ABSTRACT
A primary objective of epidemiological investigations is to describe an exposure-response association that is unlikely to be explained by factors other than those under study. Thus, all epidemiological studies require estimation of exposure. The validity of an environmental epidemiology study is largely determined by the quality of the exposure measurements; likewise, the availability of appropriate exposure assessment methods determines the design and feasibility of a study. The exposure measure should be biologically relevant and should also show a range of levels in the study population. Exposure assessment in environmental epidemiology thus makes use of temporal variability, spatial variability, or both to optimize the exposure estimates and maximize the exposure contrasts. This principle is nicely described by Geoffrey Rose (1987): “If everyone in the country had smoked
CONTENTS
Introduction ...................................................................................................................................35 Exposure Characterization ..........................................................................................................36 Principles of Epidemiological Exposure Assessment .............................................................. 37 Exposure Assessment Methods...................................................................................................38
