Application of an Ecological Risk Assessment for Evaluation of Alternatives Considered for Restoration of Oysters in Chesapeake Bay: Background and Approach

Oyster populations in Chesapeake Bay, USA, declined precipitously over the past three decades, and on-going efforts to restore the native oysters to former abundance were considered to be ineffective. Maryland and Virginia natural resource agencies proposed the introduction of a non-native Asian oyster (Crassostrea ariakensis) that is resistant to diseases affecting the native oyster and well adapted to the Chesapeake Bay environment. Numerous stakeholders raised concerns about potential adverse consequences of an introduction of a non-native species into a new environment. In response, state and federal agencies determined that an Environmental Impact Statement (EIS) should be prepared to address the environmental consequences of such an introduction as well as of seven other oyster restoration alternatives, including several involving only the native oyster. Preparation of an Ecological Risk Assessment (ERA) of the proposed action as well as all alternatives was an integral element of EIS preparation. This series of articles describes several different analyses that contributed to and collectively comprised the ERA conducted as input to the EIS. The final article of this series in HERA describes how the ERA and EIS findings were taken into account in the final decision on the preferred restoration alternative by state and federal agencies.     

Ecological Risk Assessment Guidance and Procedural Documents: An Annotated Compilation and Evaluation of Reference Materials

The scientific approach toward ecological risk assessment (ERA) has advanced greatly during the 1990s. This growth has been accompanied by the development of ERA guidance by USEPA Headquarters, individual USEPA Regions, state environmental agencies, as well as international agencies. This compilation of ERA guidance and procedural documents identifies many of the existing ERA reference materials from the regulatory and/or governmental agency arena. In addition, this compilation provides annotations pertaining to the focus of each reviewed document, and compares/contrasts the approaches presented in the documents. As such, the evaluation provides insight into some of the qualities and levels of detail provided by each document. Examples of documents which are highlighted include recently published USEPA's “Guidelines for Ecological Risk Assessment;” USEPA's “Ecological Risk Assessment Guidance for Superfund;” the U.S. Army's “Procedural Guidelines for Ecological Risk Assessments;” and Environment Canada's “Ecological Risk Assessments Under the Canadian Environmental Protection Act.”     

Simplified fate modelling in respect to ecotoxicological and human toxicological characterisation of emissions of chemical compounds

Purpose  

The impact assessment of chemical compounds in Life Cycle Impact Assessment (LCIA) and Environmental Risk Assessment (ERA) requires a vast amount of data on the properties of the chemical compounds being assessed. The purpose of the present study is to explore statistical options for reduction of the data demand associated with characterisation of chemical emissions in LCIA and ERA.     

Comparison between three different LCIA methods for aquatic ecotoxicity and a product environmental risk assessment

