ENVIRONMENTAL AUDITING: A Synoptic Approach for Assessing Cumulative Impacts to Wetlands

/ The US Environmental Protection Agency's Wetlands ResearchProgram has developed the synoptic approach as a proposed method forassessing cumulative impacts to wetlands by providing both a general and acomprehensive view of the environment. It can also be applied more broadly toregional prioritization of environmental issues. The synoptic approach is aframework for making comparisons between landscape subunits, such aswatersheds, ecoregions, or counties, thereby allowing cumulative impacts tobe considered in management decisions. Because there is a lack of tools thatcan be used to address cumulative impacts within regulatory constraints, thesynoptic approach was designed as a method that could make use of availableinformation and best professional judgement. Thus, the approach is acompromise between the need for rigorous results and the need for timelyinformation. It is appropriate for decision making when quantitative,accurate information is not available; the cost of improving existinginformation or obtaining better information is high; the cost of a wronganswer is low; there is a high demand for the information; and the situationcalls for setting priorities between multiple decisions versus optimizing fora single decision. The synoptic approach should be useful for resourcemanagers because an assessment is timely; it can be completed within one totwo years at relatively low cost, tested, and improved over time. Anassessment can also be customized to specific needs, and the results arepresented in mapped format. However, the utility of a synoptic assessmentdepends on how well knowledge of the environment is incorporated into theassessment, relevant to particular management questions.KEY WORDS: Cumulative impact assessment; Landscape ecology; Regionalprioritization     

ENVIRONMENTAL AUDITING: Risk Assessment in the Face of Controversy: Tree Clearing and Salinization in North Queensland

/ Several lines of evidence were followed to assess the risk of salinization after tree clearing in the upper Burdekin River basin in north Queensland. Conceptual, biophysical process-based approaches (pedological interpretation, event tree analysis, one-dimensional water balance modeling, and Boolean spatial analysis) were compared to empirical methods and field evidence. The convergence of all lines of conceptual reasoning to the conclusion that there exists a risk of salinization in north Queensland, consistent with field evidence of naturally occurring waterlogging and salinity, strengthens the argument against tree clearing.     

Using Wildlife as Receptor Species: A Landscape Approach to Ecological Risk Assessment

To assist risk assessors at the Department of Energy’s Savannah River Site (SRS), a Geographic Information System (GIS) application was developed to provide relevant information about specific receptor species of resident wildlife that can be used for ecological risk assessment. Information was obtained from an extensive literature review of publications and reports on vertebrate- and contaminant-related research since 1954 and linked to a GIS. Although this GIS is a useful tool for risk assessors because the data quality is high, it does not describe the species’ site-wide spatial distribution or life history, which may be crucial when developing a risk assessment. Specific receptor species on the SRS were modeled to provide an estimate of an overall distribution (probability of being in an area). Each model is a stand-alone tool consisting of algorithms independent of the GIS data layers to which it is applied and therefore is dynamic and will respond to changes such as habitat disturbances and natural succession. This paper describes this modeling process and demonstrates how these resource selection models can then be used to produce spatially explicit exposure estimates. This approach is a template for other large federal facilities to establish a framework for site-specific risk assessments that use wildlife species as endpoints.Current address: Biology Department, University of South Dakota, Vermillion, SD 57069     

Integrating Bioassessment and Ecological Risk Assessment: An Approach to Developing Numerical Water-Quality Criteria

Bioassessment is used worldwide to monitor aquatic health but is infrequently used with risk-assessment objectives, such as supporting the development of defensible, numerical water-quality criteria. To this end, we present a generalized approach for detecting potential ecological thresholds using assemblage-level attributes and a multimetric index (Index of Biological Integrity—IBI) as endpoints in response to numerical changes in water quality. To illustrate the approach, we used existing macroinvertebrate and surface-water total phosphorus (TP) datasets from an observed P gradient and a P-dosing experiment in wetlands of the south Florida coastal plain nutrient ecoregion. Ten assemblage attributes were identified as potential metrics using the observational data, and five were validated in the experiment. These five core metrics were subjected individually and as an aggregated Nutrient–IBI to nonparametric changepoint analysis (nCPA) to estimate cumulative probabilities of a threshold response to TP. Threshold responses were evident for all metrics and the IBI, and were repeatable through time. Results from the observed gradient indicated that a threshold was 50% probable between 12.6 and 19.4 g/L TP for individual metrics and 14.8 g/L TP for the IBI. Results from the P-dosing experiment revealed 50% probability of a response between 11.2 and 13.0 g/L TP for the metrics and 12.3 g/L TP for the IBI. Uncertainty analysis indicated a low (typically 5%) probability that an IBI threshold occurred at 10 g/L TP, while there was 95% certainty that the threshold was 17 g/L TP. The weight-of-evidence produced from these analyses implies that a TP concentration > 12–15 g/L is likely to cause degradation of macroinvertebrate assemblage structure and function, a reflection of biological integrity, in the study area. This finding may assist in the development of a numerical water-quality criterion for TP in this ecoregion, and illustrates the utility of bioassessment to environmental decision-making.     

