bluuebunny/crossref_metadata_2025 huggingface dataset:
A History ofHawaiian Freshwater Resources
Authors: Benbow M. Eric , McIntosh Mollie D. , Burky Albert J.
Published: July 2005

The history of Hawaiian freshwater resources begins 1500–1600 years ago, when the first Hawaiians arrived from Polynesia. Early Hawaiian freshwater management balanced human needs with ecological sustainability through community‐based taro farming. In this system, water was never diverted out of the watershed. Instead, freshwater was the lifeline that connected the mountains to the oceans. Western discovery of Hawaii brought with it privatized natural resources, cultural diversity, and a shift of agriculture from within the watersheds to sunny, but arid, landscapes. The rise of sugar cane facilitated political changes that led to the fall of the Hawaiian Monarchy and eventual statehood in the United States. However, this new agriculture was economically impossible without diverting irrigation water from the windward sides of each island, resulting in a permanent loss from the watersheds. Stream water removal eliminates habitat and disrupts a specialized life cycle of several endemic species, a life cycle that requires migration to and from the ocean. Recent petitions to enforce existing water law have sparked political debate of freshwater allocation in the face of diminished agriculture. Future management will require compromise and scientifically based strategies to bring back ecological balance and long‐term sustainability.
Water Between
A
rabs and
I
sraelis: Researching Twice‐Promised Resources
Authors: Lipchin Clive D.
Published: July 2005

The majority of Israel's water resources are transboundary and are thus, in a sense, shared with her neighbors. The most contentious are the underground aquifers of the West Bank shared between Israel and the Palestinians and the tributaries to the Jordan River that originate in the occupied Golan Heights, which belonged to Syria prior to the 1967 Six‐Day War. Since 1948, Israel has embarked on an ambitious development program for the country. The drive behind this program was the Zionist ethos of developing the land to create an attachment between the Jew and the soil. Massive agricultural and water projects ensued in the mid‐1950s and 1960s in realizing the Zionist dream. The most significant was the National Water Carrier completed in 1964. The National Water Carrier is a complex system of pipes, pumps, and canals that transfers water from the Sea of Galilee in the north to the arid Negev Desert in the south for irrigation. The repercussions of this interbasin transfer have been the decline of the flow of the Jordan River that flows south from the Sea of Galilee to the Dead Sea. Today, the Jordan River is a trickle of its former self, and the Dead Sea is at its lowest level ever.
Water and Well‐Being
Authors: Haley David
Published: July 2005

Using poetry and statements from eminent people representing many disciplines and supported by United Nations and World Health Organisation documents, this article explores the role of water as a human right, necessary to achieve the most fundamental standard of well‐being. It also addresses the part played by water in sustaining ecological well‐being and how this is integral to the relationship between humans and the environment.

Every culture expresses the very important relationship it has with water in some form or other. Here we focus on the ancient Chinese art of “geomancy,” Feng Shui, that pays particular attention to achieving well‐being through the relationship with water. However, this reverence for water as a heavenly gift, spiritual source, or common resource may be diminishing as many societies value water only as a commercial commodity that may be controlled and sold for private, industrial, and agricultural use.

Finally, the relationship between water and well‐being is considered a flowing system, a major dynamic element in the structure, pattern, and process of evolution, life, and well‐being.

If well‐being is defined as “… the maximisation of the pleasure available to us” (2) and is related to health, safety, welfare, comfort, security, happiness, goodness, and contentment, then water must play an important part in maintaining this desirable state. For without water, none of these qualities of life can be achieved. Water connects all life and water connects all aspects of well‐being, including social, economic, environmental, health, and aesthetic well‐being, as a basic human right.

Article 25, Universal Declaration of Human Rights (3) states: “Everyone has the right to a standard of living adequate for the health and well‐being of himself and his family” (3). Kofi Annan, United Nations Secretary‐General confirmed that (a)ccess to safe water is a fundamental human need and therefore, a basic human right.
Regulatory Issues and Remediation: Risk, Costs, and Benefits
Authors: Vance David B. , Jacobs James A.
Published: July 2005

Major regulatory changes have occurred over the past decade regarding enforcement and cleanup standards. These changes have occurred in part, because of the realization that enormous financial and human resources were being spent on the remediation of properties with low concentrations of residual fuel hydrocarbon (primarily gasoline and diesel) contamination with low impact to human receptors. A major report from a national laboratory in 1995 changed the regulatory approach to focus attention on the risk benefits and exposure pathways associated with subsurface fuel contamination. Risked based decision making takes into account the risk, costs, and benefits when evaluating regulatory approaches to remediation.
Islamic Water Law
Authors: Zaharuddin A. , Sabri S.
Published: July 2005

