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[Ecoefficiency: a tool to reduce solid waste production and waste of materials in health care units].

The main goal of health care units is patient care. During this process, water, energy, and different materials are used, generating liquid effluents and solid waste that require adequate treatment. Although medical waste management demands increasing attention by health care units, reduction in the generation of medical solid waste has still not been set as a priority. Using ecoefficiency techniques, it is possible to demonstrate whether a company is meeting it standards for quality, procedures, environmental control, and economic efficiency. Therefore, ecoefficient companies realize both economic and environmental benefits through progressive reduction in solid waste, liquid effluents, and air emissions. This new concept requires further dissemination among health care units, since many are making efforts to improve quality of services, but still overlook the issue of waste and generate an increasing amount of solid waste. This leads not only to waste of raw materials but also additional costs for proper waste management.

Efficiency, Organizational↗

The waste-product theory of aging: simulation of metabolic waste production.

A mathematical model of cellular metabolism is used to relate the rates of cell division and waste production to the concentrations of oxygen and glucose in the medium in which a normal diploid cell culture is grown. The metabolic model in tandem with an earlier waste-content model based on the waste-product theory of aging provides a unified cell-culture model with which population size and intracellular waste content can be calculated. Population size is measured by the number of population doublings which have been achieved. After suitable adjustment of parameters in the metabolic model, maximum values of population size are calculated numerically with the use of the unified model. Results show that the population maxima are related in a plausible way to the oxygen and glucose concentrations. The effects of temperature changes and contact inhibition of growth are also simulated. Small changes in the cell-division and waste-production rates can cause transformation to unlimited growth in the waste-content model, but the unified model is not correspondingly sensitive to changes in the oxygen and glucose concentrations or to changes in temperature.

Cell Division↗

[The development of a nutrient medium for nisin-producing streptococci utilizing the waste products from a number of biotechnology plants].

The possibility of using some waste products of the dairy and agricultural industries as nutrient substrates for the cultivation of nisin-producing streptococci was studied. Yeast production wastes as well as potato liquor, whey and dried whey as waste products were shown suitable for the growth of Streptococcus lactis and the biosynthesis of nisin. The level of the nisin production increased when corn steep liquor and glucose were added to whey and dried whey respectively.

Biotechnology↗

The waste-product theory of aging: waste dilution by cell division.

When cells divide, the quantity of waste material per cell decreases because the wastes are "diluted" by apportionment between the daughters which result from the division. The quantity of waste present in a symmetrically or asymmetrically dividing population of cells is governed by a first-order non-linear differential equation. In the derivation of the equation, it is assumed (a) that waste is created at a rate which is either constant or proportional to the amount of waste already formed, (b) that waste is neither destroyed nor transported across cell walls, and (c) that the rate of cell division at large values of time is inversely proportional to the amount of waste per cell raised to a power. Relations among the parameters of the differential equation specify conditions under which its solutions rise to a critical value. If the amount of waste per cell given by a solution of the differential equation exceeds this value, it is assumed that deleterious effects become evident and that cell death follows. Decreases in the cell division rate leading to a cessation of population growth may occur at lower levels of waste accumulation.

Cell Division↗

Consumption and production waste: another externality of tobacco use.

OBJECTIVE: To describe the waste produced by and environmental implications of individual cigarette consumption (filter tips, packages, and cartons) and tobacco manufacturing. STUDY SELECTION: All available articles and reports published since 1970 related to cigarette consumption and production waste were reviewed. DATA SOURCES: Global cigarette consumption data were used to estimate cigarette butt and packaging waste quantities. Data from the Center for Marine Conservation's International Coastal Cleanup Project were used to describe some environmental impacts of tobacco-related trash. Data from the United States Environmental Protection Agency's (EPA's) Toxics Release Inventory and reported global cigarette consumption totals were used to estimate waste production from cigarette manufacturing. DATA EXTRACTION AND SYNTHESIS: In 1995, an estimated 5.535 trillion cigarettes (27,675 million cartons and 276,753 million packages) were sold by the tobacco industry globally. Some of the wastes from these products were properly deposited, but a large amount of tobacco consumption waste ends up in the environment. Some is recovered during environmental clean-up days. For the past eight years (1990-1997), cigarette butts have been the leading item found during the International Coastal Cleanup Project; they accounted for 19.1% of all items collected in 1997. The tobacco manufacturing process produces liquid, solid, and airborne waste. Among those wastes, some materials, including nicotine, are designated by the EPA as Toxics Release Inventory (TRI) chemicals. These are possible environmental health hazards. In 1995, the global tobacco industry produced an estimated 2262 million kilograms of manufacturing waste and 209 million kilograms of chemical waste. In addition, total nicotine waste produced in the manufacture of reduced nicotine cigarettes was estimated at 300 million kilograms. CONCLUSIONS: Laws against littering relative to cigarette butts could be better enforced. Additional taxes might be levied on cigarette products that would then be directed to environmental clean-up efforts. The tobacco industry should improve the biodegradability of filters, reduce packaging waste, and educate its customers. Worksites and public buildings should be encouraged or required to supply appropriate disposal mechanisms at all building entrances. Public awareness campaigns about the magnitude and prevention of cigarette consumption waste could be developed through partnerships among environmental groups, health organisations, and environmental protection agencies. Tobacco production waste should be a source of concern and regulation by governments throughout the world; it contains numerous chemicals which may be considered health hazards, not the least of which is nicotine produced in the manufacture of low-nicotine cigarettes.

