The importance of variations in in vitro dosimetry to support risk assessment of inhaled toxicants.

The impact of airborne pollutants on human health is determined by what pollutant it is, how much we breathe in, for how long and how often. Testing in animals is cumbersome and results may not reflect human health impacts. Advanced cell models of the human lung allow prediction of the health impact of many different exposure scenarios. Here, we compare different models and exposure methods and provide criteria that may assist in designing experiments, interpreting the results, and thus assessing the risks posed by airborne pollutants. We recommend (1) determining what infor­mation is needed to plan the experiment, (2) choosing an exposure method that is suitable for the pollutant of interest, (3) determining the amount of pollutant that interacts with the human lung, to relate this to realistic deposition in the lung, and (4) considering the time between the exposure and measurement of the effect.