A paradigm for ecological risk assessment

The 1983 National Academy of Sciences paradigm for conducting human health risk assessment is considered with respect to ecological risk assessment. This four-step paradigm fails to capture key intrinsic differences between the two types of analysis, specifically: identity of risk targets and receptors; identity of the appropriate level of ecological organization at which the risk is expressed; variability of endpoint with respect to risk receptor; and the existence ofrisk cascades through ecological feedback loops. We propose an alternative paradigm that includes a preliminary step,receptor identification, in which chemical partitioning is combined with a conceptual model of the ecosystem to identify appropriate risk targets. In addition, we propose formal inclusion ofendpoint identification and explicit consideration of risk cascades in arelationship assessment in which interactive feedback loops are considered in an iterative process. The proposed paradigm preserves the steps of hazard identification, exposure assessment, dose-response assessment (renamedresponse assessment) and risk characterization, although specific modifications are recommended.     

Indirect Effects in Aquatic Ecotoxicology: Implications for Ecological Risk Assessment

Understanding toxicant effects at higher levels of biological organization continues to be a challenge in ecotoxicology and ecological risk assessment. This is due in part to a tradition in ecotoxicology of considering the direct effects of toxicants on a limited number of model test species. However, the indirect effects of toxicity may be a significant factor influencing the manner in which ecosystem structure and function respond to anthropogenic stressors. Subsequently, failure to incorporate indirect effects into risk assessment paradigms may be a significant source of uncertainty in risk estimates. The current paper addresses the importance of indirect effects in an ecotoxicological context. Laboratory, mesocosm, and whole ecosystem research into indirect effects is reviewed. The implications of indirect effects for ecological risk assessment and potential areas of profitable future research are also discussed.     

环境风险评价的实践与发展

环境风险评价（Environmental Risk Assessment ERA）是环境影响评价的一个重要分支,主要分析评价环境中的潜在危险。本文围绕开展ERA的必要怀、国内外ERA发展现状等方面进行了评述,在此基础上针对目前ERA工作中的不足提出了三点建议。     

Perspectives of the Scientific Community on the Status of Ecological Risk Assessment

/ Views from a wide variety of practicing environmental professionals on the current status of ecological risk assessment (ERA) indicate consensus and divergence of opinion on the utility and practice of risk assessment. Central to the debate were the issues of whether ERA appropriately incorporates ecological and scientific principle into its conceptual paradigm. Advocates argue that ERA effectively does both, noting that much of the fault detractors find with the process has more to do with its practice than its purpose. Critics argue that failure to validate ERA predictions and the tendency to over-simplify ecological principles compromise the integrity of ERA and may lead to misleading advice on the appropriate responses to environmental problems. All authors felt that many improvements could be made, including validation, better definition of the ecological questions and boundaries of ERA, improved harmonization of selected methods, and improvements in the knowledge base. Despite identified deficiencies, most authors felt that ERA was a useful process undergoing evolutionary changes that will inevitably determine the range of environmental problems to which it can be appropriately applied. The views expressed give ERA a cautious vote of approval and highlight many of the critical strengths and weaknesses in one of our most important environmental assessment tools.KEY WORDS: Ecological risk assessment; Ecology; Probability     

Towards an Integrated Approach to Natural Hazards Risk Assessment Using GIS: With Reference to Bushfires