Water is considered one of the most profound elements in Islam. Water is also necessary for cleaning one's home and personal effects, as well as for general hygiene. It is indispensable to agriculture and industry:
He it is who sends down water from the sky. With it, we bring forth plants of every kind
(6:99). It cannot be denied that all human beings rely on water for life and good health, but for Muslims, water is first and foremost, a social good in Islam. It is also regarded as a blessing from Allah that gives and sustains all life in this world. Furthermore, the word “water” appears sixty‐three times in the holy book of Muslims, Al‐Quran. This indicator shows the importance of water in our daily life.
The Clean Water Act
Authors: Ryan Timothy J.
Published: July 2005

The Clean Water Act established the priorities and structure for regulating pollution releases into the waters of the United States. The Act's major subchapters include six Titles: (I) Research and Related Programs, (II) Grants for Construction of Treatment Works, (III) Standards and Enforcement, (IV) Permits and Licenses, (V) General Provisions, and (VI) State Water Pollution Control Revolving Funds. The Act continued requirements to set water quality standards for all contaminants in surface waters and made it unlawful to discharge any pollutant from a single, or point, source into navigable waters, unless permitted. It also funded the construction of sewage treatment plants under the construction grants program and recognized the need for planning to address the critical problems posed by diffuse, or nonpoint, sources of pollution.
Activated Carbon: Ion Exchange and Adsorption Properties
Authors: Saha Basu
Published: July 2005

Several techniques have been developed and used to remove and/or recover a wide range of micropollutants from water and a variety of industrial effluents. Adsorption using activated carbon is well established for the removal of organic molecules from aqueous solution, but to a much lesser extent for the removal of toxic heavy metals.

Here, the preparation, properties, and metal sorption performance of a range of as‐received and oxidized samples of granular activated carbon that were either prepared or modified in the author's laboratory are discussed. Samples were evaluated for the removal of trace toxic metal ions from aqueous solutions. Batch and column experiments have been performed to elucidate the relationship between sorptive performance and the physical and chemical structure of these materials.
Bromide Influence on Trihalomethane and Haloacetic Acid Formation
Authors: Chellam Shankar
Published: July 2005

An undesired consequence of adding chemicals such as chlorine to disinfect drinking water is the formation of disinfection byproducts (DBPs). Exposure to high doses of DBPs has been shown to cause cancers as well as adverse reproductive effects in laboratory animals. In contrast, epidemiological studies have not been able to conclusively establish a causal link between chlorinated drinking water containing DBPs to an increased cancer risk in humans consuming them. Regardless, federal regulations restricting the concentrations of several DBP classes (including four trihalomethanes and five haloacetic acids) have been established by the Environmental Protection Agency to reduce any potential risks they may pose. This section briefly describes the effects of changes in the relative concentrations of bromide ion and natural organic matter on the formation and speciation of trihalomethanes and haloacetic acids. Special emphasis is given to the formation of all nine haloacetic acids containing chlorine and bromine even though current and regulations anticipated in the near term do not address them. Additionally, it is shown that even though water treatment processes such as nanofiltration and granular activated carbon reduce the total concentrations of DBP precursors, they shift the relative speciation of THMs and HAAs toward the more brominated ones.
Irrigation Water Quality in Areas Adjoining River
Y
amuna at
D
elhi,
I
ndia
Authors: Jain Chakresh K. , Sharma Mukesh K.
Published: July 2005

The groundwater quality of areas adjoining the River Yamuna in Delhi (India) has been assessed for the suitability of groundwater for irrigation. Thirty‐eight groundwater samples from shallow and deep aquifers were collected each during pre‐ and postmonsoon seasons in the year 2000 and analyzed for various parameters. The suitability of groundwater for irrigation has been evaluated based on salinity, sodium adsorption ratio (SAR), residual sodium carbonate (RSC), and boron content. According to the U.S. Salinity Laboratory classification of irrigation water, more than 50% of the samples fall in water type C3‐S1 (high salinity and low SAR). Such water cannot be used on soils that have restricted drainage. Even with adequate drainage, special management for salinity control may be required and plants with good tolerance should be selected. About 30% of the samples fall in water type C3‐S2 (high salinity and medium SAR). Such water will induce an appreciable sodium hazard in finely textured soils that have good cation exchange capacity, especially under low leaching conditions.
Physiological Biomarkers and the
T
rondheim Biomonitoring System
Authors: Zachariassen Karl Erik
Published: July 2005

A biomarker is a cellular, biochemical, or physiological parameter that changes when an organism is affected by an environmental pollutant. Biomarkers mainly establish early warning systems in environmental monitoring. Biomarkers must be used by scientists with care, because the response of a biomarker does not necessarily imply that injurious effects have developed. Correct interpretations require that biomarkers are considered within the functional system they are parts of, i.e., by considering them as physiological parameters. Biomarkers should accordingly be classified into different categories, dealing with exposure, toxic impact, and pollutant‐specific fingerprinting. The
Trondheim Biomonitoring System
is an attempt to develop a differentiated biomarker system of this kind.

