This bibliography lists 99 articles on risk assessment and risk communication as it relates to water resources, risk assessment theories, and methodologies dated 1995 - 1999. This bibliography updates Risk Assessment and Communication Related to Water Resources II (QB96-04). All articles are from the AGRICOLA database.
This electronic bibliography is intended primarily to provide awareness of recent investigations and discussions of a topic and is not intended to be in-depth and exhaustive. The inclusion or omission of a particular publication or citation should not be construed as endorsement or disapproval. Citations are arranged alphabetically by title and abstracts are included where available. All citations are in English unless otherwise noted.
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Descriptors: pinus-radiata, hardboard, waste water, pulp mill effluent, factory-effluents, toxicity, risk assessment, biological indicators, rainbow-trout, daphnia-pulex vibrio, vibrio-fischeri.
Abstract: The risk assessment of two kinds of wastewaters from a hardboard mill were determined by acute toxicity tests. Three different bioindicators, water fleas from a local stream (Daphnia pulex), local fish hatchery specimens (Salmo gaird neri), and a bacterial test ( Vibrio fischeri Microtox test) were considered. The three tests showed a wide range of sensitivities and presented different but compatible LC50/EC50 values, with S. gairdneri being the most sensitive. The obtained toxicity v alues could serve as a reference to evaluate the toxicity of wastewater from this type of industries.
Descriptors: Drinking water, Health-aspects, Congresses, Contamination, Water supply,
Descriptors: water pollution, contamination.
Abstract: The vulnerability of a shallow aquifer in south-central Kansas to contamination by atrazine (2-chloro-4, ethylamino-6-isopropylamine-s-triazine) was assessed by analyzing unsaturated zone soil and sediment samples from about 60 dryla nd and irrigated sites using an ultrasensitive immunoassay (detection level 0.02 microgram/kg) with verification by gas chromatography/mass spectrometry (GC/MS). Samples were collected at depths of 0 to 1.2 m (i.e., the root zone), 1.2 to 1.8 m, and 1.8 t o 3.0 m during two time periods-prior to planting and after harvest of crops. About 75% of the samples contained detectable concentrations of parent atrazine. At the shallow sampling depth, atrazine concentrations ranged from 0.5 to approximately 12 micro gram/kg. Atrazine concentrations at the intermediate (1.2-1.8m) depth generally were <1.0 microgram/kg, with most of the concentrations <0.10 microgram/kg, which suggests substantial degradation of parent atrazine in the root zone. Likewise, atrazin e concentrations from the deepest (1.8-3.0 m) depth ranged from <0.02 to 033 microgram/kg. The metabolite deethylatrazine (2-amino-4, chloro-6-isopropylamine-s-triazine) was detected by GC/MS only in 2 of 60 samples with concentrations of 1.4 and 1.5 m icrogram/kg. The reconnaissance survey shows that, in spite of atrazine use ranging from 1 to 5 or more years, there does not appear to be a significant buildup of parent compound below the root zone. Therefore, the unsaturated zone does not appear to be a major storage compartment of atrazine contamination for the underlying shallow aquifer.
Descriptors: water pollution, risk, geographical-information-systems, land use, watersheds, Montana, risk assessment.
Descriptors: water-harvesting, arid-zones, risk assessment, simulation models, stochastic-models.
Descriptors: pesticides, agricultural-chemicals, environmental impact, soil, water, risk assessment, simulation models, soil-pollution water pollution,
Descriptors: waterborne-diseases, risk assessment.
Abstract: The resurgence of outbreaks of waterborne diseases in the United States underscores the need for quantitative methods for assessing the human health risks associated with various types of waterborne pathogens in diverse environments (e.g., drinking water, waste water, recreational water) under different exposure scenarios (e.g., ingestion, inhalation from aerosols). An expert panel developed a three-stage general framework for conducting risk assessments of waterborne pathogens. An i nitial problem formulation stage involving all stakeholders identifies the purpose of the risk assessment, the critical issues to be addressed, and how the results might be used to protect public health. The analysis characterizes both the exposure and th e health effects. This compilation of quantitative and qualitative data, expert opinion, and other information yields a host/pathogen profile that explicitly identifies the assumptions and uncertainties associated with the profile. The final stage, risk c haracterization, states the likelihood and types and magnitude of effects likely to be observed in the exposed population under the expected exposure scenario, including all the inherent assumptions and uncertainties. This characterization will be used by risk managers and policy makers to reduce human health risks and by risk communication specialists to inform the public.
Descriptors: soil-pollution, polluted-soils, pollution-control, risk assessment, literature-reviews, pollutants, industrial-wastes.
Descriptors: atrazine, water quality, opportunity costs, cost benefit analysis, regulations, environmental policy, substitution, triazines, weed control, maize, sorghum, environmental impact, economic impact, application-methods, application depth , simulation models, USA, comprehensive-economic-and-environmental-policy-evaluation-system-ceepes-model, simulation-model, post emergence application, benefit risk tradeoffs.
Descriptors: aquifers, groundwater pollution, risk assessment, water-flow, unsaturated-flow, groundwater-flow hydrology, mapping, geographical information systems, simulation models, USA, vulnerability models.