This paper develops a GIS-based integrated approach to risk assessment in natural hazards, with reference to bushfires. The challenges for undertaking this approach have three components: data integration, risk assessment tasks, and risk decision-making. First, data integration in GIS is a fundamental step for subsequent risk assessment tasks and risk decision-making. A series of spatial data integration issues within GIS such as geographical scales and data models are addressed. Particularly, the integration of both physical environmental data and socioeconomic data is examined with an example linking remotely sensed data and areal census data in GIS. Second, specific risk assessment tasks, such as hazard behavior simulation and vulnerability assessment, should be undertaken in order to understand complex hazard risks and provide support for risk decision-making. For risk assessment tasks involving heterogeneous data sources, the selection of spatial analysis units is important. Third, risk decision-making concerns spatial preferences and/or patterns, and a multicriteria evaluation (MCE)-GIS typology for risk decision-making is presented that incorporates three perspectives: spatial data types, data models, and methods development. Both conventional MCE methods and artificial intelligence-based methods with GIS are identified to facilitate spatial risk decision-making in a rational and interpretable way. Finally, the paper concludes that the integrated approach can be used to assist risk management of natural hazards, in theory and in practice.     

Models to Assess the Risk of Snow and Wind Damage in Pine, Spruce, and Birch Forests in Sweden

3 are damaged annually by snow and wind, roughly corresponding to a value of US$150 million, and in Europe, the damage amounts to hundreds of millions of US dollars each year. To help to reduce these losses, tools for risk assessment within forest management have been developed. Predictions were developed of the risk of damage from snow and wind to Scots pine (Pinus sylvestris L.), Norway spruce [Picea abies (L.) Karst.] and Birch (Betula spp. L.) plots using tree, stand, and site characteristics. The data were obtained from 6756 permanent sample plots within the Swedish National Forest Inventory, which were inventoried twice at five-year intervals between 1983 and 1992. Input data for model development used measurements from the first inventory of tree characteristics for the largest sample tree, stand, and site data, and records of snow and wind damage from the second inventory. Models were developed for three different regions for pine- and spruce-dominated sites, while models for the whole country were developed for birch sites. In general the estimated proportion of damaged plots was highly overestimated (31.7%–56.2%), compared with the observed proportion of 3.4%–11.9%. The models for Norway spruce comprising tree, stand, and site data show the best predictability of damaged plots, with 60.6%–67.6% of plots correctly classified. It is concluded that the models developed can be used to detect sites with a high probability of damage from snow and wind, and thus be used as tools to reduce future damage and costs in practical forestry.     

Computerized Map of Risk to Manage Wildlife Species in Urban Areas

For the last 20 years, human–wildlife conflicts have been rapidly increasing in towns. Although people want “greener” cities, the expansion of disliked species causes problems that are difficult to manage and to reduce. The complexity of the numerous factors involved in these human–wildlife relations needs the development of a comprehensive tool for urban planners. Today, with the development of computers and geographical information systems, it is easier to analyze and combine different spatial data as methods used for the management of risks in studies of natural hazards. Here we present a method for assessing and mapping the risk in cases of human–wildlife conflict. An application to starling management in a town in western France will show the efficiency of our methods to combine information given by a network of experts and to highlight higher risk sites. The map of risk provides a spatial result useful for comprehension, communication between people and agencies, and public education.     

Applying Ecological Risk Principles to Watershed Assessment and Management

Considerable progress in addressing point source (end of pipe) pollution problems has been made, but it is now recognized that further substantial environmental improvements depend on controlling nonpoint source pollution. A watershed approach is being used more frequently to address these problems because traditional regulatory approaches do not focus on nonpoint sources. The watershed approach is organized around the guiding principles of partnerships, geographic focus, and management based on sound science and data. This helps to focus efforts on the highest priority problems within hydrologically-defined geographic areas. Ecological risk assessment is a process to collect, organize, analyze, and present scientific information to improve decision making. The U.S. Environmental Protection Agency (EPA) sponsored three watershed assessments and found that integrating the watershed approach with ecological risk assessment increases the use of environmental monitoring and assessment data in decision making. This paper describes the basics of the watershed approach, the ecological risk assessment process, and how these two frameworks can be integrated. The three major principles of watershed ecological risk assessment found to be most useful for increasing the use of science in decision making are (1) using assessment endpoints and conceptual models, (2) holding regular interactions between scientists and managers, and (3) developing a focus for multiple stressor analysis. Examples are provided illustrating how these principles were implemented in these assessments.     

