982 resultados para Water safety


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Reuse of treated sewage effluent for the irrigation of horticultural crops is being propounded and practiced as a means of alleviating pressure on freshwater resources. Concerns have been raised. however, as to the risk to human health, primarily disease, associated with this practice. Quantitative Microbial Risk Assessment (QMRA) is a useful tool for estimating this risk. We describe how QMRA works and the current state of knowledge of the components of QMRA models for the horticultural reuse scenario.

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Community Water Fluoridation (CWF) is the adjustment of fluoride concentration in community drinking water to a level that confers optimal protection from dental caries (Truman et al 2002). It is supported by many authorities as the single most effective public health measure for reducing dental caries (DHS 2007). It has consistently been shown to be effective in reducing the prevalence and severity of dental caries in populations following its introduction (NHMRC 1999). The most dramatic reductions (50-60%) were demonstrated in the earlier studies although more recent research has still shown reductions of between 30 and 50% (Truman et al 2002). Despite the strong scientific evidence for its beneficial effects and safety the issue of the appropriateness of CWF is often the focus of public debate. Proponents argue that it reduces dental caries. is safe and cost effective. and that it provides significant benefits to all social classes (Slade et al 1995: Slade et a 1996: Spencer et al 1996). Opponents question its efficacy and safety and argue that its addition to community water supplies is unethical mass medication (Colquhoun 1990: Diesendorf 1986: Diesendorf et al 1997).

More recently, however, there have been important questions raised regarding the continuing benefit of CWF over and above that produced by the widespread use of other sources of fluoride (toothpaste. mouth rinses. varnish and other professionally applied fluorides). Generally, dental caries has declined steeply in the last thirty years and many have observed that dental caries has also reduced in parts of Australia and other countries where there has never been CWF or where it has ceased. It has been suggested that because of the current low population levels of dental caries and the increase in alternate sources of fluoride, CWF no longer offers the benefits it may have in the past. Given this notion, together with the concerns of a minority subgroup of the population regarding the safety of CWF, it is valuable to examine current evidence to answer the question: Is there still a role for CWF in Australia?

This paper will firstly examine the history of water fluoridation and its mechanisms of action. Secondly. trends in dental decay experience over the last three decades with particular emphasis on social and geographical inequities in Australia will be described. We also review the current state of scientific evidence for the benefits of CWF including the contribution it makes to the reduction of oral health inequalities. In light of this we will provide a response to the question posed above.

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Since World War II, however, the term has increasingly referred to law enforcement operations, as a means to enforce trade sanctions, to prevent the movement of weapons of mass destruction (WMDs), and particularly in the Caribbean Sea, to prevent the smuggling of illicit drugs. Such ambiguity should allow flexibility when deciding whom should be targeted, as well as allowing states with veto powers in the UN Security Council, which may legitimately ship nuclear weapons and materials, to avoid being targeted as long as they do not export WMDs to rogue states or non-state groups or individuals.2 The ISPS Code was created under the auspices of the International Maritime Organization (IMO) and is part of the 1974 Safety of Life at Sea Convention (SOLAS) concerning the safety of merchant ships.

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Nearly all drinking water distribution systems experience a "natural" reduction of disinfection residuals. The most frequently used disinfectant is chlorine, which can decay due to reactions with organic and inorganic compounds in the water and by liquid/solids reaction with the biofilm, pipe walls and sediments. Usually levels of 0.2-0.5 mg/L of free chlorine are required at the point of consumption to maintain bacteriological safety. Higher concentrations are not desirable as they present the problems of taste and odour and increase formation of disinfection by-products. It is usually a considerable concern for the operators of drinking water distribution systems to manage chlorine residuals at the "optimum level", considering all these issues. This paper describes how the chlorine profile in a drinking water distribution system can be modelled and optimised on the basis of readily and inexpensively available laboratory data. Methods are presented for deriving the laboratory data, fitting a chlorine decay model of bulk water to the data and applying the model, in conjunction with a simplified hydraulic model, to obtain the chlorine profile in a distribution system at steady flow conditions. Two case studies are used to demonstrate the utility of the technique. Melbourne's Greenvale-Sydenham distribution system is unfiltered and uses chlorination as its only treatment. The chlorine model developed from laboratory data was applied to the whole system and the chlorine profile was shown to be accurately simulated. Biofilm was not found to critically affect chlorine decay. In the other case study, Sydney Water's Nepean system was modelled from limited hydraulic data. Chlorine decay and trihalomethane (THM) formation in raw and treated water were measured in a laboratory, and a chlorine decay and THM model was derived on the basis of these data. Simulated chlorine and THM profiles agree well with the measured values available. Various applications of this modelling approach are also briefly discussed.

