Hội đồng Nghiên cứu Quốc gia (NRC năm 1991) mô tả con người tiếp xúc với một chất gây ô nhiễm như là một sự kiện bao gồm tiếp xúc với chất gây ô nhiễm cụ thể nồng độ | CHAPTER 5 Exposure Characterization David R. Patrick CONTENTS I. Introduction II. Important Exposure Assessment Concepts III. The Components of the Indoor Air Exposure Assessment A. Identifying Pollutants and Sources of Indoor Air Contaminants B. Determining Exposure Pathways and Environmental Fate C. Measuring or Estimating Indoor Air Concentrations D. Identifying Exposed Populations E. Integrating Exposure Assessment Techniques 1. VoCs 2. Polycyclic Aromatic Hydrocarbons PAHs 3. Lead 4. Environmental Tobacco Smoke F. Uncertainty in Exposure Characterization 1. Location of Exposed Population 2. Population Lifestyles and Activity Patterns 3. Human Intake 4. Emission Characteristics 5. Duration and Frequency of Exposure 6. Environmental Fate and Transport Bibliography I. INTRODUCTION The National Research Council NRC 1991 described human exposure to a contaminant as an event consisting of contact with a specific contaminant concentra 1999 by CRC Press LLC tion at a boundary between the human and the environment . lung or skin for a specific interval. Total exposure is determined by multiplying the concentration by the exposure time. Exposure is translated into a biologically effective dose as some or all of the contaminant is absorbed or deposited in the body a process that can depend upon numerous factors including chemical and physical properties of the contaminant mode of entry into the body breathing rate and metabolic factors. As such an exposure assessment can require evaluation of some or all of the following sources environmental media through which exposure occurs transport from the source to the receptor chemical and physical transformations routes of entry to the body intensity and frequency of contact and spatial and temporal concentration patterns. There are three basic methods for estimating human exposure to an environmental contaminant. The first two are direct measures of exposure while the third is an indirect measure of exposure. 1. A person .