An Approach for Evaluating the Effectiveness of Various Ozone Air Quality Standards for Protecting Trees

We demonstrate an approach for evaluating the level of protection attained using a variety of forms and levels of past, current, and proposed Air Quality Standards (AQSs). The U.S. Clean Air Act requires the establishment of ambient air quality standards to protect health and public welfare. However, determination of attainment of these standards is based on ambient pollutant concentrations rather than prevention of adverse effects. To determine if a given AQS protected against adverse effects on vegetation, hourly ozone concentrations were adjusted to create exposure levels that “just attain” a given standard. These exposures were used in combination with a physiologically-based tree growth model to account for the interactions of climate and ozone. In the evaluation, we used ozone concentrations from two 6-year time periods from the San Bernardino Mountains in California. There were clear differences in the level of vegetation protection achieved with the various AQSs. Based on modeled plant growth, the most effective standards were the California 8-hr average maximum of 70 ppb and a seasonal, cumulative, concentration-weighted index (SUM06), which if attained, resulted in annual growth reductions of 1% or less. Least effective was the 1-hr maximum of 120 ppb which resulted in a 7% annual reduction. We conclude that combining climate, exposure scenarios, and a process-based plant growth simulator was a useful approach for evaluating effectiveness of current or proposed air quality standards, or evaluating the form and/or level of a standard based on preventing adverse growth effects.     

PROFILE: Risk Assessment as an Environmental Management Tool: Considerations for Freshwater Wetlands

/ This paper presents a foundation for improving the risk assessmentprocess for freshwater wetlands. Integrating wetland science, i.e., use of anecosystem-based approach, is the key concept. Each biotic and abiotic wetlandcomponent should be identified and its contribution to ecosystem functionsand societal values determined when deciding whether a stressor poses anunreasonable risk to the sustainability of a particular wetland.Understanding the major external and internal factors that regulate theoperational conditions of wetlands is critical to risk characterization.Determining the linkages between these factors, and how they influence theway stressors affect wetlands, is the basis for an ecosystem approach.Adequate consideration of wetland ecology, hydrology, geomorphology, andsoils can greatly reduce the level of uncertainty associated with riskassessment and lead to more effective risk management. In order to formulateeffective solutions, wetland problems must be considered at watershed,landscape, and ecosystem scales. Application of an ecosystem approach can begreatly facilitated if wetland scientists and risk assessors work together todevelop a common understanding of the principles of both disciplines.KEY WORDS: Ecological risk assessment; Freshwater wetlands;Environmental pollution; Chemical stressors; Physical stressors; Biologicalstressors     

ENVIRONMENTAL AUDITING: The Functional Unit in the Life Cycle Inventory Analysis of Degreasing Processes in the Metal-Processing Industry

1 and C₂ hydrocarbons (trichloroethane, trichloroethene, tetrachloroethene, dichloromethane). Measures aiming at the reduction of toxic emissions and ozone depletion potential (ODP) may possibly lead to a shift of environmental impacts towards higher energy consumption, emission of waste water, and volatile organic compounds (VOC) with photochemical oxidant creation potential (POCP). The present article concerns itself with a life cycle assessment of the three main degreasing processes in order to compare their integral environmental impacts with one another. This is supplemented by presenting the methodology of the life cycle inventory life cycle inventory analysis (LCI). Generally, the applicability of the established LCI method can be shown quite clearly. However, some difficulties arise, especially at the stage of the goal definition, as the use of the process and the functional unit cannot be pinned down as easily and neatly as for most other products. The definition of the use of the process and the functional unit is not as straightforward as for most products. Among the potential functional units identified are the mass of removed impurities, cleaning time, cleaning work, percentage of purity, throughput of parts, loads, mass or surface and virtual coefficients. The mass of removed impurities turned out to be the most suitable parameter for measuring the technical performance of degreasing processes. The article discusses background, purpose, scope, system boundaries, target group, process tree and representativeness of the present study.     

A Procedure for Performing Population-Level Ecological Risk Assessments

/ In 1997, Oregon enacted amendments to its state hazardous waste site cleanup law which emphasize risk-based remedial action decisions. In a departure from US EPA practice, the amended statute and associated rules require that protection of ecological receptors occur at the population level for all plants and animals not listed as threatened or endangered. By rule, the acceptable risklevel for populations of ecological receptors is a 10% or less chance that 20% or more of the total local population would receive an exposure greater than the toxicity reference value for a hazardous substance. This paper describes a practical procedure for performing population-level ecological risk assessments using a combination of relatively simple techniques. The procedure involves: (1) establishing a distribution of exposures and a contaminant-specific toxicity reference value, either as a point value or a distribution, for an individual receptor, (2) estimating the abundance of these receptors within their local populations, (3) estimating the probability of an individual receptor experiencing an exposure in excess of the toxicity reference value, (4) estimating the number of individual receptors in the local population likely to experience an exposure above the toxicity reference value greater than 10% of the time, and (5) determining whether this number is greater than 20% of the total local population.     

