@article{sinha_vazquez_ruiz-garcia_masera_grieshop_2024, title={Evaluating a simplified oxidation flow reactor configuration to characterize fresh and aged emissions from traditional and plancha-type cookstoves under field-like conditions}, volume={328}, ISSN={["1873-2844"]}, url={https://doi.org/10.1016/j.atmosenv.2024.120498}, DOI={10.1016/j.atmosenv.2024.120498}, abstractNote={Plancha-type stoves have been distributed for decades in Mexico to reduce household air pollution, but the influence of photochemical processing ('aging') of their emissions is unknown. Secondary organic aerosols (SOA), formed from aging biomass combustion emissions, has typically been studied in laboratories with complex setups and sophisticated instrumentation. Here, we present an evaluation of a simplified measurement approach using an oxidation flow reactor (OFR), portable instrumentation and filter samples, and its subsequent deployment in characterizing Plancha-type stove emissions in a simulated-field setting in Mexico. Evaluation of field-portable optical measurements for tracking SOA mass for a range of combustion conditions in a laboratory suggested that a field portable nephelometer/filter sampling instrument could effectively quantify time-varying fresh and aged organic aerosol (OA). However, these experiments showed that correction of the optical response with filter measurements was particularly important for aged aerosol. Next, we deployed this measurement ensemble with an OFR to measure fresh and aged emissions from two plancha-type stoves (Patsari and ONIL) and a traditional three stone fire (TSF) under field-like conditions at a test kitchen facility in Pátzcuaro, Mexico. Plancha-type stoves offered significant reductions in primary PM emissions factors (EFs) relative to TSF, with mean Patsari and ONIL elemental carbon, EC (organic matter, OM) EFs lower by ∼19% (65%) and ∼49%(83%) than TSF EFs, respectively. Further, mean Patsari and ONIL SOA emission factors (emission rates) were lower than TSF by 47% (46%) and 61% (73%), respectively, indicating that plancha stoves have the potential to reduce secondary PM formation along with fresh emissions. However, using an OFR to age time-varying real-world emissions is complex, as changes in emission concentrations and composition directly affect the OFR's chemistry, with the interaction between combustion efficiency and OH reactivity in the OFR influencing the extent of tropospheric aging emissions undergo. We outline the challenges associated with such real-time aging experiments and recommend strategies like implementing staged dilution of the flue gas or batch sampling in a smog chamber.}, journal={ATMOSPHERIC ENVIRONMENT}, author={Sinha, Aditya and Vazquez, Juan Carlos and Ruiz-Garcia, Victor and Masera, Omar and Grieshop, Andrew P.}, year={2024}, month={Jul} }
 @article{sinha_george_holder_preston_hays_grieshop_2022, title={Development of volatility distributions for organic matter in biomass burning emissions}, volume={10}, ISSN={["2634-3606"]}, url={https://doi.org/10.1039/D2EA00080F}, DOI={10.1039/d2ea00080f}, abstractNote={We present a novel filter-in-tube sorbent tube method to collect S/I-VOC samples from a range of biomass burning experiments and find that volatility distributions are relatively consistent with prior findings and across the tested combustion types.}, journal={ENVIRONMENTAL SCIENCE-ATMOSPHERES}, author={Sinha, Aditya and George, Ingrid and Holder, Amara and Preston, William and Hays, Michael and Grieshop, Andrew P.}, year={2022}, month={Oct} }
 @article{kim_sinha_george_demarini_grieshop_gilmour_2023, title={Toxicity of fresh and aged anthropogenic smoke particles emitted from different burning conditions}, volume={892}, ISSN={["1879-1026"]}, DOI={10.1016/j.scitotenv.2023.164778}, abstractNote={There is substantial evidence that photochemical reactions in the atmosphere cause physico-chemical transformation of combustion smoke, but how this processing modifies potential health effects in exposed populations is not well understood. Here we utilized a new approach to simulate photochemical aging of anthropogenic smoke emissions (a mixture of plastic, plywood, and cardboard smoke) from two different burning conditions (smoldering vs. flaming) and investigated their adverse outcomes associated with mutagenic activity and the relative potencies of different polycyclic aromatic hydrocarbons (PAHs). Aging resulted in increased oxygenated volatile organic compound (VOC) emissions but largely degraded particle-bound PAH components in the smoke. Chemical transformation during aging was more dramatic for flaming versus smoldering smoke. Due to the PAH degradation, mutagenicity of the aged smoke from flaming combustion was much lower (up to 4 times) than that of the fresh smoke on per-particle mass basis. However, on the basis of particle emitted per fuel mass burned, the aged and fresh smoke particles exhibited similar mutagenic activities, which were up to 3 times higher for smoldering versus flaming smoke emissions. Similarly, the PAH toxicity equivalent (PAH-TEQ) of the aged smoldering smoke was 3 times higher than that of the aged flaming smoke particles, suggesting that some PAHs (e.g., indeno[c,d]pyrene and benzo[b]fluoranthene) in the smoldering smoke were more photochemically stable during aging. These findings increase understanding of the evolution of smoke emitted at different burning conditions and the role of photochemical transformations on mutagenicity and PAH-induced toxicity.}, journal={SCIENCE OF THE TOTAL ENVIRONMENT}, author={Kim, Yong Ho and Sinha, Aditya and George, Ingrid J. and DeMarini, David M. and Grieshop, Andrew P. and Gilmour, M. Ian}, year={2023}, month={Sep} }
