{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,3]],"date-time":"2026-09-03T12:12:32Z","timestamp":1788437552383,"version":"build-2803163510"},"reference-count":67,"publisher":"American Chemical Society (ACS)","issue":"34","license":[{"start":{"date-parts":[[2026,8,20]],"date-time":"2026-08-20T00:00:00Z","timestamp":1787184000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000139","name":"U.S. Environmental Protection Agency","doi-asserted-by":"publisher","award":["68HERC19D0010"],"award-info":[{"award-number":["68HERC19D0010"]}],"id":[{"id":"10.13039\/100000139","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100001160","name":"Health Effects Institute","doi-asserted-by":"publisher","award":["143815"],"award-info":[{"award-number":["143815"]}],"id":[{"id":"10.13039\/100001160","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100006140","name":"Oil and Natural Gas","doi-asserted-by":"publisher","award":["NA"],"award-info":[{"award-number":["NA"]}],"id":[{"id":"10.13039\/100006140","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/na","name":"National Science Foundation","doi-asserted-by":"publisher","award":["1942601"],"award-info":[{"award-number":["1942601"]}],"id":[{"id":"10.13039\/na","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,9,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Previous studies in Pennsylvania identified localized \u201chotspots\u201d of elevated salinity (Cl\u2013, Ba2+, Sr2+) in shallow groundwater thought to be associated with unconventional oil and gas (UOG) operations. Because produced water generated during UOG operations is both highly saline and enriched in radium, accidental releases could increase groundwater salinity and radium activity. Elevated salinity from other sources such as road salt or septic tanks could also release radium from aquifer solids through cation exchange. Therefore, we measured combined radium activity (226+228Ra) in shallow groundwater (n = 91) and tested for associations with UOG wells, historical surface impoundments, or reported spills within 1, 3, or 5 km. All samples were below U.S. EPA maximum contaminant levels [0.185 Bq\/L (5 pCi\/L)] and consistent with regional background values. Radium activities were statistically greater within 3 km of spills and impoundments and correlated positively with the density of UOG wells within 3 km. Although radium correlated with Cl\u2013, Ba2+, and Sr2+, other geochemical indicators, Na\/Cl, Cl\/Br, and 228\/226Ra, indicate that radium was likely not directly derived from UOG fluids. Only six samples were consistent with produced water mixing with shallow groundwater. Instead, most of the salinity was primarily attributed to shallow sources that released matrix-bound radium.<\/jats:p>","DOI":"10.1021\/acs.est.6c05003","type":"journal-article","created":{"date-parts":[[2026,8,20]],"date-time":"2026-08-20T22:01:27Z","timestamp":1787263287000},"page":"24342-24351","source":"Crossref","is-referenced-by-count":0,"title":["Matrix-Derived\nRadium\nMobilization in Shallow Aquifers\nNear Unconventional Oil and Gas Operations"],"prefix":"10.1021","volume":"60","author":[{"ORCID":"https:\/\/orcid.org\/0009-0004-2654-3502","authenticated-orcid":true,"given":"Allison","family":"Fenske","sequence":"first","affiliation":[{"name":"Pennsylvania State University , , 208 Engineering Collaborative Research and Education Building, 556 White Course Drive , , ,","place":["University Park, Pennsylvania, United States, 16802"]},{"name":"Juniata College, Brumbaugh Academic Center , , 1700 Moore Street , , ,","place":["Huntingdon, Pennsylvania, United States, 16652"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jianfeng","family":"Su","sequence":"additional","affiliation":[{"name":"Syracuse University , , 204 Heroy Geology Laboratory, 900 South Crouse Avenue , , ,","place":["Syracuse, New York, United States, 13244"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jennifer","family":"Baka","sequence":"additional","affiliation":[{"name":"Pennsylvania State University , , 302 Walker Building, 302 N Burrows Road , , ,","place":["University Park, Pennsylvania, United States, 16802"]},{"name":"Pennsylvania State University , , 217 Earth and Engineering Sciences Building, 656 White Course Drive , , ,","place":["University Park, Pennsylvania, United States, 