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Nearly all drinking water distribution systems experience a "natural" reduction of disinfection residuals. The most frequently used disinfectant is chlorine, which can decay due to reactions with organic and inorganic compounds in the water and by liquid/solids reaction with the biofilm, pipe walls and sediments. Usually levels of 0.2-0.5 mg/L of free chlorine are required at the point of consumption to maintain bacteriological safety. Higher concentrations are not desirable as they present the problems of taste and odour and increase formation of disinfection by-products. It is usually a considerable concern for the operators of drinking water distribution systems to manage chlorine residuals at the "optimum level", considering all these issues. This paper describes how the chlorine profile in a drinking water distribution system can be modelled and optimised on the basis of readily and inexpensively available laboratory data. Methods are presented for deriving the laboratory data, fitting a chlorine decay model of bulk water to the data and applying the model, in conjunction with a simplified hydraulic model, to obtain the chlorine profile in a distribution system at steady flow conditions. Two case studies are used to demonstrate the utility of the technique. Melbourne's Greenvale-Sydenham distribution system is unfiltered and uses chlorination as its only treatment. The chlorine model developed from laboratory data was applied to the whole system and the chlorine profile was shown to be accurately simulated. Biofilm was not found to critically affect chlorine decay. In the other case study, Sydney Water's Nepean system was modelled from limited hydraulic data. Chlorine decay and trihalomethane (THM) formation in raw and treated water were measured in a laboratory, and a chlorine decay and THM model was derived on the basis of these data. Simulated chlorine and THM profiles agree well with the measured values available. Various applications of this modelling approach are also briefly discussed.

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The nephrology educators network [NEN] recognised in 2007 that inequities existed in the access and delivery of evidence based renal education programs particularly to nurses in regional and remote areas. To address this, a web-based approach to learning, through the development of peer reviewed, interactive nephrology e-learning programs was adopted. These programs aligned with the tenets of e-learning instructional design and afforded more effective and consistent clinical support and induction for nurses in the renal specialty. The e-learning programs promote a standardised evidence-based approach to nephrology education and were developed by content experts from across Australia and New Zealand. The design methodology avoided the duplication of resources while also encouraging knowledge transfer between participating health organisations.

This paper will discuss the development and successful implementation of these e-learning programs across renal healthcare units in Australasia. Implemented packages include: Introduction to Buttonhole Cannulation – featuring an interactive ultrasound and cannulation application; Introduction to Haemodialysis; Introduction to Peritoneal Dialysis [PD], featuring simulated PD machines, allowing for the teaching of troubleshooting without compromising patient safety. E-learning programs are further supported through interactive case scenarios that present unfolding real world simulations and enable learners to meet different patients and manage their care while learning about key messages relating to renal health. Modules currently in development include; Acute Kidney Injury; Fluid Assessment, Water Quality and Vascular Access. The implementation of these programs assist the facilitation of positive change in teaching and learning practices in nephrology nursing aimed at improving patient outcomes.

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Fresh produce is increasingly implicated in food-related illnesses. Escherichia coli can survive in soil and water and can be transferred onto plant surfaces through farm management practices such as irrigation. A trial was conducted to evaluate the impact of field conditions on E. coli persistence on iceberg lettuce irrigated with contaminated water, and the impact of plant injury on the persistence of E. coli. Lettuce heads were injured at 14, 7, 3, 2, 1, and 0 days before inoculation, with uninjured heads used as a control. All lettuce heads (including controls) were overhead irrigated with a mixture of nonpathogenic E. coli strains (10^sup 7^ CFU/ml). E. coli counts were measured on the day of inoculation and 5 days after, and E. coli was detected on all lettuce head samples. Injury immediately prior to inoculation and harvest significantly (P = 0.00067) increased persistence of E. coli on lettuce plants. Harsh environmental conditions (warm temperatures, limited rainfall) over 5 days resulted in a 2.2-log reduction in E. coli counts on uninjured lettuce plants, and lettuce plants injured more than 2 days prior to inoculation had similar results. Plants with more recent injuries (up to 2 days prior to inoculation) had significantly (P = 7.6 × 10^sup -6^) greater E. coli persistence. Therefore, growers should postpone contaminated water irrigation of lettuce crops with suspected injuries for a minimum of 2 days, or if unavoidable, use the highest microbiological quality of water available, to minimize food safety risks.

