Showing papers by "United States Environmental Protection Agency published in 1998"
TL;DR: Clark, Lynch, and Wyckoff as discussed by the authors have been employed at the American Institute of Biological Sciences (AIBS) since 1998, where they were employed in the Department of Botany, Duke University, Durham, NC 27708; Chris Fastie and Stephen T. Jackson are at the University of Wyoming, Laramie, WY 82701; George Hurtt and Stephen Pacala are at Princeton University, Princeton, NJ 08544-1003; Carter Johnson is at South Dakota State University, Brookings, SD 57007; George A. King is
Abstract: James S. Clark, Jason Lynch, and Peter Wyckoff are in the Department of Botany, Duke University, Durham, NC 27708; Chris Fastie and Stephen T. Jackson are in the Department of Botany, University of Wyoming, Laramie, WY 82701; George Hurtt and Stephen Pacala are in the Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544-1003; Carter Johnson is in the Department of Horticulture and Forestry, South Dakota State University, Brookings, SD 57007; George A. King is at Dynamic Corporation, US EPA National Health and Environmental Effects Research Laboratory, Corvallis, OR 97333; Mark Lewis is in the Math Department, University of Utah, Salt Lake City, UT 84112; Colin Prentice is at the School of Ecology, Lund University, Lund, Sweden; Eugene W. Schupp is in the Department of Rangeland Resources, Utah State University, Logan, UT 84322; and Thompson Webb III is in the Department of Geological Sciences, Brown University, Providence, RI 029121846. ? 1998 American Institute of Biological Sciences. A plausible explanation
705 citations
TL;DR: The potential role of environmental endocrine disruption in the induction of breast, testicular, and prostate cancers, as well as endometriosis, is evaluated and some of the ongoing activities to deal with this matter are listed.
Abstract: This report is an overview of the current state of the science relative to environmental endocrine disruption in humans, laboratory testing, and wildlife species. Background information is presented on the field of endocrinology, the nature of hormones, and potential sites for endocrine disruption, with specific examples of chemicals affecting these sites. An attempt is made to present objectively the issue of endocrine disruption, consider working hypotheses, offer opposing viewpoints, analyze the available information, and provide a reasonable assessment of the problem. Emphasis is placed on disruption of central nervous system--pituitary integration of hormonal and sexual behavioral activity, female and male reproductive system development and function, and thyroid function. In addition, the potential role of environmental endocrine disruption in the induction of breast, testicular, and prostate cancers, as well as endometriosis, is evaluated. The interrelationship of the endocrine and immune system is documented. With respect to endocrine-related ecological effects, specific case examples from the peer-reviewed literature of marine invertebrates and representatives of the five classes of vertebrates are presented and discussed. The report identifies some data gaps in our understanding of the environmental endocrine disruption issue and recommends a few research needs. Finally, the report states the U.S. Environmental Protection Agency Science Policy Council's interim position on endocrine disruption and lists some of the ongoing activities to deal with this matter.
702 citations
TL;DR: The results of this pooled analysis confirm that lead-contaminated house dust is the major source of lead exposure for children and demonstrate that a strong relationship between interior dust lead loading and children's blood lead levels persists at dust lead levels considerably below the U.S. Department of Housing and Urban Development's current postabatement standards and the Environmental Protection Agency's guidance levels.
458 citations
Mississippi State University1, Vanderbilt University2, University of Maryland, Baltimore3, United States Environmental Protection Agency4, North Carolina State University5, Loyola University Medical Center6, University of Louisiana at Monroe7, University of Michigan8, Bayer Corporation9, Rutgers University10, University of Minnesota11
TL;DR: A group of experts convened to examine scientific questions using the organophosphorus (OP) pesticides as the case study concluded that OP pesticides act by a common mechanism of toxicity if they inhibit acetylcholinesterase by phosphorylation and elicit any spectrum of cholinergic effects.
