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Clark CJ, Casey JA, Bell ML, Plata DL, Saiers JE, Deziel NC. Accuracy of self-reported distance to nearest unconventional oil and gas well in Pennsylvania, Ohio, and West Virginia residents and implications for exposure assessment. J Expo Sci Environ Epidemiol 2024:10.1038/s41370-023-00637-8. [PMID: 38448680 DOI: 10.1038/s41370-023-00637-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 12/12/2023] [Accepted: 12/13/2023] [Indexed: 03/08/2024]
Abstract
Self-reported distances to industrial sources have been used in epidemiology as proxies for exposure to environmental hazards and indicators of awareness and perception of sources. Unconventional oil and gas development (UOG) emits pollutants and has been associated with adverse health outcomes. We compared self-reported distance to the nearest UOG well to the geographic information system-calculated distance for 303 Pennsylvania, Ohio, and West Virginia residents using Cohen's Weighted Kappa. Agreement was low (Kappa = 0.18), and self-reports by Ohioans (39% accuracy) were more accurate than West Virginians (22%) or Pennsylvanians (13%, both p < 0.05). Of the demographic characteristics studied, only educational attainment was related to reporting accuracy; residents with 12-16 years of education were more accurate (31.3% of group) than those with <12 or >16 years (both 16.7%). Understanding differences between objective and subjective measures of UOG proximity could inform studies of perceived exposures or risks and may also be relevant to adverse health effects. IMPACT: We compared objective and self-reported measures of distance to the nearest UOG well for 303 Appalachian Basin residents. We found that residents' self-reported distance to the nearest UOG well had limited agreement with the true calculated distance category. Our results can be used to inform the collection and contextualize the use of self-reported data in communities exposed to UOGD. Self-reported metrics can be used in conjunction with objective assessments and can be informative regarding how potentially exposed populations perceive environmental exposures or risks and could provide insights into awareness of distance-related policies, such as setbacks.
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Affiliation(s)
- Cassandra J Clark
- Department of Environmental Health Sciences, Yale School of Public Health, 60 College St., New Haven, CT, 06510, USA.
| | - Joan A Casey
- Department of Environmental and Occupational Health Sciences, University of Washington School of Public Health, 3980 15th Ave NE, Seattle, WA, 98195, USA
| | - Michelle L Bell
- Yale School of the Environment, 195 Prospect Street, New Haven, CT, 06511, USA
| | - Desiree L Plata
- Department of Civil and Environmental Engineering, Parsons Laboratory, Massachusetts Institute of Technology, 15 Vassar Street, Cambridge, MA, 02139, USA
| | - James E Saiers
- Yale School of the Environment, 195 Prospect Street, New Haven, CT, 06511, USA
| | - Nicole C Deziel
- Department of Environmental Health Sciences, Yale School of Public Health, 60 College St., New Haven, CT, 06510, USA
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2
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Clark CJ, Warren JL, Saiers JE, Ma X, Bell ML, Deziel NC. Predictors of early life residential mobility in urban and rural Pennsylvania children with acute lymphoblastic leukemia and implications for environmental exposure assessment. J Expo Sci Environ Epidemiol 2023:10.1038/s41370-023-00636-9. [PMID: 38148338 DOI: 10.1038/s41370-023-00636-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 12/08/2023] [Accepted: 12/12/2023] [Indexed: 12/28/2023]
Abstract
BACKGROUND Residential mobility can introduce exposure misclassification in pediatric epidemiology studies using birth address only. OBJECTIVE We examined whether residential mobility varies by sociodemographic factors and urbanicity/rurality among children with cancer. METHODS Our study included 400 children born in Pennsylvania during 2002-2015 and diagnosed with leukemia at ages 2-7 years. Addresses were obtained from state registries at birth and diagnosis. We considered three aspects of mobility between birth and diagnosis: whether a child moved, whether a mover changed census tract, and distance moved. We evaluated predictors of these aspects in urban- and rural-born children using chi-square, t-tests, and regression analyses. RESULTS Overall, 58% of children moved between birth and diagnosis; suburban/rural-born children were more likely to move than urban-born children (67% versus 57%). The mean distance moved was 16.7 km in suburban/rural-born and 14.8 km in urban-born movers. In urban-born children, moving between birth and diagnosis was associated with race, education, participation in the Nutrition Program for Women, Infants and Children (WIC), and census tract-level income (all χ2 p < 0.01). Urban-born movers tended to be born in a census tract with a higher Social Vulnerability Index than non-movers (t-test p < 0.01). No factors were statistically significantly associated with any of the residential mobility metrics in suburban/rural-born children, although the sample size was small. IMPACT STATEMENT In this study of a vulnerable population of children with cancer, we found that rural-born children were more likely to move than urban-born children, however, the frequency of movers changing census tracts was equivalent. Mobility in urban-born children, but not rural-born, was associated with several social factors, although the sample size for rural-born children was small. Mobility could be an important source of misclassification depending on the spatial heterogeneity and resolution of the exposure data and whether the social factors are related to exposures or health outcomes. Our results highlight the importance of considering differences in mobility between urban and rural populations in spatial research.