Descriptors: Biological assay, Toxicity testing, Hazardous wastes, Ecological risk assessment.
Descriptors: drinking-water, risk assessment, Maryland, Virginia.
Descriptors: water pollution, point sources, surface water, contamination, atrazine, nitrogen, sediment, water quality, cropping-systems, comparisons, pollution control, alternative farming, simulation models, risk, economic evaluation, costs, ret urns, meteorological factors, Kansas, contaminant loadings, non-point-source pollution, alternative-versus-conventional-cropping-systems, risk-analysis.
Descriptors: pesticides, risk assessment, simulation models,.
Descriptors: groundwater pollution, pollutants.
Abstract: A one-dimensional groundwater transport equation with two uncertain prameters, groundwater velocity and longitudinal dispersivity, is investigated in this paper. The analytical uncertainty of the predicted contaminant concentration i s derived by the first-order mean-centered uncertainty analysis. The risk of the contaminant transport is defined as the probability that the concentration exceeds a maximum acceptable upper limit. Five probability density functions including the normal, lognormal, gamma, Gumbel, and Weibull distributions are chosen as the models for predicting the concentration distribution. The risk for each distribution is derived analytically based on the conditional probability. The mean risk and confidence interval are then computed by Monte Carlo simulation where the groundwater velocity and longitudinal dispersivity are assumed to be lognormally and normally distributed, respectively. Results from the conditional expectation of an assumed damage function show that the unconditional expectation generally underestimates the damage for low risk events. It is found from the sensitivity analysis that the mean longitudinal dispersivity is the most sensitive parameter and the variance of longitudinal dispersivity is the least sensitive one among those distribution models except the gamma and Weibull distributions.
Descriptors: polluted- soils, soil pollution, reclamation, bioremediation, groundwater pollution, petroleum-hydrocarbons, polycyclic hydrocarbons, biological treatment, petroleum, risk, industrial wastes, UK, heating oil.
Abstract: The approach to land reclamation in the UK has traditionally relied upon the use of cover and concealment which can leave a legacy of problems below the ground. Alternatively, the bulk export of materials to licensed landfill has oft en been used, but this (a) simply transfers a problem, (b) can cause considerable disruption, and (c) is becoming increasingly expensive. Remedial strategies involving the use of barrier systems or off-site removal both have their place in the efficient a nd economic development of contaminated sites. However, there is now increasing interest in the use of on-site technology which can provide cost savings and by treating, destroying or stabilizing contamination, can serve to minimize future liabilities. Th e design, costing and application of treatment, as opposed to cover or disposal, depends fundamentally on understanding the problem and evaluating the capabilities and availability of appropriate technologies. With reference to UK case studies, this paper highlights some of the options available and routes taken in order to achieve site-specific, commercially-acceptable, remedial responses.
Descriptors: contaminants, risk-factors, uncertainty, risk assessment.
Abstract: Evaluation of environmental risks posed by potentially hazardous substances requires achieving a balance between over, and underprotection, i.e., between societal benefits posed by the use of particular substances and their potential risks. Uncertainty (e.g., only laboratory data may be available, field or epidemiological data may be limited and less than clear-cut, etc.) will always exist and is often conservatively dealt with by the use of so-called "safety" or "unce rtainty" factors, some of which remain relatively little changed since their origin in 1945. Extrapolations involving safety factors for both aquatic and terrestrial environments include inter, and intraspecies, acute-to-chronic, lowest, to no-observ ed-effect concentration (NOEC), and laboratory-to-field extrapolation (e.g., extrapolation of laboratory results to the field). To be realistic, such extrapolations need to have a clear relationship with the field effect of concern and to be based on good science. The end result is, in any case, simply an estimate of a field NOEC, not an actual NOEC. Science-based versus policy-driven safety factors, including their uses and limitations, are critically examined in the context of national and international legislation on risk assessment. Key recommendations include providing safety factors as a potential threshold effects range instead of a discrete number and using experimental results rather than defaulting to safety factors to compensate for lack of inf ormation. This latter recommendation has the additional value of rendering safety factors predictive rather than simply protective. We also consider the so-called "Precautionary Principle," which originated in 1980 and effectively. addresses ri sk by proposing that the safety factor should be infinitely large.
Descriptors: estuaries, water quality, monitoring, risk assessment.
Abstract: The goal of this study was to assess a new toxicological risk ranking model, field validate it with results from a battery of sediment and water column bioassays, and identify correlations of model output with fish community and popu lation metrics. The model has five components: severity of effect, degree of response, bioassay variability, consistency, and number of measured endpoints. The model can reliable reduce an array of ambient toxicity data into a site-specific metric that is appropriate for comparisons with other metrics, such as Index of Biotic Integrity (IBI) or community diversity indices. The model is tolerant of variable amounts of data between stations. It does not generate probability limits without repeated sampling. The model can identify trends between sampling stations and document where chemical contamination is contributing to community impacts as well as where toxicological impacts are not likely to be contributing to observed population level impairment. The m odel was evaluated with field/laboratory data, Test sites were located in tributaries of Chesapeake Bay watersheds that are impacted by industrial, urban, and agricultural land use patterns. The toxicological risk scores correlate with fish community heal th metrics. The strongest correlations were between sediment toxicity risk and bottom trawl fish community diversity index.
