A comparison of toxicity mechanisms of dust storm particles collected in the southwest of Iran on lung and skin using isolated mitochondria

Dust storms are events of considerable extent and of frequent occurrence in deserts and on their margins. Each year many areas of Iran are affected by dust storms, and the intensity of these storms is higher in the western parts of the country. The toxicity of dust particles partly depends on their concentration. In this study, suspensions containing particles of one, two, and three filters were used and then these particles were dissolved in polar (normal saline) and non-polar (dimethyl sulfoxide) solvents to final concentrations of 2, 5, or 10 mg/ml dust particles for further toxicity assessments. For the assessment of toxicity, rat mitochondria were isolated from lung and skin and then parameters of mitochondrial toxicity including: decreased complex II activity, increased reactive oxygen species (ROS) formation, mitochondrial membrane potential collapse, mitochondrial swelling, and cytochrome c release were evaluated. Our results showed that with the increasing dust concentration (number of filters) mitochondrial ROS formation, mitochondrial swelling, and mitochondrial membrane potential collapse and also cytochrome c release were significantly elevated in both lung and skin tissues compared with related unexposed mitochondria. Our findings suggested that higher particle concentration of 10 mg/ml leads to more mitochondrial dysfunction, which ultimately ends in either apoptosis or necrosis in both lung and skin tissues. Particles that damage mitochondria probably contain both polar and non-polar such as metal ions components.