[A personal sampling and an area sampling--exposure concentration and environmental concentration]

Two methods for the evaluation of air contaminant in a work environment are personal sampling to measure the exposure concentration for the evaluation of the exposure level to workers and area sampling that measures the environmental concentration for the evaluation of the clean level in the work environment. The aim of these samplings is different but they are used to measure the concentration in the same work environment. It is important to understand the difference between the exposure concentration and the environmental one in the same work environment. In this report, the relationship between the exposure concentration and the environmental one is investigated by using previous reported data. The difference between the exposure concentration and the environmental one is very large for all data, but the exposure concentrations agree well with the environmental ones when the both concentrations were measured by the same apparatus in some work environments.