Descriptors: aquifers, silt-loam-soils, clay-loam-soils, groundwater pollution, pollution-control, contaminants, tetrachloroethylene, trichloroethylene, sorption, diffusion, diffusion models, mathematical-models, prediction, risk assessment, milit
ary-areas, Delaware, groundwater-remediation, silty-clay-loam-soils, Dover-air-force-base.
Abstract: Analysis of subsurface soil cores from the site of a field-scale groundwater remediation experiment at Dover Air Force Base, Delaware, has revealed that tetrachloroethane (PCE) and trichloroethene (TCE) contamination extends into an aquitard underlying a groundwater aquifer. The site location is well downgradient of the locations of contaminant release, and the aquitard contamination is believed to have begun when contaminated groundwater first arrived in the overlying aquifer. Using independent estimates of sorption and diffusion properties in the accoutered layers, mathematical modeling based on diffusion in laminate slabs has been used to make inferences regarding the historical concentration conditions in the overlying aquifer. T he results suggest that plume arrival occurred within the last two decades, with some important differences in the inferred TCE and PCE plume histories. The diffusion model was also applied toward predicting future aquitard concentrations and fluxes under scenarios based on the current condition as a starting point and hypothesized conditions of future groundwater cleanup. The results demonstrate how accoutered sampling and diffusion modeling can provide essential information relevant to forensic analysis , risk assessment, and subsurface cleanup.
Descriptors: Groundwater pollution, Health-aspects, Public-opinion, Wells, Health-risk assessment.
Descriptors: pesticides, toxicity, aquatic-environment, risk assessment, toxicology, ecotoxicology.
Abstract: Risk assessment of pesticides for aquatic ecosystems is typically based on comparisons of exposure and effect concentrations at a variety of levels (tiers). At the highest tier, effects assessment can involve generating data under fi eld conditions, typically in mesocosm experiments. However, interpreting the ecological significance of effects measured in these studies can be difficult because ecological factors can influence the outcome of perturbations in the real world. The influen ce of ecological factors is not readily addressed experimentally and so a strategic modelling approach is proposed which may aid in defining acceptability of effects.
Descriptors: Pollution, environmental-aspects, ecological risk assessment, Environmental chemistry.
Descriptors: biocides, exposure, toxicity, aquatic organisms, risk, industrial-applications.
Abstract: A tiered approach was employed to determine risks posed to aquatic organisms exposed to dibromonitrilopropionamide (DBNPA). Tier one assessments used conservative exposure and toxicity data and indicated that potential toxicity warra nted a more rigorous risk assessment. Tier two used discharge and stream flow data to develop a probabilistic model of DBNPA concentrations reaching the stream. Predicted 90th percentile in-stream DBNPA concentrations were compared to all available toxici ty data for aquatic organisms at several different trophic levels. The EC10 for one organism was similar to the calculated 90th percentile of DBNPA concentrations in streams. Using the complete EC10 data set and comparing the 10th percentile EC10 with the 90th percentile environmental concentration. DBNPA did not pose a measurable risk to the aquatic ecosystem.
Descriptors: atrazine, exposure, toxicity, aquatic organisms, aquatic-environment nontarget-organisms nontarget-effects water pollution, water quality, risk, usa.
Abstract: The triazine herbicide atrazine (2-chloro-4-ethylamino-6-isopropyl-amino-s-triazine) is one of the most used pesticides in North America. Atrazine is principally used for control of certain annual broadleaf and grass weeds, primarily in corn but also in sorghum, sugarcane, and, to a lesser extent, other crops and landscaping. Atrazine is found in many surface and ground waters in North America, and aquatic ecological effects are a possible concern for the regulatory and regulated com munities. To address these concerns an expert panel (the Panel) was convened to conduct a comprehensive aquatic ecological risk assessment using probabilistic risk assessment techniques. The environmental exposure assessment concentrated on monitoring da ta from Midwestern watersheds, the area of greatest atrazine use in North America. This analysis revealed that atrazine concentrations rarely exceed 20 micrograms/L in rivers and streams that were the main focus of the aquatic ecological risk assessment. Following storm runoff, biota in lower-order streams may be exposed to pulses of atrazine greater than 20 micrograms/L, but these exposures are short-lived. The assessment also considered exposures in lakes and reservoirs. Atrazine residues were widespre ad in reservoirs (92% occurrence), and the 90th percentile of this exposure distribution for early June to July was about 5 micrograms/L. Mathematical simulation models of chemical fate were used to generalize the exposure analysis to other sites and to a ssess the potential effects of reduction in the application rates. Based on an integration of laboratory bioassay data, field effects studies, and environmental monitoring data from watersheds in high-use areas in the Midwestern United States, the Panel c oncluded that atrazine does not pose a significant risk to the aquatic environment. It is recommended that site-specific risk assessments be conducted at these sites to assess possible ecological effects in the context of the uses to which these ecosystem s are pu t and t he effectiveness and cost-benefit aspect of any risk mitigation measures that may be applied.