 @article{sinha_islam_grieshop_2021, title={Influence of Stove, Fuel, and Oxidation Flow Reactor Conditions on Aging of Laboratory-Generated Cookstove Emissions}, volume={5}, ISSN={["2472-3452"]}, url={https://doi.org/10.1021/acsearthspacechem.1c00081}, DOI={10.1021/acsearthspacechem.1c00081}, abstractNote={Oxidation flow reactor (OFR) experiments are a useful way to explore secondary organic aerosol (SOA) production during photochemical aging of biomass combustion emissions. Here, we extend previous work by studying SOA formed by emissions from three cookstoves used in low-income settings (Philips, Chulika, and three-stone fire (TSF)) while varying the fuel type (red Oak and loblolly Pine) and OFR operating conditions. Differences in SOA formation across fuel types were relatively minor, with SOA formation increases of <30% for Oak vs Pine experiments. Mass spectral fragments (f44, f43, and f60) from aged Oak and Pine emissions generally spanned the same continuum with combustion technology playing a larger role in dictating aged OA evolution than the fuel type. Combustion technology also has a much greater influence on net aerosol climate forcing relative to interfuel differences. The OFR was operated under "wet" and "dry" conditions, to study the impacts of more or less tropospherically relevant oxidation conditions on SOA formation, respectively. SOA formation did not vary dramatically across OFR conditions and was larger by up to 27% for the TSF and 5% for the Philips for "wet" operation. OA spectral differences were greater, with f44 up to 28% greater for "wet" operating conditions at similar levels of aging. Overall, changes in reactor operation were not sufficient to alter major conclusions from previous work where the OFR was operated under conditions similar to the "dry" conditions applied here. Positive matrix factorization analyses on SOA spectra identified two factors, a transient oxidation factor and a uniformly aged factor, which were similar across experiments.}, number={6}, journal={ACS EARTH AND SPACE CHEMISTRY}, publisher={American Chemical Society (ACS)}, author={Sinha, Aditya and Islam, Mohammad Maksimul and Grieshop, Andrew}, year={2021}, month={Jun}, pages={1575–1590} }
 @article{sinha_saleh_robinson_ahern_tkacik_presto_sullivan_robinson_donahue_2018, title={Mass accommodation coefficients of fresh and aged biomass-burning emissions}, volume={52}, ISSN={["1521-7388"]}, DOI={10.1080/02786826.2017.1413488}, abstractNote={ABSTRACT Most chemical transport models treat the partitioning of semi-volatile organic compounds (SVOCs) with the assumption of instantaneous thermodynamic equilibrium. However, the mass accommodation coefficients, α, of biomass-burning organic aerosol (BBOA) are largely unconstrained. During the FLAME-IV campaign, we thermally perturbed aged and fresh BBOA with a variable residence time thermodenuder and measured the resulting change in particle mass concentration to restore equilibrium. We used this equilibration profile to retrieve an effective α for components of BBOA that dictated this profile and found that the mass accommodation coefficients lie within the range 0.1 ≪ α ⩽ 1. A simple plume dilution model shows a maximum of only a 7% difference between a dynamical and an instantaneous equilibrium partitioning model using our best-estimate value for α. This supports continued use of the equilibrium assumption to treat partitioning of biomass-burning emissions in chemical-transport models. Copyright © 2018 American Association for Aerosol Research}, number={3}, journal={AEROSOL SCIENCE AND TECHNOLOGY}, author={Sinha, Aditya and Saleh, Rawad and Robinson, Ellis S. and Ahern, Adam T. and Tkacik, Daniel S. and Presto, Albert A. and Sullivan, Ryan C. and Robinson, Allen L. and Donahue, Neil M.}, year={2018}, pages={300–309} }
 @article{reece_sinha_grieshop_2017, title={Primary and Photochemically Aged Aerosol Emissions from Biomass Cookstoves: Chemical and Physical Characterization}, volume={51}, ISSN={0013-936X 1520-5851}, url={http://dx.doi.org/10.1021/acs.est.7b01881}, DOI={10.1021/acs.est.7b01881}, abstractNote={Secondary organic aerosol (SOA) formation during photo-oxidation of primary emissions from cookstoves used in developing countries may make important contributions to their climate and air quality impacts. We present results from laboratory experiments with a field portable oxidation flow reactor (F-OFR) to study the evolution of emissions over hours to weeks of equivalent atmospheric aging. Lab tests, using dry red oak, measured fresh and aged emissions from a 3 stone fire (TSF), a "rocket" natural draft stove (NDS), and a forced draft gasifier stove (FDGS), in order of increasing modified combustion efficiency (MCE) and decreasing particulate matter emission factors (EF). SOA production was observed for all stoves/tests; organic aerosol (OA) enhancement factor ranged from 1.2 to 3.1, decreasing with increased MCE. In primary emissions, OA mass spectral fragments associated with oxygenated species (primary biomass burning markers) increased (decreased) with MCE; fresh OA from FDGS combustion was especially oxygenated. OA oxygenation increased with further oxidation for all stove emissions, even where minimal enhancement was observed. More efficient stoves emit particles with greater net direct specific warming than TSFs, with the difference increasing with aging. Our results show that the properties and evolution of cookstove emissions are a strong function of combustion efficiency and atmospheric aging.}, number={16}, journal={Environmental Science & Technology}, publisher={American Chemical Society (ACS)}, author={Reece, Stephen M. and Sinha, Aditya and Grieshop, Andrew P.}, year={2017}, month={Jul}, pages={9379–9390} }