16802"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9780-212X","authenticated-orcid":true,"given":"Brandon","family":"Forsythe","sequence":"additional","affiliation":[{"name":"Pennsylvania State University , , 116 Deike Building, 55 N Burrows Road , , ,","place":["University Park, Pennsylvania, United States, 16802"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lara","family":"Williams","sequence":"additional","affiliation":[{"name":"Pennsylvania State University , , 116 Deike Building, 55 N Burrows Road , , ,","place":["University Park, Pennsylvania, United States, 16802"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0111-7361","authenticated-orcid":true,"given":"Samuel W.","family":"Shaheen","sequence":"additional","affiliation":[{"name":"University of Minnesota , , 150 John T. Tate Hall, 116 Church Street SE , , ,","place":["Minneapolis, Minnesota, United States, 55455"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6113-7532","authenticated-orcid":true,"given":"Tao","family":"Wen","sequence":"additional","affiliation":[{"name":"Syracuse University , , 204 Heroy Geology Laboratory, 900 South Crouse Avenue , , ,","place":["Syracuse, New York, United States, 13244"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9574-2693","authenticated-orcid":true,"given":"Susan L.","family":"Brantley","sequence":"additional","affiliation":[{"name":"Pennsylvania State University , , 217 Earth and Engineering Sciences Building, 656 White Course Drive , , ,","place":["University Park, Pennsylvania, United States, 16802"]},{"name":"Pennsylvania State University , , 116 Deike Building, 55 N Burrows Road , , ,","place":["University Park, Pennsylvania, United States, 16802"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6434-5118","authenticated-orcid":true,"given":"Nathaniel R.","family":"Warner","sequence":"additional","affiliation":[{"name":"Pennsylvania State University , , 208 Engineering Collaborative Research and Education Building, 556 White Course Drive , , ,","place":["University Park, Pennsylvania, United States, 16802"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"316","published-online":{"date-parts":[[2026,8,20]]},"reference":[{"issue":"12","key":"2026090307140916600_cit1","doi-asserted-by":"publisher","first-page":"7149","DOI":"10.1021\/acs.est.8b01123","article-title":"Big Groundwater\nData Sets Reveal Possible Rare Contamination Amid Otherwise Improved\nWater Quality for Some Analytes in a Region of Marcellus Shale Development","volume":"52","author":"Wen","year":"2018","journal-title":"Environ. Sci. Technol."},{"issue":"2","key":"2026090307140916600_cit2","doi-asserted-by":"publisher","first-page":"1091","DOI":"10.1021\/acs.est.1c05081","article-title":"Assessing Unconventional\nOil and Gas Exposure in the Appalachian Basin: Comparison of Exposure\nSurrogates and Residential Drinking Water Measurements","volume":"56","author":"Clark","year":"2022","journal-title":"Environ. Sci. Technol."},{"issue":"28","key":"2026090307140916600_cit3","doi-asserted-by":"publisher","first-page":"11250","DOI":"10.1073\/pnas.1221635110","article-title":"Increased\nStray Gas Abundance in a Subset of Drinking Water Wells near Marcellus\nShale Gas Extraction","volume":"110","author":"Jackson","year":"2013","journal-title":"Proc. Natl. Acad. Sci.\nU. S. A."},{"key":"2026090307140916600_cit4","doi-asserted-by":"publisher","first-page":"8172","DOI":"10.1073\/pnas.1100682108","article-title":"Methane Contamination\nof Drinking Water Accompanying Gas-Well Drilling and Hydraulic Fracturing","volume":"108","author":"Osborn","year":"2011","journal-title":"Proc. Natl. Acad. Sci. U. S. A."},{"issue":"20","key":"2026090307140916600_cit5","doi-asserted-by":"publisher","first-page":"6325","DOI":"10.1073\/pnas.1420279112","article-title":"Evaluating a Groundwater Supply Contamination Incident\nAttributed to Marcellus Shale Gas Development","volume":"112","author":"Llewellyn","year":"2015","journal-title":"Proc. Natl. Acad. Sci. U. S. A."},{"issue":"14","key":"2026090307140916600_cit6","doi-asserted-by":"publisher","first-page":"10010","DOI":"10.1021\/acs.est.2c00001","article-title":"Geochemical\nEvidence of Potential\nGroundwater Contamination with Human Health Risks Where Hydraulic\nFracturing Overlaps with Extensive Legacy Hydrocarbon Extraction","volume":"56","author":"Shaheen","year":"2022","journal-title":"Environ. Sci. Technol."