Descriptors: Soil pollution, Congresses, Soil ecology, Soil remediation.
Descriptors: Contaminated sediments, Environmental aspects, Congresses, Ecological risk assessment.
Descriptors: lead, exposure, wild-birds, game birds, predatory-birds, lead-poisoning, nontarget-effects, nontarget-organisms risk.
Abstract: There is increasing concern that birds in terrestrial ecosystems may be exposed to spent lead shot. Evidence exists that upland birds, particularly mourning doves (Zenaida macroura), ingest spent lead shot and that raptors ingest lea d shot by consuming wounded game. Mortality, neurological dysfunction, immune suppression, and reproductive impairment are documented effects of exposure to lead in birds. An ecological risk assessment on the impact of lead shot exposure in upland birds w as conducted and is presented in the context of the new United States Environmental Protection Agency's Ecological Risk Assessment Paradigm. A considerable amount of spent lead shot is released into the environment each year from shooting and hunting. Dov es collected from fields that are cultivated to attract mourning doves for hunting activities show evidence of ingestion of spent lead shot. Because lead can cause both acute and chronic toxicity if ingested by birds, and because there is evidence of wide spread deposition of lead shot in terrestrial ecosystems, concern for impacts on upland game birds and raptors seems warranted. Although this ecological risk assessment does not clearly define a significant risk of lead shot exposure to upland game birds, this issue merits continued scrutiny to protect our upland game bird and raptor resources.
Descriptors: crop-management, water-management, watersheds, pollution, point-sources, pollution-control, economic-analysis, risk, simulation, stochastic-processes, water quality, programs, subsidies, Georgia, non-point-source-pollution.
Descriptors: Environmental-health, Russia-Federation, Maps, Health-risk assessment, Environmentally-induced-diseases.
Descriptors: pesticides, water pollution, soil pollution
Descriptors: contaminants, water-supply irrigation-water risk assessment,
Descriptors: pulp-mill-effluent, pollutants, toxicity, aquatic-invertebrates, risk assessment.
Descriptors: Environmental-toxicology, Congresses, Pollution, Environmental-aspects, Health-risk assessment, Environmental-health.
Descriptors: dairy-effluent application-to-land, application-rates, losses-from-soil, nitrogen, phosphorus, leaching, irrigation, dairy-farming, cynodon-dactylon, lolium-multiflorum, water pollution, risk, texas, risk assessment.
Descriptors: mercury, exposure, risk assessment, food-intake, fish, freshwater-fishes, food-contamination, water pollution, lakes, rivers, American Indians, British Columbia.
Descriptors: wetlands, pollutants, pollution, phosphorus, retention, risk assessment, bayesian-theory, decision-making, linear models, Florida, constructed-wetlands, phosphorus-retention, nonpoint-source-pollution.
Abstract: Using wetlands as a sink of nutrients, phosphorus in particular, is becoming an increasingly attractive alternative to conventional wastewater treatment technology. In this paper, we briefly review the mechanism of phosphorus retenti on in wetlands, as well as previous modeling efforts. A Bayesian method is then proposed for estimating the long-term phosphorus accretion rate in wetlands through a piecewise linear model of outflow phosphorus concentration and phosphorus mass loading ra te. The Bayesian approach was used for its simplicity in computation and its ability to accurately represent uncertainty. Applied to an Everglades wetland, the Bayesian method not only produced the probability distribution of the long-term phosphorus accr etion rate but also generated a relationship of acceptable level of "risk" and optimal phosphorus mass loading rate for the proposed constructed wetlands in south Florida. The latter is a useful representation of uncertainty which is of interest to decision makers.
Descriptors: agricultural-land, xeric-soils, soil-pollution, water pollution, risk assessment, land-evaluation, land use, soil-types, soil-water-regimes, intensification, models, hydrology, Spain, extensification, land-vulnerability-evaluation-mod el, pantanal-model<.p>
Descriptors: groundwater pollution, groundwater, water-purification, polluted-water, risk assessment, databases, estimated-costs, Georgia.
Descriptors: agricultural land, nitrogen, losses-from-soil, leaching, runoff, evaluation, estimation, crop-management, cropping systems, soil management, soil properties, simulation models, groundwater-pollution, risk assessment, water quality, en vironmental protection, pollution control, irrigation water, water management, Wyoming, Nebraska, Colorado, Kansas, New Mexico, Oklahoma, Texas.
Descriptors: pollution-control, groundwater pollution, risk, family farms, prevention, dairy farms, water quality, decision making, farmers' attitudes, surveys, educational programs, program evaluation, Minnesota, pollution prevention programs.
Descriptors: water quality, farm-income, environmental-protection, risk, agricultural-production, nitrates, pesticides, percolation, runoff, motad, regulation, stochastic-processes, indexes, Oklahoma, target-motad.
