Ecological risk assessments

A similar process is followed for ecological risk assessment. Because of the tremendous number of different species and their different sensitivities to chemicals, the 

Once these steps have been completed, the final step of problem formulation is to develop an analysis plan, which defines how the gocds, endpoints, and measures of effect will be evaluated at the site. 

To illustrate these steps, let s compare two sites with identical contamination in surface water and sediment. At one site, the surface water and sediment is part of a recreational fishing area (e.g., a lake stocked with trout). At the other site, the surface 

For the second example, the goal would be to protect individual ospreys from eating fish contaminated by chemiccds in the surface water and sediments. Because the osprey is a protected species, we need to manage effects at the level of the individual in a risk assessment. Because the management goals and our endpoint species differ between the two sites, our assessment endpoints and measures of effect will also differ. Based on our perceived relative value of the two habitats, we can tolerate more effects on individual trout at the first site than we can to individual ospreys at the second site. 

There are two components to the analysis phase characterization of exposure and characterization of effects. Overall, this phase is similar to the exposure and toxicity assessment components of a human health risk assessment. The primary differences relate to the variety of ways in which exposure and toxicity can be measured in an ecological risk assessment. 

Problem formulation a qualitative evaluation of contaminant release, migration and fate identification of contaminants of concern, receptors, exposure pathways and known ecological effects of the contaminants and selection of end-points for further study. The term end-point is used to describe the expected or anticipated effect of a contaminant on an ecological receptor (USEPA, 1989c). 

Exposure assessment a quantification of contaminant release, migration and fate characterization of exposure pathways and receptors and measurement or estimation of exposure point concentrations (USEPA, 1989c). 

Ecological effects assessment literature reviews, field studies and toxicity tests linking contaminant concentrations to effects on ecological receptors (USEPA, 1989c). 

The subarea of risk assessment that deals with the effects of chemicals upon the environment is known as environmental risk assessment or ecological risk assessment. This subarea deals with effects on nonhuman species and entire ecological systems on landscape and regional scales. Risk assessment as applied to environmental toxicology is discussed extensively in Chapter 12. 

As noted above, risk assessment provides a linkage from the science of environmental risk assessment to the making of environmental policy. Policy is made by a variety of groups, including the general public, governmental entities, and industry. 

The scheme presented (Fig. 10.1) describes the subsequent steps of ecological risk assessment that are suggested by the USEPA (1998). The use 

As necessary acquire data, iterate process, monitor results 

Problem formulation. Within this process all available information about a contaminated site is collected including the nature of the contaminants and their sources, obvious effects and potential receptors as well as environmental recipients. Within this very first stage of the risk assessment procedure, an assessment endpoint has to be determined. Assessment endpoints are the expression of an environmental value (represented by an ecological entity) that is at risk, e.g. a distinct population that faces harm due to pollution. It has to be emphasised that toxicity-test endpoints or other measurement endpoints (in general, measured effects under test conditions) in most cases do not represent assessment endpoints (response of population or ecosystem in the field). Measurement endpoints should be representative for assessment endpoints or have a known relationship to the assessment endpoint allowing the extrapolation of data. 

Characterisation of exposure. This process intends to estimate how much of a harmful chemical substance is for how long in contact with a specified organism. Exposure characterisation is usually a complex process that should consider physico-chemical properties of pollutants and the site (e.g. to estimate influencing factors such as the availability of contaminants), as well as naturally occurring pollutant degradation. For contaminated soils, exposure is usually estimated with measurement of toxicant concentrations by chemical analysis 

One method for assessing bioavailability is via pore-water concentrations. Pore-water concentrations are arguably better overall predictors of bioavailability and effects on the terrestrial ecosystem than measurements of total soil concentrations of contaminants. Peijnenburg et al. (1997) showed that for several substances risks 

Environmental and Human Health Standards for Water and Soil 

A wide range of research publications has identified various soil properties and their potential influence on substance behavior. Soil properties such as organic matter, iron, manganese, and aluminum (hydro)oxide concentrations, cation exchange capacity, and pH can all affect the bioavailability, form, and toxicity of substances. 

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Landis, W.G., Moore, D.R.J., and Norton, S.B. (1998). Ecological risk assessment looking in, looking ont. In P. Donben (P) (Ed.) Pollution Risk Assessment and Management, Chichester, U.K., John Wiley 273-310. 

Suter, G.W. (Ed.) (1993). Ecological Risk Assessment, Boca Raton, FL Lewis. 

EPA (1998) Framework for Ecological Risk Assessment. 63 FR93. EPA/630/R-95/002F. 

Its Role in Ecological Risk Assessment and Risk Management Swindoll, Stahl, Ells, editors 2000... 

A Case Study Advancing Ecological Risk Assessment Methods in the EPA, Office of Pesticide Programs, Final Report from FIFRA Scientific Advisory Panel. USEPA, Washington, DC (2001). Also available on the World Wide Web http //www.epa.gov/scipoly/sap 001/index.htm, accessed September 2002. 

Studies may be designed for estimating exposures to a wide array of wildlife, including birds, mammals and amphibians. Many regulatory requirements involve birds, and less emphasis is currently placed on other species. As regulatory requirements evolve, ecological risk assessments will be required for more species. This may require alternative approaches for food item analysis to allow estimates of pesticide ingestion. 