Activation of regulatory mechanisms that compensate for the impact of the pollutant is used as
exposure biomarkers
. If the compensatory response is insufficient, the regulated parameter will gradually be displaced beyond tolerable limits. Hence, the regulated parameters may be used as
toxicity biomarkers
. Finally, the combined response of several biomarkers may be specific for different pollutants, and complex responses may develop sets of pollutant‐specific
fingerprint biomarkers
.
Biochemical Oxygen Demand and Other Organic Pollution Measures
Authors: Pasco Neil F. , Hay Joanne M.
Published: July 2005

Biochemical oxygen demand (BOD) is the most important and widely used environmental index for monitoring organic pollutants in wastewater. The current international standard method is the five‐day BOD assay (BOD5). The test measures the amount of dissolved oxygen required for the microbial oxidation of carbonaceous organic material under specified conditions. The test has its widest application in measuring waste loadings to treatment plants and in evaluating the BOD‐removal efficiency of such treatment systems.

Practical difficulties exist associated with the BOD5test, including sensitivity to temperature and oxygen concentration, impact of toxins, lack of stoichiometric validation, and the need to dilute samples. The test is labor intensive with variable results, but the major drawback continues to be the five‐day measurement time.

For all its shortcomings and the availability of a number of related measurement techniques, the BOD5assay remains the preferred test for reporting the oxygen requirements of wastewaters, effluents, and polluted waters, in part, because of its international regulatory status, but also because it uniquely simulates the microbial decomposition of organic wastes in the environment, thereby approximating the response of natural ecosystems.
Active Biomonitoring (ABM) by Translocation of Bivalve Molluscs
Authors: Smolders Roel , Voets Judith , Bervoets Lieven , Blust Ronny , Wepener Victor
Published: July 2005

The advantages of ABM for biomonitoring purposes are:

Experiments can be performed for aknown exposure period.

All organisms have asimilar life historyat the start of the exposure.

It is easy tocompare different sites, even if the organisms are not normally present at the exposure locations.

Acomparison between transplanted and indigenous organismscan indicate to what extent the indigenous organisms are adapted to the location or can give information about uptake kinetics of pollutants. Indigenous species can be “genetically protected,” and thus the use of transplanted organisms can circumvent this adaptation processes, making the comparison among different sites more precise and the use of nonadapted species more sensitive.

Compared with laboratory‐bred organisms, transplanted organisms arebetter acclimatedto changing environmental conditions, and thus the impact of field exposure through, e.g., climatological shock, will be less pronounced.
Dose‐Response of Mussels to Chlorine
Authors: Rajagopal S. , Van Der Velde G. , Venugopalan V. P. , Jenner H. A.
Published: July 2005

Chlorine, like any other biocide, produces a dose‐dependent response in organisms. However, the response is dependent on a number of parameters. Chlorination of cooling water leaves residuals and by‐products that are potential pollutants in the receiving water body and can impact nontarget organisms. Therefore, it is imperative to generate data on the chlorine dose–response relationships of important fouling organisms, such as various mussel species, for efficient but environmentally acceptable biofouling control. Data are presented to show the effects of mussel size (shell length), season of sample collection (spawning vs. nonspawning season), nutritional status (fed vs. nonfed), and acclimation temperature (5–30°C) on the mortality pattern of different mussel species under continuous chlorination (0.5–5 mg L−1). From the data, it can be concluded that although various factors can influence the dose–response relationships of mussels, generalization is not possible because of species specificity. Among the various parameters, mussel species, mussel size, status of byssal attachment, spawning season, and acclimation temperature have significant effect on chlorine tolerance of mussels, whereas nutritional status shows very little effect.
Colloids and Dissolved Organics: Role in Membrane and Depth Filtration
Authors: Leppard Gary G. , Buffle Jacques
Published: July 2005

A colloid is operationally defined as any particulate with a least dimension in the range of 1.0–0.001 µm; the range includes macromolecules, but not conventional dissolved substances, which tend to be smaller (1, 2). For environmental scientists, aquatic colloids are being redefined as any particulate that provides a molecular milieu into and onto which chemicals can escape from bulk water and whose movement is not significantly affected by gravitational settling (3). In practice, colloids and dissolved substances are often defined by a filter operation (4, 5). Living microbes, when sufficiently small, can also be considered colloids, albeit colloids capable of very complex behavior (2).