Abstract: A farm-level risk programming framework is presented which evaluates income/environmental risk tradeoffs. This framework uses a time-series of environmental risk indices to incorporate the stochastics, multiattribute characteristics of environmental outcomes associated with agricultural production practice. The model is applied to a representative farm in the Oklahoma Panhandle region of the Central High Plains. Results indicate that expected income is sensitive to nitrate loading re strictions, and relatively less sensitive to pesticide loading restrictions. Results also indicate that prescriptions derived using deterministic environmental risk measures may ignore significant probabilities of exceeding an environmental standard.
Descriptors: angling, crabs, fish consumption, polluted water, estuaries, risk assessment, risk-behavior, food-safety, food beliefs, food-contamination, health hazards, New York, New Jersey, risk-perception, crabbing, fish and crab consumption.
Descriptors: water quality, bioassay, Toxicity-testing, water pollution, toxicology, aquatic organisms, Effect of water pollution.
Descriptors: environmental assessment, analysis, risk, philosophy, decision-making.
Descriptors: drinking-water, urban-areas, contaminants, toxicity, chromosome-aberrations, fibroblasts, in-vitro toxicity, public-health risk, Iran.
Descriptors: mapping-units, agricultural-chemicals, pollutants, nitrate, transport-processes, unsaturated-flow, groundwater pollution, models, hydrological-data, hydrology, geology, databases, geographical information systems, spatial-variation, e nvironmental impact, risk assessment, Texas, vadose-zone, state-soil-geographic-database, hydrogeology, spatial-analysis.
Descriptors: geographical information systems, simulation models, solutes, transport, groundwater-pollution, risk assessment, uncertainty.
Descriptors: water quality management, Great-Lakes, Health-risk assessment.
Descriptors: water quality management, Great-Lakes, Health-risk assessment.
Descriptors: Pollution - Environmental aspects, Environmental-toxicology, Ecological risk assessment.
Descriptors: Pollution-Environmental aspects, Pollutants, Toxicology, Environmental-risk-assessment.
Descriptors: Hydrogeology, Maryland, Aberdeen-Proving-Ground, Groundwater-flow, Hazardous-substances, risk assessment.
Descriptors: pesticide residues, environmental impact, fuzzy-logic, expert-systems, groundwater-pollution, water pollution, air pollution, risk assessment, leaching, runoff, volatilization, toxicity, man, application methods, ipest-expert-system.
Descriptors: risk assessment, environmental-policy, regulations, pollution, health-risk-assessment.
Descriptors: mercury, power-stations, smoke, emission, air-pollution, deposition, water pollution, food-chains, freshwater-fishes, vegetation, crops, food-contamination, risk, probability-analysis, mathematical models, simulation models,.
Descriptors: mercury, contamination, sewage-sludge, application-to-land, organic-amendments, uptake, zea-mays, triticum-aestivum, reclamation, coal-mined-land risk, public-agencies, Illinois, EPA.
Descriptors: groundwater pollution, polluted-water, groundwater, risk, risk assessment, neoplasms, man, benzene, tetrachloroethylene, probability-analysis, drinking-water contamination, probability, California, reliability-methods.
Abstract: The effect of parameter uncertainty and overly conservative measures on risk assessment has been addressed in numerous researches. Most of the work conducted to date is based on the use of the classic Monte Carlo simulation method (M CS) as a probabilistic modeling tool. Although the MCS is robust and asymptotically convergent, it lacks computational efficiency when the simulated probability is small. Furthermore, the sensitivity information can only be obtained with additional comput ational effort. First, and second-order reliability methods (FORM and SORM) have been developed in the structural analysis field and have been recently applied to ground-water contaminant transport and remediation problems. In this work, we extend the app lication of the reliability methods to the probabilistic assessment of cancer risk due to ground-water contamination. Results of the reliability methods compared well with a published case study of PCE contamination of a ground-water supply in California. The target risk level is extended over a larger range, and the sensitivity of the probability of failure to the relevant random variables is analyzed. The application of the methods to another case study, cancer risk due to the ingestion of benzene conta minated water, further illustrates a systematic way of directly accounting for the intrinsic uncertainty of the transport and fate model parameters involved in the risk assessment procedure. The probability of exceeding the target risk level in this case was found to be most sensitive to the uncertainty in the parameters describing the ground-water transport process.
Descriptors: groundwater pollution, aquifers, contaminants, pollutants, groundwater flow, transport-processes, hydrology, risk assessment, decision making, simulation models, conceptual models, quantitative models.
Abstract: The prevalent and straightforward routine of impulsively collecting masses of new data for studies relating to ground-water contamination can be inefficient and costly as it does not provide optimal value from existing hydrogeologic and other information. A preliminary guidance framework is outlined, for early stage monetary risk assessments prior to any new measurements, considering both the probability and the economical consequences of contamination. The framework is aimed at prov iding a basis for cost-effective decision-making regarding ground-water protection and management actions. It centers on improved conceptual hydrogeological site descriptions based on existing information and professional judgments prior to any new measur ements. A key aspect of the framework is to derive maximum possible quantitative understanding of risks from limited prior available qualitative information. The framework has a dual-site approach, assuming a situation of a contaminant source site and a r eceptor site. A two-step procedure leads to the monetary risk assessment with respect to existing compliance levels: (1) conceptual model development, and (2) quantitative model realization, addressing the probability of contaminant release at the contami nation source, the hydraulic connection between the source and the receptor, and the contaminant transport conditions. The purpose of the framework is twofold: (1) to provide a risk assessment framework which optimizes use of professional judgment for stu dies where data are limited, and (2) to give synergistic interpretive values that complement field measurements and that can be used as prior estimates in more detailed studies.
