Yoko Masue-Slowey
Yoko Masue-Slowey, Ph.D.
Managing Scientist
Environmental & Earth Sciences
  • New York

Dr. Masue-Slowey specializes in the fate and transport of contaminants in soil and aquatic environments. She has 11 years of experience investigating metal contaminants, most extensively, arsenic. She also has broad experience investigating natural organic carbon in soils. In particular, she has expertise in microbe-driven transformation of metal contaminants and mineral surface chemistry.

Dr. Masue-Slowey’s analytical expertise includes synchrotron-based x-ray spectroscopy (XAS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD), atomic absorption spectroscopy (AA), inductively coupled plasma (ICP), and ion chromatography (IC). She has extensive experience designing laboratory model experiments to decipher the process of contaminant partitioning between the solid and aqueous phases.

At Stanford University, Dr. Masue-Slowey investigated how a chemical impurity within a soil mineral, along with physical heterogeneity creating dual flow domains (i.e., advection and diffusion), affects the fate and transport of arsenic. She also determined the solubility of a newly discovered arsenic-containing compound. At Texas A&M University, she designed a mixed iron and aluminum sorbent and tested the efficacy of arsenic removal to optimize arsenic sequestration, and the stability of sludge that results from the process.

Before joining Exponent, Dr. Masue-Slowey worked as a National Science Foundation (NSF) Earth Science postdoctoral fellow at the University of California–Santa Barbara and Stanford University. There, she investigated the effects of millimeter- to centimeter-scale physical heterogeneity, such as preferential flow paths, on microbial processing of soil organic carbon, resulting in greenhouse gas emission. She led a group of scientists to uncover systematic changes in the microbial community, radiocarbon age (residence time of carbon), and soil organic-carbon chemistry, using advanced analytical techniques such as high-throughput Ilumina sequencing and near-edge x-ray absorption fine structure (NEXAFS) spectroscopy.

Dr. Masue-Slowey has published multiple articles in peer-reviewed journals and has served as a peer reviewer for several scientific journals and for the NSF. In addition, she was an instructor at Stanford University, where she taught a field-based course in soil chemical processes.

CREDENTIALS & PROFESSIONAL HONORS

  • Ph.D., Environmental Earth System Science, Stanford University, 2009
  • M.S., Soil Science, Texas A&M University, 2004
  • B.S., Plant and Environmental Soil Sciences, Texas A&M University, 2002, magna cum laude
  • NSF Postdoctoral Fellowship in Earth Sciences, 2011–2013

    U.S. Geological Survey, Texas Water Resource Institute research scholarship, 2003–2004

    Outstanding Senior honored by the American Society of Agronomy, 2002

    Distinguished Student, College of Agriculture and Life Sciences (TAMU), 2002

LANGUAGES

  • Japanese

Publications

Masue-Slowey Y, Slowey AJ, Michel FM, Webb SM, Fendorf S. Constraints on precipitation of the ferrous arsenite solid H7Fe4(AsO3)5. Journal of Environmental Quality 2014; 43(3):947–954. doi:10.2134/jeq2013.08.0340

Masue-Slowey Y, Ying SC, Kocar BD, Pallud C and Scott Fendorf. Dependence of arsenic fate and transport on biogeochemical heterogeneity arising from the physical structure of soils and sediments. Journal of Environmental Quality 2013; 42:4:1119–1129.

Ying SC, Masue-Slowey Y, Kocar BD, Griffis SD, Webb SM, Marcus MA, Francis CA, Fendorf S. Distributed microbially- and chemically-mediated redox processes controlling arsenic dynamics within Mn-/Fe-oxide constructed aggregates. Geochimica et Cosmochimica Acta 2012; 96(1):294–303.

Kim E, Masue-Slowey Y, Fendorf S, Luthy RG. Intra-particle migration of mercury(II) in granular polysulfide-rubber-coated activated carbon (PSR-AC). Chemosphere 2012; 86:648–654.

Zhuang Y, Ahn S, Seyfferth AL, Masue-Slowey Y, Fendorf S, Luthy RG. Dehalogenation of polybrominated diphenyl ethers and polychlorinated biphenyl by bimetallic, impregnated, and nanoscale zerovalent iron. Environmental Science and Technology 2011; 45(11):4896–4903.

Masue-Slowey Y, Kocar BD, Jofre S, Mayer KU, Fendorf S. Transport implications resulting from internal redistribution of arsenic and iron within constructed soil aggregates. Environmental Science and Technology 2011; 45(2):582–588.

Masue-Slowey Y, Loeppert RH, Fendorf S. Alteration of ferrihydrite reductive dissolution and transformation by adsorbed As and structural Al: Implications for As retention. Geochimica et Cosmochimica Acta 2011; 75(3):870–886.

Pallud C, Masue-Slowey Y, Fendorf S Aggregate-scale spatial heterogeneity in reductive transformation of ferrihydrite resulting from coupled biogeochemical and physical processes. Geochimica et Cosmochimica Acta 2010; 74(10):2811–2825.

