Effects of Quartz, Airborne Particulates and Fly Ash Fractions from a Waste Incinerator on Elastase Release by Activated and Nonactivated Rabbit Alveolar Macrophages

Abstract

Elastase release from cultured, activated and nonactivated rabbit alveolar macrophages (AM) was investigated after stimulation by different environmentally related mineral dusts (50–1000 μg/10⁶ cells). Eight different dusts were analyzed for element contents and grain size: one rural and three urban airborne dusts, a coarse and a fine fraction of a sieved waste incinerator fly ash, a sonicated coarse fly ash fraction, and the standard quartz dust DQ 12. The fine fly ash fraction, the sonicated coarse fly ash fraction, and the quartz dust DQ 12 enhanced elastase release by activated AM. Only one of the tested airborne dusts effected a comparable elastase release. The untreated coarse fraction of the fly ash did not cause a significant increase of extracellular elastase activities. Elastase release was dependent on particle numbers and chemical composition and correlated best with barium and tin contents. Nonactivated AM released higher elastase activities than activated AM at low-dose levels. The possible role of dust-induced elastase secretion in the pathogenesis of emphysema is discussed.