Environmental Monitoring↗

The waste-product theory of aging: cell division rate as a function of waste volume.

The rate of cell division is calculated as a function of waste product volume in U-787CG human diploid glial cells grown in vitro. The calculation is based on two earlier mathematical models. One is a compartmental analysis in which cell division rate is obtained from data on the fraction of cells which become sterile as the passage level increases. A second model is used to calculate the amount of waste per cell from the observed rate of waste accumulation in a non-dividing population and from the division rate calculated with the use of the first model. Results from the two models are correlated to obtain the desired function relating cell division rate to waste volume. If cellular aging is taken to mean loss of the ability of cells to divide, and if, as in the waste-product theory, this loss is attributed to waste accumulation, the calculated results show that aging is evident at waste levels well below those at which non-dividing populations can survive. Thus the process of cell division may be much more sensitive to waste accumulation than other cellular processes needed for the maintenance of life.

Aging↗

Utilizing waste products from the food production and processing industries.

Waste in the food industry is characterized by a high ratio of product-specific waste. Not only does this mean that the generation of this waste is unavoidable, but also that the amount and kind of waste produced, which consists primarily of the organic residue of processed raw materials, can scarcely be altered if the quality of the finished product is to remain consistent. The utilization and disposal of product-specific waste is difficult, due to its inadequate biological stability, potentially pathogenic nature, high water content, potential for rapid autoxidation, and high level of enzymatic activity. The diverse types of waste generated by various branches of the food industry can be quantified based on each branches' respective level of production. Moreover; the origins of each type of waste and a tabulated overview of the traditional agricultural methods for reusing the waste are discussed. Additionally, alternative methods of waste management have emerged, which target the most important contents of the waste. In conclusion, new possibilities for the utilization of food industry waste are described.

Conservation of Natural Resources↗

The waste-product theory of aging: transformation to unlimited growth in cell cultures.

A differential equation governing intracellular waste content is solved numerically to determine the circumstances under which the growth of an in vitro cell population is limited. Parameter values derived from data on human glial cell cultures are employed. It is assumed that a) waste accumulation depresses the rate of cellular reproduction and b) intracellular waste is diluted by cell division, but is not otherwise eliminated. Population size depends upon two parameters: the rate of waste production and the rate of cell division in the absence of waste. If the rate of waste production is sufficient, the population size approaches an asymptote as in phase III growth in vitro. If a lower rate of waste production allows the cells to outmultiply the waste, growth is unlimited as in a transformed cell population. The asymptotic population size and the threshold for unlimited growth are remarkably sensitive to small changes in the values of the two rate parameters unless the ratio of their values is constant. This suggests that there may be a cellular mechanism that relates the waste production and cell division rates.

Aging↗

Genotoxicity assessment of waste products of aluminum plasma etching with the SOS chromotest.

We evaluated 36 characteristic waste products from the plasma etching of aluminum for genotoxicity with the SOS chromotest. The majority of the samples showed genotoxic activity in tester strain Escherichia coli PQ37 without metabolic activation using S9 mix. In the presence of S9, a deactivation of the samples was regularly observed. Comparable studies with the Salmonella/microsome (Ames) test using tester strains Salmonella typhimurium TA98 and TA100 indicated actual mutagenicity of waste products. Gas chromatograms of the organic constituents of all waste products were performed in parallel with the genotoxicity assays. In contrast to the similarity of the peak patterns of all chromatograms, the biological effects of individual waste samples showed large differences. Information on chemical composition and the SOS chromotest results of a representative sample recovered over a period of 2 years is given. For this sample, the influences of sample preparation and cytotoxic matrix effects on the test parameters are also shown.

