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ECOFRAM: Aquatic Risk Assessment

Jeffrey Giddings
Springborn Laboratories Inc.

Paul Hendley
Zeneca Ag Products.

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Risk Quotient = Exposure Concentration / Effect Concentration

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Probabilistic Risk Characterization

graph of a curve with y-axis of probability of occurrence and x-axis of magnitude of effect

Probabilistic Risk Characterization

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Exposure Distribution

graph of connected points with y-axis of exceedance frequency and x-axis of concentration (mg/L)

Exposure Distribution

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Exposure Analysis

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Probability of Exceeding LC50

graph of connected points with y-axis of exceedance frequency and x-axis of concentration (mg/L) and vertical line representing LC50 and intersecting horizontal line representing probability of exceeding LC50

Probability of Exceeding LC50

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Probability of Mortality

3 graphs: first of connected points with y-axis of frequency and x-axis of concentration; second of connected points with y-axis of mortality (%) and x-axis of concentration; third a curve with y-axis of probability and x-axis of mortality (%)

Probability of Mortality

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Extrapolation to Population Effect

3 graphs: first of connected points with y-axis of mortality (%) and x-axis of concentration; second a curve with y-axis of pop. decline (%) and x-axis of mortality (%); third a curve with y-axis of pop.decline (%) and x-axis of concentration

Extrapolation to Population Effect

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Another Endpoint: the PR50

graph of curve with y-axis of pop.decline (%) and x-axis of concentration. line indicators included: vertical line of PR50 and horizontal line of 50% population reduction

Another endpoint: the PR50

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Probability of Population Decline

3 graphs: first of connected points with y-axis of frequency and x-axis of concentration; second a curve with y-axis of pop. decline (%) and x-axis of concentration; third a curve with y-axis of probability and x-axis of pop.decline (%)

Probability of Population Decline

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Distribution of Species Sensitivity

graph of distribution of LC50's for chlorpyrifos for arthropods and for fish.  y-axis of sensitivity rank (percentile) and x-axis of concentration (ng/L)

Distribution of LC50's for Chlorpyrifos

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Probability of Affecting Species

3 graphs: first of connected points with y-axis of frequency and x-axis of concentration; second of best-fit line through points with y-axis of % of LC50s and x-axis of concentration; third a curve with y-axis of probability and x-axis of species affected (%)

Probability of Affecting Species

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Pulsed Exposure

Diazinon Concentrations
San Joaquin River at Laird Park
1991-1992

graph of connected points with y-axis of diazinon concentration (ng/L) and x-axis of months from 10/91 to 10/92

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Assessing Effects of Pulsed Exposures

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Other Components of Effects Analysis

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Outstanding Issues

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Summary of Tools for Effects Assessment

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Risk Assessment Process

flow diagram of step 1 and step 2 of process with headings: aquatic effects, process, aquatic exposure, and scenario / scale

Risk Assessment Process (Steps 1 and 2)

Risk Assessment Process (Steps 3 and 4)

flow diagram of step 3 and step 4 of process with headings: aquatic effects, process, aquatic exposure, and scenario / scale

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