Background and Objective  In the OMNIITOX project 11 partners have the common objective to improve environmental management tools for the assessment of (eco)toxicological impacts. The detergent case study aims at: i) comparing three Procter &c Gamble laundry detergent forms (Regular Powder-RP, Compact Powder-CP and Compact Liquid-CL) regarding their potential impacts on aquatic ecotoxicity, ii) providing insights into the differences between various Life Cycle Impact Assessment (LCIA) methods with respect to data needs and results and iii) comparing the results from Life Cycle Assessment (LCA) with results from an Environmental Risk Assessment (ERA). Material and Methods  The LCIA has been conducted with EDIP97 (chronic aquatic ecotoxicity) [1], USES-LCA (freshwater and marine water aquatic ecotoxicity, sometimes referred to as CML2001) [2, 3] and IMPACT 2002 (covering freshwater aquatic ecotoxicity) [4]. The comparative product ERA is based on the EU Ecolabel approach for detergents [5] and EUSES [6], which is based on the Technical Guidance Document (TGD) of the EU on Environmental Risk Assessment (ERA) of chemicals [7]. Apart from the Eco-label approach, all calculations are based on the same set of physico-chemical and toxicological effect data to enable a better comparison of the methodological differences. For the same reason, the system boundaries were kept the same in all cases, focusing on emissions into water at the disposal stage. Results and Discussion  Significant differences between the LCIA methods with respect to data needs and results were identified. Most LCIA methods for freshwater ecotoxicity and the ERA see the compact and regular powders as similar, followed by compact liquid. IMPACT 2002 (for freshwater) suggests the liquid is equally as good as the compact powder, while the regular powder comes out worse by a factor of 2. USES-LCA for marine water shows a very different picture seeing the compact liquid as the clear winner over the powders, with the regular powder the least favourable option. Even the LCIA methods which result in die same product ranking, e.g. EDIP97 chronic aquatic ecotoxicity and USES-LCA freshwater ecotoxicity, significantly differ in terms of most contributing substances. Whereas, according to IMPACT 2002 and USES-LCA marine water, results are entirely dominated by inorganic substances, the other LCIA methods and the ERA assign a key role to surfactants. Deviating results are mainly due to differences in the fate and exposure modelling and, to a lesser extent, to differences in the toxicological effect calculations. Only IMPACT 2002 calculates the effects based on a mean value approach, whereas all other LCIA methods and the ERA tend to prefer a PNEC-based approach. In a comparative context like LCA the OMNIITOX project has taken the decision for a combined mean and PNEC-based approach, as it better represents the ‘average’ toxicity while still taking into account more sensitive species. However, the main reason for deviating results remains in the calculation of the residence time of emissions in the water compartments. Conclusion and Outlook  The situation that different LCIA methods result in different answers to the question concerning which detergent type is to be preferred regarding the impact category aquatic ecotoxicity is not satisfactory, unless explicit reasons for the differences are identifiable. This can hamper practical decision support, as LCA practitioners usually will not be in a position to choose the ’right’ LCIA method for their specific case. This puts a challenge to the entire OMNIITOX project to develop a method, which finds common ground regarding fate, exposure and effect modelling to overcome the current situa-tion of diverging results and to reflect most realistic conditions.     

Using Ecological Risk Assessment Principles in a Source Water Protection Assessment

It has become increasingly common to apply ecological risk assessment (ERA) principles to watershed and regional scale environmental management. This article describes the application of watershed ERA principles to the development of a source water protection assessment and a strategic watershed management plan. The primary focus was on the protection of drinking water quality, a concern typically addressed by human health risk assessors. The approach emphasizes adaptations to the problem formulation phase of ERA (defining assessment endpoints, developing conceptual models and an analysis plan) suitable for watershed management planning in a multi-objective, multi-stressor context. Physical, chemical, and biological attributes were selected for primary drinking water quality assessment endpoints, and coupled with additional assessment endpoints relevant to other environmental and social management objectives. Conceptual models helped the planning team to better understand and communicate the multiple natural and human stressors in the watershed and the causal pathways by which they affected drinking water. The article provides an example of the types of adaptations that can make ERA principles suitable for watershed management related to human health goals, and illustrates the efficiency of integrating health and ecological assessments.     

Human Health Risk Assessment of Naturally Occurring Radioactive Materials in Produced Water—A Case Study

Human health effects from naturally occurring radioactive materials (NORM) in produced water are of concern due to their bioavailability and bioaccumulation characteristics in finfish and shellfish species used for human consumption. Being chemically similar to calcium, radium concentrates mostly in bones, shells, and exoskeletons. Previous studies have been based on the whole-body bioaccumulation of radium in fish where the distribution of radium in bone/exoskeleton and the edible parts of fish were not considered separately and thus the predicted risks were relatively high. In this article, the distribution of radium in the non-edible and edible parts of fish and the probability of exposure to a produced water plume have been studied in order to characterize human health risks. A probabilistic hydrodynamic model has been incorporated in this study. Using the concentration distribution approach, the mean cancer risks to humans were predicted in the range of 8.6 × 10^?7 to 9.5 × 10^?7, which were 2.6 to 2.7 times less than the risks predicted by using the whole body concentrations. The exceedence probability of maximum permissible human health cancer risk of 1 × 10^?4 is close to zero. At a risk level of 1 × 10^?6, the exceedence probability is 21% whereas in the whole body concentration approach it is between 45 to 49%. In this study, no effect on fish from exposure to NORM components in produced water was found.     