Aluminum↗

Potato pulp: microbiological characterization, physical modification, and application of this agricultural waste product.

Potato pulp, one of the agricultural waste products obtained in high quantities during starch production, contains starch, cellulose, hemicelluloses, pectin, proteins, free amino acids and salts. It exhibits physical and physicochemical properties of a typical colloid. It is mainly used, in a dried and pelleted form, as cattle feed. Its autochthonic microbial flora (bacteria, fungi) was identified and studied with a view towards the degradative potential of the microorganisms and ways of conserving the pulp for subsequent technical applications; 33 isolates (28 bacteria, 4 fungi, 1 yeast), belonging to 15 genera were characterized. Biological conservation was possible at very low oxygen pressure, brought about by the autochthonic anaerobic microorganisms causing acidification. Chemical conservation was achieved with sorbic acid. By treatment with hot water vapour under pressure (autoclaving), followed by a pressure release procedure, intact cells in the pulp (both potato cells and microorganisms, not spores) were destroyed, and their contents and wall fragments were set free. This process resulted in low drying costs and was a prerequisite for the production of a powder that can be used as glue or as animal feed.

Adhesives↗

[Endotracheal suctioning using a 24-hour continuous system. Can costs and waste products be reduced?].

Suctioning of the airways is often required in critically ill, intubated, or tracheotomised patients. In addition to the primary cost of these disposable materials, expenditures for waste disposal and environmental problems due to plastics should also be considered. In this study, the primary costs and amount of waste products of the closed suction system "Trach Care" were compared with a conventional disposable system. Other advantages and disadvantages of a closed suction system are discussed. METHODS. In this prospective, randomised investigation, both the open disposable suction system and the closed Trach Care system were used, in 60 patients (30 in each group) who were intubated for 1 week or more. During the first 7 days, we counted the number of times endotracheal suctioning was performed and measured the time it took. The costs of purchasing the systems, amounts of waste products, and costs of disposal were compared. RESULTS. The frequency of endotracheal suctioning was quite different from patient to patient and varied from 6 to 41 times per day. On average it was necessary 15 times per day per patient in both groups. Using the disposable system, a mean time of 3.5 min was measured in contrast to 2.5 min with the closed system. The costs of purchase were much lower with the disposable system taking into account all materials needed (17.36 DM vs 53.36 DM per day), whereas the weight of litter produced by the closed system was lower (429 g vs 745 g per day), the costs of disposal being accordingly different. During endotracheal suctioning O2 desaturation was not observed with the closed system, whereas in patients with acute respiratory failure O2 saturation fell rapidly from 90% to as far as 70% when a disposable system was used. CONCLUSION. The closed Trach Care suction system is more expensive to acquire, but may reduce the risk of exogenous nosocomial pneumonias as disconnections from the ventilator are minimised. The workload, weight of waste products, and costs of disposal are lower using the Trach Care system. From the physician's viewpoint, the main advantage of the Trach Care system becomes evident in patients with acute respiratory failure and patients with elevated intracranial pressure. In these cases, we now favor the Trach Care system as a matter of principle.

Anesthesiology↗

[Use of natural sorbents for removal of mutagens from liquid fluorine-organic waste products of monomer FC-141 manufacture].

Study of total mutagenic effects of liquid fluorine-organic waste products of monomer FC-141 manufacture has been carried out. Induction of gene mutations according to the mechanism of pair base replacement and shift of reading frame and induction of chromosomal aberrations, in particular deletions and translocations, has been shown. Expediency of use of natural sorbents for mutageneity removal from fluorine-organic waste products was investigated. Zeolites and glauconites appeared to be the most effective ones.

Adsorption↗

The viability of cells in the waste products of CO2-laser evaporation of Cloudman mouse melanomas.