Descriptors: herbicide-residues, leaching, risk assessment, usage, ranking, risk, groundwater-pollution, application-rates, half-life sorption, probability, simulation models, statistical-analysis, Denmark, hasse-diagram-analysis.
Descriptors: Pesticides, Environmental-aspects, Missouri, Pesticides-risk assessment, water quality.
Descriptors: maize-soils, nitrate, runoff, leaching, losses-from-soil, soil-variability, simulation-models, regression-analysis, mathematical models, risk assessment, water pollution, nitrogen-fertilizers, application-rates, crop-production, land-
productivity, environmental-policy, pollution-control, stochastic-processes, New York, groundwater-loading-effects-of-agricultural-management-systems, GLEAMS.
Abstract: The purpose of this study was to understand the implications of farm-to-farm and regional variations in N runoff and leaching for targeting specific policies to reduce nutrient contamination. To do this, we estimated distributions of runoff and leaching for individual soils on nearly 150 farms in three farm production regions of New York and ranked the distributions according to second degree stochastic dominance criteria (SSD). Based on these rankings, it was evident that cropland a cross farms and regions of New York is so heterogeneous that it is impossible to target polices to reduce nitrate contamination based on farm or regional characteristics. A much clearer ranking was found when soils were grouped by productivity group as me asured by corn (Zea mays L.) yield. Based on the estimated elasticities of nitrate runoff and leaching with respect to N application, one can target those areas where contamination problems are most severe by focusing on soils with potential yields greate r than 125 bu/acre. For it to make sense to target lower productivity soils, the productivity of additional N application at the margin on the highest yielding soils would have to be about double that of the lower yielding group. Evidence indicates that t he ratios of productivities are less than unity in all three production regions.
Descriptors: groundwater pollution, pollutants, chlorinated-hydrocarbons, metals, organic-compounds risk, risk assessment, pesticide-residues, classification, pollution-sources
Descriptors: probability, analysis, probability, computer-analysis, computer-software, water pollution, groundwater pollution, risk, dairy-effluent, application-to-land, waste water treatment, dairy-wastes, lagoons, computer-simulation, permanent- grasslands, nutrient-uptake runoff, Texas.
Descriptors: Soil-pollution, Groundwater pollution, Pollution-Risk-assessment, Soil-pollution, Groundwater pollution, Europe.
Descriptors: pulp-and-paper-industry, fuel-oils, lubricants, oil-spills, fuel-tanks, prevention, pollution-control, water pollution, groundwater pollution, monitoring.
Descriptors: Health-risk assessment, Environmental health.
Descriptors: agricultural-land, ecosystems, ecology, monitoring, environmental assessment, remote-sensing, soil-surveys, land use, surveys, sustainability, farming-systems, risk assessment, soil-degradation, water quality, use-efficiency, cycling, nutrients, landscape, pollutants, air-pollution, mathematical models, Canada.
Descriptors: chlorine-dioxide, bleaching-agents, bleaching, wood-pulp, pulp-mill-effluent, organochlorine-compounds, aquatic-environment, risk assessment, literature-reviews.
Descriptors: soil-pollution, contamination, risk assessment, fuzzy-logic, uncertainty, soil, information, reliability.
Descriptors: water pollution, rivers, pesticide-residues, pollutants, metals, volatile-compounds, polycyclic-hydrocarbons, water-supply, drinking-water, risk assessment, hazards, carcinogens, Korea, hazard-identification, polycyclic-aromatic-hydro carbons, risk-management.
Descriptors: groundwater-extraction, groundwater-flow, aquifers, streams, environmental impact, mathematical models, simulation models, stream-flow, northern-scotland, stream-aquifer-interactions.
Abstract: The Lower Old Red Sandstones in northern Strathmore have favourable hydrogeological conditions for groundwater development. A scheme was proposed to abstract water in the north Esk catchment in order to augment water supplies to loca l villages, and a production borehole was drilled into the Edzell Sandstones to give a design yield of 2420 m3/d. However, this scheme has been abandoned because of concern that the abstraction would significantly reduce the flow in a nearby stream which is an important salmonid fishery. This study demonstrates the potential value of using a stream-aquifer numerical model in an environmental risk assessment for the proposed scheme.
Descriptors: Agricultural-risk assessment, Environmental-risk assessment.
Descriptors: Environmental-risk assessment, Human-ecology, Environmental-toxicology.
Descriptors: mercury, exposure, risk assessment, food-intake, fish, freshwater-fishes, food-contamination, water pollution, rivers, food-chains, mato-grosso.
Descriptors: drinking-water, water quality, pathogens, bacteria, literature-reviews.
