In air environmental epidemiology, which evaluates human exposure to air pollutants present in the general atmosphere and their health effects, assessing the level of exposure to air pollutants for individual subjects (individual exposure assessment) is an extremely important and challenging task. Ultrafine particles ( UFPs ) are extremely small, with a particle diameter of 100 nm or less, and their environmental concentrations are often expressed not by weight but by number concentration (particles/ cm³ ). Furthermore, UFP exposure is suspected to have cardiovascular and central nervous system effects. In recent years, Land Use Regression Models (LUR models), which use geospatial information as the dependent variable, have been frequently used in the assessment of individual exposure to air pollutants, and there have been reports on UFPs as well. However, in Japan, there is insufficient information on the spatial distribution of UFPs that can be applied to the assessment of individual exposure to UFPs . Therefore, in this study, we attempted to construct an LUR model applicable to the assessment of individual exposure to UFPs , using Yokohama City as the target area. This presentation reports on the model construction and actual exposure assessment.
