Water Testing Laboratories Research Articles

Proficiency testing schemes for the assessment of Legionella PCR methodologies

Standard operating procedures used for the detection of bacteria in environmental samples are primarily based on bacterial growth on specific culture media and confirmation by biochemical and/or immunological tests. In the case of Legionella, isolation on BCYE-α medium is the standard method, although it presents a number of drawbacks, and for this reason, the implementation of molecular methods, mainly those based on PCR, has increased over the last years. Following the ISO/IEC 17025, laboratories need an external evaluation of their work to assure the quality of the results they are producing, and the participation in proficiency testing (PT) schemes is compulsory. For those water-testing laboratories using PCR methods for Legionella, we have developed a PT scheme accredited according to ISO/IEC 17043. The preparation and the statistical analysis of the results are performed following this standard and the ISO 13528. The used samples have a very rapid and easy to use format, consisting of tablets with inactivated freeze-dried Legionella cells or freeze-dried Legionella DNA. In this PT scheme, participants evaluate both Legionella pneumophila and Legionella spp. detection systems and control the whole PCR process from the water sample concentration until the PCR results.

Purification and Quality of Drinking Water: Issues and Concerns

The Philippines is commiued to achieve the United Nations Millennium Development Goal Number 7 to halve by 2015 the proportion of population without sustainable access to safe drinking water and safe sanitation. This paper analyzes and discusses the puri lication processes and quality of drinking water and their regulation in the country; it further discusses issues and concerns and makes recommendations. The Local Water Utilities Administration (L WUA) have more than 6,280 water service providers (WSPs) which provide potable water to the country's 92 million population. The purification processes employed by the WSPs, such as Manila Water Inc. (large scale) and Laguna Water District (medium scale), rely mainly on conventional water purilication methods that include coagulation/flocculation. sedimentation, liltration and disinfection. The chemical disinfectant used is either chlorine (large scale) or chlorine dioxide (medium scale). Bottled water manufacturers use a combination of methods such as filtration, reverse osmosis, ozonation and others. The standards for drinking water quality are defined in the Philippine National Standards for Drinking Water 2007 (DOH Administrative Order No. 2007-2012) and apply to "all waterworks officials, developers and operators of water supply systems both government and private entities, water refilling station operators, water vending machine operators, ice manufacturers, all establishments and institutions that supply or serve drinking water. drinking water laboratories, health and sanitation authorities, the general public and all others concerned". Bottled drinking water manufacturers must also comply with Good Manufacturing Practices based on DOH-BFAD Administrative Order No. 18-A series of 1993, since bottled water is considered a food product and is directly regulated by the DOH Food and Drug Administration. It is recommended that existing policies on the quality of drinking water and monitoring procedures be reviewed and harmonized for all WSPs including water districts, bottled drinking water manufacturers. refilling stations and small bottlers. DOH should be empowered in terms or budget, structure and equipment. to effectively monitor and enforce compliance with quality guidelines. including monitoring of refilling stations and all bottled water manufacturers. Policies for recognition (more accurate term than accreditation) of water testing laboratories by DOI I should be: updated and should include laboratory space requirement and qualifications of persons certifying reports of analyses and evaluating laboratories. In addition to providing sate drinking water to its increasing population, the Philippine government should strive to strengthen the regulation or water service providers to ensure that thc standards for good quality drinking water arc met and sustained.

Arsenic content in ground and canal waters of Punjab, North-West India

Groundwater is the primary source of drinking water for more than 95% of the population in Punjab. The world health organization and US Environment Protection Agency recently established a new maximum contaminant level of 10 ppb for arsenic in drinking water. The arsenic concentration of deep water tube wells located in Amritsar city used for domestic supply for urban population ranged from 3.8 to 19.1 ppb with mean value of 9.8 ppb. Arsenic content in hand pump water varied from 9 to 85 ppb with a mean value of 29.5 ppb. According to the safe limit of As, 54% and 97%, water samples collected from deep water tube wells and hand pumps, respectively, were not fit for human consumption. Arsenic content in canal water varied from 0.3 to 8.8 ppb with a mean value of 2.89 ppb. Canal water has got higher oxidation potential followed by deep tube well and hand pump water. The present study suggests the regular monitoring of arsenic content in deep tube well and shallow hand pump waters by water testing laboratories. The consumption of water having elevated concentration of As above the safe limit must be discouraged. In south-western districts of Punjab, it recommends the use of canal water for drinking purposes and domestic use by rural and urban populations than ground water sources.

