Mercury Study Report to Congress

By Environmental Protection Agency

Book Id: WPLBN0000155599
Format Type: PDF eBook
File Size: 3.0 MB
Reproduction Date: 2007

Title:	Mercury Study Report to Congress
Author:	Environmental Protection Agency
Volume:
Language:	English
Subject:	Ecology, Natural resource issues, Environemtal protection
Collections:	Environmental Awareness Library Collection
Historic Publication Date:
Publisher:	United States Environmental Protection Agency


Citation APA MLA Chicago Agency, E. P. (n.d.). Mercury Study Report to Congress. Retrieved from http://www.gutenberg.cc/

Description
Excerpt: Exposure was characterized in a progressive manner, with varying reliance on computer models for mercury deposition and fate. The objective of this analysis was to characterize the extent to which piscivorous wildlife are exposed to mercury originating from airborne emissions. Details on exposure assessment inputs, methods and results can be found in Volumes III and IV of this Report. Three general approaches were used, which are described as follows.

Table of Contents
TABLE OF CONTENTS Page U.S. EPA AUTHORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv SCIENTIFIC PEER REVIEWERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v WORK GROUP AND U.S. EPA/ORD REVIEWERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viii LIST OF TABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix LIST OF FIGURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x LIST OF SYMBOLS, UNITS AND ACRONYMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi EXECUTIVE SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ES-1 1. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 2. PROBLEM FORMULATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 2.1 Stressor Characteristics: Mercury Speciation and Cycling . . . . . . . . . . . . . . . . . . . . . 2-1 2.1.1 Mercury in Air . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3 2.1.2 Mercury in Surface Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4 2.1.3 Mercury in Soil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5 2.2 Potential Exposure Pathways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5 2.2.1 Exposure Pathways in Aquatic Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5 2.2.2 Exposure Pathways in Terrestrial Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9 2.2.3 Summary of Aquatic and Terrestrial Exposure Pathways . . . . . . . . . . . . . . . 2-10 2.3 Ecological Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11 2.3.1 Bioaccumulation of Mercury . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11 2.3.2 Individual Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-26 2.3.3 Population Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-30 2.3.4 Communities and Ecosystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-36 2.3.5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-37 2.4 Ecosystems Potentially at Risk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-37 2.4.1 Highly Exposed Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-38 2.4.2 Lakes and Streams Impacted by Acid Deposition . . . . . . . . . . . . . . . . . . . . . 2-38 2.4.3 Dissolved Organic Carbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-39 2.4.4 Factors in Addition to pH and DOC that Contribute to Increased Bioaccumulation of Mercury in Aquatic Biota . . . . . . . . . . . . . . . . . . . . . . . 2-39 2.4.5 Sensitive Species . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-39 2.5 Endpoint Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-39 2.6 Conceptual Model for Mercury Fate and Effects in the Environment . . . . . . . . . . . . 2-40 2.7 Analysis Plan . . . . . . . . . . . . . . . . . . .