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Affiliation(s)
- Cassandra J Clark
- Yale School of Public Health, Department of Environmental Health Sciences, 60 College St., New Haven, CT, 06510, USA.
| | - Joshua L Warren
- Yale School of Public Health, Department of Biostatistics, 60 College St., New Haven, CT, 06510, USA
| | - James E Saiers
- Yale School of the Environment, 195 Prospect Street, New Haven, CT, 06511, USA
| | - Xiaomei Ma
- Yale School of Public Health, Department of Chronic Disease Epidemiology, 60 College St., New Haven, CT, 06510, USA
| | - Michelle L Bell
- Yale School of the Environment, 195 Prospect Street, New Haven, CT, 06511, USA
| | - Nicole C Deziel
- Yale School of Public Health, Department of Environmental Health Sciences, 60 College St., New Haven, CT, 06510, USA
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Li Y, Siegel HG, Thelemaque NA, Bailey KR, Moncrieffe P, Nguyen T, Clark CJ, Johnson NP, Soriano MA, Deziel NC, Saiers JE, Plata DL. Conventional Fossil Fuel Extraction, Associated Biogeochemical Processes, and Topography Influence Methane Groundwater Concentrations in Appalachia. Environ Sci Technol 2023; 57:19702-19712. [PMID: 37982799 DOI: 10.1021/acs.est.3c01862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2023]
Abstract
The production of fossil fuels, including oil, gas, and coal, retains a dominant share in US energy production and serves as a major anthropogenic source of methane, a greenhouse gas with a high warming potential. In addition to directly emitting methane into the air, fossil fuel production can release methane into groundwater, and that methane may eventually reach the atmosphere. In this study, we collected 311 water samples from an unconventional oil and gas (UOG) production region in Pennsylvania and an oil and gas (O&G) and coal production region across Ohio and West Virginia. Methane concentration was negatively correlated to distance to the nearest O&G well in the second region, but such a correlation was shown to be driven by topography as a confounding variable. Furthermore, sulfate concentration was negatively correlated with methane concentration and with distance to coal mining in the second region, and these correlations were robust even when considering topography. We hypothesized that coal mining enriched sulfate in groundwater, which in turn inhibited methanogenesis and enhanced microbial methane oxidation. Thus, this study highlights the complex interplay of multiple factors in shaping groundwater methane concentrations, including biogeochemical conversion, topography, and conventional fossil extraction.
