Indoor ozone/human chemistry and ventilation strategies
Artikel i vetenskaplig tidskrift, 2019

This study aimed to better understand and quantify the influence of ventilation strategies on occupant-related indoor air chemistry. The oxidation of human skin oil constituents was studied in a continuously ventilated climate chamber at two air exchange rates (1 h-1 and 3 h-1 ) and two initial ozone mixing ratios (30 and 60 ppb). Additional measurements were performed to investigate the effect of intermittent ventilation ("off" followed by "on"). Soiled t-shirts were used to simulate the presence of occupants. A time-of-flight-chemical ionization mass spectrometer (ToF-CIMS) in positive mode using protonated water clusters was used to measure the oxygenated reaction products geranyl acetone, 6-methyl-5-hepten-2-one (6-MHO) and 4-oxopentanal (4-OPA). The measurement data were used in a series of mass balance models accounting for formation and removal processes. Reactions of ozone with squalene occurring on the surface of the t-shirts are mass transport limited; ventilation rate has only a small effect on this surface chemistry. Ozone-squalene reactions on the t-shirts produced gas-phase geranyl acetone, which was subsequently removed almost equally by ventilation and further reaction with ozone. About 70% of gas-phase 6-MHO was produced in surface reactions on the t-shirts, the remainder in secondary gas-phase reactions of ozone with geranyl acetone. 6-MHO was primarily removed by ventilation, while further reaction with ozone was responsible for about a third of its removal. 4-OPA was formed primarily on the surfaces of the shirts (~60%); gas-phase reactions of ozone with geranyl acetone and 6-MHO accounted for ~30% and ~10%, respectively. 4-OPA was removed entirely by ventilation. The results from the intermittent ventilation scenarios showed delayed formation of the reaction products and lower product concentrations compared to continuous ventilation.

ToF-CIMS

indoor environment

ozone

squalene

air exchange rate

oxygenated volatile organic compounds

Författare

Christian Mark Salvador

Göteborgs universitet

G. Beko

Danmarks Tekniske Universitet (DTU)

Charles J. Weschler

Rutgers Environmental and Occupational Health Sciences Institute

Danmarks Tekniske Universitet (DTU)

Glenn Morrison

The University of North Carolina at Chapel Hill

Michael Le Breton

Göteborgs universitet

Mattias Hallquist

Göteborgs universitet

Lars Ekberg

Installationsteknik

CIT Energy management AB

Sarka Langer

IVL Svenska Miljöinstitutet

Chalmers, Arkitektur och samhällsbyggnadsteknik, Installationsteknik

Indoor Air

0905-6947 (ISSN) 1600-0668 (eISSN)

Vol. 29 6 913-925

Ämneskategorier

Kemiska processer

Annan kemiteknik

Annan kemi

DOI

10.1111/ina.12594

PubMed

31420890

Mer information

Senast uppdaterat

2019-12-02