@article { ISI:000432417400011,
	title = {Diurnal Variability and Emission Pattern of Decamethylcyclopentasiloxane (D-5) from the Application of Personal Care Products in Two North American Cities},
	journal = {ENVIRONMENTAL SCIENCE \&amp; TECHNOLOGY},
	volume = {52},
	number = {10},
	year = {2018},
	month = {MAY 15},
	pages = {5610-5618},
	abstract = {Decamethylcyclopentasiloxane (D-5) is a cyclic volatile methyl siloxane (cVMS) that is widely used in consumer products and commonly observed in urban air. This study quantifies the ambient mixing ratios of D-5 from ground sites in two North American cities (Boulder, CO, USA, and Toronto, ON, CA). From these data, we estimate the diurnal emission profile of D-5 in Boulder, CO. Ambient mixing ratios were consistent with those measured at other urban locations; however, the diurnal pattern exhibited similarities with those of traffic-related compounds such as benzene. Mobile measurements and vehicle experiments demonstrate that emissions of D-5 from personal care products are coincident in time and place with emissions of benzene from motor vehicles. During peak commuter times, the Ds/benzene ratio (w/w) is in excess of 0.3, suggesting that the mass emission rate of D-5 from personal care product usage is comparable to that of benzene due to traffic. The diurnal emission pattern of D-5 is estimated using the measured Ds/benzene ratio and inventory estimates of benzene emission rates in Boulder. The hourly D-5 emission rate is observed to peak between 6:00 and 7:00 AM and subsequently follow an exponential decay with a time constant of 9.2 h. This profile could be used by models to constrain temporal emission patterns of personal care products.},
	issn = {0013-936X},
	doi = {10.1021/acs.est.8b00506},
	author = {Coggon, Matthew M. and McDonald, Brian C. and Vlasenko, Alexander and Veres, Patrick R. and Bernard, Francois and Koss, Abigail R. and Yuan, Bin and Gilman, Jessica B. and Peischl, Jeff and Aikin, Kenneth C. and DuRant, Justin and Warneke, Carsten and Li, Shao-Meng and de Gouw, Joost A.}
}