A LABORATORY INTERCOMPARISON OF RADON IN WATER MEASUREMENTS IN MAINE

Naturally occurring radon exists in ground water and drinking water supplies. Many water testing laboratories provide measurements of radon in water for the public. No known national intercomparison program exists to verify the accuracy of the laboratories measuring radon in water in Maine or the Northeast. In recognition of this situation, the State of Maine Radiation Control Program sanctioned an intercomparison study for laboratories registered in Maine to measure radon in water. The University of Maine supplied each laboratory with water samples of various radon concentrations, served as the reference laboratory, and analyzed the results. Of the nine participating laboratories, eight use the liquid scintillation method while the ninth uses the E-PERM method to measure radon in water. Presented here are the results of this intercomparison study with a tabulation of the materials and methods used by the laboratories. The results from five of the nine testing laboratories showed significant discrepancies with those of the reference laboratory, typically due to low measurements.

The Laboratory Response Network: Before, during, and after the 2001 anthrax incident

Abstract The Laboratory Response Network (LRN) was established in 1999 in response to the worldwide concern for the potential use of biological or chemical agents in the commission of acts of terrorism. One such example was the numerous “hoax” letters allegedly containing the agent of anthrax that were mailed to a variety of agencies, including family planning clinics. As a result of this realistic threat, the Centers for Disease Control and Prevention, in partnership with the Federal Bureau of Investigation and the Association of Public Health Laboratories, created the LRN for the purpose of strengthening the nation's capacity to provide immediate and sustained laboratory testing and communication in the event of public health emergencies, particularly in response to acts of bioterrorism. From the time of its establishment to the present, the LRN has been successful in integrating the public and private health laboratory communities, in addition to expanding its original focus of medical laboratories to military laboratories, veterinary laboratories, agricultural laboratories, food and water testing laboratories, and international laboratories. The original designation of laboratories as Levels A, B, C, and D was revised to Sentinel, Reference, and Federal laboratories. They now function as an integrated network, with the major goal being to ensure that the nation's public health and private sector laboratories, along with other select laboratories, are prepared and equipped to respond to a biological or chemical act of terrorism in an appropriate and integrated manner. The lessons learned during the anthrax investigation in 2001 clearly demonstrated the need for an integrated network of laboratories, education, and training of technical personnel and the development of rapid detection and confirmatory technology. The American Society for Microbiology is one of many partners in the LRN and is responsible for maintaining and developing sentinel level testing protocols to either “rule out” or refer possible agents of bioterrorism. The mission of the LRN has been expanded to include not only biological and chemical terrorism, but also emerging infectious diseases and other public health threats and emergencies.

Consequences of acute and chronic exposure to arsenic in children.

Arsenic is a toxic chemical and may cause adverse health effects in children and adults. It is known to affect the nervous, gastrointestinal, and hematological systems and cause skin and internal cancers in people exposed to levels greater than 300 ppb in their drinking water. For most people, the major exposure to arsenic comes from food (8 to 14 microg inorganic arsenic per day), but when the arsenic level in water is elevated, drinking water becomes the predominant source of exposure. Because it is very difficult to limit arsenic exposure from food, it would be wise to limit arsenic exposure from those more controllable sources. Pediatricians should ascertain the levels of arsenic in drinking water of patients with high arsenic levels, using the supplier or, in the case of private wells, a professional water-testing laboratory assay. The Safe Drinking Water Act does not cover private wells or those water systems with less than 15 hook-ups or those that serve less than 25 people. Pediatricians should instruct parents to use prepared baby formulas or prepare them using water with the arsenic removed and to curtail playing time for younger children in places that have sand containing large amounts of arsenic. Such procedures will limit arsenic exposure to a minimum.

A field test for the assessment of faecal contamination of potable water

A simple, sensitive, rapid, inexpensive paper strip impregnated with Salmonellal E. coli medium (SEM) was formulated, and placed in a test tube. When potable water of 10 ml was added to the test tube it detected the faecal contamination of water samples within 16-48 h when incubated at room temperature from 20 to 35 degrees C. The positive results were indicated when the medium turned black (hydrogen sulfide production) for the presence of Salmonella sp. and/or the formation of a red ring (free indole from tryptophan) when a few drops of Kovac's reagent was added for the presence of coliform bacteria (E. coli). More than 600 water samples were tested with the new test (SEM) and results showed 99% agreement with that of the standard most probable number (MPN) coliform test and also proved highly successful in the field when it was employed to detect both Salmonella and E. coli. Different water testing laboratories involved in a water quality monitoring programme and governmental agencies evaluated the test media and reported that the test was user friendly, reliable and simple to perform in the field and will be especially useful for screening of both urban and rural water supplies for routine monitoring of bacteriological contamination.

