2019_EJRNL_PP_SARA_M__DUNCAN_1.pdf
Terbatas Lili Sawaludin Mulyadi
» ITB
Terbatas Lili Sawaludin Mulyadi
» ITB
Water-soluble organic gas (WSOG) concentrations
are elevated in homes. However, WSOG sources, sinks, and
concentration dynamics are poorly understood. We observed
substantial variations in 23 residential indoor WSOG concentrations
measured in real time in a North Carolina, U.S., home over several
days with a high-resolution time-of-flight chemical ionization mass
spectrometer equipped with iodide reagent ion chemistry (I-HRToF-CIMS). Concentrations of acetic, formic, and lactic acids
ranged from 30?130, 15?53, and 2.5?360 ?g m?3
, respectively.
Concentrations of several WSOGs, including acetic and formic
acids, decreased considerably (?30?50%) when the air conditioner
(AC) cycled on, suggesting that the AC system is an important sink
for indoor WSOGs. In contrast to nonpolar organic gases, indoor
WSOG loss rate coefficients were substantial for compounds with
high oxygen-to-carbon (O/C) ratios (e.g., 1.6?2.2 h?1 for compounds with O/C > 0.75 when the AC system was off). Loss rate
coefficients in the AC system were more uncertain but were estimated to be 1.5 h?1
. Elevated concentrations of lactic acid
coincided with increased human occupancy and cooking. We report several WSOGs emitted from cooking and cleaning as well
as transported in from outdoors. In addition to indoor air chemistry, these results have implications to exposure and human health.