440 citations
TL;DR: In this paper, the photoreaction of the colored dissolved organic matter (CDOM) in sunlight caused a decrease in UV and visible absorbance that occurred most rapidly in the UV-B (280−315 nm) region.
Abstract: Photoreactions of dissolved organic matter can affect the oxidizing capacity, nutrient dynamics, trace gas exchange, and color of surface waters. This study focuses on factors that affect the photoreactions of the colored dissolved organic matter (CDOM) in the Satilla River, a coastal river that has high concentrations of dissolved organic carbon (DOC) (2.0 ± 0.2 mM C) and iron (12 ± 2 μM) in its freshwater reach. Quantum yields for the photoproduction of dissolved inorganic carbon (DIC) and carbon monoxide (CO) from Satilla CDOM decreased exponentially in the 300−450 nm spectral region. Photoreaction of the CDOM in sunlight caused a decrease in UV and visible absorbance that occurred most rapidly in the UV-B (280−315 nm) region, indicating that CDOM photoreactions can enhance exposure of aquatic organisms to DNA-damaging UV radiation. The role of iron in the photooxidation was investigated by adding fluoride ions or deferoxamine mesylate (DFOM) to the water to form unreactive Fe3+ complexes, thus inhibit...
396 citations
TL;DR: Analysis of the trophic transfer potentials of trace elements for which data are available in zooplankton, bivalves, and fish, suggests that slight variations in assimilation efficiency or elimination rate constant may determine whether or not some trace elements are biomagnified.
366 citations
TL;DR: It is demonstrated that ACE is important for achieving in vivo fertilization and that sperm from mice lacking both ACE isozymes show defects in transport within the oviducts and in binding to zonae pellucidae, establishing that somatic ACE in males is not essential for their fertility.
Abstract: The angiotensin-converting enzyme (ACE; EC 3.4.15.1) gene (Ace) encodes both a somatic isozyme found in blood and several other tissues, including the epididymis, and a testis-specific isozyme (testis ACE) found only in developing spermatids and mature sperm. We recently used gene targeting to disrupt the gene coding for both ACE isozymes in mice and reported that male homozygous mutants mate normally but have reduced fertility; the mutant females are fertile. Here we explore the male fertility defect. We demonstrate that ACE is important for achieving in vivo fertilization and that sperm from mice lacking both ACE isozymes show defects in transport within the oviducts and in binding to zonae pellucidae. Males generated by gene targeting that lack somatic ACE but retain testis ACE are normally fertile, establishing that somatic ACE in males is not essential for their fertility. Furthermore, male and female mice lacking angiotensinogen have normal fertility, indicating that angiotensin I is not a necessary substrate for testis ACE. Males heterozygous for the mutation inactivating both ACE isozymes sire wild-type and heterozygous offspring at an indistinguishable frequency, indicating no selection against sperm carrying the mutation.
331 citations
TL;DR: A review of the literature published on the genotoxicity of industrial wastes and effluents using short-term genetic bioassays is presented, and potential sources of genotoxic activity are identified.
Abstract: In excess of several million pounds of genotoxic and/or carcinogenic industrial wastes are released into the U.S. environment each year. Chemical characterization of these waste materials can rarely provide an adequate assessment of their genotoxicity and potential hazard. Bioassays do not require prior information about chemical composition and can effectively assess the genotoxicity of complex waste materials. The most commonly used genotoxicity assay has been the Salmonella mutagenicity assay. Results with this system have shown that the genotoxic potency of industrial wastes can vary over 10 orders of magnitude, from virtually nondetectable to highly potent. Industries employing similar industrial processes generally release wastes of similar potency. Extremely high potency wastes include those from furazolidone and nitrofurfural production. Pulp and paper mills, steel foundries, and organic chemical manufacturing facilities also discharge wastes of noteworthy potency. Treatment and remediation of some wastes, such as pulp and paper mill effluents, have been shown to reduce or eliminate genotoxicity. However, in other cases, treatment and remediation have been shown to enhance genotoxicity, such as for fungal treatment of oils. Analyses of samples collected from areas known to receive industrial wastes and effluents have shown that genotoxins can accumulate in the receiving environment and have adverse effects on indigenous biota. The evaluation of hazardous wastes and effluents by genotoxicity assays may provide data useful not only for hazard identification but for comparative risk assessment.
