Organism’s responses to a long-term inhalation of silica-containing submicron particles of an industrial aerosol

S N Solovyeva,I E Valamina,L I Privalova,D K Kuznetsov,M P Sutunkova,I A Minigalieva,V Ya Shur,V B Gurvich,T V Slyshkina,B A Katsnelson,I V Zubarev

doi:10.1088/1757-899x/699/1/012054

Abstract

Female white rats were exposed during up to 6 months 5 times a week, 4 hr per day in a “nose only” inhalation device to an aerosol containing predominantly submicron (nanoscale included) particles of amorphous silica in the concentration 2.6±0.6 or 10.6±2.1 mg/m3. In an auxiliary experiment with a single-shot intratracheal instillation of these particles, it was shown that they induced a pulmonary cell response comparable with that to highly cytotoxic and fibrogenic standard quartz powder DQ12. However, in the long-term inhalation test, the studied aerosol proved to be of very low systemic toxicity and fibrogenicity. This paradox may be explained by low SiO2 retention in lungs and other organs due to a relatively high in vivo solubility of these nanoparticles. Nevertheless, their genotoxic action and transnasal penetration into the brain should make one give a cautious overall assessment of this aerosol as an occupational or environmental hazard.

Highlights

While engineered SiO2 nanoparticle toxicity is being widely investigated, mostly on cell lines or in acute animal experiments [1,2,3,4,5,6,7,8,9], and a lot of others, the practical importance of industrial condensation aerosols with a high SiO2 particle content and the theoretical interest in it seems to be neglected
In an auxiliary experiment with a single-shot intratracheal instillation of these particles, it was shown that they induced a pulmonary cell response comparable with that to highly cytotoxic and fibrogenic standard quartz powder DQ12
We carried out an experiment to study the response of the lower airways free cells obtained from rats exposed, 24 h before bronchoalveolar lavage, to a single-shot intratracheal instillation of the same particles suspended in normal saline in comparison with the response to the highly cytotoxic and fibrogenic standard quartz dust DQ12

Summary

Introduction

While engineered SiO2 nanoparticle toxicity is being widely investigated, mostly on cell lines or in acute animal experiments [1,2,3,4,5,6,7,8,9], and a lot of others, the practical importance of industrial condensation aerosols with a high SiO2 particle content and the theoretical interest in it seems to be neglected. Female white rats were exposed during up to 6 months 5 times a week, 4 hr per day in a “nose only” inhalation device to an aerosol containing predominantly submicron (nanoscale included) particles of amorphous silica in the concentration 2.6±0.6 or 10.6±2.1 mg/m3.

Results

Conclusion