Andersson, Ulla B

Assarsson, Eva

Bohgard, Mats

Dierschke, Katrin

Eriksson, A

Gudmundsson, Anders

Isaxon, Christina

Nielsen, Jörn

Nöjgaard, J Klenö

Wierzbicka, Aneta

English

Lund University Publications

LUND UNIVERSITYPO Box 117221 00 Lund+46 46-222 00 00Generation of Nano Size Particles from Limonene/Ozone Reactions for ControlledHuman Exposures in a ChamberIsaxon, Christina; Wierzbicka, Aneta; Eriksson, A; Gudmundsson, Anders; Nielsen, Jörn;Dierschke, Katrin; Assarsson, Eva; Andersson, Ulla B; Nöjgaard, J Klenö; Bohgard, MatsPublished in:European Aerosol Conference 20092009Link to publicationCitation for published version (APA):Isaxon, C., Wierzbicka, A., Eriksson, A., Gudmundsson, A., Nielsen, J., Dierschke, K., Assarsson, E.,Andersson, U. B., Nöjgaard, J. K., & Bohgard, M. (2009). Generation of Nano Size Particles fromLimonene/Ozone Reactions for Controlled Human Exposures in a Chamber. European Aerosol Conference2009, T108A08.Total number of authors:10General rightsUnless other specific re-use rights are stated the following general rights apply:Copyright and moral rights for the publications made accessible in the public portal are retained by the authorsand/or other copyright owners and it is a condition of accessing publications that users recognise and abide by thelegal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private studyor research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portalRead more about Creative commons licenses: https://creativecommons.org/licenses/Take down policyIf you believe that this document breaches copyright please contact us providing details, and we will removeaccess to the work immediately and investigate your claim.Download date: 08. Oct. 2022Generation of nano size particles from limonene/ozone reactions, for controlled human exposures in a chamber  C Isaxon1, J Pagels1, A Wiertzbicka1, A Eriksson1, A Gudmundsson1, J Nielsen2, K Dierschke2, E Assarsson2, U Andersson2, J Klenö Nöjgaard3 and M Bohgard1 1 Division of Ergonomics and Aerosol Technology (EAT) Lund Institute of Technology, Lund, Sweden 2 Division of Occupational and Environmental Medicine and Psychiatric Epidemiology, Lund University, Lund, Sweden 3 Department of Atmospheric Environment, University of Aarhus, Denmark  Keywords: Aerosol Generation, Fine Particles, Health Effects of Aerosols, Indoor Aerosols, VOCs  An aim of this study has been to develop a method to generate a stable, reproducable terpene/ozone aerosol and deliver it to the exposure chamber while the aerosol still is fresh. An additional aim has been to study the detailed and complex reaction chemistry. The aerosol generated in this study is utilized for exposure of healthy human test subjects in a controlled chamber setting, during and after which various medical responses are being investigated.  Limonene is a common terpene constituent in many consumer products used in indoor settings. On reaction with ambient ozone the oxidation species rapidly form condensed-phase products, which significantly elevate the indoor levels of ultra fine aerosol particles. The size range and the complex chemical composition of the various reaction products and intermediaries suggest that they are likely to cause adverse effects human health. (Rohr et al 2003).  Terpene vapor is generated continuously by passing pure nitrogen (2 lpm) through a glass bottle containing 6.7 ml of commercial essential oil (lemon oil, oleum citri, Interlam ab), consisting of 60-95 % d-limonene. The VOC level is monitored with a photoinization detector (Photovac 2020) at the outlet of the glass bottle. Ozone is generated by a spark discharge generator using filtered dry air, and is added to the ventilation air flow just downstream the inlet for terpene vapours. The ventilation air passes HEPA and active carbon filter before vapor flow and ozone are added, just prior to entering the 21.6 m3 stainless steel exposure chamber. The behaviour of pure limonene in the exposure chamber is studied in separate experiments. During the exposures particle mass concentration in the chamber is monitored with a Tapered Element Oscillating Microbalance (TEOM, Rupprecht & Patashnic Co inc.) and particle number concentration and size distribution by a Scanning Mobility Particle Sizer  system (consisting of a CPC 3010, TSI Inc and a long column Hauke DMA). An aerosol mass spectrometer (AMS, Aerodyne research inc.) is used for investigating the oxidation states and the elemental composition, with regards to carbon, hydrogen and oxygen, of the reactants. Upon reaction with ozone there is an immediate burst of nucleation particles (5-25 nm), which due to condensation and coagulation processes grow in size to 150 nm (air exchange rate of 4.5 h-1). In 2-3 hours the system reaches steady state with mainly a single mode of particles in the mean diameter range of 95-105 nm. Particles are slowly generated by nucleation at steady state. Prior to reacting with limonene vapor the concentration of ozone is 40 ppb. The ozone is almost completely consumed by the terpenes, leaving a residual ozone level in the exposure chamber of 5-8 ppb. Since ozone itself is an airway irritant, a low ozone level inside the chamber is of importance in the exposure studies. After reaching steady state, the generation system delivers a stable aerosol with regards to particle size, number and mass concentration, as shown in figure 1.  Figure 1. Number and mass concentration during an exposure event. At 12.30 the exposure chamber is evacuated. The generation method developed resulted in a stable and reproducible terpene/ozone aerosol, and has been successfully used in human exposure studies. Rohr A C, Weschler C J, Koutrakis P, Spengler J D, Generation and Quantification of Ultrafine Particles through Terpeen/Ozone Reaction in a Chamber Setting, Aerosol Science and Technology 37:65-78, 2003 This study is supported by FAS, the Swedish Council for Working life and Social Research. Cite abstract as Author(s) (2009), Title, European Aerosol Conference 2009, Karlsruhe, Abstract T108A08

Generation of Nano Size Particles from Limonene/Ozone Reactions for Controlled Human Exposures in a Chamber

https://lup.lub.lu.se/search/files/5643663/1482399.pdf

Generation of Nano Size Particles from Limonene/Ozone Reactions for Controlled Human Exposures in a Chamber

Abstract

Similar works

Full text

Available Versions

Lund University Publications