Filtration for water scientists is the separation of particulates from a liquid, achieved by passing a suspension through a porous solid. Through the application of membrane filters and/or depth filters, filtration protocols are commonly used (1) to concentrate or remove particulate matter and (2) to separate suspended particulates into size classes for subsequent biological, chemical, or physical analyses. In water treatment, one discriminates between membrane filters, which are porous membranes that concentrate particulates at or close to the upper filter surface, and depth filters. The latter are relatively inexpensive filters with high collection efficiencies and flow rates that entrap particulates within the filter interior.
Use of Luminescent Bacteria and theLUXGenes for Determination of Water Quality
Authors: Ulitzur Nirit , Ulitzur Shimon
Published: July 2005

Various approaches and technologies that utilize luminescent bacteria for determination of water quality are described. The use of intact luminescent bacteria for analytical purposes has some clear advantages: the light of a single bacterium may reach about 30,000 quanta/s/cell; thus, one can use a simple luminometer to detect light generated by a few hundred cells/mL. Chemophysical and biological factors that affect cell respiration, the rate of protein or lipid synthesis, promptly alter the level of luminescence. The use of freeze‐dried luminescent bacteria for analytical purposes is not different, in practice, from other biochemical tests. Numerous studies described the use of natural luminescent bacteria or recombinantlux‐carrying bacteria for rapid assessment of toxic components in aqueous environments. The commercially available bioassays are described in detail (Microtox, ToxScreen, Mutatox, Vitotox), as well as recent developments in automating toxicity tests for online monitoring. Also described are tests utilizing luminescent bacteria for determination of nutrients in water [such as assimilable organic carbon (AOC) and biochemical oxygen demand (BOD)]. All in all, the bioluminescence tests for detecting water toxicants as well as for measuring elementary nutrients have been shown to be simple, rapid, and relatively inexpensive tools for monitoring water quality.
Development and Application of Sediment Toxicity Tests for Regulatory Purposes
Authors: Hartl M.G.J. , van Pelt F.N.A.M. , O'Halloran J.
Published: July 2005

Undisturbed sediments tend to accumulate many chemical compounds, and so act as both as sinks of sources of contaminants. Currently, the ecotoxicological assessment of sediments is mainly restricted to chemical analysis and acute toxicity testing using microorganisms. Sediments are not homogenous, but are composed of whole sediment, sediment‐water interface, pore water, and elutriate. Examination of any single sediment phase may be insufficient to give an accurate ecotoxicological assessment. A comprehensive assessment of potential sediment toxicity requires the consideration of multiple exposure phases and multiple test models representing different trophic levels. We recommend that sediment toxicity assessments should be further developed and evaluated to be used in a tiered approach, consisting of screening using short‐term general toxicity tests (Tier 1); hazard identification applying more specific (multiple) endpoints in multiorganism experiments, representing different trophic levels and habitats associated with sediments, as well as different modes of bioavailability by using both sediment extracts and whole sediments (Tier 2); andin situecosystem function, e.g., lifetime reproductive success, and components of biodiversity (Tier 3). Here we summarize some of the key sediment toxicity test systems in use and/or under development.
SOFIE
: An Optimized Approach for Exposure Tests and Sediment Assays
Authors: Vink Jos P. M. , Rotteveel Serge , Miermans Cornelis J. H.
Published: July 2005

The use of biological sensors, rather than chemical measurements, appears promising for risk assessments of contaminated environments provided that the assay is able to mimic natural conditions. As an alternative to the standard bioassay protocol, a new technique was developed that meets this requirement, leaving sample and geochemical conditions intact. Exposure tests were conducted with two aquatic species that occur in sediment and water, respectively. Comparison between the two methods showed that the standard protocol tends to overestimate risks for PAHs and underestimates the risks for heavy metals, in terms of accumulated amounts. Sample handling largely affected chemical speciation, and exposure concentrations deviated from the ones observed in the undisturbed setting. This new approach may contribute to better‐founded quality criteria for sediments.
Dishwashing Water Quality Properties
Authors: Wernersson Eva Ståhl , Johansson Erik , Håkanson Håkan
Published: July 2005

In all types of professional and domestic dishwashing, water is used as a rinse medium. This article describes the difference between the quality of the dishwaters used in hand dishwashing and machine dishwashing. The dishwashing process and the detergents determine the dishwashing parameters like pH, temperature, and time. The microbiological activity and COD in the dishwater have been evaluated for the above parameters. Differences in the aerobic plate count (APC) for dishwater coming from hand dishwashing and dishwashers are compared, as well as the content of
Enterobacteriaceae
and
Bacillus cereus
. The environmental aspects on the water consumption for different types of dishwashing processes are reported. Also the methods to reduce the microbiological activity in dishwater are discussed.
Disinfection By‐product Precursor Removal from Natural Waters
Authors: Yoon Yeomin , Sinha Shahnawaz , Sohn Jinsik
Published: July 2005

This study provides a general overview on coagulation and its effectiveness in removing natural organic matter (NOM, i.e., a major disinfection byproduct (DBP) precursor) from natural waters for DBP minimization using various conventional metal coagulants such as alum and iron. Although other technologies such as activated carbon adsorption and membrane filtration are available to reduce DBP precursors, these alternative technologies are comparatively expensive processes. For the time being, coagulation may remain the reliable technology of choice for DBP minimization. In addition, identification of DBP precursors based on detailed NOM characterization and fractionation techniques can provide mechanisms for how these precursor materials could effectively be controlled in natural waters. Once identified, these potential precursor materials could then be effectively removed by in‐depth knowledge of coagulants and coagulation techniques.
Alternative Disinfection Practices and Future Directions for Disinfection By‐product Minimization
Authors: Weintraub June M. , Wright J. Michael , Venkatapathy Raghuraman
Published: July 2005