322 citations
TL;DR: The selective impairments of heterozygous mice in a spatial learning task suggest that the hippocampal/cortical dopaminergic system may be uniquely vulnerable to the partial loss of the D1A receptor.
303 citations
TL;DR: The relationship of total and methyl mercury concentrations in fish to those of sediments from corresponding locations was fish-species dependent, in addition to several abiotic factors, and among fish species analyzed, hardhead cat fish, gafftopsail catfish, and sand seatrout contained the highest concentrations of mercury.
Abstract: Concentrations of total mercury and methyl mercury were determined in sediment and fish collected from estuarine waters of Florida to understand their distribution and partitioning. Total mercury concentrations in sediments ranged from 1 to 219 ng/g dry wt. Methyl mercury accounted for, on average, 0.77% of total mercury in sediment. Methyl mercury concentrations were not correlated with total mercury or organic carbon content in sediments. The concentrations of total mercury in fish muscle were between 0.03 and 2.22 (mean: 0.31) μg/g, wet wt, with methyl mercury contributing 83% of total mercury. Methyl mercury concentrations in fish muscle were directly proportional to total mercury concentrations. The relationship of total and methyl mercury concentrations in fish to those of sediments from corresponding locations was fish-species dependent, in addition to several abiotic factors. Among fish species analyzed, hardhead catfish, gafftopsail catfish, and sand seatrout contained the highest concentrations of mercury. Filtered water samples from canals and creeks that discharge into the Florida Bay showed mercury concentrations of 3–7.4 ng/L, with methyl mercury accounting for <0.03–52% of the total mercury. Consumption of fish containing 0.31 μg mercury/g wet wt, the mean concentration found in this study, at rates greater than 70 g/day, was estimated to be hazardous to human health.
285 citations
TL;DR: In this paper, an intermediate-scale land cover data set is generated for the conterminous United States using U.S. Standard Federal Regions (USFR) on a region-by-region basis using a standard land cover classification legend.
Abstract: As part of the activities of the Multi-Resolution Land Characteristics (MRLC) Interagency Consortium, an intermediate-scale land cover data set is being generated for the conterminous United States. This effort is being conducted on a region-by-region basis using U.S. Standard Federal Regions. To date, land cover data sets have been generated for Federal Regions 3 (Pennsylvania, West Virginia, Virginia, Maryland, and Delaware) and 2 (New York and New Jersey). Classification work is currently under way in Federal Region 4 (the southeastern United States), and land cover mapping activities have been started in Federal Regions 5 (the Great Lakes region) and 1 (New England). It is anticipated that a land cover data set for the conterminous United States will be completed by the end of 1999. A standard land cover classification legend is used, which is analogous to and compatible with other classification schemes. The primary MRLC regional classification scheme contains 23 land cover classes.
TL;DR: With 12 pesticides that mode of action judgments can be made, 11 disrupt thyroid-pituitary homeostasis only; no chemical is mutagenic only; and acetochlor may have both antithyroid and some Mutagenic activity.