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Affiliation(s)
- Yunpo Li
- Department of Civil and Environmental Engineering, Parsons Laboratory, Massachusetts Institute of Technology, 15 Vassar Street, Cambridge, Massachusetts 02139, United States
| | - Helen G Siegel
- The School of the Environment, Yale University, 195 Prospect Street, New Haven, Connecticut 06511, United States
| | - Nathalie A Thelemaque
- Department of Civil and Environmental Engineering, Parsons Laboratory, Massachusetts Institute of Technology, 15 Vassar Street, Cambridge, Massachusetts 02139, United States
| | - Kathleen R Bailey
- Department of Civil and Environmental Engineering, Parsons Laboratory, Massachusetts Institute of Technology, 15 Vassar Street, Cambridge, Massachusetts 02139, United States
| | - Priya Moncrieffe
- Department of Civil and Environmental Engineering, Parsons Laboratory, Massachusetts Institute of Technology, 15 Vassar Street, Cambridge, Massachusetts 02139, United States
| | - Timothy Nguyen
- Department of Civil and Environmental Engineering, Parsons Laboratory, Massachusetts Institute of Technology, 15 Vassar Street, Cambridge, Massachusetts 02139, United States
| | - Cassandra J Clark
- Yale School of Public Health, Department of Environmental Health Sciences, Yale University, 60 College Street, New Haven, Connecticut 06512, United States
| | - Nicholaus P Johnson
- Yale School of Public Health, Department of Environmental Health Sciences, Yale University, 60 College Street, New Haven, Connecticut 06512, United States
| | - Mario A Soriano
- The School of the Environment, Yale University, 195 Prospect Street, New Haven, Connecticut 06511, United States
| | - Nicole C Deziel
- Yale School of Public Health, Department of Environmental Health Sciences, Yale University, 60 College Street, New Haven, Connecticut 06512, United States
| | - James E Saiers
- The School of the Environment, Yale University, 195 Prospect Street, New Haven, Connecticut 06511, United States
| | - Desiree L Plata
- Department of Civil and Environmental Engineering, Parsons Laboratory, Massachusetts Institute of Technology, 15 Vassar Street, Cambridge, Massachusetts 02139, United States
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Siegel HG, Nason SL, Warren JL, Prunas O, Deziel NC, Saiers JE. Investigation of Sources of Fluorinated Compounds in Private Water Supplies in an Oil and Gas-Producing Region of Northern West Virginia. Environ Sci Technol 2023; 57:17452-17464. [PMID: 37923386 PMCID: PMC10653085 DOI: 10.1021/acs.est.3c05192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 10/20/2023] [Accepted: 10/25/2023] [Indexed: 11/07/2023]
Abstract
Per- and polyfluoroalkyl substances (PFASs) are a class of toxic organic compounds that have been widely used in consumer applications and industrial activities, including oil and gas production. We measured PFAS concentrations in 45 private wells and 8 surface water sources in the oil and gas-producing Doddridge, Marshall, Ritchie, Tyler, and Wetzel Counties of northern West Virginia and investigated relationships between potential PFAS sources and drinking water receptors. All surface water samples and 60% of the water wells sampled contained quantifiable levels of at least one targeted PFAS compound, and four wells (8%) had concentrations above the proposed maximum contaminant level (MCL) for perfluorooctanoic acid (PFOA). Individual concentrations of PFOA and perfluorobutanesulfonic acid exceeded those measured in finished public water supplies. Total targeted PFAS concentrations ranged from nondetect to 36.8 ng/L, with surface water concentrations averaging 4-fold greater than groundwater. Semiquantitative, nontargeted analysis showed concentrations of emergent PFAS that were potentially higher than targeted PFAS. Results from a multivariate latent variable hierarchical Bayesian model were combined with insights from analyses of groundwater chemistry, topographic characteristics, and proximity to potential PFAS point sources to elucidate predictors of PFAS concentrations in private wells. Model results reveal (i) an increased vulnerability to contamination in upland recharge zones, (ii) geochemical controls on PFAS transport likely driven by adsorption, and (iii) possible influence from nearby point sources.
