Effects of ozone on human blood plasma

Ozone is one of the most toxic atmospheric pollutants and reacts rapidly with organic compounds. It is generally accepted that the oxidizing ability of ozone is responsible for its biologically adverse affects. Consequently, many studies have examined the effects of ozone on individual biological antioxidants. However, this gives limited information since human cells and body fluids contain many different antioxidants. The authors have studied the reactions of ozone with an important representative biological extracellular fluid, human blood plasma. Freshly obtained plasma was exposed to ozone for different times up to four hours. The disappearance of plasma antioxidants in relation to the appearance of lipid hydroperoxides was examined. They found that urate disappears fastest in ozone-exposed plasma and quantitatively appears to be the single most important antioxidant reacting with ozone. In addition, detectable amounts of lipid hydroperoxides were formed before any of the antioxidants were completely consumed. Oxidation products of uric acid were detected in ozone-exposed plasma.