},{"key":"2026090307140916600_cit7","doi-asserted-by":"publisher","DOI":"10.1007\/978-1-4614-0046-2","volume-title":"Produced Water: Overview of Composition,\nFates, and Effects","author":"Neff","year":"2011"},{"key":"2026090307140916600_cit8","doi-asserted-by":"publisher","first-page":"57","DOI":"10.1016\/j.coal.2013.12.010","article-title":"The Strontium\nIsotopic Evolution of Marcellus Formation Produced Waters, Southwestern\nPennsylvania","volume":"126","author":"Capo","year":"2014","journal-title":"Int. J. Coal Geol."},{"key":"2026090307140916600_cit9","unstructured":"Dresel, P. E.; Rose, A. W.\n          Chemistry and Origin\nof Oil and Gas Well Brines in Western Pennsylvania; Harrisburg, 2010. https:\/\/catalog.libraries.psu.edu\/catalog\/12742742 (accessed 2025\u201312\u201329)."},{"issue":"5","key":"2026090307140916600_cit10","doi-asserted-by":"publisher","first-page":"1224","DOI":"10.1039\/D0EM00066C","article-title":"Geochemical and Isotope Analysis\nof Produced Water from the Utica\/Point Pleasant Shale, Appalachian\nBasin","volume":"22","author":"Tasker","year":"2020","journal-title":"Environ. Sci.:Processes Impacts"},{"key":"2026090307140916600_cit11","doi-asserted-by":"publisher","first-page":"17862","DOI":"10.1021\/acs.est.4c03371","article-title":"Wastewaters\nCoproduced with Shale Gas Drive Slight Regional Salinization of Groundwater","volume":"58","author":"Shaheen","year":"2024","journal-title":"Environ. Sci. Technol."},{"issue":"2","key":"2026090307140916600_cit12","doi-asserted-by":"publisher","first-page":"865","DOI":"10.1007\/s10653-017-0031-6","article-title":"Detecting\nthe Effects of Coal Mining,\nAcid Rain, and Natural Gas Extraction in Appalachian Basin Streams\nin Pennsylvania (USA) through Analysis of Barium and Sulfate Concentrations","volume":"40","author":"Niu","year":"2018","journal-title":"Environ. Geochem. Health"},{"key":"2026090307140916600_cit13","doi-asserted-by":"publisher","first-page":"896","DOI":"10.1126\/science.aaz2185","article-title":"Large-Sample Evidence\non the Impact\nof Unconventional Oil and Gas Development on Surface Waters","volume":"373","author":"Bonetti","year":"2021","journal-title":"Science"},{"issue":"5","key":"2026090307140916600_cit14","doi-asserted-by":"publisher","first-page":"2563","DOI":"10.1021\/acs.est.6b05749","article-title":"Unconventional Oil\nand Gas Spills: Risks, Mitigation Priorities, and State Reporting\nRequirements","volume":"51","author":"Patterson","year":"2017","journal-title":"Environ. Sci. 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E.; Youk, A. O.; Yuan, J.-M.; Maynard, D.; Andrew Mrkva, A.; Melanie Stangl, W.; Wu, F.\n          Final Report for Pennsylvania Department\nof Health, Bureau of Epidemiology Hydraulic Fracturing Epidemiology\nResearch Studies: Asthma Outcomes: Pittsburgh,\nPA, 2023. https:\/\/paenv.pitt.edu\/assets\/Report_Asthma_outcomes_revised_2023_July.pdf (accessed 2026\u201304\u201302)."},{"issue":"12","key":"2026090307140916600_cit20","doi-asserted-by":"publisher","first-page":"1676","DOI":"10.1289\/ehp.1003224","article-title":"Health Effects\nof Naturally Radioactive Water Ingestion: The Need for Enhanced Studies","volume":"119","author":"Canu","year":"2011","journal-title":"Environ. Health Perspect."},{"key":"2026090307140916600_cit21","doi-asserted-by":"publisher","first-page":"1261","DOI":"10.2105\/AJPH.80.10.1261","article-title":"Leukemia Incidence\nand Radioactivity\nin Drinking Water in 59 Iowa Towns","volume":"80","author":"Fuortes","year":"1990","journal-title":"Am. J. Public\nHealth"},{"issue":"5","key":"2026090307140916600_cit22","doi-asserted-by":"publisher","first-page":"305","DOI":"10.1136\/oem.53.5.305","article-title":"Radium in Drinking Water and Risk\nof Bone Cancer in\nOntario Youths: A Second Study and Combined Analysis","volume":"53","author":"Finkelstein","year":"1996","journal-title":"Occup. Environ. Med."},{"key":"2026090307140916600_cit23","volume-title":"Radium in Drinking Water and the Incidence\nof Osteosarcoma","author":"Cohn","year":"2003"},{"key":"2026090307140916600_cit24","first-page":"565","article-title":"Radium\nin Drinking Water and the Risk of Death from Bone Cancer among Ontario\nYouths","volume":"151","author":"Finkelstein","year":"1994","journal-title":"CMAJ"},{"key":"2026090307140916600_cit25","doi-asserted-by":"publisher","first-page":"9398","DOI":"10.1021\/acs.est.9b02395","article-title":"Occurrence\nand Sources of Radium in Groundwater Associated with Oil Fields in\nthe Southern San Joaquin Valley, California","volume":"53","author":"McMahon","year":"2019","journal-title":"Environ. Sci. Technol."