High risk water pollution hazards affecting Aveiro coastal lagoon (Portugal) – A habitat risk assessment using InVEST

Anthropogenic pressures put at jeopardy ecosystem services (ES) provided by natural habitats. Ecosystem Based Management (EBM) approaches can support policymakers dealing with physical, chemical, and biological stresses caused by high-risk water pollution (HRWP) and sudden-accidental pollution (SAP). The objective of this study is to evaluate how alarming HRWP pressures might become in fragile marine, coastal, estuarine, and freshwater socio-ecological systems (MCEF-SES) surrounded by heavily industrialized and urbanized areas. To this end a spatially explicit analysis, using the InVEST-Habitat Risk Assessment (InVEST-HRA) model in combination with expert judgement from researchers from various fields, is performed. An application is provided for the case of the Ria de Aveiro (RdA) coastal lagoon in Portugal. Results show high spatial variance of HRWP hazards across RdA, with one major multi-layer risk hotspot at the center of the research area and a second patch of multiple risk hotspots towards the North of RdA. Salines emerge as the most threatened habitat followed by Intertidal flats and Saltmarshes. The most significant water pollution risk sources contributing to Salines cumulative risk are Fossil fuel processing, storage and sale units, Industrial units, Aquaculture, and the Marinas. Industries involving dangerous substances in the region threaten primarily Watercourses. This study confirms the InVEST-HRA model in combination with expert judgement is a transparent and easily replicable approach to build ES-based knowledge about habitat risks threatening MCEF-SES in a Natura 2000 site heavily pressured by HRWP hazards. After further valuation analysis, pondering gains and losses from regional development and environmental protection, this knowledge can support the planning and management of coastal areas and the prioritization of pollution abatement interventions. In particular, by estimating the loss that HRWP causes in the value of ecosystem services, defining HRWP abatement policies, assessing the effectiveness, costs and benefits of those abatement policies and, ultimately, evaluating the results for the well-being of local communities through global efficiency analysis, cost-benefit analysis or cost-effectiveness analysis. Hence, it bridges the gap between an informed EBM and the development policies of fragile regions.     

Biological responses of the sea urchin, Arbacia punctulata, to lead contamination for an estuarine ecological risk assessment

An estuarine ecological risk assessment for thePortsmouth Naval Shipyard (PNS) Kittery, ME, wasconducted utilizing the U.S. EPA's Framework forEcological Risk Assessment (ERA). As part of theanalysis phase of the ERA, laboratory studies wereconducted to develop quantitative exposure-responserelationships for lead (Pb), a key contaminant ofconcern for PNS, in order to evaluate the role of Pbin the ecological stress observed near PNS, and toestimate the probability of ecological risk associatedwith Pb contamination at the site. Biological effectsof exposure to Pb via sediment or diet were evaluatedusing several life stages of the sea urchin, Arbacia punctulata. This strategy was employedbecause echinoderm species, including A.punctulata, are amenable to laboratory testing andhave been used frequently to assess the toxicity ofestuarine waters and sediments. In addition, lifestage-specific biological effects could be comparedand integrated into projections of population-levelresponses to Pb. Results indicated that adult seaurchins accumulated Pb in direct proportion toexposure medium Pb concentration, whether exposureoccurred via sediment or diet. High Pb concentrationsreduced survival and gamete production in females, buthad no effect on the viability of produced gametes. Aqueous Pb exposure concentrations that producedadverse effects on adult sea urchin survival andreproduction were also directly toxic to early lifestages. In addition to their utility for this ERA,these results have applicability for the prediction ofbiological effects or the retrospective analysis ofcausal relationships at other estuarine sites.     