The Determinants of Success in Implementing an Expert System in State Government

There are few tasks that managers dread as much as employee discipline. Except for cases in which the offense is severe enough to warrant termination, a manager must continue to interact daily with the employee after a punishment has been imposed. When the employee must be fired, the manager often fears that a lawsuit may not be far behind. Thus, when faced with the need to discipline an employee, supervisors might welcome help in figuring out what to do. That is the purpose of the computer expert system called the Supervisor Assistance System, created by the Florida Department of Highway Safety and Motor Vehicles (hereafter referred to as the Florida Department of Motor Vehicles). With the Supervisor Assistance System, a supervisor can first consult with the computer to determine if the employee's offense is actionable under departmental rules. If it is, the supervisor responds to a series of questions about the employee and the details of the offense. The computer then generates one or more recommendations for suggested actions to discipline the employee, along with supportive information from personnel rules. An expert system--one application of artificial intelligence--is a computerized decision-making software that structures expertise in a specific area and emulates human decision-making. The software helps users make a logical decision given its knowledge base drawn from laws, regulations, and human expertise.(1) Public agencies have used expert systems for over a decade, and they are becoming more common for a wide variety of purposes (Leonard-Barton and Sviokla, 1988; Martin, 1991). Social service departments use expert systems to determine eligibility for food stamps or refugee assistance, law enforcement units access solved and unsolved burglary cases through a computerized network to get a profile of possible perpetrators of an unsolved crime, and water testing laboratories apply for state license through an expert system. Although expert systems began as stand-alone computer programs, large public agencies are integrating their expert systems into their information data bases, and thus users may not even recognize their expert system as such (Hedberg, 1995). Most studies of public sector expert systems conclude that their promise is great, as they offer users significant potential benefits: increased productivity, improved service delivery effectiveness, and better problem anticipation (Hadden, 1989; McGowan and Lombardo, 1986; Shangraw, 1987). However, such systems have proven difficult to implement and institutionalize (Hadden, 1989, 204; Hauser and Hebert, 1992; Rubin, 1986). Few empirical studies of expert system implementation have been undertaken to assess what determines the extent to which public-sector decision makers will use an expert system initiated within their organization.(2) This article develops a model of the determinants of the degree to which managers utilize an expert system, and tests the model by examining how managers in the Florida Department of Motor Vehicles react to their expert system. The results offer lessons on how to implement an expert system in an agency so that the organization can achieve the benefits of computer technology. The Florida Department of Highway Safety and Motor Vehicles Supervisor Assistance System The Florida Department of Motor Vehicles developed the Supervisor Assistance System to provide consultations for its Supervisors on handling some 45 different employee offenses that can result in disciplinary actions.(3) (See Appendix 1 for a list of all offenses.) For any type of offense, the Supervisor Assistance System asks questions about the incident under investigation as well as other related information, such as the employee's prior disciplinary record and work history. (As an illustration, Appendix 2 presents the specific questions that the system asks a supervisor for the offense absent without authorized leave. …

PerspectiveInorganic Certified Reference Materials in ‘water’What do we have, what do we need?†

An inventory was prepared of the Certified Reference Materials (CRMs) available on the international market for the matrix ‘water’. There are different types or classes of water available, ranging from artificial (distilled, lyophilised) to more natural origin (rain-, river, lake, estuarine, sea-water). Determinants covering both major and trace elements for each water class are summarised. The lists may suggest that most determinants/matrices have been made available through the various suppliers of CRMs. However, on looking at the reality of everyday analytical performance in many routine water-testing laboratories, the quality assurance of the analysis of a surprisingly large number of compounds is not supported by the availability of dedicated CRMs. That these are not necessarily obscure determinants is illustrated using examples from the field of environmental freshwater monitoring practices, and from certain aspects of climate research analyses in the marine environment. It is concluded that there is a need for an exchange of information on the needs between the producers of CRMs and the routine analysts. This may lead to the availability, and the common use, of CRMs that support the quality assurance of day-to-day routine analyses of water.

Water analysis on tap

North West Water spent £20 million and five years automating its water testing laboratory. The author describes how manufacturing principles shaped the laboratory's design. The laboratory uses a factory-style production system for analysis, with the more repetitive and mundane tasks being carried out by automated equipment. The extensive use of automation means that, in comparison with a 'traditional' laboratory, a much greater floor area is required to accommodate equipment, while the need for bench space is reduced. Within the overall laboratory project there were three major subprojects: sample scheduling, development of the automated systems, and development of the laboratory management system.