Examination of the bio-durability of Wollastonite fibres

: Bellmann, B.; Muhle, H.

Abstract
Wollastonite is a naturally occuring calcium silicate which can break down into fibrous particles by the mechanical action of grinding. Since about 1950 wollastonite has been used extensively in the ceramics and plastics industries, and in some applications as a substitute for asbestos. Commercial samples of wollastonite have been used to prepare two fractions by aerosol separation techniques which according to the American Conference of Governmental Industrial Hygienists (ACGIH) can be deposited either throughout the human lungs or mainly in the alveolar area. In order to examine their bio-durability, these fractions were introduced intratracheally into rats. The distribution of the fibres in the lung was checked using a scanning electron microscope (SEM) 2 days after injection after sacrifice of animals. A relatively even distribution of fibres both in the bronchi as well as in the bronchioli and the alveoli was observed.