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Affiliation(s)
- Helen G. Siegel
- School
of the Environment, Yale University, 195 Prospect Street, New Haven, Connecticut 06511, United States
| | - Sara L. Nason
- Connecticut
Agricultural Experiment Station, 123 Huntington Street, New
Haven, Connecticut 06504, United States
| | - Joshua L. Warren
- School
of Public Health, Yale University, 60 College Street, New Haven, Connecticut 06510, United States
| | - Ottavia Prunas
- Swiss
Tropical and Public Health Institute, 2 Kreuzstrasse, Allschwill, Basel 4123, Switzerland
| | - Nicole C. Deziel
- School
of Public Health, Yale University, 60 College Street, New Haven, Connecticut 06510, United States
| | - James E. Saiers
- School
of the Environment, Yale University, 195 Prospect Street, New Haven, Connecticut 06511, United States
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5
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Gaughan C, Sorrentino KM, Liew Z, Johnson NP, Clark CJ, Soriano M, Plano J, Plata DL, Saiers JE, Deziel NC. Residential proximity to unconventional oil and gas development and birth defects in Ohio. Environ Res 2023; 229:115937. [PMID: 37076028 PMCID: PMC10198955 DOI: 10.1016/j.envres.2023.115937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 03/30/2023] [Accepted: 04/16/2023] [Indexed: 05/03/2023]
Abstract
BACKGROUND Chemicals used or emitted by unconventional oil and gas development (UOGD) include reproductive/developmental toxicants. Associations between UOGD and certain birth defects were reported in a few studies, with none conducted in Ohio, which experienced a thirty-fold increase in natural gas production between 2010 and 2020. METHODS We conducted a registry-based cohort study of 965,236 live births in Ohio from 2010 to 2017. Birth defects were identified in 4653 individuals using state birth records and a state surveillance system. We assigned UOGD exposure based on maternal residential proximity at birth to active UOG wells and a metric specific to the drinking-water exposure pathway that identified UOG wells hydrologically connected to a residence ("upgradient UOG wells"). We estimated odds ratios (ORs) and 95% confidence intervals (CIs) for all structural birth defects combined and specific birth defect types using binary exposure metrics (presence/absence of any UOG well and presence/absence of an upgradient UOG well within 10 km), adjusting for confounders. Additionally, we conducted analyses stratified by urbanicity, infant sex, and social vulnerability. RESULTS The odds of any structural defect were 1.13 times higher in children born to mothers living within 10 km of UOGD than those born to unexposed mothers (95%CI: 0.98-1.30). Odds were elevated for neural tube defects (OR: 1.57, 95%CI: 1.12-2.19), limb reduction defects (OR: 1.99, 95%CI: 1.18-3.35), and spina bifida (OR 1.93; 95%CI 1.25-2.98). Hypospadias (males only) was inversely related to UOGD exposure (OR: 0.62, 95%CI: 0.43-0.91). Odds of any structural defect were greater in magnitude but less precise in analyses using the hydrological-specific metric (OR: 1.30; 95%CI: 0.85-1.90), in areas with high social vulnerability (OR: 1.27, 95%CI: 0.99-1.60), and among female offspring (OR: 1.28, 95%CI: 1.06-1.53). CONCLUSIONS Our results suggest a positive association between UOGD and certain birth defects, and findings for neural tube defects corroborate results from prior studies.
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Affiliation(s)
- Casey Gaughan
- Department of Ecology and Evolutionary Biology, Yale College, New Haven, CT, USA; Department of Environmental Health Sciences, Yale School of Public Health, New Haven, CT, USA
| | - Keli M Sorrentino
- Department of Environmental Health Sciences, Yale School of Public Health, New Haven, CT, USA
| | - Zeyan Liew
- Department of Environmental Health Sciences, Yale School of Public Health, New Haven, CT, USA
| | - Nicholaus P Johnson
- Department of Environmental Health Sciences, Yale School of Public Health, New Haven, CT, USA
| | - Cassandra J Clark
- Department of Environmental Health Sciences, Yale School of Public Health, New Haven, CT, USA
| | - Mario Soriano
- Yale School of the Environment, Yale University, New Haven, CT, USA; High Meadows Environmental Institute, Princeton University, Princeton, NJ, USA
| | - Julie Plano
- Department of Environmental Health Sciences, Yale School of Public Health, New Haven, CT, USA
| | - Desiree L Plata
- Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - James E Saiers
- Yale School of the Environment, Yale University, New Haven, CT, USA
| | - Nicole C Deziel
- Department of Environmental Health Sciences, Yale School of Public Health, New Haven, CT, USA.
