Proceedings paper

Scand J Work Environ Health 1995;21 suppl 2:15-18    pdf

Particle activity and in vivo pulmonary response to freshly milled and aged alpha-quartz

by Shoemaker DA, Pretty JR, Ramsey DM, McLaurin JL, Khan A, Teass AW, et al

This study examined the possibility of freshly fractured -quartz being more toxic and inflammatory in vivo than aged quartz of the same composition and particle size. Fresh quartz was generated by a jet mill, and used immediately, while aged dust was stored for two months before use. Both the production of hydrogen peroxide and hydroxyl radicals and the analysis of surface radicals verified the enhanced surface activity of fresh quartz. Male Fischer 344 rats were exposed to fresh or aged -quartz by inhalation (20 mg·m3, 5 h per day, 5 d per week, for 2 weeks) and their pulmonary responses were determined 1--3 d postexposure. Exposure to aged quartz resulted in an increase in cytotoxic and inflammatory parameters. In comparison, the inhalation of freshly cleaved quartz resulted in dramatically greater increases in all of the pulmonary responses. This finding suggests that exposure to freshly machined quartz may result in a greater risk of pulmonary disease.