SEARCH · PubMed Health
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.
A thorny problem facing many hospital managers (often the environmental services manager) today is how to safely handle and dispose of infectious and hazardous waste in a cost-effective fashion. This is a very complex issue, involving myriad regulations, ethical issues, and cost analysis.
Ipomea aquatica is a wetland plant, which floats in water bodies and is being used as a vegetable. This plant has ability to remove Cr(VI) from the contaminated water by transforming Cr (VI) to Cr (III). This adsorption of Cr(VI) basically takes place in roots of this plant. The contact time required to bring down Cr(VI) concentration below the permissible level (0.05 mg/1) is 30 to 40 days for this plant, and that varies with varying initial concentration. The lower level of contamination requires greater contact time than the higher one to bring down Cr(VI) below the permissible level. Recovery (94 +/- 1%) of chromium from the treated plant has been reported in this paper, and at the same time disposal problem also dose not arise. The study revealed that the plant Ipomea aquatica adsorbs Cr(VI) from the contaminated water very slowly compared to the other reported plants.
Past and present residents of the Love Canal area near Niagara Falls, New York, fear that they and their homes have been contaminated by toxic wastes seeping out from nearby chemical disposal sites. Hundreds of landfills nationwide are as potentially dangerous as Love Canal. In the absence of a statutory remedy, victims of contamination must rely upon common law theories of lability in order to recover damages for injuries suffered as a result of toxic waste contamination. This Note examines the merits and deficiencies of four common law theories: negligence, strict liability, nuisance and trespass. The Note concludes that none of these remedies is adequate to assure recovery to a person injured by toxic waste disposal, and recommends that legislation be adopted to ensure that victims of toxic waste contamination can be compensated for their injuries.
We have investigated the mutagenic activity of extracts from the wastewater of sewage treatment plants in municipal waste incinerators and evaluated the relative contribution of various routes of emission from the incinerator to the total output of mutagens. The mutagenicity of wastewater extracts from a complete combustion incinerator was 10% of that from an incomplete combustion unit. About 90% of all the mutagens produced in a municipal incinerator are discharged into the atmosphere as emission gases, and 10% are disposed of in the wastewater treatment plants. Most of the mutagens in wastewater treatment plants are not decomposed by normal aeration times, but are removed by adsorption onto suspended solids.
Several methods of contaminated crop disposal after phytoextraction process (composting, compaction, incineration, ashing, pyrolysis, direct disposal, liquid extraction) have been described. Advantages and disadvantages of methods are presented and discussed. Composting, compaction and pyrolysis are the pretreatment steps, since significant amount of contaminated biomass will still exist after each of the process. Four methods of final disposal were distinguished: incineration, direct disposal, ashing and liquid extraction. Among them, incineration (smelting) is proposed as the most feasible, economically acceptable and environmentally sound.
With the proliferation of bloodborne diseases in the United States, more attention is being focused on the issues of infectious medical waste and its disposal. Home care organizations must be aware of the potential risks involved in handling infectious wastes, and adhere to industry standards of disposal and transport. Education of staff, patients, and community about the management of infectious waste is crucial in today's healthcare arena.
One hospital's search for a new incinerator that would meet antipollution regulations led to selection and installation of a system that also conserves energy through heat reclamation.
Landfilling is probably, the most popular disposal method for the management of domestic and industrial waste. Unfortunately, many landfills around the world do not include leachate collection systems and present a considerable risk to the underlying aquifers. There have been numerous reports on groundwater contamination in the vicinity of unprotected landfills, paying particular attention to specific organic contaminants. This problem is especially pronounced in landfills which, in addition to ordinary domestic refuse, contain waste of industrial origin. Jakusevec, the main landfill of the city of Zagreb, belongs to this category. The recently completed remediation programme for Jakusevec included comprehensive investigations with the aim to quantify various organic contaminants in solid waste and establish their possible infiltration into the underlying soils and groundwater. A detailed analyses using chromatographic and mass spectrometric techniques made it possible to identify a number of contaminants. According to their origin, the identified compound classes can be divided into the two main categories: markers of biological waste and its microbial transformation and markers of anthropogenic waste. Our investigations have shown that the composition of organic contaminants changes dramatically during the vertical transport from the solid waste through the unsaturated zone of soil to aquifer sediments, which involves both physicochemical and biotransformation processes. The vertical transport of polar organic contaminants was very efficient and led to a significant contamination of the aquifer in the vicinity of the landfill.
