Combustion Processes as a Source of High Levels of Indoor Hydroxyl Radicals through the Photolysis of Nitrous Acid

• DOI: 10.1021/acs.est.5b01905
• Publication Date: 2015-05-05T19:41:21Z
• Authors: V. Bartolomei; E. Gomez Alvarez; J. Wittmer; S. Tlili; R. Strekowski; B. Temime-Roussel; E. Quivet; H. Wortham; C. Zetzsch; J. Kleffmann; S. Gligorovski
• Keywords: Nitrous acid; Hydroxyl radical; Nitrous oxide

Hydroxyl radicals (OH) are known to control the oxidative capacity of atmosphere but their influence on reactivity within indoor environments is believed be little importance. Atmospheric direct sources OH include photolysis ozone and nitrous acid (HONO) ozonolysis alkenes. It has been argued that ultraviolet light fraction solar spectrum largely attenuated environments, thus, limiting extent photolytic sources. Conversely, alkenes suggested as main pathway formation settings. According this hypothesis radical concentrations span in range only 104 105 cm–3. However, recent measurements a school classroom yielded peak values at moderate intensity measured evenings 1.8 × 106 cm–3 were attributed HONO. In work, we report results from chamber experiments irradiated with varying intensities order mimic realistic lighting conditions. The exhaust burning candle was introduced typical source causing sharp HONO, also nitrogen oxides (NOx). HONO yields concentration values, for indoors lightning conditions estimated 5.7 ×· 1.6 107 Excellent agreement exists between levels determined by chemical clock those calculated simple PSS model. These findings suggest significant takes place our dwellings consequences reactivity—that is, secondary oxidants—ought studied hereafter.