Abstract: Of 240 pesticides screened for carcinogenicity by the U.S. Environmental Protection Agency Office of Pesticide Programs, at least 24 (10%) produce thyroid follicular cell tumors in rodents. Thirteen of the thyroid carcinogens also induce liver tumors, mainly in mice, and 9 chemicals produce tumors at other sites. Some mutagenic data are available on all 24 pesticides producing thyroid tumors. Mutagenicity does not seem to be a major determinant in thyroid carcinogenicity, except for possibly acetochlor; evidence is less convincing for ethylene thiourea and etridiazole. Studies on thyroid-pituitary functioning, including indications of thyroid cell growth and/or changes in thyroxine, triiodothyronine, or thyroid-stimulating hormone levels, are available on 19 pesticides. No such antithyroid information is available for etridiazole, N-octyl bicycloheptene dicarboximide, terbutryn, triadimefon, and trifluralin. Of the studied chemicals, only bromacil lacks antithyroid activity under study conditions. Intrathyroidal and extrathyroidal sites of action are found: amitrole, ethylene thiourea, and mancozeb are thyroid peroxidase inhibitors; and acetochlor, clofentezine, fenbuconazole, fipronil, pendimethalin, pentachloronitrobenzene, prodiamine, pyrimethanil, and thiazopyr seem to enhance the hepatic metabolism and excretion of thyroid hormone. Thus, with 12 pesticides that mode of action judgments can be made, 11 disrupt thyroid-pituitary homeostasis only; no chemical is mutagenic only; and acetochlor may have both antithyroid and some mutagenic activity. More information is needed to identify other potential antithyroid modes of thyroid carcinogenic action.
TL;DR: The results indicated that the Pseudomonas-selective PCR primers were highly specific and may represent a powerful tool for pseudomonas population structure analyses and taxonomic confirmations.
Abstract: Pseudomonas species are plant, animal, and human pathogens; exhibit plant pathogen-suppressing properties useful in biological control; or express metabolic versatilities valued in biotechnology and bioremediation. Specific detection of Pseudomonas species in the environment may help us gain a more complete understanding of the ecological significance of these microorganisms. The objective of this study was to develop a PCR protocol for selective detection of Pseudomonas (sensu stricto) in environmental samples. Extensive database searches identified a highly selective PCR primer pair for amplification of Pseudomonas 16S rRNA genes. A protocol that included PCR amplification and restriction analysis, a general cloning and sequencing strategy, and phylogenetic analyses was developed. The PCR protocol was validated by testing 50 target and 14 nontarget pure cultures, which confirmed the selectivity to 100%. Further validation used amplification of target sequences from purified bulk soil DNA followed by cloning of PCR products. Restriction analysis with HaeIII revealed eight different fragmentation patterns among 36 clones. Sequencing and phylogenetic analysis of 8 representative clones indicated that 91.7% of the products were derived from target organisms of the PCR protocol. Three patterns, representing only 8.3% of the 36 clones, were derived from non-Pseudomonas or chimeric PCR artifacts. Three patterns, representing 61.1% of the clones, clustered with sequences of confirmed Pseudomonas species, whereas two patterns, representing 30.6% of the clones, formed a novel phylogenetic cluster closely associated with Pseudomonas species. The results indicated that the Pseudomonas-selective PCR primers were highly specific and may represent a powerful tool for Pseudomonas population structure analyses and taxonomic confirmations.
TL;DR: Consensus was reached regarding the significant intermediary roles of cell proliferation and PPAR-alpha receptor expression and activation in tumor formation and risk assessments based on tumor data may not be appropriate.
TL;DR: The same acute exposure to As, V, or Zn that activated MAPK was sufficient to induce a subsequent increase in IL-8 protein expression in BEAS cells, suggesting that MAPK may mediate metal-induced expression of inflammatory proteins in human bronchial epithelial cells.
Abstract: We have previously shown that in vitro exposure to metallic compounds enhances expression of interleukin (IL)-6, IL-8, and tumor necrosis factor-α in human bronchial epithelial cells. To characteri...
TL;DR: The results indicated that no species was consistently most sensitive, and that a suite of aquatic plant test species may be needed to perform accurate risk assessments of herbicides.
