Hydroxyl Radical Production by Air Pollutants in Epithelial Lining Fluid Governed by Interconversion and Scavenging of Reactive Oxygen Species

• DOI: 10.1021/acs.est.1c03875
• Publication Date: 2021-10-06T22:03:35Z
• Authors: Steven Lelieveld; Jake Wilson; Eleni Dovrou; Ashmi Mishra; Pascale S. J. Lakey; Manabu Shiraiwa; Ulrich Pöschl; Thomas Berkemeier
• Keywords: Hydroxyl radical; Reactive nitrogen species; Scavenger

Air pollution is a major risk factor for human health. Chemical reactions in the epithelial lining fluid (ELF) of respiratory tract result formation reactive oxygen species (ROS), which can lead to oxidative stress and adverse health effects. We use kinetic modeling quantify effects fine particulate matter (PM2.5), ozone (O3), nitrogen dioxide (NO2) on ROS formation, interconversion, reactivity, discuss different chemical metrics stress, such as cumulative production hydrogen peroxide (H2O2) hydroxyl radical (OH) conversion. All three air pollutants produce that accumulate ELF H2O2, serves reservoir species. At low PM2.5 concentrations (<10 μg m-3), we find less than 4% all produced H2O2 converted into highly OH, while rest intercepted by antioxidants enzymes serve buffering agents. elevated (>10 however, Fenton chemistry overwhelms effect leads tipping point fate, causing strong nonlinear increase OH production. This shift enhanced provide tentative mechanistic explanation how inhalation induces