TY - JOUR
T1 - Factors Controlling the Risks of Co-occurrence of the Redox-Sensitive Elements of Arsenic, Chromium, Vanadium, and Uranium in Groundwater from the Eastern United States
AU - Coyte, Rachel M.
AU - Vengosh, Avner
N1 - Funding Information:
The authors gratefully acknowledge funding from the National Science Foundation (EAR-1733637). They thank the individuals who welcomed them to their homes, businesses, and places of worship, allowing them to collect the large dataset. They also thank the six anonymous reviewers for their extensive and critical review that significantly improved the quality of the manuscript.
Publisher Copyright:
Copyright © 2020 American Chemical Society.
PY - 2020/4/7
Y1 - 2020/4/7
N2 - The co-occurrence of contaminants in drinking water may pose enhanced risks to health beyond the effects of single contaminants. Here, we investigated the co-occurrence of four health-relevant redox-sensitive elements (U, As, V, and Cr) in 1494 groundwater wells across North Carolina. The highest concentrations of these elements were measured mostly in groundwater from fractured igneous and metamorphic formations throughout the Piedmont region. Arsenic occurred most frequently in suboxic to mixed redox character groundwater, whereas U, V, and Cr occurred mostly in oxic groundwater. Occurrences of As, and to a lesser extent U, increased with pH, likely reflecting desorption, while higher Cr and V levels were measured in near-neutral pH and oxic groundwater, reflecting greater sensitivity to redox conditions. Due to similar geochemistry, V and Cr co-occurred most frequently. Concentrations of V and Cr(VI) co-exceeded health recommendations from the NC Department of Health and Human Services in up to 84% of wells from the King's Mountain Belt and the Charlotte and Milton Belts of the Piedmont region. This study highlights the large gap between health recommendations and enforceable regulations and demonstrates a degree of co-occurrence between redox-sensitive elements, which may pose additional risks to groundwater-reliant individuals.
AB - The co-occurrence of contaminants in drinking water may pose enhanced risks to health beyond the effects of single contaminants. Here, we investigated the co-occurrence of four health-relevant redox-sensitive elements (U, As, V, and Cr) in 1494 groundwater wells across North Carolina. The highest concentrations of these elements were measured mostly in groundwater from fractured igneous and metamorphic formations throughout the Piedmont region. Arsenic occurred most frequently in suboxic to mixed redox character groundwater, whereas U, V, and Cr occurred mostly in oxic groundwater. Occurrences of As, and to a lesser extent U, increased with pH, likely reflecting desorption, while higher Cr and V levels were measured in near-neutral pH and oxic groundwater, reflecting greater sensitivity to redox conditions. Due to similar geochemistry, V and Cr co-occurred most frequently. Concentrations of V and Cr(VI) co-exceeded health recommendations from the NC Department of Health and Human Services in up to 84% of wells from the King's Mountain Belt and the Charlotte and Milton Belts of the Piedmont region. This study highlights the large gap between health recommendations and enforceable regulations and demonstrates a degree of co-occurrence between redox-sensitive elements, which may pose additional risks to groundwater-reliant individuals.
UR - http://www.scopus.com/inward/record.url?scp=85083003357&partnerID=8YFLogxK
U2 - 10.1021/acs.est.9b06471
DO - 10.1021/acs.est.9b06471
M3 - Article
C2 - 32167307
AN - SCOPUS:85083003357
SN - 0013-936X
VL - 54
SP - 4367
EP - 4375
JO - Environmental Science & Technology
JF - Environmental Science & Technology
IS - 7
ER -