In Malta all of the waste produced is mixed and deposited at various sites around the island. None of these sites were purpose built, and all of the waste is above groundwater level. The landfills are not engineered and do not contain any measures to collect leachate and gases emanating from the disposal sites. Another waste, which is disposed of in landfills, is pulverized fuel ash (PFA), which is a by-product of coal combustion by the power station. This has been disposed of in landfill, because its use has been precluded due to the radioactivity of the ashes. The aim of this study was to analyze the chemical composition of the pulverized fuel ash and to attempt to utilize it as a cement replacement in normal concrete mixes in the construction industry. The levels of radiation emitted from the ashes were measured by gamma spectrometry. The results of this study revealed that although at early ages cement replacement by PFA resulted in a reduction in compressive strength (P=0), when compared to the reference concrete at later ages the strengths measured on concrete cores were comparable to the reference concrete (P>0.05). The utilization of PFA up to 20% cement replacement in concrete did not raise the radioactivity of the concrete. In conclusion, utilization of PFA in the construction industry would be a better way of disposing of the ashes rather than controlling the leachate and any radioactivity emitted by the landfilled ashes.
In December 1999, 28,000 m3 of sediment was dredged from two sites within the harbour at Coffs Harbour, NSW. Dredging was carried out using a trailing suction hopper-dredge which transported the spoil to a shallow (6 m) site within the adjacent Solitary Islands Marine Park for disposal. Evaluation of the effects of the dredge-spoil dumping at the receiving site was conducted by taking replicated van Veen grab samples at the disposal site and at two control sites, before, immediately after, and three months after dumping. The results indicated that dredge-spoil dumping had no detectable effect on either the structure of the invertebrate community or the physical characteristics of sediment at the receiving site. Although there were some significant faunistic differences between samples from the disposal site and the control sites immediately following dumping, these were related to pre-existing differences between sites rather than to the effects of dredge-spoil disposal. Four principal factors are likely to have contributed to the lack of impact: (i) dredged material had similar sedimentary characteristics to those at the receiving site; (ii) dredged material was free from contaminants; (iii) the disposal method systematically distributed a number of shallow layers of sediment over the disposal site and thus motile macrofauna had the opportunity to migrate upwards between passes of the barge; and (iv) the disposal site was in a high energy environment where the resident biota are likely to be adapted to dynamic sedimentary conditions. The lack of detectable effects suggests that the disposal strategy was one which minimized impacts within an area which has high conservation value and should thus be adopted as a model for future works within the region.
To retard the migration of iodine released from a spent fuel after the break of a container, the reducing effects on the concentration of the iodide by container corrosion products and some buffer additives were examined in a solution with bentonite. Iron and copper, and their corrosion products scarcely reduced the iodide concentration. And kaolinite, chalcopyrite, pyrite, copper ore and galena, known as having a sorption property for iodine, did not noticeably sorb the iodide. However, palm active carbon, silver metal and Ag2O lowered the iodide concentration. Especially, Ag2O put into a disposal container would effectively hinder the migration of iodine to the outside of a disposal vault without a great loss if the pore size of the compacted buffer layer is maintained below 1 mu m.
Sustainable solid waste management is a strategy for achieving environmental quality in both the developed and the developing world. Environmental quality is a necessary condition for an increase in per capita welfare over time. The paper suggests alternative instruments for solid waste reduction, re-use and recycling. But to be able to apply the suggested economic instruments, the quantities and composition of the waste must be known. Having identified the current instruments of Botswana's solid waste management (regulatory measures, environmental education, and economic instruments of property rates, service levy, and sanitation fees), the paper argues that these do not go far enough in enhancing environmental protection. Alternative instruments such as solid waste collection and disposal levies, deposit refund schemes, and product levies are suggested. It is also suggested that public environmental education and regulatory measures should be strengthened.
Fifty-nine patients returned a confidential mailed questionnaire, to determine their procedures for disposal of CAPD waste including bags, fluids and needles, and to assess their instruction and opinions on health risks from their wastes. Patients came predominantly from rural communities. Sixty four percent used disposal boxes for used needles, 80% discarded drained bags in the garbage without wrapping them in plastic and 7 to 17% of patients discarded needles straight to the garbage, depending on circumstances. Thirty seven percent did not recall receiving instruction on waste disposal, and of those who did, instructions came predominantly from nurses. Twenty of 32 patients who had suffered peritonitis disposed of their bags during peritonitis in the same manner as when they did not have peritonitis. Most patients (61%) felt issues dealing with CAPD waste disposal were "important" or "very important", but fewer "agreed" or "strongly agreed" that it posed a health risk to others (16%) or to the environment (10%). Inconsistencies in methods of disposal and potential risks of infection dictate that guidelines must be developed to deal with these issues.