Fendorf S, Nico PS, Kocar BD, Masue Y, Tufano KJ. Arsenic chemistry in soils and sediments. In: Synchrotron-Based Techniques in Soils and Sediments. Balwant S, Gräfe M (eds), Elsevier, Burlington, MA, 34:357–378, 2010.

Masue Y, Loeppert RH, Kramer TA. Arsenate and arsenite adsorption and desorption behavior on coprecipitated aluminum:iron hydroxides. Environmental Science and Technology 2007; 41(3);837–842.

Borch T, Masue Y, Kukkadapu RK, Fendorf S. Phosphate imposed limitations on biological reduction and alteration of ferrihydrite. Environmental Science and Technology 2007; 41(1):166–172.

Presentations and Published Abstracts

Masue-Slowey Y. Impacts of soil structure on contaminant and carbon dynamics. Invited, University of Wyoming, Department of Ecosystem Science and Management, 2013.

Masue-Slowey Y. Impacts of physical and chemical complexity on contaminant dynamics. Invited, The University of British Columbia and The University of South Carolina, 2013.

Masue-Slowey Y, Loeppert RH, Fendorf S. Alteration of reductive ferrihydrite dissolution and transformation by adsorbed As and structural Al. Invited, Misasa-IV Solar System Exploration and Few Geosciences Symposium, Tottori, Japan, 2012.

Masue-Slowey Y, Chadwick OA, Fendorf S. Metabolic constrains on organic matter turnover within subsurface soils. The American Geophysical Union fall meeting, San Francisco, CA, 2011.

Masue-Slowey Y, Kocar BD, Jofre SAB, Mayer UK, Pallud C, Fendorf S. Fate and transport of arsenic from constructed soil aggregates. Goldschmidt Conference, Knoxville, TN. 2010.

Sharma R, Masue-Slowey Y, Fendorf S. Role of adsorbed arsenic and structural aluminum on Fe(II) retention and transformation of ferrihydrite. The American Geophysical Union Fall Meeting, San Francisco, CA, 2009 (mentee presentation).

Masue-Slowey Y, Fendorf S. Development of arsenic and iron biogeochemical gradient within constructed aggregate upon redox fluctuation. Goldschmidt Conference, Davos, Switzerland, 2009.

Masue-Slowey Y, Bedore P, Fendorf S. Development of arsenic and iron biogeochemical gradients upon anaerobiosis at soil aggregate scale. The 7th International Symposium for Subsurface Microbiology, Shizuoka, Japan, 2008.

Masue-Slowey Y, Tufano KJ, Loeppert RH, Fendorf S. Alteration in arsenic retention upon reductive transformation of alumino-ferrihydrite. Soil Science Society of America Annual Meeting, New Orleans, LA, 2007.

Masue Y, Borch T, Kocar BD, Fendorf S. Arsenic attenuation upon bioreduction of ferrihydrite. 19th General Meeting of the International Mineralogical Association, Kobe, Japan, 2006.

Masue Y, Borch T, Fendorf S. Factors affecting arsenic retention under anaerobic conditions. Invited, International Symposium 21st Century COE program at Kanazawa University, Japan, 2005.

Masue Y, Kocar BD, Borch T, Fendorf S Arsenic retention on ferrihydrite: Stability under aerobic and anaerobic conditions. 230th American Chemical Society Meeting, Washington D.C. 2005.

Masue Y, Loeppert RH, White GN, Kramer T. Adsorption, desorption, and stabilization behavior of arsenic(V) on Al3+ substituted Fe3+ oxides. 7th International Conference on the Biochemistry of Trace Elements, Uppsala, Sweden, 2003.

Masue Y, Loeppert RH, Kramer T. Influence of counterion on adsorption and desorption behavior of arsenic on ferrihydrite and Al-substituted analogs. American Society of Agronomy Annual Meeting, Denver, CO, 2003..


Additional Information

Peer Reviewer

Environmental Science & Technology

Geochimica et Cosmochimica Acta

Journal of Hazardous Materials

Journal of Asian Earth Sciences

National Science Foundation Low Temperature Geochemistry proposal

Knowledge

News & Events

CREDENTIALS & PROFESSIONAL HONORS

  • Ph.D., Environmental Earth System Science, Stanford University, 2009
  • M.S., Soil Science, Texas A&M University, 2004
  • B.S., Plant and Environmental Soil Sciences, Texas A&M University, 2002, magna cum laude
  • NSF Postdoctoral Fellowship in Earth Sciences, 2011–2013

    U.S. Geological Survey, Texas Water Resource Institute research scholarship, 2003–2004

    Outstanding Senior honored by the American Society of Agronomy, 2002

    Distinguished Student, College of Agriculture and Life Sciences (TAMU), 2002

LANGUAGES

  • Japanese