Mercury Study Report to Congress

By Environmental Protection Agency

Book Id: WPLBN0000155597
Format Type: PDF eBook:
File Size: 1.35 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 Protection Agency, B. E. (n.d.). Mercury Study Report to Congress. Retrieved from http://gutenberg.cc/

Description
Excerpt: The following conclusions are presented in approximate order of degree of certainty in the conclusion, based on the quality of the underlying database. The conclusions progress from those with greater certainty to those with lesser certainty. Consumption of fish is the dominant pathway of exposure to methylmercury for fishconsuming humans. There is a great deal of variability among individuals in these populations with respect to food sources and fish consumption rates. As a result, there is a great deal of variability in exposure to methylmercury in these populations. The anthropogenic contribution to the total amount of methylmercury in fish is, in part, the result of anthropogenic mercury releases from industrial and combustion sources increasing mercury body burdens in fish. As a consequence of human consumption of the affected fish, there is an incremental increase in exposure to methylmercury.

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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiv LIST OF SYMBOLS, UNITS AND ACRONYMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv EXECUTIVE SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ES-1 1. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 2. APPROACH TO EXPOSURE ASSESSMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 2.1 Modeling Exposures near Mercury Emissions Sources . . . . . . . . . . . . . . . . . . . . . . . . 2-1 2.1.1 Description of Computer Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 2.1.2 Estimates of Background Mercury . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3 2.2 Description of Hypothetical Exposure Scenarios for Humans . . . . . . . . . . . . . . . . . . . 2-4 2.2.1 Hypothetical Location Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4 2.2.2 Description of Hypothetical Human Exposure Scenarios . . . . . . . . . . . . . . . . 2-5 2.3 Summary of Exposure Parameter Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9 2.4 Emissions Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12 2.5 Predicted Concentrations in Environmental Media . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12 3. PREDICTED INDIVIDUAL EXPOSURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1 3.1 Illustration of Exposure Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1 3.1.1 Concentrations in Environmental Media and Biota . . . . . . . . . . . . . . . . . . . . . 3-2 3.1.2. Results for Hypothetical Exposure Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . 3-6 3.2 Results of Combining Local and Regional Models - Predicted Human Exposure . . . 3-12 3.2.1 Inhalation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12 3.2.2 Agricultural Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12 3.2.3 Urban Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-37 3.2.4 Fish Ingestion Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-37 3.3 Issues Related to Predicted Mercury Exposure Estimates . . . . . . . . . . . . . . . . . . . . . . 3-38 3.4 Summary Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-39 4. POPULATION EXPOSURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 4.1 Fish Consumption among the General U.S. Population . . . . . . . . . . . . . . . . . . . . . . . . 4-1 4.1.1 Patterns of Fish Consumption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 4.1.2 Frequency of Consumption of Fish Based on Surveys of Individ