Abstract: This data relates to the relative sensitivity of five species of aquatic macrophytes and six species of algae to four commonly used herbicides (atrazine, metribuzin, alachlor, and metoachlor). Toxicity tests consisted of 96 hour (duckweed and algae) or 14 day (submerged macrophytes) static exposures. The triazine herbicides (atrazine and metribuzin) were significantly more toxic to aquatic plants than were the acetanilide herbicides (alachlor and metolachlor). Toxicity studies ranked metribuzin > atrazine > alachlor > metolachlor in decreasing order of overall toxicity to aquatic plants. Relative sensitivities of macrophytes to thse herbicides decreased in the order of Ceratophyllum > Najas > Elodea > Lemna > Myriophyllum. Relative sensitivities of algae to herbicides decreased in the order of Selenastrum > Chlorella > Chlamydomonas > Microcystis > Scenedesmus > Anabaena. Algae and macrophytes were of similar overall sensitivities to herbicides. Data indicated that Selenastrum, a commonly tested green alga, was generally more sensitive compared to other plant species. Lemna minor, a commonly tested floating vascular plant, was of intermediate sensitivity, and was fivefold less sensitive than Ceratophyllum, which was the most sensitive species tested. The results indicated that no species was consistently most sensitive, and that a suite of aquatic plant test species may be needed to perform accurate risk assessments of herbicides.
TL;DR: In this article, the authors investigated the relationship between stream chemistry and watershed land cover at the regional scale, and analyzed data from 368 wadeable streams sampled in the mid-Atlantic region of the U.S. during spring 1993-1994.
Abstract: In order to investigate the relationship between stream chemistry and watershed land cover at the regional scale, we analyzed data from 368 wadeable streams sampled in the mid-Atlantic region of the U.S. during spring 1993–1994. Study sites were selected using a probability sample and the digitized version of the 1:100,000 scale USGS map stream network as the sample population. Both classified Thematic Mapper (TM) and USGS Land Use/Land Cover (LULC) data were used to quantify land cover in the study watersheds. On average, the most common land cover was forest (77%) followed by agriculture (20%), and urban (1%). Multiple regression analysis showed that concentrations of Cl−, nutrients, acid neutralization capacity, and base cations were the analytes most strongly related to watershed land cover. Despite large differences in resolution and age of the TM and LULC data sources, similar results were obtained with the two sources. Using a greater number of land cover subclasses did not greatly improve the land cover-chemistry relationships. Ecoregions with predominantly forested land cover had weaker relationships than ecoregions with more agricultural and/or urban land cover. In studies or databases without land cover information, Cl− concentration is a good surrogate indicator for general human disturbance in the watershed.
TL;DR: Cigarette smoking among teenagers was associated with increases in disomic sperm and a diminution in specific aspects of semen quality that may affect male fertility and may increase future chances of fathering offspring with aneuploidy syndromes.
TL;DR: The most parsimonious phylogenetic tree places the high-elevation species, B. andrewsi, as the sister taxon to the other Asian Bufo populations; these high-Elevation populations are postulated to have had a vicariant origin approximately 5 million years before present.
TL;DR: The Clean Water Act defines concentrated animal feeding operations as point sources of pollution that are required to obtain permits to discharge into waters of the USA and all other agricultural sources are considered nonpoint and are not regulated under federal law as mentioned in this paper.
Abstract: Pollution of lakes, rivers, and estuaries from agricultural sources of P is a major water quality problem in the USA. This paper explains the regulatory and nonregulatory programs developed by the U.S. Environmental Protection Agency (USEPA) to implement its legal mandate to control water pollution from these sources. The Clean Water Act defines concentrated animal feeding operations as point sources of pollution that are required to obtain permits to discharge into waters of the USA. All other agricultural sources are considered nonpoint and are not regulated under federal law. The USEPA provides grant money to the states to develop and implement nonpoint source programs. The Coastal Zone Act Reauthorization Amendments of 1990 requires coastal states to adopt nonpoint management measures that are backed by enforceable policies and mechanisms. For water bodies that continue to be impaired despite the basic implementation of these laws and other programs, states are required to develop a total maximum daily load (TMDL). The TMDL process is the quantitative basis for reaching water quality standards. The USEPA is putting a new emphasis on controlling nutrient pollution sources to meet the goal of the Clean Water Act.
