Zoltan Szabo


Zoltan Szabo, a research hydrologist with US Geological Survey, led the radionuclide occurrence and mobility assessment for the National Water Quality Assessment (NAWQA) program, with special focus on National Radium occurrence completed in 2012 (Szabo et al. 2012; http://water.usgs.gov/nawqa/trace/radium/). Desorption of radium in acidic, anoxic, and mineralized geochemical environments was documented. He has co-authored the NAWQA cycle III 10-year research plan for radionuclides. He worked on methods development for radionuclide analyses including Radium-224 now included in Standard Methods (21st ed, 7500-E) and analytical methods challenges of complex matrices including high TDS natural waters (Szabo et al., 2005, 2012) and waste brines (Szabo et al., 2008; 2010). The 1998 report regarding Radium occurrence in southern NJ won the USGS Report of the Year Award for the Northeastern USA sparking EPA’s effortsto define occurrence of this radioelement. He continues to work on occurrence of radioisotopes of uranium, lead, and polonium. Zoltan Szabo’s recent work has expanded to provide contributions on the occurrence of a broad suite of “emerging” contaminants in ground/surface water used for drinking water, including waste water personal-care and pharmaceutical organic compounds and ethanol  He has been working on characterizing waste streams from septic tanks affecting ground-water quality and sewage discharge affecting surface water, as well as examining the effect of various treatment systems for these compounds, from septic systems to municipal systems. He has also been working on addressing toxicology of sediments. He has helped design, test and implement "ultra-clean" ground-water sampling protocols for trace elements, including mercury, and is working on defining mercury distribution in the environment for coastal regions. He is recipient of American Water Works Assoc. Researcher of the Year (2007, NJ Chapter). He received his MSc in geology from Ohio State University using strontium isotopes as ground-water flow tracers. He has more than 65 full length publications and more than 100 abstracts, mostly devoted to radionuclide occurrence and mercury chemistry.


Zoltan Szabo as a research hydrologist with the U.S. Geological Survey, New Jersey Water Science Center, has been investigating the occurrence and mobility of radon and radium since 1985 and has been the national leader in defining the occurrence of short-lived radium-224 in ground water. He is one of three authors cited for radionuclide studies by USEPA in the Radionuclide Rule of 2000 and the accompanying Radionuclide NODA (Notice of Data Availability). He is serving on the USGS NAWQA Program Trace-Element Synthesis Team on radionuclide occurrence; the NIEHS (National Institute Environmental Health & Safety) Superfund Basic Research Program Committee (SBRP); the American Water Works Assoc. Research Foundation (AWWARF) Radionuclide Technical Advisory Committee; and serves as a technical advisor to the USGS NWQL (National Water Quality Laboratory) to the radionuclide and tritium-helium analytical services and associated contracts.