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The single most important asset for the conservation of Australia’s unique and globally significant biodiversity is the National Reserve System, a mosaic of over 10,000 discrete protected areas on land on all tenures: government, Indigenous and private,including on-farm covenants, as well as state, territory and Commonwealth marine parks and reserves.THE NATIONAL RESERVE SYSTEMIn this report, we cover major National Reserve System initiatives that have occurred in the period 2002 to the present and highlight issues affecting progress toward agreed national objectives. We define a minimum standard for the National Reserve System to comprehensively, adequately and representatively protect Australia’s ecosystem and species diversity on sea and land. Using government protected area, species and other relevant spatial data, we quantify gaps: those areas needing to move from the current National Reserve System to one which meets this standard. We also provide new estimates of financial investments in protected areas and of the benefits that protected areas secure for society. Protected areas primarily serve to secure Australia’s native plants and animals against extinction, and to promote their recovery.BENEFITSProtected areas also secure ecosystem services that provide economic benefits forhuman communities including water, soil and beneficial species conservation, climatemoderation, social, cultural and health benefits. On land, we estimate these benefitsare worth over $38 billion a year, by applying data collated by the Ecosystem ServicesPartnership. A much larger figure is estimated to have been secured by marineprotected areas in the form of moderation of climate and impact of extreme eventsby reef and mangrove ecosystems. While these estimates have not been verified bystudies specific to Australia, they are indicative of a very large economic contributionof protected areas. Visitors to national parks and nature reserves spend over $23.6 billion a year in Australia, generating tax revenue for state and territory governments of $2.36 billion a year. All these economic benefits taken together greatly exceed the aggregate annual protected area expansion and management spending by all Australian governments, estimated to be ~$1.28 billion a year. It is clear that Australian society is benefiting far greater than its governments’ investment into strategic growth and maintenance of the National Reserve System.Government investment and policy settings play a leading role in strategic growth of the National Reserve System in Australia, and provide a critical stimulus fornon-government investment. Unprecedented expansion of the National Reserve System followed an historic boost in Australian Government funding under Caring for Our Country 2008–2013. This expansion was highly economical for the Australian Government, costing an average of only $44.40 per hectare to buy and protect land forever. State governments have contributed about six times this amount toward the expansion of the National Reserve System, after including in-perpetuity protected area management costs. The growth of Indigenous Protected Areas by the Australian Government has cost ~$26 per hectare on average, including management costs capitalised in-perpetuity, while also delivering Indigenous social and economic outcomes. The aggregate annual investment by all Australian governments has been ~$72.6 million per year on protected area growth and ~$1.21 billion per year on recurrent management costs. For the first time in almost two decades, however, the Australian Government’s National Reserve System Program, comprising a specialist administrative unit and funding allocation, was terminated in late 2012. This program was fundamental in driving significant strategic growth in Australia’s protected area estate. It is highly unlikely that Australia can achieve its long-standing commitments to an ecologically representative National Reserve System, and prevent major biodiversity loss, without this dedicated funding pool. The Australian Government has budgeted ~$400 million per year over the next five years (2013-2018) under the National Landcare and related programs. This funding program should give high priority to delivery of national protected area commitments by providing a distinct National Reserve System funding allocation. Under the Convention on Biological Diversity (CBD), Australia has committed to bringing at least 17 percent of terrestrial and at least 10 per cent of marine areas into ecologically representative, well-connected systems of protected areas by 2020 (Aichi Target 11).BIODIVERSITY CONSERVATIONAustralia also has an agreed intergovernmental Strategy for developing a comprehensive, adequate and representative National Reserve System on land andsea that, if implemented, would deliver on this CBD target. Due to dramatic recent growth, the National Reserve System covers 16.5 per cent of Australia’s land area, with highly protected areas, such as national parks, covering 8.3 per cent. The marine National Reserve System extends over one-third of Australian waters with highly protected areas such as marine national parks, no-take or green zones covering 13.5 per cent. Growth has been uneven however, and the National Reserve System is still far from meeting Aichi Target 11, which requires that it also be ecologically representative and well-connected. On land, 1,655 of 5,815 ecosystems and habitats for 138 of 1,613 threatened species remain unprotected. Nonetheless, 436 terrestrial ecosystems and 176 threatened terrestrial species attained minimum standards of protection due to growth of the National Reserve System on land between 2002 and 2012. The gap for ecosystem protection on land – the area needed to bring all ecosystems to the minimum standard of protection – closed by a very substantial 20 million hectares (from 77 down to 57 million hectares) between 2002 and 2012, not including threatened species protection gaps. Threatened species attaining a minimum standard for habitat protection increased from 27 per cent to 38 per cent over the decade 2002–2012. A low proportion of critically endangered species meeting the standard (29 per cent) and the high proportion with no protection at all (20 per cent) are cause for concern, but one which should be relatively easy to amend, as the distributions of these species tend to be small and localised. Protected area connectivity has increased modestly for terrestrial protected areas in terms of the median distance between neighbouring protected areas, but this progress has been undermined by increasing land use intensity in landscapes between protected areas.A comprehensive, adequate and representative marine reserve system, which meetsa standard of 15 per cent of each of 2,420 marine ecosystems and 30 per cent of thehabitats of each of 177 marine species of national environmental significance, wouldrequire expansion of marine national parks, no-take or green zones up to nearly 30per cent of state and Australian waters, not substantially different in overall extentfrom that of the current marine reserve system, but different in configuration.Protection of climate change refugia, connectivity and special places for biodiversityis still low and requires high priority attention. FINANCING TO FILL GAPS AND MEET COMMITMENTSIf the ‘comprehensiveness’ and ‘representativeness’ targets in the agreed terrestrial National Reserve System Strategy were met by 2020, Australia would be likely to have met the ‘ecologically representative’ requirement of Aichi Target 11. This would requireexpanding the terrestrial reserve system by at least 25 million hectares. Considering that the terrestrial ecosystem protection gap has closed by 20 million hectares over the past decade, this required expansion would be feasible with a major boost in investment and focus on long-standing priorities. A realistic mix of purchases, Indigenous Protected Areas and private land covenants would require an Australian Government National Reserve System investment of ~$170 million per year over the five years to 2020, representing ~42 per cent of the $400 million per year which the Australian Government has budgeted for landcare and conservation over the next five years. State, territory and local governments, private and Indigenous partners wouldlikewise need to boost financial commitments to both expand and maintain newprotected areas to meet the agreed National Reserve System strategic objectives.The total cost of Australia achieving a comprehensive, adequate and representativemarine reserve system that would satisfy Aichi Target 11 is an estimated $247 million.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Since 2004, Brazil has been the leading exporter of chicken. Because of the importance of this sector in the Brazilian economy, food safety must be ensured by control and monitoring of the production stages susceptible to contamination, such as the chilling process. The goal of this study was to evaluate changes in microbial levels on chicken carcasses and in chilling water after immersion in a chilling system for 8 and 16 h during commercial processing. An objective of the study was to encourage discussion regarding the Brazilian Ministry of Agriculture Livestock and Food Supply regulation that requires chicken processors to completely empty, clean, and disinfect each tank of the chilling system after every 8-h shift. Before and after immersion carcasses were collected and analyzed for mesophilic bacteria, Enterobacteriaceae, conforms, and Escherichia coli. Samples of water from the chilling system were also analyzed for residual free chlorine. The results do not support required emptying of the chiller tank after 8 h; these tanks could be emptied after 16 h. The results for all carcasses tested at the 8- and 16-h time points indicated no significant differences in the microbiological indicators evaluated. These data provide both technical and scientific support for discussing changes in federal law regarding the management of immersion chilling water systems used as part of the poultry processing line.

