A5054443305- Atmospheric chemistry and aerosols
- Air Quality and Health Impacts
- Atmospheric aerosols and clouds
- Air Quality Monitoring and Forecasting
- Marine and coastal ecosystems
- Atmospheric Ozone and Climate
- Aquatic Ecosystems and Phytoplankton Dynamics
- Catalytic Processes in Materials Science
- Fire effects on ecosystems
- Spectroscopy and Laser Applications
- Aeolian processes and effects
- Catalysis and Oxidation Reactions
- Advanced Proteomics Techniques and Applications
- Aerospace Engineering and Energy Systems
- Crystal Structures and Properties
- Thermography and Photoacoustic Techniques
- Mineralogy and Gemology Studies
- Soil erosion and sediment transport
- Reproductive tract infections research
- Vehicle emissions and performance
- Biocrusts and Microbial Ecology
- Spectroscopy Techniques in Biomedical and Chemical Research
- Algal biology and biofuel production
- Toxic Organic Pollutants Impact
- Hydrology and Watershed Management Studies
University of Michigan
2017-2025
Research Triangle Park Foundation
2023
Environmental Protection Agency
2023
VA Office of Research and Development
2023
Michigan United
2017-2020
Ann Arbor Center for Independent Living
2018
California Department of Public Health
2014
United States Air Force
1995
Acid-catalyzed reactions between gas- and particle-phase constituents are critical to atmospheric secondary organic aerosol (SOA) formation. The aerosol-phase state is thought influence the reactive uptake of gas-phase precursors particles by altering diffusion rates within particles. However, few experimental studies have explored precise role on processes. This laboratory study systematically examines coefficient (γ) trans-β-isoprene epoxydiol (trans-β-IEPOX), predominant IEPOX isomer,...
Acid-driven multiphase chemistry of isoprene epoxydiols (IEPOX), key oxidation products, with inorganic sulfate aerosol yields substantial amounts secondary organic (SOA) through the formation organosulfur compounds. The extent and implications inorganic-to-organic conversion, however, are unknown. In this article, we demonstrate that extensive consumption occurs, which increases IEPOX-to-inorganic concentration ratio (IEPOX/Sulfinorg), as determined by laboratory measurements....
Isoprene-derived secondary organic aerosol (SOA) is mainly formed through acid-catalyzed reactive uptake of isoprene-derived epoxydiols (IEPOX) onto sulfate particles. The effect IEPOX-derived SOA on the physicochemical properties existing aerosols and resulting capacity for further formation remains unclear. This study systematically examined influences phase state, morphology, acidity pre-existing particles, as well their implications reactivity evolution these By combining thermodynamic...
Aerosol phase state is critical for quantifying aerosol effects on climate and air quality. However, significant challenges remain in our ability to predict quantify during its evolution the atmosphere. Herein, we demonstrate that (liquid, semisolid, solid) exhibits a diel cycle mixed forest environment, oscillating between viscous, semisolid at night liquid with separation day. The viscous nighttime particles existed despite higher relative humidity were independently confirmed by bounce...
Harmful algal blooms (HABs) caused by cyanobacteria in freshwater environments produce toxins (e.g., microcystin) that are harmful to human and animal health. HAB frequency intensity increasing with greater nutrient runoff a warming climate. Lake spray aerosol (LSA) released from lakes has been identified on lakeshores after transport inland, including HABs, but little is known about the potential for be incorporated into LSA. In this study, samples were collected two Michigan: Mona during...
In freshwater lakes, harmful algal blooms (HABs) of Cyanobacteria (blue-green algae) produce toxins that impact human health. However, little is known about the lake spray aerosol (LSA) produced from wave-breaking in HABs. this study, LSA were laboratory samples collected Lake Michigan and Erie during HAB nonbloom conditions. The incorporation biological material within individual HAB-influenced particles was examined by single-particle mass spectrometry, scanning electron microscopy with...
Methyltetrol sulfates are unique tracers for secondary organic aerosols (SOA) formed from acid-driven multiphase chemistry of isoprene-derived epoxydiols. 2-Methyltetrol sulfate diastereomers (2-MTSs) the dominant isomers and single most-abundant SOA in atmospheric fine particulate matter (PM2.5), but their sinks remain unknown. We investigated oxidative aging authentic 2-MTS by gas-phase hydroxyl radicals (•OH) at a relative humidity 61 ± 1%. The effective rate constant this heterogeneous...
Physicochemical analysis of individual atmospheric aerosols at the most abundant sizes in atmosphere (<1 μm) is analytically challenging, as hundreds to thousands species are often present femtoliter volumes. Vibrational spectroscopies, such infrared (IR) and Raman, have great potential for probing functional groups single particles ambient pressure temperature. However, diffraction limit IR radiation limits traditional microscopy > ∼10 μm, which less relevance aerosol health climate...
Wildfire activity is increasing in the continental U.S. and can be linked to climate change effects nutrient emissions, with potential on downwind ecosystems.
Aerosols containing biological material (i.e., bioaerosols) impact public health by transporting toxins, allergens, and diseases the climate nucleating ice crystals cloud droplets. Single particle characterization of primary aerosol particles (PBAPs) is essential, as individual physicochemical properties determine their impacts. Vibrational spectroscopies, such infrared (IR) or Raman spectroscopy, provide detailed information about components within atmospheric aerosols but these techniques...
