Cytotoxicity of abrasive blasting substitutes.
Vallyathan-V; Greskevitch-M; Jones-W; Castranova-V
Toxicologist 1999 Mar; 48(1-S):118
Increased morbidity and mortality from sandblasting with crystalline silica continues to occur even when respiratory protection is used. Because of the high risk of acute silicosis and increased mortality associated with the use of silica in sand blasting, it is banned in many industrialized countries and many substitutes are now being commercially used. We studied few of the most frequently used substitutes for in vitro cytotoxicity and tested aerosolized dusts within two hours of blasting and after aging for four weeks. Treated sand, sand, garnet, coal slag, specular hematite, and staurolite were collected by drawing air from a blasting area through a cyclone precipitator and then onto a 47 mm, 0.8 microm FWS-B filter within one meter of the operator's breathing zone. Samples of the pre-blasted and post-blasted materials were used for chemical and electron microprobe analyzes and compared. Samples prepared on polycarbonate filters were analyzed by scanning electron microscopy, x-ray spectrometry, and plasma emission spectrometry. Cytotoxicity studies using rat alveolar macrophage monitored cell viability, and leakage of lactate dehydrogenase (LDH) and N-acetyl-Beta-D glucosaminidase (NAG). Measurements of hydroxyl radical (OH) generation and lipid peroxidation potential were also made on blasted dusts. The blasting process changed the trace metal content of all the blasted particles. Blasting generally increased the relative proportion of iron in blasted materials. This iron was apparently derived from the steel plates that were blasted. Blasting also resulted in the generation of particles with an average diameter of 1 microm. Both fresh and aged blasted particles decreased rat alveolar macrophage viability and increased enzyme release to varying degrees. Toxicity was generally more distinct for staurolite, coal slag, and garnet compared to sand. The OH generation from all freshly blasted particles was generally higher than from aged particles. Lipid peroxidation potential was greatest for garnet and staurolite. This study demonstrates that silica sand blasting substitutes are not without biological effects and in some instances the cytotoxicity exceeds that of sand and may provoke lung injury.
Animal-studies; Laboratory-animals; Statistical-analysis; Analytical-methods; Analytical-chemistry; Exposure-assessment; Toxicology; Toxins; Toxic-materials; Particulate-dust; Airborne-particles; Silica-dusts; Silicates; Quartz-dust; Abrasive-blasting; Metal-dusts; Metal-poisoning; Metallic-dusts; Lung-irritants; Lung-disorders
The Toxicologist. Society of Toxicology 38th Annual Meeting, March 14-18, 1999, New Orleans, Louisiana