The effect of compact formulations on the environmental profile of Northern European granular laundry detergents Part II: Life Cycle assessment

The environmental profile of laundry detergents at three time points (1988, 1992, and 1998) were compared on the basis of two distinct, complementary approaches: Environmental Risk Assessment (ERA) and Life-Cycle Assessment (LCA). The results are presented in this paper and its accompanying paper in this issue (Part I: Product Environmental Risk Assessment). Life-Cycle Inventory (LCI) data from The Netherlands and Sweden were used for this retrospective analysis. The chosen time period studied (1988 - 1998) spans significant, multiple formulation and process change in laundry detergents, including the introduction of compact, then super-compact, granular detergents. Cradle-to-Gate LCAs based on 1 kg of finished product (from raw material supply to packaged finished product leaving the suppliers site) revealed no significant differences between the products themselves, as manufactured between 1988, 1992 and 1998. Cradle-to-Grave LCAs based on 1000 wash cycles (from raw material supply to disposal of used product) indicated that the consumption of raw materials and energy, as well as environmental emissions (air, water and solid waste), decreased after the introduction of compact detergents in 1988. The LCAs revealed that a number of category indicator values decreased (for acidification, aquatic toxicity greenhouse effects, eutrophication, toxicity, ozone depletion and smog). Furthermore, the results of the LCAs support the conclusion that the differences between The Netherlands and Sweden are due to (1) differences in electrical generation between the countries, (2) differences in energy consumption during consumer use, (3) differences in detergent dosage per wash and (4) differences in the wastewater treatment infrastructure.     

Ecological Risk Assessment for Terrestrial Ecosystems: The Summary of Discussions and Recommendations from the Adelaide Workshop (April 2004)

The Ecological Risk Assessment (ERA) workshop focused on the anthropogenic contaminants in the terrestrial environment, addressing various components of the ERA process. These included sources, exposure pathways, bioavailability, and toxicity to receptor organisms as well as risk communication. It was concluded that although the overseas experience on ERA for terrestrial ecosystems (e.g., International Standards or guidelines from the European Union and the United States) is very useful, it is not directly applicable to Australia due to the differences in receptor organisms, contaminants, soil, and environmental conditions. Workshop discussions stressed on the need for making ERA locally relevant (in terms of choice of receptor organisms, sampling strategy, and bioavailability considerations). The workshop discussions highlighted the need of better appreciation of both the similarities and the clear differences between aquatic and terrestrial ERAs. The availability of reliable data, problems with databases, estimation of bioavailability, and extrapolations from laboratory to field were noted among the key limitations. ERA—being inherently complex and involving a range of environmental compartments, target receptor, and exposure pathways—at a minimum requires a multidisciplinary approach to address the complexities. Bringing a multidisciplinary team together often proves a major challenge in ERA. The delegates called for continued efforts in this area and formation of a network or working group in Australia.     

Risk Assessment and Invasion Characteristics of Alien Plants in and Around the Agro-Pastoral Ecotone of Northern China

Two risk assessment protocols were adopted to assess the risks posed by alien plants that naturalized or non-naturalized in the agro-pastoral ecotone of northern China (AGENC). In this study the Risk Assessment for Central Europe method revealed that more than two-thirds of the 19 naturalized and four-fifths of the 17 non-naturalized alien plants presented high or moderate risk, and all 36 alien plants were considered to be rejected for their potential agricultural and environmental risks under the Australian Weed Risk Assessment system. On the characteristics of plant invasions, more attention should be given to disturbed habitats rather than these relative natural or closed ecosystems, and also be prudent and careful of the alien plants that are introduced as useful plants from North or South America and unintentional introduction from Europe. Moreover, annuals needed special attention: three-quarters of the alien plants were annual species, only a few were biennial (8.3%), perennial (11.1%), liana and tree plants (2.8%). Plant invasions are not extremely serious in the AGENC, but there are several alien plants that have naturalized and spread themselves in the region. However, attention should be given in the future to predicting and preventing plant invasions in this fragile region.     