Disinfection of public water supplies is required in many countries to inactivate microbial pathogens and protect public health. Chlorine is the predominant disinfectant used worldwide for this purpose. While chlorine disinfection provides significant benefit, it can create certain disinfection by‐products (DBPs) such as trihalomethanes and haloacetic acids that may cause adverse health effects. The formation of DBPs depends on the type of disinfectant used, the presence of precursors, and operational parameters such as disinfectant dose, pH, and temperature. Thus, there are essentially three approaches to reduce the occurrence of any particular DBP: (1) alternative disinfection with, for example, chloramine, chlorine dioxide, ozone or ultraviolet radiation; (2) other treatment options (e.g., that reduce either the presence of DBP precursors or the amount of disinfectant needed); (3) approaches aimed at source water, such as watershed protection to limit the addition of DBP precursors to waterways, or the use of source water with naturally low precursor levels. The advantages and disadvantages of these options are discussed, including usage information, operational concerns, disinfectant properties, and potential impact on the occurrence of specific DBPs in drinking water supplies.
Chlorination By‐products
Authors: Michael Wright J. , Venkatapathy Raghuraman , Weintraub June M.
Published: July 2005

Disinfection of drinking water is considered one of the most successful public health interventions, effectively eliminating various waterborne diseases from many parts of the world. Chlorination is used for primary and secondary disinfection of drinking water and remains the predominant disinfectant choice worldwide. A disadvantage of chlorine and other disinfectants is their ability to react with organic and inorganic matter in water to form disinfection by‐products (DBPs). Teratogenic and carcinogenic effects have been detected in toxicological studies of DBPs, and epidemiological studies have also reported associations between DBP exposures and carcinogenic, reproductive, and developmental endpoints. Despite recent analytical improvements, many DBPs remain unidentified. The trihalomethanes are the most studied and regulated DBPs, although drinking water regulations and guidelines have been developed for several other DBPs. Exposure to DBPs can occur through ingestion, inhalation, and dermal contact depending on factors such as volatility and water usage behavior. For example, exposure to the volatile trihalomethanes can occur through all three routes of exposure, while exposure to nonvolatile haloacetic acids is primarily through ingestion. While the potential health effects associated with DBPs remain unclear, individual exposures can be reduced via point‐of‐use treatment (e.g., boiling or filtering water) prior to consumption.
Environmental Applications with Submitochondrial Particles
Authors: Oakes Diana J. , Pollak John K.
Published: July 2005

Classic toxicological methods often evaluate the outcomes of exposures to single chemicals. In the present environment, in which exposures to chemical mixtures have been significantly increased, it is inappropriate to only evaluate the toxic effects of individual chemicals. For the past 24 years, the Organization for Economic Co‐operation and Development (OECD) has provided standardized test protocols to evaluate aquatic toxicity with laboratory‐based single‐species toxicity tests, such as fish, Daphnia spp., and algae. These bioassays provide useful data of the overall toxicities of chemical mixtures that are present in aqueous samples. An example of a subcellular bioassay, is the submitochondrial particle (SMP) Test. With this test, we use the cellular organelle, the mitochondrion, which is present in all eukaryotic (nucleated) cells. Mitochondria are effectively the powerhouses of the cell, providing over 90% of all energy produced in all eukaryotic organisms. Past studies have demonstrated that the SMP test is a useful pre‐screening tool for evaluating the toxic effects of aqueous media or chemical formulations. The major limitation of the SMP test as well as other cellular and subcellular
in vitro
assays is that they cannot account for pharmacokinetic and pharmacodynamic processes that may affect the actions of chemicals
in vivo
.
Eutrophication and Organic Loading
Authors: Lowe Scott A.
Published: July 2005

Eutrophication and poor water quality are inevitably linked to excessive amounts of organic loading. Organic material comprising carbon, nitrogen, and phosphorus breaks down in the receiving waterbody. This decomposition of organic matter consumes dissolved oxygen and releases nutrients that feed algal growth. Waterbodies that have low dissolved oxygen and excess algae are termed eutrophied. Organic matter may originate from many different sources. Historically, the largest sources were discharges of raw sewage. Other sources of organic loads include wastewater treatment plants, industrial facilities, agricultural runoff, stormwater, combined sewer overflows, urban runoff, and runoff from natural systems such as forests.

The connection between eutrophication and organic loading was first realized in the 1870s by engineers in London. They concluded that when sewage was discharged into local rivers, the level of dissolved oxygen (DO) dropped, and the amount of algae increased. In other words, the rivers were eutrophied.