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6
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Soriano MA, Warren JL, Clark CJ, Johnson NP, Siegel HG, Deziel NC, Saiers JE. Social Vulnerability and Groundwater Vulnerability to Contamination From Unconventional Hydrocarbon Extraction in the Appalachian Basin. Geohealth 2023; 7:e2022GH000758. [PMID: 37064218 PMCID: PMC10100439 DOI: 10.1029/2022gh000758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 02/20/2023] [Accepted: 03/07/2023] [Indexed: 06/19/2023]
Abstract
Unconventional oil and gas (UOG) development, made possible by horizontal drilling and high-volume hydraulic fracturing, has been fraught with controversy since the industry's rapid expansion in the early 2000's. Concerns about environmental contamination and public health risks persist in many rural communities that depend on groundwater resources for drinking and other daily needs. Spatial disparities in UOG risks can pose distributive environmental injustice if such risks are disproportionately borne by marginalized communities. In this paper, we analyzed groundwater vulnerability to contamination from UOG as a physically based measure of risk in conjunction with census tract level sociodemographic characteristics describing social vulnerability in the northern Appalachian Basin. We found significant associations between elevated groundwater vulnerability and lower population density, consistent with UOG development occurring in less densely populated rural areas. We also found associations between elevated groundwater vulnerability and lower income, higher proportions of elderly populations, and higher proportion of mobile homes, suggesting a disproportionate risk burden on these socially vulnerable groups. We did not find a statistically significant association between elevated groundwater vulnerability and populations of racial/ethnic minorities in our study region. Household surveys provided empirical support for a relationship between sociodemographic characteristics and capacity to assess and mitigate exposures to potentially contaminated water. Further research is needed to probe if the observed disparities translate to differences in chemical exposure and adverse health outcomes.
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Affiliation(s)
- Mario A. Soriano
- School of the EnvironmentYale UniversityNew HavenCTUSA
- Integrated GroundWater Modeling CenterHigh Meadows Environmental InstitutePrinceton UniversityPrincetonNJUSA
| | - Joshua L. Warren
- Department of BiostatisticsSchool of Public HealthYale UniversityNew HavenCTUSA
| | - Cassandra J. Clark
- Department of Environmental Health SciencesSchool of Public HealthYale UniversityNew HavenCTUSA
| | - Nicholaus P. Johnson
- Department of Environmental Health SciencesSchool of Public HealthYale UniversityNew HavenCTUSA
| | | | - Nicole C. Deziel
- Department of Environmental Health SciencesSchool of Public HealthYale UniversityNew HavenCTUSA
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7
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Soriano MA, Deziel NC, Saiers JE. Regional Scale Assessment of Shallow Groundwater Vulnerability to Contamination from Unconventional Hydrocarbon Extraction. Environ Sci Technol 2022; 56:12126-12136. [PMID: 35960643 PMCID: PMC9454823 DOI: 10.1021/acs.est.2c00470] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 07/29/2022] [Accepted: 08/01/2022] [Indexed: 05/19/2023]
Abstract
Concerns over unconventional oil and gas (UOG) development persist, especially in rural communities that rely on shallow groundwater for drinking and other domestic purposes. Given the continued expansion of the industry, regional (vs local scale) models are needed to characterize groundwater contamination risks faced by the increasing proportion of the population residing in areas that accommodate UOG extraction. In this paper, we evaluate groundwater vulnerability to contamination from surface spills and shallow subsurface leakage of UOG wells within a 104,000 km2 region in the Appalachian Basin, northeastern USA. We test a computationally efficient ensemble approach for simulating groundwater flow and contaminant transport processes to quantify vulnerability with high resolution. We also examine metamodels, or machine learning models trained to emulate physically based models, and investigate their spatial transferability. We identify predictors describing proximity to UOG, hydrology, and topography that are important for metamodels to make accurate vulnerability predictions outside their training regions. Using our approach, we estimate that 21,000-30,000 individuals in our study area are dependent on domestic water wells that are vulnerable to contamination from UOG activities. Our novel modeling framework could be used to guide groundwater monitoring, provide information for public health studies, and assess environmental justice issues.
