%0 Journal Article
%T Quantification of particle-induced inflammatory stress response: a novel approach for toxicity testing of earth materials
%A Andrea D Harrington
%A Stella E Tsirka
%A Martin AA Schoonen
%J Geochemical Transactions
%D 2012
%I BioMed Central
%R 10.1186/1467-4866-13-4
%X By measuring the production of ROS and the viability of cells, an inflammatory stress response (ISR) indicator is defined. This approach normalizes the ROS upregulation with respect to the number of viable cells at the time of measurement. We conducted experiments on a series of minerals and soils that represent materials that are inert (i.e., glass beads, anatase, and a soil with low trace element content), moderately reactive (i.e., soil with high trace element content), and highly reactive (i.e., pyrite). Inert materials generated the lowest ISR, averaging 350% compared to the control. Acid washed pyrite produced the highest ISR (1,100 fold higher than the control). The measurements conducted as a function of time showed a complex response. Most materials showed an increase in ISR with particle loading.The amount of cellularly generated ROS and cell viability combined provide a better understanding of particle-induced oxidative stress. The results indicate that some earth materials may solicit an initial burst of ROS, followed by a second phase in which cell viability decreases and ROS production increases, leading to a high ISR value. Hence, measurements conducted over a range of particle loading combined with multiple data measurements up to 24 hours can provide new insights in the possible effect of exposure to earth materials on human health.The inhalation of mineral, coal, and volcanic dust can lead to a spectrum of lung diseases [1-12]. Even in cases where the disease origin is clear (e.g., asbestosis, silicosis and coal workers' pneumoconiosis (CWP)), it is often unclear what role the earth material plays in the mechanism of pathogenesis (disease development). However, a common factor appears to be the upregulation of reactive oxygen species (ROS) in lung cells upon exposure [9,13-18]. ROS are short-lived intermediate reduction products of molecular oxygen: superoxide (O2ˇ¤ -), hydrogen peroxide (H2O2), and hydroxyl radical (ˇ¤OH) [19,20]. Although their for
%U http://www.geochemicaltransactions.com/content/13/1/4