Raw sewage contains organic matter (including pathogens that make it so harmful when mixed in drinking water). The typical composition by weight of raw sewage is about 42% carbon (C), 7% nitrogen (N), and 1% phosphorus (P). The remaining 50% is water. This is also our human stoichiometry.
Land Use Effects on Water Quality
Authors: Steenson Ross A.
Published: July 2005

Factors that determine water quality at a site include climate, geology, biology, and land use (anthropogenic practices). Water quality varies naturally as the result of differing natural environments, but anthropogenic practices can override these natural variations. During the last several decades, research and regulatory efforts in the United States have largely focused on understanding and limiting water quality effects from specific or localized anthropogenic sources, which are termed point sources.

Point sources include farms; industrial facilities where chemicals are manufactured, used, or stored; landfills; sewage treatment plants; hazardous waste sites; mines; and construction sites.
Lead and its Health Effects
Authors: Quazi Shahida , Sarkar Dibyendu , Datta Rupali
Published: July 2005

Lead (Pb) is ubiquitous in nature, but anthropogenic activities have exacerbated the levels of Pb in the environment. In anthropogenically impacted systems, the primary sources of Pb include industrial activities such as mining operations, vehicle emissions, coal burning, refuse incineration, pesticide applications, and industrial outdoor paints applied to structural surfaces, which can increase the background soil lead levels by orders of magnitude. Between 1986 and 1995, the average Pb concentrations throughout the United States decreased by nearly 78%, with the total Pb emission decreasing about 32% as a result of the use of unleaded gasoline in automobiles, leaving Pb in paint‐impacted soils as the principal source of exterior Pb exposure. The air quality standard stipulated by the EPA for Pb is 1.5 µg/m3measured as an annual maximum quality average concentration. Lead exposure mainly occurs through inhalation of air and ingestion of Pb in food, paint, water, soil, or dust. It accumulates in blood, bones, and soft tissue and affects various organs of the body. High levels of Pb can result in anemia, kidney diseases, reproductive disorders, and neurological impairments with children being affected at levels as low as 10 µg/dL or less. Although chelation therapy for Pb poisoning has been used for more than 40 years to increase urinary excretion of Pb and decease the total body burden, its use is controversial. This has prompted researchers to consider the role of adequate nutrition, especially calcium and iron, in the prevention of the adverse effects of Pb with special reference to the reduction of Pb mobilization due to calcium intake.
Microbial Dynamics of Biofilms
Authors: Li Baikun
Published: July 2005

Biofilm is formed through the attachment and growth of microorganisms on a surface submerged in an aqueous medium. It is characterized as a matrix of cells and an associated extracellular polymeric substance (EPS) matrix. The biofilm systems can be beneficial in biological wastewater treatment for contaminants and nutrient removal. However, biofilm formation also leads to a variety of operational problems in industry and water supply systems. A distinct feature of biofilm is the heterogeneity of structure and metabolism. In terms of biofilm structure heterogeneity, the physical structure (e.g., porosity, biomass density), EPS, and channel structure inside biofilm are extensively explored in this article. In terms of biofilm metabolic heterogeneity, the differing activity of cells associated with the depth in biofilm is discussed. In addition, the microbial dynamics in two important biofilm wastewater treatment systems, sulfur reducing biofilm and nitrification/denitrification biofilm, are discussed. Finally, different mechanisms for biofilm detachment, which is the comprehensive result of mature biofilm, microbial stratification, and anoxic/anaerobic bacteria inside biofilm, are described.
Remediation and Bioremediation of Selenium‐Contaminated Waters
Authors: Higashi Richard M. , Cassel Teresa A. , Skorupa Joseph P. , Fan Teresa W.‐M.
Published: July 2005

Selenium (Se) is a trace element that occurs naturally in soils, water, biota, and food. It is nutritionally required, but Se in excess is toxic to aquatic‐associated wildlife such as fish and birds. Exposure to Se primarily occurs through the diet, not by direct exposure to water; therefore it is vital to account for the “biogeochemistry” of Se—the complex paths by which it moves from contaminated water up the foodweb. As a consequence, waterborne Se is an inappropriate focus for remediation, and this entry illustrates how such a focus can inadvertently misguide major remediation efforts. In fact, there is no fixed “target concentration” for remediation to achieve, as universally accepted water or tissue threshold concentrations for the protection of wildlife are likely to remain controversial for some time to come. This can stymie the traditional remediation strategies of containment, removal, or treatment. One approach to Se remediation that functions under changing regulatory limits is mitigation of wildlife impacts through “alternative” and “compensation” habitats. Also, strategies that take advantage of the natural biogeochemistry, such as algal volatilization of Se, may provide cost‐effective management of contaminated water; however, this approach must be combined with foodweb interruption to prevent Se bioaccumulation.
Oil Pollution
Authors: Ketkar Kusum W. , Chair Rajiv Gandhi
Published: July 2005

The word oil refers to hydrocarbons—crude oil, gasoline, heating oil, fuel oil, diesel, jet fuel, and other refined oil‐based products. Oil pollution refers to input of hydrocarbons into a water body, either on the surface of the earth or underground. Oil may directly enter surface water bodies like ponds, rivers, streams, and oceans, and it may leach into underground water. Recognizing that moving water cleans itself, oil pollution occurs when more oil enters water than natural, physical, and chemical processes can absorb it.

