analyzed. The waste oil was administered by gavage for 14 or 28 days to male and female Wistar rats. Neither death nor behavioral changes occurred after subchronic treatment or during a 14-day posttreatment period. Only slight effects on body weights, clinical chemistry, and hematology data were seen in the exposed animals, although the livers of all waste oil-exposed rats of both sexes showed remarkable hypertrophic degenerations. Genotoxicological investigations were performed through the Ames assay (Salmonella assay) and the Micronucleus assay. The contaminated oil sample caused clear genotoxic effects in both test systems.

Administration, Oral↗
PubMed2002

Medical waste production and disposal arising from renal replacement therapy.

The treatment of end stage renal disease (ESRD) makes extensive use of pre-sterilised disposable items that are contaminated by blood or other body fluids following use. Commonly these items are incinerated. Because they contain substantial amounts of polyvinylchloride (PVC), their incineration releases polychlorinated dibenzo p dioxins (PCDD) and polychlorinated di benzo p furans (PCF), as well as heavy metals. A consequence of the release of these substances has been the introduction of legislation controlling waste disposal. These issues are likely to impact on the management of waste at the healthcare facility level. In parallel, new PVC-free materials for use in renal replacement therapies have been developed whose incineration is less controversial environmentally.

Environmental Pollutants↗
PubMed2005

Characterisation of radioactive waste products associated with plant decommissioning.

The inventory of radioactivity that must be considered in the decommissioning of a typical 1000 MWe Spanish pressurised water reactor (PWR) was investigated as part of a generic plant decommissioning study. Analyses based on DORT models (in both R-Z and R-theta geometries) were used with representative plant operating history and core power distribution data in defining the expected neutron environment in regions near the reactor core. The activation analyses were performed by multiplying the DORT scalar fluxes by energy-dependent reaction cross sections (based on ENDF/B-VI data) to generate reaction rates on a per atom basis. The results from the ORIGEN2 computer code were also used for determining the activities associated with certain nuclides where multi-group cross section data were not available. In addition to the bulk material activation of equipment and structures near the reactor, the activated corrosion-product (or 'crud') deposits on system and equipment surfaces were considered. The projected activities associated with these sources were primarily based on plant data and experience from operating PWR plants.

Computer Simulation↗
PubMed1987

Radionuclide content of and 222Rn emanation from building materials made from phosphate industry waste products.

The radionuclide content and 222Rn emanation coefficients of selected construction materials were determined. The materials were analyzed for 226Ra, 228Ra and 40K by gamma-ray spectrometry. Mineral wool insulation, which is made from Tennessee phosphate slag, and commonly used insulation, which is made from blast furnace slag, had similar concentrations of these radionuclides. Concrete blocks made with phosphate slag had enhanced 226Ra and 228Ra contents when compared to ordinary concrete block. The mineral wool insulation materials which were examined had emanation coefficients that were a few (2-6) times 10(-3). All other materials had emanation coefficients that ranged from 6 X 10(-4) to 4 X 10(-2).

Air Pollutants↗
PubMed1998

Urea: diverse functions of a 'waste' product.

1. The urea cycle is essentially the simultaneous operation of two linear pathways, both primitive and widespread among animals; one is for arginine synthesis and the other is for arginine degradation to ornithine and urea. 2. All animals may have the genetic capacity to express a urea cycle and many diverse groups of animals, from flatworms to mammals, have a functional urea cycle. 3. Evolutionary changes in vertebrates of carbamylphosphate synthetase (CPS) are directed from glutamine-dependent (CPSIII) towards NH3-dependent (CPSI) ureagenesis. Invertebrates, cartilagenous fish and the coelacanth have CPSIII (i.e. glutamine-dependent), whereas lungfish, amphibians and amniote vertebrates have CPSI; the teleost Heteropneustes has CPSI-like activity. That the coelacanth has CPSIII and Heteropneustes has 'CPSI' suggests that the form of CPS may by physiologically related (CPSIII in a balancing solute role and CPSI in a terrestrial, air-breathing excretion role) rather than being phylogenetically constrained. 4. Urea is a major balancing osmolyte in marine cartilagenous fish, the coelacanth and a few amphibians and some aestivating terrestrial amphibians. It is a storage osmolyte in cocoon-forming aestivating lungfish and amphibians. 5. Urea contributes towards positive buoyancy in marine cartilagenous fish. 6. Urea functions for non-toxic N transport in ruminant and pseudoruminant mammals. 7. Urea is a major solute in the mammalian (but not avian) kidney, contributing to a renal medullary osmotic gradient; it is substantially reabsorbed by mammalian nephrons. 8. Urea is used as a preferred nitrogenous waste compared with ammonia at high ambient pNH3 or pH, with water restriction, or air breathing. 9. Urea synthesis maintains acid-base balance by the 1:1 stoichiometry of removal of HCO3- and NH4+.

Animals↗
PubMed1985

[Polycyclic aromatic hydrocarbon content of waste products of the coal-tar industry and the mutagenic effect of soot extracts].