My recent work has broadly expanded to provide significant new information on the occurrence of a broad suite of “emerging” contaminants in ground/surface water used for drinking water, including various short-lived radionuclides, waste water personal-care and pharmaceutical organic compounds, and the “species” of mercury and arsenic, knowledge of which allows for a more “process-based” understanding of the distribution of the “undifferentiated or total” element in ground/surface water. This work has had considerable impact on scientific understanding of radionuclide occurrence. I routinely work with other USGS and University researchers and with Safe Drinking Water regulatory programs both at the State and Federal levels, including USEPA and the Nuclear Regulatory Commission, and with American Water Works Assoc., especially in regard to these contaminants.I have designed studies to more thoroughly document the effects of natural isotope variations on variability in gross alpha-particle activity in ground water and effects of holding time after sample collection.  In collaboration with Tom Kraemer, NRP, I have shown that the most common source of short-term elevated alpha-particle activity in drinking water supplies is Ra-224. In a national survey for the NAWQA program we have shown that the presence of Ra-224 in ground water occurs throughout the Nation, and have demonstrated that alpha-recoil enrichment in ground water is likely in addition to desorption in acidic and reducing environments. I worked with American Public Health Assoc. to have an analytical method included in the 21st edition of Standard Methods for Ra-224 analysis. I have also worked on improving testing methods for progeny of Ra-224 that also emit alpha radioactivity in water samples, including Rn-220 and Pb-212; these isotopes have been identified to occur in waters of the North Atlantic Coastal Plain in concentrations of concern. Finally, in collaboration with Tom Kraemer, NRP, I have worked on identifying the range of U isotopic variations in ground water from various aquifer types. I have designed studies studying the occurrence of waste water personal-care and pharmaceutical organic compounds in the environment. Some of these studies have been in regards to occurrence in “traditional” media for occurrence such as surface water affected by sewage discharge. I have worked on studies regarding seasonal variations in concentrations as well as studies concerning the efficacy of various removal (treatment) techniques. My most novel studies have been with regards to a somewhat less traditional media for study, septic tank discharges to shallow ground waters. I have helped design and implement "ultra-clean" sampling protocols allowing determination of Hg at the ng/L level and fine tuning sampling techniques. Our recent studies show mercury speciation and species concentration distribution varies with land use in ground and surface waters. I collaborate with researchers at local universities and serves as a committee member for graduate student candidates or as senior project advisor (most students: Rutgers University). I have worked extensively on establishing the use of new age-dating technologies in ground-water studies and am most involved with Tritium/Helium-3 age dating and defining helium occurrence.He has worked with isotopes as tracers of ground-water movement, including use of tritium, helium-3, and stable isotopes of nitrogen and strontium.


Selected Recent Publications

Barringer, J.L., Szabo, Zoltan, Reilly, P.A., and Riskin, M.L., 2013, Variable contributions of mercury from groundwater to a first-order urban coastal plain stream in New Jersey, USA: Water, Air, Soil Pollution, v. 224, no. 4, article 1475, p. 1-25. [doi:10.1007/s11270-013-1475-7]


Barringer, J.L., Szabo, Zoltan, Wilson, T.P., Bonin, J.L., Kratzer, Todd, Cenno, Kimberly, Romagna, Terri, Alebus, Marzooq, and Hirst, Barbara, 2011, Sources and mobility of arsenic and metals in water and sediments of a shallow aerated and alum-dosed lake, northwestern New Jersey, USA: Environmental Geochemistry Health, v. 33, p. 1-22.  [DOI:10.1007/s10653-010-9289-7] 


Burnett, W.C., Dulaiova, Henrietta, Dimova, Natasha, Parsa, Bahman, and Szabo, Zoltan, 2007, Measuring thoron (220Rn) in natural waters : in Warwick, Peter, ed., Environmental Radiochemical Analysis, Volume III., Transactions of the Royal Chemical Society, RSC Publishing, Cambridge, England, p. 24-37.


Szabo, Zoltan, dePaul, V.T., Gardner, P.L., Kopera, A.J., and Goodman, Jenny, 2006, Radon-222 occurrence in ground water in New Jersey, with emphasis on the Highlands Province: inGates, A.E., ed., Environmental geology of the Highlands, 23rd Annual Meeting of the Geological Association of New Jersey, Ramapo, N.J., Oct. 2006.


Barringer, J.L., Szabo, Zoltan, Schneider, Donald, Atkinson, W.D., and Gallagher, R.A., 2006, Mercury concentrations in ground water, septage, leach-field effluent, and soils in residential areas, New Jersey Coastal Plain: Science Total Environment, v. 361, p. 144-162.


Barringer, J.L., and Szabo, Zoltan, 2006, Overview of studies of mercury concentrations in water from the New Jersey Coastal Plain: Water Soil Air Pollution, v. 175, p. 193-221.


Koterba, M.T., Andres, A.S., Vrabel, J.P., Crilley, D.M., Szabo, Zoltan, DeWild, J.F., Aiken, G.R., and Reyes-Padro, Betzaida, 2006, Occurrence and distribution of mercury in the surficial aquifer, Long Neck Peninsula, Sussex County, Delaware, 2003-04: U.S. Geological Survey Scientific Investigations Report 2006-5011, 159 p.