The viability of cells present in waste products originating during CO2-laser evaporation of Cloudman S91 mouse melanomas was investigated. Cytologic smears showed mainly carbonized particles and thermally damaged cells but some morphologically intact cells as well. Viability was tested with the trypan blue test, by in vitro culture and intramuscular and intraperitoneal inoculations in syngeneic mice. No dye-excluding cells were found in the trypan blue test. Growth was noted neither in vitro nor in vivo in the 127 mice, intramuscularly or intraperitoneally injected with 10(5) x 10(5)/10 microliter smoke or debris particles, and killed four weeks after inoculation. Viable tumor cells, derived from a Cloudman melanoma cell line and added to the smoke and debris suspensions, remained viable. Thus, a toxic influence of smoke and debris particles in viable tumor cells, which would make the viability tests meaningless, was excluded. It is highly unlikely that viable tumor cells do occur in the waste products of CO2-laser tumor vaporization.

Animals↗

The biological waste product formation in the light of the membrane hypothesis of aging.

The membrane hypothesis of aging (MHA) explains the biological waste product (lipofuscin) formation as a disbalance between the rates of protein synthesis and damage, as well as of elimination of the damaged components. Although, this concept has not been refuted on the basis of any experimental evidence, it has neither been widely accepted. During the last decade the general interest has turned toward the molecular genetics so intensely, that research aimed at clarifying cell biological mechanisms became so to say hibernated. Nowadays it is being recognized more and more that after the complete description of the human genetic code, attention has to be dedicated again to the cellular mechanisms explaining the function of the gene products (proteins). In this context, our experimental findings described during the recent years may become again the subject of interest. We have shown that the in vivo inhibition of the lysosomal thiol-proteinase functions by sublethal doses of leupeptin in young, adult and old mice results in a considerable increase (about 30%) of the immobile fraction of membrane proteins in hepatocyte plasma membrane, meanwhile the lateral diffusion constant of the still mobile membrane proteins increased. These observations were interpreted as signs of a general slowing down of protein turnover in the plasma membrane, just by inhibiting the elimination mechanisms in the lysosomes. This paper will discuss the theoretical conclusions and significance of these findings for the biological waste product formation, as a basic cell biological function.

Journal Article↗

Ammonotely in a passerine nectarivore: the influence of renal and post-renal modification on nitrogenous waste product excretion.

Most aquatic vertebrates are ammonotelic, whereas terrestrial vertebrates are typically uricotelic or ureotelic. However, the principal form of nitrogenous waste product in the urine of an animal may vary, depending on environmental conditions. Anna's hummingbird (Calypte anna) was found to switch from uricotely at high ambient temperature (T(a)) to ammonotely at lower T(a), when energy demands and consequent nectar intake rates were high. In extension of this, we hypothesised that nectarivorous birds would switch from uricotely to ammonotely when water intake rates were high or when protein or salt intake rates were low. We examined the influence of water, electrolyte and protein intake and of T(a) on the excretion of ammonia, urea and urate (uric acid and its salts) in nectarivorous Palestine sunbirds (Nectarinia osea). The proportion of ammonia in ureteral urine and excreted fluid was not influenced by total water or salt intake or by T(a). Protein intake did not influence nitrogenous waste product concentrations in ureteral urine. However, when protein intake was reduced, the proportion of ammonia in excreted fluid was higher because of the reduced urate concentration. This reduction in urate concentration leads to 'apparent' ammonotely. We suggest that ammonotely may not be a unique feature of nectarivorous birds. It could occur in any species in which breakdown of urate in the hindgut allows the uric acid-nitrogen concentration in the excreta to fall below that of the ammonia-nitrogen concentration.

Ammonia↗

Amnio-allantoic fluid exchange for the prevention of intestinal damage in gastroschisis. III: Determination of the waste products removed by exchange.

Experimental amnio-allantoic fluid (AAF) exchange has been shown to prevent intestinal damage in the chicken embryo gastroschisis model. AAF contains both urinary and gastrointestinal waste products (UWP and GIWP). An experimental study was performed to find the waste products responsible for this intestinal damage. Gastroschisis was created in 20 chick embryos. Half were treated with AAF exchange, the other half were not treated. AAF samples were obtained for biochemical determination of urea nitrogen and creatinine as UWP, bile acids and bilirubin as GIWP at the end of the incubation. Intestines were evaluated by light microscopy. While GIWP (Bile salts and bilirubin) were significantly removed from AAF by exchange, the levels of UWP (urea nitrogen and creatinine) were unaffected. Intestinal wall thickness was less in the exchange group compared to the untreated group. The unchanged levels of UWP after AAF exchange may be attributed to their relatively rapid production compared to GIWP. Dilution of GIWPs by AAF exchange results in prevention of the intestinal damage in gastroschisis.

Allantois↗