Descriptors: pesticides, groundwater pollution, risk assessment, techniques, leaching, usage, toxicity, indexes, environmental impact, mathematical models, comparisons, man, health-protection, monitoring, decision-making, Virginia, pesticide-pollu
tion-potential, leaching-potential, total-mobility-index, impact-potential-score, relative-mobility-index, relative-toxicity-index, relative-usage-index, relative-extent-index, relative-loading-index.
Abstract: A technique for screening pesticides with respect to their overall risk to potential contamination of groundwater was developed for the purpose of selecting priority pesticides for groundwater monitoring programs. The risk assessment technique considers leaching potential, extent of usage, and toxicity of pesticides. These three factors were integrated to obtain an index, the Impact Potential Score (IPS). To evaluate leaching potential, a second index, Total Mobility Index (TMI) was also developed. The two indices were evaluated for their performance by applying them to a monitored watershed in Virginia's Coastal Plain. TMI predictions were compared against five years of groundwater monitoring data. TMI performed fairly well in ident ifying the top few high mobility pesticides. The IPS can be effectively used to select "high risk" pesticides for groundwater monitoring programs and for qualitative risk assessment. Incorporation of risk screening techniques, into environmental management decision processes is useful for evaluation of pesticide contamination potential of groundwater.
Descriptors: Hazardous-wastes, risk assessment, Hazardous-waste-sites, Management.
Descriptors: water-resources, groundwater, aquifers, groundwater pollution, risk assessment, decision-analysis, water-supply design, groundwater-flow, simulation models, stochastic models, villages, pollutants, transport-processes.
Abstract: The application of a decision analysis methodology to a small-scale water-supply/aquifer-contamination problem is presented. The main characteristic of the study is the development of a series of alternative strategies to ensure a co ntinuous water supply to a village under variable risk conditions. It is assumed that the risks involved in the analysis reflect the uncertainty as to the hydraulic conductivity. Thus, a stochastic simulation model for groundwater flow and contaminant tra nsport is employed in order to evaluate the implications of uncertainty in the system's behaviour upon the overall design decisions. Alternative decision strategies are formulated by considering both actual and probabilistic costs, and they are finally co mpared using a risk-cost-benefit objective function.
Descriptors: Water-resources-development, Decision-making, Congresses, risk assessment.
Descriptors: Health-risk assessment, Health-behavior, Decision-making, Environmental-health-Decision-making.
Descriptors: groundwater pollution, radionuclides, uranium, iodine, technetium, chromium, fluoride, chloroform, trichloroethylene, carbon-tetrachloride pollutants, nitrate, power-industry, nuclear-energy, risk-assessment, groundwater-flow costs, w ater-purification, cost-benefit-analysis, USA, cyanide.
Descriptors: pesticides, insecticides, herbicides, pesticide-residues, insecticide-residues, herbicide-residues, water pollution, rivers, persistence, physicochemical-properties, solubility, usage, vapor-pressure risk, ranking, Italy.
Descriptors: polluted-soils, sediment, pollutants, toxicity, tests, bioassays, contaminants, soil-flora, soil-enzymes, biological-activity-in-soil, respiration, mineralization, microbial-degradation, nitrogen, carbon, microbial-activities, literat ure-reviews.
Descriptors: contaminants, polluted-soils toxicology, ecotoxicology.
Descriptors: waste-disposal-sites, public-opinion, risk perception, surveys, demography, socioeconomics, multivariate-analysis, Colorado, Nebraska, Oklahoma, Texas, Utah.
Abstract: Decisions regarding hazardous waste facility siting are now open to extensive public debate. Efforts on the part of public officials and private companies to site waste management facilities have been thwarted by public opposition. U sing survey data from leaders and residents in communities which are hosting or siting facilities, this study examines their sociodemographic characteristics, knowledge, levels of trust, perceptions of risk, perceptions of economic impacts, perceptions of equity issues and the differential effects of these factors on acceptance of local waste facility siting. Leaders in these communities were more supportive of local waste facility siting than were other community residents. The major determinant of leade rs' acceptance of waste siting was their perceptions of the economic benefits of a facility to the community. Although this was also important to residents, perceptions of health, safety, and environmental contamination risks had larger effects on their a cceptance of such facilities.
Descriptors: plant-protection, pesticides, environmental impact, nontarget-effects, risk assessment, soil-pollution, water pollution, toxicity, mathematical models, ecotoxicology, assessment models.
Descriptors: pig-farming, pig-manure, watersheds, rivers, water pollution, environmental impact, risk-assessment, Italy.
Descriptors: wetlands, ecosystems, riparian-vegetation, forest-ecology, habitats, community-ecology, biological indicators, indexes, stress, decision-making, risk assessment, Pennsylvania, middle-atlantic-states-of-usa, environmental-stressors.
Descriptors: agricultural soils, irrigated soils, solutes, agricultural chemicals, leaching, movement-in-soil, risk assessment, water pollution, point sources, stochastic models, spreading, soil variability, spatial variation, soil water content,
bulk density, evapotranspiration, irrigation water, soil depth, water-management, Washington, local-versus-field-scale-transport-parameters, nonpoint source pollution, net-applied-water-distribution, solute spreading.