A Procedure for Ecological Tiered Assessment of Risks (PETAR)

Several procedures for Ecological Risk Assessment (ERA) have been suggested. The use of these existing procedures often relies on availability of existing data and/or on large resources for acquisition of new ones. This paper presents a three-tiered procedure for retrospective evaluation of risks adapted to limited resources and scarce background information of relevance for risk assessments, such as in developing countries. The tiers require successively more detailed investigations. The approach assures that resources available for site-specific investigations are directed towards well-formulated questions raised during previous stages of the assessment. The first tier, the preliminary assessment, is a qualitative evaluation of existing information on anthropogenic stressors, sources of stressors and expected ecological effects. The second tier is a regional risk assessment; a semi-quantitative evaluation of ecological risks, over large geographical areas, which results in a ranking of sources and stressors having the greatest potential for ecological impact and ranking of subareas inside the study area more likely to be impacted. The final tier is a site-specific and quantitative risk assessment, at a smaller scale and requiring more resources, that incorporates methodologies for establishing causality between exposure to multiple stressors and effects on specific endpoints of ecological and societal relevance.     

A rough guide to population change in exploited fish stocks

Interpreting how populations will change in response to exploitation is essential to the sound management of fish stocks. While deterministic models can be of use in evaluating sustainable fishing rates, the inherent variability of fish populations limits their value. In this paper a probabilistic approach is investigated which avoids having to make strong assumptions about the functional relationship between spawning stock size and the annual number of young fish (recruits) produced. Empirical probability distributions for recruits are derived, conditioned on stock size, and used to indicate likely stock changes under different fishing mortality rates. The method is applied to cod ( Gadus morhua ) in the North Sea to illustrate how population change can be inferred and used by fishery managers to choose fishing mortality rates which are likely to achieve sustainable exploitation.     

Technical Critique of the Multimedia,Multipathway, Multireceptor Risk Assessment Model

The U.S. Environmental Protection Agency (USEPA) is developing the Multimedia, Multipathway, Multireceptor Risk Assessment (3MRA) model to evaluate potential human and ecological risks associated with the disposal of solid wastes designated as hazardous wastes in nonhazardous waste management units. USEPA intends to use the 3MRA model to determine national exit levels that will allow solid wastes that theoretically pose acceptable human and ecological risks to be safely managed in Subtitle D nonhazardous waste management units. We critically evaluated the 3MRA model to determine whether the methodology, interim modules, and input parameters are appropriate and scientifically defensible. Overall, our review of the 3MRA model indicates that it contains many conservative assumptions that may limit the validity of the model results and its use as a national model adequate for making regulatory decisions. Many of the assumptions and data inputs used to model the pathways involved in the transport of chemicals from a waste management unit are flawed. Other specific concerns include the lack of model validation, incompatibility of data between modules, and overestimation of potential human and ecological exposures. Before using the 3MRA model, we recommend that USEPA consider whether the 3MRA model is either an appropriate or accurate tool for evaluating the disposal of hazardous wastes nationwide.     

A probabilistic view of immunology: drawing parallels with physics

Regulating the strength and class of an immune response requires lymphocytes to act as complex signal integrating "machines", taking information from multiple sources while making decisions that affect the final outcome. Describing and understanding the decision-making behaviour of lymphocytes within the context of the dynamic multifaceted immune system appears immensely complicated. In this article I contrast two alternative frameworks, the deterministic and the probabilistic as competing paths to achieve successful quantitative immune models. As the two alternatives are traditional scientific rivals, I use the probabilistic fields in physics to highlight the potential value of the probabilistic perspective in immunology.     