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Affiliation(s)
- Mario A. Soriano
- School
of the Environment, Yale University, New Haven, Connecticut 06511, United States
| | - Nicole C. Deziel
- School
of Public Health, Yale University, New Haven, Connecticut 06510, United States
| | - James E. Saiers
- School
of the Environment, Yale University, New Haven, Connecticut 06511, United States
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8
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Deziel NC, Clark CJ, Casey JA, Bell ML, Plata DL, Saiers JE. Assessing Exposure to Unconventional Oil and Gas Development: Strengths, Challenges, and Implications for Epidemiologic Research. Curr Environ Health Rep 2022; 9:436-450. [PMID: 35522388 PMCID: PMC9363472 DOI: 10.1007/s40572-022-00358-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/11/2022] [Indexed: 12/20/2022]
Abstract
PURPOSE OF REVIEW Epidemiologic studies have observed elevated health risks in populations living near unconventional oil and gas development (UOGD). In this narrative review, we discuss strengths and limitations of UOG exposure assessment approaches used in or available for epidemiologic studies, emphasizing studies of children's health outcomes. RECENT FINDINGS Exposure assessment challenges include (1) numerous potential stressors with distinct spatiotemporal patterns, (2) critical exposure windows that cover long periods and occur in the past, and (3) limited existing monitoring data coupled with the resource-intensiveness of collecting new exposure measurements to capture spatiotemporal variation. All epidemiologic studies used proximity-based models for exposure assessment as opposed to surveys, biomonitoring, or environmental measurements. Nearly all studies used aggregate (rather than pathway-specific) models, which are useful surrogates for the complex mix of potential hazards. Simple and less-specific exposure assessment approaches have benefits in terms of scalability, interpretability, and relevance to specific policy initiatives such as set-back distances. More detailed and specific models and metrics, including dispersion methods and stressor-specific models, could reduce exposure misclassification, illuminate underlying exposure pathways, and inform emission control and exposure mitigation strategies. While less practical in a large population, collection of multi-media environmental and biological exposure measurements would be feasible in cohort subsets. Such assessments are well-suited to provide insights into the presence and magnitude of exposures to UOG-related stressors in relation to spatial surrogates and to better elucidate the plausibility of observed effects in both children and adults.