TL;DR: Comparisons of LCegg50s indicate that the tested species were approximately 8 to 38 times less sensitive to TCDD than lake trout, the most sensitive species evaluated to date.
Abstract: The toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to fathead minnow (Pimephales promelas), channel catfish (Ictalurus punctatus), lake herring (Coregonus artedii), medaka (Oryzias latipes), white sucker (Catastomus commersoni), northern pike (Esox lucius), and zebrafish (Danio danio) were observed during early life-stage development after waterborne exposure of fertilized eggs. Species sensitivity based on TCDD-Cegg (TCDD concentration in eggs) was determined by effects observed over a 32-d period for all species except lake herring in which a 100-d period was used. Signs of TCDD toxicity, including edema, hemorrhaging, and craniofacial malformations were essentially identical to those observed in salmonids following TCDD egg exposure and preceded or accompanied mortality most often during the period from hatch through swim-up. The no-observed-effect concentrations and lowest-observed-effect concentrations, based on significant decreases in survival and growth as compared to the controls, ranged from 175 and 270 pg/g for lake herring to 424 and 2,000 pg/g for zebrafish, respectively. Shapes of concentration–response curves, expressed as TCDD-Cegg versus percent mortality, were similar for all species and were consistently steep suggesting that the mechanism of action of TCDD is the same among these species. The LCegg50s (concentrations in eggs causing 50% lethality to fish at test termination) ranged from 539 pg/g for the fathead minnow to 2,610 pg/g for zebrafish. Comparisons of LCegg50s indicate that the tested species were approximately 8 to 38 times less sensitive to TCDD than lake trout, the most sensitive species evaluated to date. When LCegg50s are normalized to the fraction lipid in eggs (LCegg,l50s), the risk to early life stage survival for the species tested ranges from 16- to 180-fold less than for lake trout.
TL;DR: In this article, the authors present a simulation model designed to determine the impact on congestion of policies for dealing with travel time uncertainty, which combines a supply side model of congestion delay with a discrete choice econometric demand model that predicts scheduling choices for morning commute trips.
TL;DR: Ecosystem management is widely proposed in the popular and professional literature as the modern and preferred way of managing natural resources and ecosystems as discussed by the authors, and seven core principles of ecosystem management define and bound the concept and provide operational meaning: (1) ecosystem management reflects a stage in the continuing evolution of social values and priorities; it is neither a beginning nor an end; ecosystem management is place-based and the boundaries of the place must be clearly and formally defined.
TL;DR: In this paper, a mass balance of surface water genotoxicity for St. Lawrence river at Montreal indicates that over 85% of the total contributions from the Montreal region are non-industrial in origin.
Abstract: Despite the noteworthy genotoxic potency of many industrial wastewaters, the genotoxic hazard posed to the downstream ecosystem and its associated biota will be determined by genotoxic loading. Municipal wastewaters, although ranking low in potency, can achieve loading values that are several orders of magnitude greater than those of most industries. Although these wastewaters are generally mixtures of wastes from several different sources, the volumetric proportion of the daily discharge that is of industrial origin rarely exceeds 30%. Genotoxicity calculations for the Montreal Urban Community (MUC) municipal wastewater treatment facility indicate that over 90% of the genotoxic loading (31.1 kg benzo(a)pyrene equivalents per day) is nonindustrial in origin. Moreover, a mass balance of surface water genotoxicity for St. Lawrence river at Montreal indicates that over 85% of the total contributions from the Montreal region are nonindustrial in origin. Additional calculations for the Great Lakes, and other rivers throughout the world, provide further support of a strong relationship between surface water genotoxicity and population. Despite some information about physical/chemical properties, the identity of the putative genotoxins in municipal wastewaters and surface waters remains a mystery. Likely candidates include potent genotoxins, such as N-nitroso compounds and aromatic amines, known to be present in human sanitary wastes, as well as genotoxic PAHs known to be present in many municipal wastewaters. Calculations based on literature data indicate that human sanitary wastes may be able to account for a substantial fraction (4–70%) of the nonindustrial loading from municipal wastewaters. Similar calculations suggest that pyrogenic PAHs that enter municipal wastewaters via surface runoff can only account for a small fraction (
TL;DR: In this article, the quantity of dead wood (downed and standing dead) in 25 long-term (up to 30 yr) permanent forest plots located in six different life zones of Venezuela was determined.