          [http://md.water.usgs.gov/publications/sir-2006-5011/index.html] or [http://pubs.er.usgs.gov/usgspubs/sir/sir20065011].


Barringer, J.L., Szabo, Zoltan, Kauffman, L.J., Barringer, T.H., Stackelberg, P.E., Ivahnenko, Tamara, Rajagopalan, Shilpa, and Krabbenhoft, D.P., 2005,  Mercury concentrations in water from an unconfined aquifer system, New Jersey Coastal Plain: Science Total Environment, v. 346, p. 169-183.


Szabo, Zoltan, dePaul, V.T., Kraemer, T.F., Parsa, Bahman, 2005, Occurrence of radium-224 and comparison to that of radium-226 and radium-228 in water from the unconfined Kirkwood-Cohansey Aquifer System, Southern New Jersey: U.S. Geological Survey Scientific Investigations Report 2004-5224, 92 p. [http://pubs.er.usgs.gov/pubs/sir/sir20045224]]


Szabo, Zoltan, Zapecza, O.S., Oden, J.H., and Rice, D.E., 2005, Radiochemical sampling and analysis of shallow ground water and sediment at the BOMARC Missile Facility, east-central New Jersey, 1999-2000: U.S. Geological Survey Scientific Investigations Report 2005-5062, 87 p. [http://pubs.er.usgs.gov/pubs/sir/sir20055062]


Szabo, Zoltan, Oden, J.H., Gibs, Jacob, Rice, D.E. and Ding, Yuan, 2002, Variation in aluminum, iron, and particle concentrations in oxic ground-water samples collected by use of tangential-flow filtration with low-flow sampling:Proceedings of International Society for Optical Engineering, v. 4575, Chemical and biological early warning monitoring for water, food, and ground, p. 42-61.


Focazio, M.J., Szabo, Zoltan, Kraemer, T.F., Mullin, A.H., Barringer, T.H. and dePaul, V.T., 2001, Occurrence of selected radionuclides in ground water used for drinking water in the United States: A reconnaissance Survey, 1998: U.S. Geological Survey Water Resources Investigations Report 00-4273, 35 p.

[http://water.usgs.gov/pubs/wri/wri004273/pdf/ wri004273.pdf]


Gibs, Jacob, Szabo, Zoltan, Ivahnenko, Tamara and Wilde, F. D., 2000, Change in field turbidity and trace-element concentrations during well purging: Ground Water, v. 38, no. 4, p. 577-588.


Szabo, Zoltan and dePaul, V.T., 1998, Radium-226 and Radium-228 in shallow ground water, southern New Jersey: U.S. Geological Survey Fact Sheet FS-062-98, 6 p.



Strzelecki, Ryszard, Wolkowicz, Stanislaw, Wolkowicz, Wojciech, Mamont-Ciesla, Kalina, Mose, D.G., Szabo, Zoltan, Ivahnenko, Tamara and Mushrush, G.W., 1998, Evaluation of geologic radon potential in two regions in southwestern and southern Poland: in 4th International Symposium and Exhibition on Environmental Contamination in Central and Eastern Europe, Warsaw, Poland, 7 p.


Szabo, Zoltan, Pucci, A.A., Jr. and Feigenson, M.D., 1997, Sr-isotopic evidence for leakage of pore water from clay-silt confining units to the Atlantic City 800-foot Sand, Atlantic City, New Jersey: in Miller, K.G. and Snyder, S.W. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, V. 150X, p. 343-354.



Szabo, Zoltan, Rice, D.E., Plummer, L.N., Busenberg, Eurybades, Drenkard, Stefan and Schlosser, Peter, 1996, Age dating of shallow groundwater with chlorofluorocarbons, tritium/helium-3, and flow path analysis, southern New Jersey coastal plain: Water Resources Research, v. 32, no. 4, p. 1023-1038.