Contents - trdoer40006

Contents

Preface.........................................................................................................................vi

1--Overview of Ecological and Human Health Risk Assessment Guidance for

Dredged Material Management..............................................................................3

Purpose and Organization .......................................................................................3

Purpose ................................................................................................................3

Organization of the document .............................................................................4

Background ..............................................................................................................5

What is Risk Assessment?.......................................................................................5

Proper Timing for Risk Assessment........................................................................7

Risk Assessment Role in Dredged Material Risk Management Process ................8

Risk Assessment Format .........................................................................................8

Ecological and Human Health Risk Assessment Relationship .............................10

Who Can Conduct a Risk Assessment? ................................................................11

Data Collection Requirements of Risk Assessment ..............................................11

2--Problem Formulation ...........................................................................................15

Objectives of Ecological Risk Assessment ...........................................................16

Development of Conceptual Model.......................................................................18

Goals of conceptual model ................................................................................18

What are the steps in developing a conceptual model ......................................19

Step 1: Describe dredged material management activity..................................19

Step 2: Identify habitats ....................................................................................22

Step 3: Identify species and humans that may use habitats ..............................23

Step 4: Specify contaminants of concern ..........................................................26

Step 5: Describe release mechanisms................................................................32

Step 6: Describe potential routes of exposure ..................................................32

Step 7: Describe complete exposure routes ......................................................32

Sources of information for developing conceptual model ................................35

Select and Characterize Representative Receptors ...............................................37

Select and characterize human receptors...........................................................38

Select ecological receptors ................................................................................38

Characterize ecological receptors......................................................................40

Assessment and Measurement Endpoints .............................................................41

Select and Evaluate Assessment and Measurement End Points ...........................42

Selecting Assessment End Points ..........................................................................43

Selection of Measurement End Points...................................................................44

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