Abstract: Dead wood can be an important component of the carbon pool in many forests, but few measurements have been made of this pool in tropical forests, To fill this gap, we determined the quantity of dead wood (downed and standing dead) in 25 long-term (up to 30 yr) permanent forest plots located in six different life zones of Venezuela. Downed wood was separated into fine (< 10 cm in diameter) and coarse (≥ 10 cm in diameter) classes, and three decomposition states (sound, intermediate, or rotten). The total quantity of dead wood, averaged by life zone, was lowest in the dry (2.43 Mg/ha), reached a peak in the moist (42.33 Mg/ha) and decreased slightly in the wet (34.50 Mg/ha) life zone. Most of the dead wood was in the standing dead category (about 42–76% of the total). The decomposition state of dead wood in all plots was mostly rotten (45%) or intermediate (44%); there was little sound wood (11%). Turnover rates of dead wood generally ranged between 0.03/yr to 0.52/yr with no clear trend with life zone. The large amount of dead wood in some plots was equivalent to about 20 percent or less of aboveground biomass, indicating that dead wood can represent a significant amount of carbon in these forests.
TL;DR: In this article, the authors present nine fundamenal principles that should be considered when designing adaptation policy, for example, a sound understanding of the potential regional effects of climate on human and ecological systems is required to target appropriate invest- ments in adaptive responses The distribution of potential impacts across different populations and the mechanisms by which these impacts occur are also key to effective adaptation measures.
Abstract: Adaptation is an important approach for protecting human health, ecosystems, and eco- nomic systems from the risks posed by climate variability and change, and for exploiting beneficial opportunities provided by a changing climate This paper presents 9 fundamenal principles that should be considered when designing adaptation policy, for example, a sound understanding of the potential regional effects of climate on human and ecological systems is required to target appropriate invest- ments in adaptive responses The distribution of potential impacts across different populations and the mechanisms by which these impacts occur are also key to effective adaptation measures Options for coping with climatic changes must be considered in the context of multiple stressors Further, adapta- tion is likely to exhibit varying levels of effectiveness as demonstrated by current efforts to deal with climate variability Potential adverse side effects of adaptive strategies must also be accounted for to avoid solutions that are worse than the problem These issues and others are presented in this paper, with examples from various impacts studies to illustrate key points
TL;DR: The hypothesis that environmental conditions in the tropical areas of the world can support the growth and establishment of populations of faecal bacteria in the soil is supported, and water quality standards recommended by the U.S. Environmental Protection Agency may not be directly applicable to tropical island environments.
Abstract: We have previously documented that faecal indicator bacteria (Escherichia coli, faecal coliform, enterococci) recommended by the U.S. Environmental Protection Agency (USEPA) to establish recreational water quality standards are naturally found in high concentrations in the surface and subsurface of soils in Hawaii. Rain, the source of all streams in Hawaii, washes the soil sources of faecal bacteria into all the streams of Hawaii, at concentrations which consistently exceed the USEPA recreational water quality standards. The objective of this study was to test the hypothesis that faecal bacteria are able to establish themselves in the soil environments of tropical islands by conducting the same study in Guam, a tropical pacific island with warmer temperatures and higher humidity than Hawaii. The same methods and study design used in Hawaii was used in Guam. The results of the study conducted in Guam revealed that all streams contain consistently high concentrations of faecal coliform, E. coli, and enterocci which exceeded the old USEPA recreational water quality standard of 200 faecal coliform/100 ml as well as the new water quality standards of 126 E. coli/100 ml or 33 enterococci/100 ml. These same faecal indicator bacteria were recovered in high concentrations in surface and subsurface (18-36 cm depth) soil samples in Guam. Limited coastal water analysis showed that most coastal marine waters contain low concentrations of faecal bacteria but coastal waters impacted by stream run-off showed elevated levels of faecal bacteria. The results of this study support the hypothesis that environmental conditions in the tropical areas of the world can support the growth and establishment of populations of faecal bacteria in the soil. Thus, soil becomes an environmental, non-faecal source of faecal indicator bacteria. These results indicate that USEPA water quality standards may not be directly applicable to tropical island environments.