Potential infection of grazing cattle via contaminated water: a theoretical modelling approach

Wastewater discharge and agricultural activities may pose microbial risks to natural water sources. The impact of different sources can be assessed by water quality modelling. The aim of this study was to use hydrological and hydrodynamic models to illustrate the risk of exposing grazing animals to faecal pollutants in natural water sources, using three zoonotic faecal pathogens as model microbes and fictitious pastures in Sweden as examples. Microbial contamination by manure from fertilisation and grazing was modelled by use of a hydrological model (HYPE) and a hydrodynamic model (MIKE 3 FM), and microbial contamination from human wastewater was modelled by application of both models in a backwards process. The faecal pathogens Salmonella spp., verotoxin-producing Escherichia coli O157:H7 (VTEC) and Cryptosporidium parvum were chosen as model organisms. The pathogen loads on arable land and pastures were estimated based on pathogen concentration in cattle faeces, herd prevalence and within-herd prevalence. Contamination from human wastewater discharge was simulated by estimating the number of pathogens required from a fictitious wastewater discharge to reach a concentration high enough to cause infection in cattle using the points on the fictitious pastures as their primary source of drinking water. In the scenarios for pathogens from animal sources, none of the simulated concentrations of salmonella exceeded the concentrations needed to infect adult cattle. For VTEC, most of the simulated concentrations exceeded the concentration needed to infect calves. For C. parvum, all the simulated concentrations exceeded the concentration needed to infect calves. The pathogen loads needed at the release points for human wastewater to achieve infectious doses for cattle were mostly above the potential loads of salmonella and VTEC estimated to be present in a 24-h overflow from a medium-size Swedish wastewater treatment plant, while the required pathogen loads of C. parvum at the release points were below the potential loads of C. parvum in a 24-h wastewater overflow. Most estimates in this study assume a worst-case scenario. Controlling zoonotic infections at herd level prevents environmental contamination and subsequent human exposure. The potential for infection of grazing animals with faecal pathogens has implications for keeping animals on pastures with access to natural water sources. As the infectious dose for most pathogens is more easily reached for calves than for adult animals, and young calves are also the main shedders of C. parvum, keeping young calves on pastures adjacent to natural water sources is best avoided.     

Exposure Assessment of Pharmaceuticals and Their Metabolites in the Aquatic Environment: Application to the French Situation and Preliminary Prioritization

Low levels of pharmaceuticals have been detected in many countries in surface waters. As a wide range of pharmaceuticals can reach aquatic environments, a selection of molecules to survey is the first step before implementing a monitoring program. We used a simple equation to calculate Predicted Environmental Concentrations (PECs), adapted from the European Medicine Agency model used for the Environmental Risk Assessment (ERA) of human pharmaceutical. Excretion fractions for pharmaceuticals were determined for 76 compounds. Using year 2004 French drug consumption data, we determined aquatic PECs for 112 parent molecules and several metabolites. Considering excretion fractions of pharmaceuticals can lead to drastically reduce predicted concentrations reaching the aquatic environment and help to target environmentally relevant pharmaceuticals and metabolites. Calculated PECs using the described methodology are consistent with French field measurements. The simple model for calculating PECs can be used as a valuable estimation of the exposure. Risk quotient ratios were also calculated. Due to the lack of ecotoxicological data, the use of PEC/PNEC ratios is not enough informative to prioritize pharmaceuticals likely to pose a risk for surface waters. Alternative ways to prioritize risk to pharmaceuticals, combining PEC, pharmacological, and ecotoxicological data available from the literature, should be implemented.     

Adding Value to Ecological Risk Assessment with Population Modeling

Current measures used to estimate the risks of toxic chemicals are not relevant to the goals of the environmental protection process, and thus ecological risk assessment (ERA) is not used as extensively as it should be as a basis for cost-effective management of environmental resources. Appropriate population models can provide a powerful basis for expressing ecological risks that better inform the environmental management process and thus that are more likely to be used by managers. Here we provide at least five reasons why population modeling should play an important role in bridging the gap between what we measure and what we want to protect. We then describe six actions needed for its implementation into management-relevant ERA.