Assessing Intermittent or Variable Exposures at Lead Sites

By Environmental Protection Agency

Book Id: WPLBN0000026187
Format Type: PDF eBook:
File Size: 0.5 MB
Reproduction Date: 2007

Title:	Assessing Intermittent or Variable Exposures at Lead Sites
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.). Assessing Intermittent or Variable Exposures at Lead Sites. Retrieved from http://gutenberg.us/

Description
Excerpt: U.S. ENVIRONMENTAL PROTECTION AGENCY TECHNICAL REVIEW WORKGROUP FOR LEAD The Technical Review Workgroup for Lead (TRW) is an interoffice workgroup convened by the U.S. EPA Office of Solid Waste and Emergency Response/Office of Superfund Remediation and Technology Innovation (OSWER/OSRTI).

Table of Contents
TABLE OF CONTENTS 1.0 SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.0 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.1 APPROPRIATE USES OF THE TIME-WEIGHTED APPROACH . . . . . . . . . . . . . . . . . . . . . . 9 3.0 TIMEWEIGHTING EXPOSURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 3.1 SIMPLE TIMEWEIGHTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.2 VARYING INTENSITY OF EXPOSURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 3.3MATRIX APPROACH FOR EVALUATING EXPOSURE ASSUMPTIONS . . . . . . . . . . . . . . . 15 3.4 CALCULATING A PRELIMINARY REMEDIATION GOAL (PRG) . . . . . . . . . . . . . . . . . . . 16 4.0 APPLICATIONS OF THE APPROACH WITH THE IEUBK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 4.1 CONTRIBUTION OF TRACKED-IN SOIL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 4.2 APPLICABILITY OF THE APPROACH TO VARIOUS AGE GROUPS . . . . . . . . . . . . . . . . . 21 4.2.1 CHILDREN 0-84 MONTHS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 4.2.2 ADOLESCENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 4.2.3 ADULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 4.3 SEASONAL VARIABILITY IN LEAD EXPOSURE AND PBB . . . . . . . . . . . . . . . . . . . . . . . 23 4.4 INCREASED SOIL INGESTION (INCREMENTAL APPROACH) . . . . . . . . . . . . . . . . . . . . . 24 5.0 AIR PATHWAY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 6.0 UNCERTAINTIES IN THE APPROACH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 6.1 UNCERTAINTIES IN ASSUMPTIONS REGARDING SOIL INTAKE AND ABSORPTION . . . . 28 6.2 UNDERESTIMATION OF PEAK PBB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 6.3 UNCERTAINTY IN HEALTH EFFECTS FROM ACUTE, HIGH-LEVEL EXPOSURES . . . . . . 30 6.4 SEASONAL VS. ANNUAL EXPOSURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 APPENDIXA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 EXAMPLE 1: RECREATION EXPOSURE SCENARIO FOR PARK . . . . . . . . . . . . . . . . . . . . . . 32 EXAMPLE 2: RECREATIONAL & TRESPASSING EXPOSURE SCENARIO . . . . . . . . . . . . . . . . 34 EXAMPLE 3: DAYCARE EXPOSURE SCENARIO FOR INDUSTRIAL PARK DAYCARE . . . . . . 37 EXAMPLE 4: INTERMITTENT NON-RESIDENTIAL EXPOSURE FOR ADULTS . . . . . . . . . . . . 39 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 EXAMPLE 5: SEASONAL EXPOSURE: CHILDREN VISITING A SITE 4MONTHS OF THE YEAR EXAMPLE 6: LAWNMAINTENANCE NEAR A RIVER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46