[Determination of free crystalline silica in atmospheric dust]

The method for the determination of free crystalline silica (quarts), as previously described by two of the authors, has been employed on atmosphere dust of unconfined spaces. The matrix effect of atmospheric dust has been investigated in winter and in summer. The limits in the use of this method have been studied considering also what stated by law code n. 615. The results obtained on the outdoor atmospheric dust, samples from industrial as well as suburban areas, are reported. The results are evaluated in relation to the metereological records.