Sea spray aerosol (SSA) and lake (LSA) from wave breaking contribute to particulate matter (PM) in coastal regions near oceans freshwater lakes, respectively. However, SSA LSA contributions atmospheric populations inland are poorly understood because of difficulties differentiating them other sources when using bulk particle measurements. Herein, we show that episodically at a rural site northern Michigan >700 >25 km the nearest seawater Great Lakes sources, During July 2014, individual...
Atmospheric oxidation of volatile organic compounds, such as isoprene, and subsequent condensation or heterogeneous reactions lead to the formation secondary aerosol (SOA), a ubiquitous component submicron aerosol. Liquid–liquid phase-separated organic–inorganic particles have been observed in laboratory field; however, impacts multiphase on viscosity are not well understood for particles. In this study, were reacted with gaseous isoprene epoxydiol (IEPOX), an abundant product. Acidic...
Aerosol acidity increases secondary organic aerosol (SOA) formed from the reactive uptake of isoprene-derived epoxydiols (IEPOX) by enhancing condensed-phase reactions within sulfate-containing submicron particles, leading to low-volatility products. However, link between initial and resulting physicochemical properties IEPOX-derived SOA remains uncertain. Herein, we show distinct differences in morphology, phase state, chemical composition individual organic–inorganic mixed particles after...
Due in part to climate change, wildfire activity is increasing, with the potential for greater public health impact from smoke downwind communities. Studies examining effects of have focused primarily on fine particulate matter (PM2.5), but there a need better characterize other constituents, such as hazardous air pollutants (HAPs). HAPs are chemicals known or suspected cause cancer serious that regulated by United States (US) Environmental Protection Agency. Here, we analyzed concentrations...
Secondary organic aerosol (SOA), formed from the oxidation of volatile compounds (VOCs), is a large contributor to atmospheric fine particulate matter (PM2.5) and commonly present in mixed inorganic–organic submicron particles. SOA varying biogenic anthropogenic VOCs results unique physicochemical properties that modify climate impacts (i.e., water uptake). Understanding reactive uptake VOC-derived semivolatile products inorganic-SOA particles remains limited, particularly for at most...
Abstract The equatorial North Atlantic Ocean (NAO) is a nutrient‐limited ecosystem that relies on the deposition of long‐range transported iron (Fe)‐containing aerosols to stimulate primary productivity. Using microscopy, we characterized supermicron and supercoarse mode African western NAO in boreal winter/spring. We detected three particle types including dust, biological aerosol particles, freshwater diatoms (FDs). FDs contained 4% Fe by weight due surficial dust inclusions may be...
Cyanobacterial harmful algal blooms (cHABs) have the potential to adversely affect public health through production of toxins such as microcystins, which consist numerous molecularly distinct congeners. Microcystins been observed in atmosphere after emission from freshwater lakes, but little is known about effects inhaling microcystins and factors contributing microcystin aerosolization. This study quantified total concentrations water aerosol samples collected around Grand Lake St. Marys...
The acidity of atmospheric aerosols is a critical property that affects the chemistry and composition atmosphere. Many key multiphase chemical reactions are pH-dependent, impacting processes like secondary organic aerosol formation, need to be understood at single particle level due differences in particle-to-particle impact both climate health. However, analytical challenge measuring individual particles has limited pH measurements for fine (<2.5 μm) coarse (2.5–10 particles. This led...
Due to their small size, measurements of the complex composition atmospheric aerosol particles and surfaces are analytically challenging. This is particularly true for microspectroscopic methods, where it can be difficult optically identify individual smaller than diffraction limit visible light (∼350 nm) measure vibrational modes. Recently, surface enhanced Raman spectroscopy (SERS) has been applied study particles, allowing detection characterization previously undistinguishable However,...
Declining susceptibility of Neisseria gonorrhoeae to available antimicrobial agents has prompted repeated updates the Centers for Disease Control and Prevention (CDC) treatment guidelines. The only regimen currently recommended as first-line is dual therapy consisting an intramuscular dose ceftriaxone together with azithromycin or doxycycline. objective this analysis identify how adherence CDC guidelines varies by clinical practice setting.A geographically representative random sample N....
Wildfires significantly impact air quality and climate, including through the production of aerosols that can nucleate cloud droplets participate in aqueous-phase reactions. Cloud water was collected during summer months (June-September) 2010-2017 at Whiteface Mountain, New York examined for biomass burning influence. samples were classified by their smoke influence based on backward mass trajectories satellite-detected smoke. A total 1,338 over 485 days probability influence, with 49% these...
Aerosol particles are generated by wind-driven processes in regions with large bodies of freshwater, but the impact these on cloud properties and is poorly understood. Lake spray aerosol (LSA) production from freshwater wave breaking has potential to contribute formation modify acting as condensation nuclei (CCN) ice nucleating (INPs). To examine whether LSA reaches height incorporated into clouds over Laurentian Great Lakes, sampling atmospheric water was conducted Michigan during a...
Secondary organic aerosol (SOA) from acid-driven reactive uptake of isoprene epoxydiols (IEPOX) contributes up to 40% (OA) mass in fine particulate matter. Previous work showed that IEPOX substantially converts inorganic sulfates surface-active organosulfates (OSs). This decreases acidity and creates a viscous organic-rich shell poses as diffusion barrier, inhibiting additional IEPOX. To account for this "self-limiting" effect, we developed phase-separation box model evaluate...