Accidental oil spills by oil tankers are only one of many causes of oil pollution, but they attract a lot of media attention. Media attention is justified because accidents spill a lot of oil in a short period of time. For example, oil tankerExxon Valdezspilled 11 million gallons of crude oil in Prince William Sound, Alaska, in 1989. In addition to accidental oil spills, oil may enter marine environment through natural seepage, off‐shore oil drilling, illegal disposal of waste water containing oil from tankers, tank barges and other vessels, land‐based petrochemical industrial complexes, runoff containing oil from roads, oil‐contaminated stormwater, and sludge from municipalities and numerous other land‐based activities. Initially, oil‐contaminated water may enter local streams, rivers, lakes, or ponds, but ultimately it is dumped into the oceans. According to Oceana, 80% of oil dumped into the sea is from inland operators, of which 44% is the result of direct dumping or coastal drainage 33% is transported through the atmosphere, and the remaining 20% comes from accidental or deliberate spills from vessels and marine facilities (see Fig. 1) (1).
Salmonella: Monitoring and Detection in Drinking Water
Authors: Purohit Hemant J. , Kapley Atya
Published: July 2005

Salmonellaare known to be etiological agents for typhoid fever, salmonellosis, and gastrointestinal infections, and are spread by water‐ and foodborne infections in humans and animals. Detection of the causative organism is important to control the spread of disease. Here, we review the methods for detection ofSalmonellain water samples.
Trace Metal Speciation
Authors: Lead Jamie R.
Published: July 2005

Trace metals may be defined as those metals whose concentration is low enough so that their presence exerts a negligible influence on the overall chemistry of a water body. They can be contrasted with major ions that are present in sufficient amounts to affect the chemistry of the system. Major metal ions include the alkali and alkaline earth metals (Na, K, Ca, Mg) and perhaps Al, Fe, and Mn. Although there is no strict definition of a “trace metal,” we usually consider the transition metals, certain metalloids, and lanthanides. Radioactive elements are often considered separately. The potential effects on ecological and human health created by a certain number of trace metals mean that these metals are of particular importance and are the subject of intensive study. The effects of these metals may often be deleterious, but many metals are also micronutrients. In no order, some of the most important and most investigated trace metals are chromium (Cr), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd), tin (Sn), mercury (Hg), and lead (Pb).
Water Quality Management in a Forested Landscape
Authors: Williams Thomas M.
Published: July 2005

Forested watersheds produce the highest quality water of any land use. High rates of infiltration prevent surface runoff in most undisturbed temperate forests, resulting in little suspended sediment or dissolved nutrients in streams of forested areas. Suspended sediment from poorly designed logging, especially improperly located or constructed haul roads, is the most important cause of water quality impairment caused by management of forested watersheds. Using best management practices decreases the amount of sediment caused by logging or site preparation by 90%. Occasionally, dissolved nitrate‐nitrogen can be found at elevated levels. Generally, elevated nitrate has been found on soils with large amounts of soil organic nitrogen in cool climates where growth of the new forest is not rapid. Air pollution may also contribute to elevated nitrate in streams where nitrogen deposition is high.
Water Quality Management in the
U
.
S
.: History of Water Regulation
Authors: Alum Absar
Published: July 2005

One of the hallmarks of the last century is increased public awareness of water quality, which has been augmented by plummeting water quality and steadily increasing population. Though water has historically been considered a commodity free for all, in the recent past, water quality and quantity have emerged as the bases of major conflicts on local, regional, national, and international levels. Under the new paradigm, water is perceived as a marketable commodity. Like any marketable commodity, the quality of water is dictated by the type of usage and is valued based on market laws of supply and demand. In the United States, it is estimated that one acre‐foot of water used in agriculture and industry would generate revenue of $400 and $400,000, respectively. In the United States, the water quality management program has evolved over several decades. Based on the area of use and type of water, the history of water quality management can be divided into drinking water and wastewater regulations. Early legislation focused on ensuring the appropriate quality of drinking water, whereas the emergence of wastewater management is relatively new. Developing and implementing water quality standards and criteria achieve the appropriate quality of finished drinking water and reclaimed wastewater.
Road Salt
Authors: Eric Benbow M. , Merritt Richard W.
Published: July 2005