The content of 15 polycyclic aromatic hydrocarbons (PAH) in organized and nonorganized effluents of cake- and by-product processes at the Rustavi integrated iron-and-steel works was quantitatively determined by the method of low-temperature spectrofluorescence. Contents of BP and other PAH in nonorganized effluents is 100 and more times higher than those in the organized one and play a decisive role in pollution of the low atmospheric layer. The effluent is characterized by a specific PAH composition and therefore BP may be both a quantitative and a qualitative indicator of PAH. The mutagenic effect was studied by the Ames method with S. typhimurium TA 100 as a test strain. The extracts from soot of nonorganized cake-batlery effluent were studied. Simultaneously the effects of BP, of all PAH in the total and of carcinogenic PAH in concentrations corresponding to the discharge composition were studied. It is shown that BP may be used as an indicator of PAH composition and mutagenic effect.

Chemical Industry↗
PubMed1977

Mutagenicity of waste products from vinyl chloride industries.

The by-product from vinyl chloride production, EDC-tar, is a complex mixture of mainly short-chained chlorinated aliphatic hydrocarbons. This mixture has been tested for mutagenicity by means of Ames' Salmonella/mammalian microsome method. Since most of the components in the tar are poorly soluble in water, three agents were used as solvents or emulsifier: ethanol, DMSO, and Tween 80. The results with all these agents showed that EDC-tar contains direct as well as indirect mutagenic constitutents. It could be concluded that the mutagenic effect observed in the test could not be due to any significant extent to one of the main components, ethylene dichloride (1,2-dichloroethane). This substance showed a weak mutagenic effect, but only at higher concentrations than could be available in the highest concentration tested of the tar. Although the microsomal system enhanced the mutagenicity both of the EDC-tar and of 1,2-dichloroethane, this enhancement was dependent on NADPH in the case of EDC-tar but independent of NADPH with 1,2-dichloroethane. The Salmonella/mammalian microsome method seems to be a suitable tool for both mutagenicity screening of complex chemical mixtures and identification of mutagenic constituents in such mixtures.

Animals↗
PubMed1984

Evidence for the possible function of the fluorescent granular perithelial cells in brain as scavengers of high-molecular-weight waste products.

The fluorescent granular perithelium (FGP) of rats and humans under experimental and pathological conditions was examined with the electron microscope. The FGP incorporated high molecular-weight protein (ferritin) and carbon particles administered intraventricularly. In a case of spontaneous cerebral hemorrhage, the FGP was found to contain lipoidal products and minute fragmented cell debris. The FGP in a patient with lipidosis contained pale inclusion bodies. In aged individuals, the inclusion bodies formed irregular larger aggregates.

Aging↗
PubMed1990

Growth behavior of Chinese hamster ovary cells in a compact loop bioreactor. 2. Effects of medium components and waste products.

Effects of biochemical factors, i.e., medium components and metabolic byproducts, on growth of Chinese hamster ovary (CHO) cells were investigated. Glucose and ammonia were found to inhibit the growth. Kinetic analysis gave the inhibition constants, 0.14 g l-1 for ammonia and 5.0 g l-1 for glucose. Since glutamine was unstable and was a main source of ammonia, precise studies on glutamine degradation and ammonia formation process were done. By evaluating the spontaneous reactions, net glutamine utilization and net ammonia production by the cells could be estimated. It became evident that asparagine could support the growth of CHO cells as a stable substitute for glutamine. Then, a glucose fed-batch culture was grown on a glutamine free and asparagine supplemented medium. Because of (1) low glucose concentration, but (2) no glucose limitation and (3) low ammonia accumulation, the maximum total cell concentration reached 3.4 x 10(6) ml-1, which was 1.8 times greater than that in the control experiment (initial 1.15 g l-1 glucose and 0.29 g l-1 glutamine, and no glucose feed).

Ammonia↗
PubMed1980

Utilization of waste products of dehydrated onion industry for production of fodder yeast by Saccharomyces cerevisiae.

One strain of Saccharomyces cerevisiae was selected from different yeasts, isolated from black strap molasses. This microorganism was cultivated on seven fermentation media for the production of protein. Medium I exhibited the highest potentiality for formation of protein. Therefore strain 1 of S. cerevisiae and medium I were used for further studies in the formation of protein. Factors controlling production of protein were explored. The required incubation period for the fermentation process was 72 hrs, while the initial pH value of the medium was 6.0. Sucrose supported the microorganism for higher production of protein (40.96%), while the best concentration of sucrose was shown to be 10.0 g/l. The best inorganic and organic nitrogen sources for protein formation were (NH4)2HPO4, (NH4)3PO4 and yeast extract, respectively. The best concentrations of (NH4)2HPO4 and yeast extract, supporting protein formation, were 5.0 g/l and 10.0 g/l, respectively. Addition of MgSO4, ZnSO4, ferrous ammonium sulphate, copper sulphate, biotin, Ca-pantothenate, thiamine, pyridoxine, and inositol to the synthetic medium did not markedly influence high level of protein formation. Glutamic acid was the best amino acid, supporting protein formation by S. cerevisiae. Onion juice was found to be a good medium, after deletion of inhibitory volatile sulphur organic compounds, for the production of protein by S. cerevisiae. Addition of (NH4)2HPO4 to the best concentration of onion juice assisted the onion medium in production of fodder yeast, containing high level of protein. Addition of MgSO4 to onion juice and (NH4)2HPO4 did not increase the total nitrogen of the biomass. Fodder yeast, produced by onion juice medium, contained more valuable ingredients than fodder yeast, produced by synthetic medium.

Amino Acids↗