Abstract: The transfer function model is widely used to estimate solute transport patterns at the field scale. Leaching risk assessments with the transfer function model may be influenced by spatial variability in the net applied water (NAW) d istribution, but few researchers have investigated this possibility. The objective of this study was to evaluate the impact of spatial variability in the NAW distribution on leaching risk assessment and identification of leaching risk categories at the fi eld scale. Bromide concentration profiles, irrigation depths, bulk densities, and soil moisture contents were measured in 40 plots across a 57-ha potato (Solanum tuberosum L.) farm, along with field-scale evapotranspiration estimates, to estimate solute t ransport parameters. Values for field, and plot-scale means and standard deviations for the NAW distribution were estimated using the stochastic convective lognormal transfer function (CLT) model. The probability of NO3(-) leaching below a depth of 2 m wa s then estimated using field-averaged versus plot-scale estimates for the mean and standard deviation of the NAW distribution. For 30-cm NAW, NO3(-) leaching risks estimated with the CLT model and plot-scale means and standard deviations were very high in 0.4 ha of the field, high in 1.8 ha, moderate in 8.7 ha, low in 23.0 ha, and none in 23.1 ha. In contrast, when field-scale average estimates of NAW were used, there was a low risk of NO3(-) leaching for the entire field. Thus, when estimating leaching r isks using the CLT, information about spatial variability of the NAW distribution is important.
Descriptors: solutes, transport-processes, movement-in-soil, subsurface-layers, unsaturated-flow, pollutants, risk assessment, environmental-management, decision-making, data-analysis, uncertainty, simulation, simulation models, geographical infor mation systems, landscape, mapping, maps, vulnerability-mapping, landscape-scale, solute-transport models, risk-management, data-uncertainty, simulation-uncertainty.
Descriptors: groundwater pollution, geographical information systems, simulation models, risk-assessment.
Abstract: There are important challenges associated with assessing potential groundwater vulnerability hazards that may result from regional scale applications of agrochemicals. The increasing availability of Geographic Information System (GIS ) software to those involved in assisting with land use, decisions has resulted in the widespread production of multicolored risk management maps for many environmentally sensitive issues. Soil-based GIS's have recently been coupled to various solute-leac hing models to make near-surface groundwater vulnerability assessments for guidance in pesticide regulation in several states. In general, these assessments rest on soil, climatic, and chemical data that are extremely sparse and contain considerable uncer tainty. It is also important to acknowledge the uncertainty associated with the transport/fate processes that are not accounted for by the modeling approach used to make the assessment. In this paper, we review the results from a series of papers that hav e focused on characterization of uncertainty in pesticide mobility estimates, using the attenuation and retardation indices (AF and RF), for the Pearl Harbor Basin on the Hawaiian island of Oahu. Relative to data error uncertainties, we discuss the impact s of: (i) soil, climatic, and chemical data base uncertainties, (ii) reductions in data base uncertainties, (iii) extrapolation of soil data base information based on soil taxonomy and soil survey, and (iv) importing information from outside the region of interest. Relative to model error uncertainties, we compare pesticide leaching estimates from the simple AF and RF mobility indices with simulations from the EPA's Pesticide Root Zone Model (PRZM) and field observations. Finally. we outline a Regional I ntegrated Risk Assessment approach for characterizing regional scale groundwater vulnerability for near-surface nonpoint sources.
Descriptors: pesticides, pesticide-residues, water pollution, health-hazards, risk, regulations, evaluation, decision-making, soil-pollution, air-pollution, simulation models, Netherlands, agricultural-pesticides, non-agricultural-pesticides.
Descriptors: radionuclides, contaminants, uptake, phaseolus-vulgaris, zea-mays, cucurbita-pepo, fruits, stems, leaves, concentration, soil-analysis, chemical-analysis, polluted-soils, risk assessment, food-safety, public-health, New Mexico.
Descriptors: water pollution, pesticides, adverse-effects, aquatic organisms, toxicity, exposure, concentration, duration, risk assessment, ecosystems, spatial-variation, temporal-variation, simulation-models, computer-simulation, uncertainty, pro bability, agroecosystems, environmental-fate-and-transport-models.
Descriptors: watersheds, aquatic-environment, water pollution, water quality, pollutants, phosphorus, eutrophication, risk assessment, uncertainty, probability, monte-carlo-method, geographical-information-systems, watershed-management, Oklahoma,
wister-lake-watershed, nonpoint-source-pollution, pollutant-transport-and-fate models, euromod-model knowledge-uncertainty stochastic-variability.
Abstract: We present an ecological risk assessment methodology at the watershed level for freshwater ecosystems. The major component is a pollutant transport and fate model (a modified EUTROMOD) with an integrated uncertainty analysis utilizin g a two-phase Monte Carlo procedure. The uncertainty analysis methodology distinguishes between knowledge uncertainty and stochastic variability. The model assesses the ecological risk of lentic (lake) ecosystems in response to the stress of excess phosph orus resulting in eutrophication. The methodology and model were tested on the Wister Lake watershed in Oklahoma with the lake and its trophic state as the endpoint for ecological risk assessment. A geographic information system was used to store, manage, and manipulate spatially referenced data for model input.