Ultrafine particles produced by ozone/limonene reactions in indoor air under low/closed ventilation conditions

• Published in: Atmospheric environment (1994) Vol. 42; no. 18; pp. 4149 - 4159
• Main Authors: Langer, Sarka, Moldanová, Jana, Arrhenius, Karine, Ljungström, Evert, Ekberg, Lars
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.06.2008; Elsevier Science
• Subjects: Applied sciences; Atmospheric pollution; Buildings. Public works; Exact sciences and technology; Indoor air chemistry; Indoor pollution and occupational exposure; Limonene; Ozone; Pollution; Pollution indoor buildings; Secondary organic aerosol; Ultrafine particles; Indoor air chemistry; Ozone; Secondary organic aerosol; Limonene; Ultrafine particles; 1,8-p-Menthadiene; Pollutant formation; Secondary pollutant; Air quality; Ultrafine particle; Precursor; Biogenic factor; Terpene; Aerosols; Reaction mechanism; Indoor pollution; Ventilation; Oxidation; Organic compounds
• ISSN: 1352-2310; 1873-2844; 1873-2844
• DOI: 10.1016/j.atmosenv.2008.01.034

Formation of ultrafine particles, dp<100nm, from gas-phase reaction of limonene with O3 was studied. The concentration of reactants was chosen as close to realistic indoor conditions as possible. Two reaction chambers (1 and 14m3) were used. Particle number concentrations were measured using a CPC and size distributions by using a scanning mobility particle sizer (SMPS) system. Rapid formation of new particles was observed at low concentrations of reactants and close to zero ventilation rates. The maximum number of particles was correlated with the initial rate of formation of reaction products. An excess of O3 tends to give higher maximum particle concentrations. Modeling work lead to the conclusion that significant nucleation starts when the mixing ratio of “product” from the reaction Limonene+O3→productox exceeds 0.5–1ppb. The secondary particles formed by atmospheric chemistry in indoor air contribute to the total particulate matter indoors and should be considered in terms of low-dose long-term exposure.