Perceptions of Risk Associated with Use of Farm Chemicals: Implications for Conservation Initiatives

/ Data were collected from 245 farmers within the Darby Creek hydrologic unit in central Ohio to assess perceptions of risk associated with use of farm chemicals. Farmers were asked to evaluate the level of risk associated with use of agricultural chemicals for water quality, food safety, food quality, health of applicator, health of farm animals, wildlife, beneficial plants, beneficial insects, and human health. Study findings revealed that respondents perceived use of farm chemicals posed little or no threat to any of the assessed items. A composite index was formulated from the responses to the nine items and was titled Perceived Risk. Variance in the Perceived Risk index was regressed against social learning variables. The findings revealed that approximately 32% of the variance was explained by the predictive variables included in the model. It was concluded that the theoretical perspective was somewhat useful for understanding perceptions held about agricultural chemical use at the farm level. The findings are discussed in the context of future conservation and educational-information programs within the study region.KEY WORDS: Risk perception; Risk assessment; Groundwater; Pesticide contamination; Food safety; Environmental quality     

Tijuana Childhood Lead Risk Assessment Revisited: Validating a GIS Model with Environmental Data

The objective of this research was to determine the spatial distributions of childhood lead poisoning and soil lead contamination in urban Tijuana. The Bocco–Sanchez model of point-source emissions was evaluated in terms of validity and reliability. We compared the model's predicted vulnerable populations with observed cases of childhood lead poisoning in Tijuana, identified fixed point sources in the field, and analyzed 76 soil samples from 14 sites. The soil lead results were compared to the blood lead analyses performed on Tijuana children whose blood lead levels were ≥10 μg/dL, who reported that they did not use lead-glazed ceramics for cooking or storing food (n = 63). Using GIS, predicted vs observed risk areas were assessed by examining spatial patterns, including the distribution of cases per designated risk area. Chi-square analysis of expected vs observed values did not differ significantly at the p = 0.02 level, showing that the model was strikingly accurate in predicting the distribution of subjects with elevated blood lead. Results reveal that while point sources are significant, other sources of lead exposure are also important. The relative public health risk from exposure to lead in an urban setting may be assessed by distinguishing among sources of exposure and associating concentrations to blood lead levels. The results represent an iterative approach in environmental health research by linking environmental and human biomarker lead concentrations and using these results to validate an environmental model of risk to lead exposure.     

Risk-Based Analysis of Environmental Monitoring Data: Application to Heavy Metals in North Carolina Surface Waters

The state of North Carolina's Department of Environment and Natural Resources (NCDENR) conducts routine water quality monitoring throughout the state to assess the health of aquatic systems. The current study reports the results of a retrospective (1990–2000) ecological risk assessment of six heavy metals (arsenic, cadmium, copper, lead, mercury, and zinc) in 17 North Carolina basins that was conducted to estimate the risk of heavy metal toxicity to freshwater organisms and assess the sufficiency of NCDENR's monitoring data to identify water-quality-related ecological threats. Acute and chronic ecotoxicological thresholds (ETs) were calculated for each metal based upon the 10th percentile of species sensitivity distributions and were normalized for water hardness. Statewide probabilities (expressed as percentages) of a random sample exceeding acute or chronic ETs among the six metals ranged from 0.01% to 12.19% and 0.76% to 21.21%, respectively, with copper having the highest and arsenic and mercury the lowest risk. Basin-specific probabilities varied significantly depending upon water hardness and presumably watershed development. Although the majority of specific sites where data were collected were at low risk for metal toxicity, some specific sites had a high probability of toxic events associated with one or more metals. Analytical detection limits for metals were frequently higher than estimated chronic ET, limiting the ability to assess the risk of chronic toxicity in soft-water basins. Results suggest risk-based criteria may be useful for assessing and validating the sufficiency of monitoring programs and prioritizing management goals.