Finally, in the risk characterization step, the PEC/PNEC quotient that defines the risk of the substance in the environment is calculated. If the quotient (PEC/PNEC) is less than 1, the substance do not present risk to the environment. More information is available in the European Commission Technical Guidance Document on Risk Assessment [3] and in the United States Environmental Protection Agency s Guidelines for Ecological Risk Assessment [6]. 

BREEZE Risk Human health and ecological risk assessment modeling system designed... 

Analyst to conduct multipathway human health risk assessments and food-web based ecological risk assessment modeling. BREEZE risk analyst combines databases, GIS functionality, fate, transport, and exposure modeling equations into one software application... 

EcoFate EcoFate is a software package for conducting ecosystem based environmental and ecological risk assessments of chemical emissions by point and non-point sources in freshwater and marine aquatic ecosystems, including lakes, rivers and marine inlets... 

United States Environmental Protection Agency (1998) Guidelines for ecological risk assessment EPA/630/R-95/002F. Washington, DC... 

Loibner A, Jensen J, Ter Laak T, Celis R, Hartnik T (2006) In Jensen J, Mesman M (eds) Ecological risk assessment of contaminated land decision support for site specific investigations. RIVM report 711701047. Bilthoven, The Netherlands, p 19... 

Carvalho FP, Villeneuve JP, Cattini C, Tolosa I, Montenegro-Guillen S, Lacayo M, Cruz A (2002) Ecological risk assessment of pesticide residues in coastal lagoons of Nicaragua. J Environ Monit 4(5) 778-787... 

The link between the ecological/ecotoxicological risk assessment and the risk management frameworks is demonstrated. The ecological risk assessment consists of seven interactive elements (Fig. 17). The quantitative and descriptive science used to conduct ERA (Table 5) does not answer, in a direct way, the question of what should be done to manage the risk. Science determines adversity, but the public determines acceptability (Fig. 18). But acceptable risk is a highly subjective and relative term. It is time and space-specific and depends upon definitions of quality of life and robustness of the environment. 

Fig. 17 Relationship of the ecological risk management framework to the ecological risk assessment framework (modified after Stahl et al. [53])...

Hall, L.W., Jr., M.C. Scott, and W.D. Killen. 1998. Ecological risk assessment of copper and cadmium in surface waters of Chesapeake Bay watershed. Environ. Toxicol. Chem. 17 1172-1189. 

Ross, P.S., Marine mammals as sentinels in ecological risk assessment, Human Ecol. Risk... 

Similarly, the reductions in toxicity observed in laboratory toxicity tests where exposure is modified (either through the addition of sediment or by removal to clean water) are also apparent in the field. Field effect concentrations are generally observed to occur at concentrations around three to ten times above those based on standard laboratory data. Dissipation and degradation are therefore clearly the critical factors in mitigating effects of pyrethroids under field conditions. This provides reassurance that preliminary ecological risk assessments based on... 

In broad terms risk assessments are carried out to examine the effects of an agent on humans (Health Risk Assessment) and ecosystems (Ecological Risk Assessment). Environmental Risk Assessment (ERA) is the examination of risks resulting from technology that threaten ecosystems, animals and people. It includes human health risk assessments, ecological or ecotoxicological risk assessments, and specific industrial applications of risk assessment that examine end-points in people, biota or ecosystems. 

Traditionally, RA has been focused on threats to humans posed by industrial pollutants. In recent times there has been a shift to other types of hazards and affected objects (Carpenter, 1996). Ecological risk assessment (EcoRA) has already evolved into separate methodology under the general RA framework. 

A number of EIA theorists believe in incorporating formal RA methods into EIA as a way to cope with uncertainties, especially in impact prediction where a formal framework for ecological risk assessment (EcoRA) is already developed. It includes three generic phases problem formulation, analysis, and risk characterization followed by risk management. The analysis phase includes an exposure assessment and an ecological effects assessment (see, e.g., US EPA (1998)). 

Ecological risk assessment in EIA is to evaluate the probability that adverse ecological effects will occur as a result of exposure to stressors2 related to a proposed development and the magnitude of these adverse effects (Smrchek and Zeeman, 1998 US EPA, 1998 Demidova, 2002). A lion s share of site-specific EcoRAs were concerned with chemical stressors—industrial chemicals and pesticides. 

PECULIARITIES OF ECOLOGICAL RISK ASSESSMENT IN OIL TECHNOBIOGEOCHEMICAL PROVINCES... 

Figure 4. A conceptual model of the ecological risk assessment of persistent organochlorinated compounds (POCs) contamination due to riverine inputs into the Caspian Sea.

This would allow a more comprehensive ecological risk assessment, and also predict a perspective of the geoecological situation changes, in particularly, in the Northern Caspian under varying input of different pollutants into the river-sea system. 

US EPA (United States of America Environmental Protection Agency). (1998). Guidelines for Ecological Risk Assessment. Washington, DC U.S. Environmental Protection Agency. 

Russom, C. L., Anderson, E. B., Greenwood, B. E., Pilli, A. ASTER An integration of the AQUIRE data base and the QSAR system for use in ecological risk assessments. Sci. Total Environ. 1991, 109/110, 667-670. 

Frequently, the existence and source of such information is nnknown thns the data are not examined. Even when the existence and sonrces of information are known, decisions must be made in order to make an informed, and often quick decision on the next steps, even if later, one decides not to nse it for a particular application. Knowing about the relevant data gives investigators and analysts the ability to assess the data based on qnality assnrance criteria. This is especially true for users near the end of long decision processes, such as site cleanup, ecological risk assessments, and natural resource damage assessments. 

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