},{"issue":"30","key":"2026090307140916600_cit26","doi-asserted-by":"publisher","first-page":"11961","DOI":"10.1073\/pnas.1121181109","article-title":"Geochemical Evidence\nfor Possible Natural Migration of Marcellus Formation Brine to Shallow\nAquifers in Pennsylvania","volume":"109","author":"Warner","year":"2012","journal-title":"Proc. Natl. Acad.\nSci. U. S. A."},{"key":"2026090307140916600_cit27","doi-asserted-by":"crossref","unstructured":"Kozar, M. D.; McAdoo, M. A.; Haase, K. B.; Reid, L. T.\n          Groundwater\nQuality and Geochemistry of the Western Wet Gas Part of the Marcellus\nShale Oil and Gas Play in West Virginia: Reston, Virginia, 2023. DOI: 10.5066\/P9L98L0Y.","DOI":"10.3133\/sir20225094"},{"key":"2026090307140916600_cit28","doi-asserted-by":"publisher","first-page":"151914","DOI":"10.1016\/j.scitotenv.2021.151914","article-title":"A Critical Review\non the Occurrence and Distribution of the Uranium- and Thorium-Decay\nNuclides and Their Effect on the Quality of Groundwater","volume":"808","author":"Vengosh","year":"2022","journal-title":"Sci. Total Environ."},{"issue":"10","key":"2026090307140916600_cit29","doi-asserted-by":"publisher","first-page":"2125","DOI":"10.1016\/j.apgeochem.2007.04.014","article-title":"Mode of Occurrence\nand Environmental Mobility of Oil-Field\nRadioactive Material at US Geological Survey Research Site B, Osage-Skiatook\nProject, Northeastern Oklahoma","volume":"22","author":"Zielinski","year":"2007","journal-title":"Appl. Geochem."},{"key":"2026090307140916600_cit30","doi-asserted-by":"crossref","unstructured":"Rowan, E. L.; Kirby, C. S.; Kraemer, T. F.; Engle, M. A..  Radium Content of\nOil- and Gas-Field Produced waters in the Northern Appalachian Basin\n(USA): Summary and Discussion of Data; U.S.\nGeological Survey, Scientific Report 2011\u20135135, 2011. http:\/\/pubs.usgs.gov\/sir\/2011\/5135\/.","DOI":"10.3133\/sir20115135"},{"issue":"2","key":"2026090307140916600_cit31","doi-asserted-by":"publisher","first-page":"166","DOI":"10.1016\/j.apgeochem.2007.10.011","article-title":"Dissolved\nMetals and Associated Constituents in Abandoned Coal-Mine Discharges,\nPennsylvania, USA. Part 1: Constituent Quantities and Correlations","volume":"23","author":"Cravotta","year":"2008","journal-title":"Appl. Geochem."},{"issue":"7","key":"2026090307140916600_cit32","doi-asserted-by":"publisher","first-page":"1927","DOI":"10.1039\/d6em00142d","article-title":"Targeted Sampling\nReveals Localized Brine signals without Evidence of Regional Water\nQuality impacts from Unconventional Oil and Gas Development","volume":"28","author":"Su","year":"2026","journal-title":"Environ. Sci.:Processes Impacts"},{"key":"2026090307140916600_cit33","unstructured":"Baka, J.; Brantley, S. L.; Wen, T.; Warner, N. R.; Pinto, C.; Bitzer, Z.; Forsythe, B.; Fenske, A.; Su, J.; Williams, L.; Mahugu, E.\n          An Analysis of Water Quality\nin the Oldest Hydrocarbon Basin in the USA; Health Effects Institute, In Revision."},{"key":"2026090307140916600_cit34","unstructured":"Berg, T. M.; Edmunds, W. E.; Geyer, A. R.; Glover, A. D.; Hoskins, D. M.; MacLachlan, D. B.; Root, S. I.; Sevon, W. D.; Socolow, A. A.\n          Geologic Map\nof Pennsylvania (2nd Ed.); USGS National\nGeologic Map Database. https:\/\/ngmdb.usgs.gov\/Prodesc\/proddesc_34341.htm (accessed 2025\u201312\u201320)."},{"issue":"50","key":"2026090307140916600_cit35","doi-asserted-by":"publisher","first-page":"13138","DOI":"10.1073\/pnas.1701682114","article-title":"Hydraulic Fracturing near Domestic Groundwater Wells","volume":"114","author":"Jasechko","year":"2017","journal-title":"Proc. Natl. Acad. Sci. U. S. A."},{"key":"2026090307140916600_cit36","doi-asserted-by":"publisher","first-page":"105149","DOI":"10.1016\/j.apgeochem.2021.105149","article-title":"Factors Affecting\nGroundwater Quality\nUsed for Domestic Supply in Marcellus Shale Region of North-Central\nand North-East Pennsylvania, USA","volume":"137","author":"Cravotta","year":"2022","journal-title":"Appl. Geochem."},{"key":"2026090307140916600_cit37","unstructured":"PennDOT, G. I. 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E.; Saraswathula, V.; Thordsen, J. J.; Rowan, E. L.; Morrissey, E. 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