Road salt used for roadway and walkway deicing is typically sodium chloride (NaCl). The crystalline structure of NaCl lowers the freezing point of water during ice removal and prevention. Less commonly used, and more expensive, alternatives are inorganic salts containing chloride or calcium magnesium acetate (a mixture of calcium and magnesium acetates). The increased costs of these deicer alternatives dictate that, at present, NaCl is the most economical and practical agent for winter snow and ice removal. However, the impacts of NaCl on environmental resources are a concern and are understudied for many aquatic ecosystem parameters. Short‐term toxicity studies have shown that both mortality and nonlethal effects among aquatic zooplankton, macroinvertebrates, and fish are highly variable, species‐dependent, and related to test conditions. Larger scale and longer term studies that evaluate complex community and ecosystem level responses are needed for a better understanding of the effects of deicing agents in nature.
Harvesting Rainwater
Authors: Keremane Ganesh B.
Published: July 2005

Humankind's most serious challenge now might not be war or hunger or disease or even the collapse of civic order; it may be the lack of freshwater that justifies the present scenario that freshwater is a scarce resource. Although it is the commonest and the most critical stuff on the earth, water has been always an undervalued resource. For all our basic vital needs, a major portion of the water is drawn from less than 1% of the readily accessible part of the world's freshwater resources, thus making it a scarce resource. The prevailing water scarcity experienced in most of the arid and semiarid regions of the world can be attributed to high water stress and unsustainable rates of withdrawal. The trend toward irrigating farmland is responsible for much of the pressure on water supply, but poor water management and conservation practices have also contributed to the decline in the quality and availability of water. These are the reasons that water is a scarce resource in many parts of the world, mostly in the developing world. With widely available evidence of the crisis, rudimentary conservation measures, application of new technology, and sensible conservation practices could do much to stabilize water withdrawals. Harvesting rainwater is one technology.
Water Markets in
I
ndia: Economic and Institutional Aspects
Authors: Diwakara Halanaik
Published: July 2005

In India, where property rights to both surface and groundwater are ambiguous, informal selling and buying are popping up in different parts of the country. The illegal water markets are prominent because of the profit from the sale of water for nonagricultural purposes. There are no legal instruments to limit the volume of groundwater extracted, which has resulted in negative economic effects on groundwater irrigation in different parts of India. In the absence of marginal cost pricing, the true value of water is not reflected. Water is increasingly becoming a scarce resource, so water markets could be an important means of reallocating the resources to high value use. To this end, there is a dire need for suitable water laws to define property rights, regulate the volume of water extracted, implement marginal cost pricing for electricity and water, set well‐spacing norms, and promote self‐governing institutions for collective action to achieve sustainable use of resources.
Lessons from the Rising Caspian
Authors: Zonn Igor S.
Published: July 2005

The Caspian Sea is the biggest inland body of water in the world. Its surface area is roughly equivalent to the combined area of the Netherlands and Germany (about 400,000 km
2
, or 144,000 mi
2
). The surface water inflow into the sea is formed by the flow of the Volga, Ural, Terek, Sulak, Samur, and Kura Rivers, and small Caucasian and Iranian rivers. The watershed area of the Caspian Sea is 3.5 million square kilometers. The basin of the Volga River makes up nearly 40% of the territory of the catchment of the Caspian Sea, and it supplies about 80% of the total volume of annual water flow into the sea. All components of the Caspian ecosystem, directly or indirectly, to a greater or lesser extent, are influenced by river flow.
Reaching Out: Public Education and Community Involvement in Groundwater Protection
Authors: Nelson Jennifer
Published: July 2005

Throughout its existence, The Groundwater Foundation (TGF) has identified public education and community involvement as vital ingredients to successful groundwater protection activities. TGF is an international nonprofit organization based in Lincoln, Nebraska, with a mission to educate and motivate the public to care about and for groundwater. Groundwater provides drinking water to nearly half of the U.S. population (1) and is critical for other economic uses such as irrigation, agriculture, and industry. Unfortunately, because it is a hidden resource, the general public knows comparatively little about groundwater or how to protect it. Providing education to stakeholders about the value of groundwater is an excellent way to illustrate how individual and group decisions and activities can have a direct impact on the quality and quantity of local groundwater resources.
Ecoregions: A Spatial Framework for Environmental Management
Authors: Salequzzaman Md.
Published: July 2005

Ecoregionization is a process of delineating and classifying ecologically distinctive areas of ecological land. Each area can be viewed as a discrete system that has resulted from the mesh and interplay of the geologic, landform, soil, vegetative, climatic, wildlife, water, and human factors where ecological functions and processes are continuing. The dominance of any one or more of these factors varies with the given ecological land unit. This holistic approach to land classification can be applied incrementally on a scale‐related basis from site‐specific ecosystems to very broad ecosystems (1). Ecological processes, evolutionary mechanisms, and geological forces are continually reshaping landscapes across various scales of time and space and result in distinctive but dynamic ecoregions. All of the world's food and most medicines and raw materials are derived from these processes and associated biodiversity. Thus ecoregions gain their identity through spatial differences in a combination of landscape characteristics. Several factors such as topography, hydrology, and nutrients are important to identify these characteristics that may vary from one place to another in an ecoregion.