TL;DR: The high sensitivity, low cost, durability, and simplicity of the new single-use immunosensors make them well suited for various on-site applications.
Abstract: Sol−gel processing is used for the first time for the preparation of electrochemical immunosensors. One-step sensor fabrication, based on the coupling of sol−gel and screen-printing technologies, is employed. A low-temperature cured ink is prepared by dispersion of rabbit immunoglobulin G (RIgG), graphite powder, and a binder in the sol−gel solution. The enzyme-labeled antibody can readily diffuse toward the encapsulated antigen, which retains its binding properties, and the association reaction is easily detected at the dispersed graphite surface. Use of anti-RIgG labeled with alkaline phosphatase, naphthyl phosphate as the substrate, and amperometric detection at +400 mV (vs Ag/AgCl) results in a low detection limit of 5 ng/mL (32 pM) for the solution antigen. Tailoring the porosity of the ceramic−carbon matrix can be used for tuning the assay performance. The high sensitivity, low cost, durability, and simplicity of the new single-use immunosensors make them well suited for various on-site applications.
TL;DR: In this paper, the authors present relative numerical values of important components of variance, developed from the Surface Waters component of U.S. EPA's Environmental Monitoring and Assessment Program (EMAP) field data, and use them as a basis for further assumptions of values.
Abstract: The term trend describes the continuing directional change in the value of an indicator, generally upward or generally downward. Many policy questions concern trend across a number of sites, such as lakes in a region, rather than trend at a single site. Power to detect regional trend seldom is discussed, and monitoring designs suitable for detecting such trends rarely are explored. Components of variance and temporal sampling designs play central roles in characterizing trend detection. We present relative numerical values of important components of variance, developed from the Surface Waters component of U.S. EPA’s Environmental Monitoring and Assessment Program (EMAP) field data, and use them as a basis for further assumptions of values. We discuss power curves in general and present them in relation to temporal designs, years of field observation, components of variance, and the level of trend detected. Revisit designs give adequate power for moderate trend in 10–15 yr, even when revisits are less frequent than annually.
TL;DR: Although the rates of diarrhea were comparable after each of the two exposures, the clinical severity as determined by the mean number of unformed stools passed was lower after reexposure, and the number of anti-Cryptosporidium immunoglobulin G and A seroconversions increased after secondary exposure, but the C. parvumserum antibody response did not correlate with the presence or absence of infection.
Abstract: Healthy adults are susceptible to infection with small numbers of Cryptosporidium parvum oocysts, resulting in self-limited infection. We investigated if infection of humans with C. parvum is protective 1 year after primary exposure. At 1 year after a primary challenge with 30 to 106 oocysts, 19 healthy immunocompetent adults were rechallenged with 500 oocysts and monitored for the development of infection and/or illness. Oocyst excretion was quantitated by direct immunofluorescence with a C. parvum-specific monoclonal antibody, and anti-C. parvum antibodies in serum were detected by an enzyme-linked immunosorbent assay. Fewer subjects shed oocysts after the second exposure (3 of 19; 16%) than after the first exposure (12 of 19; 63%) (P < 0.005). Although the rates of diarrhea were comparable after each of the two exposures, the clinical severity as determined by the mean number of unformed stools passed was lower after reexposure (11.25 versus 8.62; P < 0.05). The number of anti-Cryptosporidium immunoglobulin G and A seroconversions increased after secondary exposure. However, the C. parvum serum antibody response did not correlate with the presence or absence of infection.