Ecological Risks Perspectives from Poland and the United States (1990) / Chapter Skim
Currently Skimming:
The Role of Ecological Risk Assessment in Environmental Decision Making
The Role of Ecological Risk Assessment in Environmental Decision Making
Pages 77-88
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From page 77... ...
An ecosystem nsk assessment is defined as a set of procedures for measuring risk to the environment associated with the use of substances through an objective and probabilistic exercise based on empirical data and scientific judgment. The results of such a risk assessment can then be used to provide a consistent means of estimating the limiting concentrations of substances that will produce no unacceptably negative effects on ecosystems which are potentially exposed to the substance.
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From page 78... ...
concentrations as parallel lines and demonstrates that increasingly more accurate and statistically reliable estimates of these concentrations will result from a sequential series of tests completed along the x axis of the graph. Using the risk assessment process, increasingly more accurate estimates of fate and effects can be made to the point where it becomes possible to state with a high degree of confidence that environmental concentrations and biological effects will likely result in negative environmental consequences.
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From page 79... ...
The process of making and reviewing an environmental risk assessment can be broken down into ten stages (Beck et al., 1981~. These stages and how they are related to each other are shown in Figure 2.
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From page 80... ...
These estimates can be helpful in projecting exposures, but their chief value is in suggesting how extensively the material should be tested for environmental properties, e.g., the rate of chemical and biological degradation. Then, from the results of the environmental fate tests, more refined predictions of environmental concentrations can be made.
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From page 81... ...
ECOTOXICOLOGY: THE PRACTICE OF RISK ASSESSMENTS Ecotoxicology can be defined as the study of the fate and effects of toxic agents in ecosystems. Ecotoxicology is the study of toxic effects on biota particularly on populations and communities—and their interactions with processes controlling the functioning of defined ecosystems.
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From page 82... ...
Although each program derives it differently, the final result is the application of either a safety factor or an assessment factor to account for uncertainty. Although the two programs are similar in their approach to assessing ecological risk, the quantity of data used to make assessments is strikingly different: TSCA assessments tend to be data-poor while FIFING assessments are usually data-rich.
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From page 83... ...
In assessing risks to PMN chemicals, OTS uses the quotient or ratio method. The specific equation used is: Environmental Concentration/Concern Level = Risk If the quotient is equal to or greater than 1, the conclusion is that adverse effects are likely to occur to the population of organisms represented by the toxicity data.
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From page 84... ...
For this discussion, the important term used in FIFRA is "risk to the environment." In order for the EPA Administrator to determine if there will be an unreasonable risk to the environment from the use of a pesticide, an ecological risk assessment from a pesticides perspective involves estimating the likelihood or probability that adverse effects (e.g., mortality to single species of organisms; reductions in populations of non-target organisms due to acute, chronic, and reproductive effects; or disruption in community and ecosystem level functions) will occur, are occurring, or have occurred.
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From page 85... ...
hazard data includes, for example, laboratory fish, aquatic invertebrate, or bird LC50 values, and effect levels for fish and avian reproduction tests. Environmental exposure is a function of two data components.
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From page 86... ...
Specific information and testing data are necessary in order to conduct an ecological risk assessment for a pesticide. Under FIFRA, EPA is not responsible for producing the data needed to make an ecological risk assessment.
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From page 87... ...
The science is complex and addresses a broad range of issues that are frequently the focus of public concern and international policy. ~day, many ecological risk assessment protocols are modifications of methods used to characterize risk to public health.
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