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Since the nineteenth century ships have been using ballast water (BW) for safety, stability, propulsion and maneuverability, as well as to redress loss of fuel weight and water consumption, and to maintain structural stress at acceptable levels. Ballast water has been spreading many non-native species around the globe, but little is known about the extent and potential significance of ship-mediated transfer of microorganisms. The global movements of ballast water by ships create a long-distance dispersal mechanism for human pathogens that may be important in the worldwide distribution of microorganisms, as well as for the epidemiology of waterborne diseases. Only a few studies have been carried out on this subject, most of them involving ballast water containing crustacean larvae and phytoplankton. Specialized microbiological studies on these waters are necessary to avoid a repeat of what happened in 1991, when epidemic cholera was reported in Peru and rapidly spread through Latin America and Mexico. In July of 1992, Vibrio cholerae was found in the USA and the Food and Drug Administration (FDA) determined that it came from ballast water of ships whose last port of call was in South America. In Brazil, just a few studies about the subject have been performed. An exploratory study by the Brazilian National Health Surveillance Agency (Agencia Nacional de Vigilancia Sanitaria - ANVISA) found in ballast water different microorganisms, such as fecal coliforms, Escherichia coli, Enterococcus faecalis, Clostridium perfringens, coliphages, Vibrio cholerae O1 and Vibrio cholerae non-O1. Until now, Brazil has been focusing only on organisms transported to its territory from other countries by ballast water, to avoid their establishment and dissemination in Brazilian areas. Studies that can assess the probability that water ballast carries pathogenic microorganisms are extremely important, as is the examination of ships that arrive in the country. Treatment of the human infections caused by BW exists but none is completely safe and efficient.

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In this study, micronucleus (MN) and chromosome aberration (CA) tests in Allium cepa (onion) were carried out in order to make a preliminary characterization of the water quality of the Atibaia River in an area that is under the influence of petroleum refinery and also to evaluate the effectiveness of the treatments used by the refinery. For these evaluations, seeds of A. cepa were germinated in waters collected in five different sites related with the refinery in ultra-pure water (negative control) and in methyl methanesulfonate solution (positive control). According to our results, we can suggest that even after the treatments (physicochemical, biological and stabilization pond) the final refinery effluent could induce chromosome aberrations and micronucleus in meristematic cells of A. cepa and that the discharge of the petroleum refinery effluents in the Atibaia River can interfere in the quality of this river. (C) 2009 Elsevier B.V. All rights reserved.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)