Using sharps containers for needle disposal to minimise the risk of accidental puncture with a needle after giving an injection is recommended. This permits immediate disposal of the needle. Various commercial and makeshift containers are available, examples of which are illustrated. We recommend to avoid recapping of needles, but should it be necessary the following tip by Dr Hilton is appropriate.
Human exposures to air pollution control (APC) residues released from 6 landfills were modeled and assessed. Following a qualitative risk characterisation, direct and indirect exposures were quantified. Site-specific air dispersion modeling was conducted for PM(10), PCDDs/PCDFs, Pb, Cd, As and Cr(VI) concentrations at the closest residential points of exposure for 4 landfill sites accepting, in total, 75% w/w of the APC residues disposed of in 2000-2001 (UK). Inhalation risks, assessed by reference to air quality standards at residential exposure points, were assessed as insignificant. Preliminary modeling suggested that indirect exposures from PCDDs/PCDFs at the 95th percentile level for the site where APC deposition rates were highest could potentially exceed the tolerable daily soil intake (TDSI) but this warrants further study given the model limitations. These results offer an initial screen of the significance of potential risks from APC disposal, which is of value in addressing concerns about the uncertainty of potential risks to human health from bulk APC disposal at strategic locations.
Very little research has been undertaken on the impacts of human toilet waste disposal in non-serviced sites in the wild. The objective of the present project was to determine the relative impacts of the mechanical disturbance of digging during the burial of toilet waste (faeces and toilet paper), and urination, on Tasmanian vegetation types that occur in areas used for wild country camping, in order to develop appropriate guidelines. The mechanical disturbance of digging cat-holes 15 cm deep, typical of those used for toilet disposal in the Tasmanian wild, had largely negative effects on the growth of a few native plant species. These effects were of little or no conservation significance. The nutrient additions simulated by the addition of artificial urine to undug ground and dug ground had largely positive effects on nine distinct types of native vegetation, encouraging the growth of many plant species at many sites, while discouraging the growth of moss at one site. No weed species found at any of the sites were significantly affected by the treatments. Thus, it appears that scattered disposal of urine, even combined with digging, is unlikely to present a major conservation problem in the Tasmania's wild country, and that present guidelines are appropriate, where achievable.
The landfills of fly ash are the problem of all power plants because this disposed fly ash is not used in any work. This research studies the potential of using disposed fly ashes which have disposal time of 6-24 months from the landfill of Mae Moh power plants in Thailand to replace Portland cement type I. Median particle sizes of disposed fly ashes between 55.4 and 99.3 microm were ground to reduce the sizes to about 7.1-8.4 microm. Both original and ground disposed fly ashes were investigated on physical and chemical properties. Compressive strengths of disposed fly ash mortars were determined when Portland cement type I was replaced by disposed fly ashes at the rate of 10%, 20%, and 30% by weight of cementitious material (Portland cement type I and disposed fly ash). The results presented that most particles of original disposed fly ashes were solid and sphere with some irregular shape while those of ground disposed fly ashes were solid and irregular shape. CaO and LOI contents of disposed fly ashes with different disposal times had high variation. The compressive strengths of original disposed fly ash mortars were low but those of ground disposed fly ash mortars at the age of 7 days were higher than 75% of the standard mortar and increased to be higher than 100% after 60 days. From the results, it could be concluded that ground disposed fly ashes were excellent pozzolanic materials and could be used as a partial replacement of cement in concrete, even though they were exposed to the weather for 24 months.
This paper presents a comparison of dry anaerobic digestion reactors fed with differently sorted municipal organic solid wastes. One reactor was fed with source sorted organic wastes and a second reactor was fed with mixed organic wastes consisting of grey wastes, mechanically selected municipal solid wastes and sludge. The two reactors utilised the same process (Valorga) and operational conditions at full scale. The results of the study emphasise the influence of the kind of treated material on the process performances, especially in terms of biogas and methane production, thus, energy reclamation. The reactor treating the source sorted organic waste and the reactor treating the mixed organic wastes generated some 200 m3 and 60 m3 of biogas per ton of waste treated, respectively, while the specific methane production was some 0.40 and 0.13 m3CH4/kgTVS, respectively. The mass balance and the final fate of the digested material from the two reactors were also clearly different. As for the costs, these were some 29 Euro per ton of treated waste (50% for personnel) and 53 Euro/ton for disposing of the rejected materials. Incomes were some 100 Euro/ton (on average) and an other 15 Euro/ton came from green certificates. The initial investment was 16 million Euros.