Exposure assessment needs in studies of acute health effects.

It is known that pollutants in the outdoor and indoor environments are associated with acute adverse effects on health. The acute health effects produced include a wide range, from minor biological changes to causes of illness and exacerbation of disease, to death. Valid assessment of total exposures in various microenvironments are much more meaningful in terms of the various health responses. Short and long exposure times are both important, especially as related to the locations of such exposure and activities engaged in at the time. The quantitative character of exposure-response relationships will require more extensive research on obtaining appropriate exposure information, including monitoring and validating exposures and time activities, and on further modelling. More knowledge is also needed regarding the quantitative nature of the acute health effects, combined effects of different pollutants, and on the effects of various co-variates, effect-modifiers, and confounders. Efforts should also consist of promoting acute health effects studies that have appropriate monitoring and exposure assessment.