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Affiliation(s)
- Nicole C. Deziel
- grid.47100.320000000419368710Department of Environmental Health Sciences, Yale School of Public Health, 60 College St., New Haven, CT 06510 USA
| | - Cassandra J. Clark
- grid.47100.320000000419368710Department of Environmental Health Sciences, Yale School of Public Health, 60 College St., New Haven, CT 06510 USA
| | - Joan A. Casey
- grid.21729.3f0000000419368729Department of Environmental Health Sciences, Columbia University Mailman School of Public Health, 630 West 168th Street, Room 16-416, New York, NY 10032 USA
| | - Michelle L. Bell
- Yale School of the Environment, 195 Prospect St., New Haven, CT 06511 USA
| | - Desiree L. Plata
- grid.116068.80000 0001 2341 2786Department of Civil and Environmental Engineering, Parsons Laboratory, Massachusetts Institute of Technology, 15 Vassar Street, Cambridge, MA 02139 USA
| | - James E. Saiers
- Yale School of the Environment, 195 Prospect St., New Haven, CT 06511 USA
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9
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Clark CJ, Johnson NP, Soriano M, Warren JL, Sorrentino KM, Kadan-Lottick NS, Saiers JE, Ma X, Deziel NC. Unconventional Oil and Gas Development Exposure and Risk of Childhood Acute Lymphoblastic Leukemia: A Case-Control Study in Pennsylvania, 2009-2017. Environ Health Perspect 2022; 130:87001. [PMID: 35975995 PMCID: PMC9383266 DOI: 10.1289/ehp11092] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 06/15/2022] [Accepted: 06/29/2022] [Indexed: 05/19/2023]
Abstract
BACKGROUND Unconventional oil and gas development (UOGD) releases chemicals that have been linked to cancer and childhood leukemia. Studies of UOGD exposure and childhood leukemia are extremely limited. OBJECTIVE The objective of this study was to evaluate potential associations between residential proximity to UOGD and risk of acute lymphoblastic leukemia (ALL), the most common form of childhood leukemia, in a large regional sample using UOGD-specific metrics, including a novel metric to represent the water pathway. METHODS We conducted a registry-based case-control study of 405 children ages 2-7 y diagnosed with ALL in Pennsylvania between 2009-2017, and 2,080 controls matched on birth year. We used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between residential proximity to UOGD (including a new water pathway-specific proximity metric) and ALL in two exposure windows: a primary window (3 months preconception to 1 y prior to diagnosis/reference date) and a perinatal window (preconception to birth). RESULTS Children with at least one UOG well within 2km of their birth residence during the primary window had 1.98 times the odds of developing ALL in comparison with those with no UOG wells [95% confidence interval (CI): 1.06, 3.69]. Children with at least one vs. no UOG wells within 2km during the perinatal window had 2.80 times the odds of developing ALL (95% CI: 1.11, 7.05). These relationships were slightly attenuated after adjusting for maternal race and socio-economic status [odds ratio (OR) =1.74 (95% CI: 0.93, 3.27) and OR=2.35 (95% CI: 0.93, 5.95)], respectively). The ORs produced by models using the water pathway-specific metric were similar in magnitude to the aggregate metric. DISCUSSION Our study including a novel UOGD metric found UOGD to be a risk factor for childhood ALL. This work adds to mounting evidence of UOGD's impacts on children's health, providing additional support for limiting UOGD near residences. https://doi.org/10.1289/EHP11092.
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Affiliation(s)
- Cassandra J. Clark
- Department of Environmental Health Sciences, Yale School of Public Health, Yale University, New Haven, Connecticut, USA
| | - Nicholaus P. Johnson
- Department of Environmental Health Sciences, Yale School of Public Health, Yale University, New Haven, Connecticut, USA
- Center for Perinatal, Pediatric and Environmental Epidemiology, Yale University Schools of Public Health and Medicine, New Haven, Connecticut, USA
| | - Mario Soriano
- Yale School of the Environment, Yale University, New Haven, Connecticut, USA
| | - Joshua L. Warren
- Department of Biostatistics, Yale School of Public Health, Yale University, New Haven, Connecticut, USA
| | - Keli M. Sorrentino
- Center for Perinatal, Pediatric and Environmental Epidemiology, Yale University Schools of Public Health and Medicine, New Haven, Connecticut, USA
| | - Nina S. Kadan-Lottick
- Georgetown Lombardi Comprehensive Cancer Center, Washington, District of Columbia, USA
| | - James E. Saiers
- Yale School of the Environment, Yale University, New Haven, Connecticut, USA
| | - Xiaomei Ma
- Department of Chronic Disease Epidemiology, Yale School of Public Health, Yale University, New Haven, Connecticut, USA
| | - Nicole C. Deziel
- Department of Environmental Health Sciences, Yale School of Public Health, Yale University, New Haven, Connecticut, USA
- Center for Perinatal, Pediatric and Environmental Epidemiology, Yale University Schools of Public Health and Medicine, New Haven, Connecticut, USA
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10
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Xiong B, Soriano MA, Gutchess KM, Hoffman N, Clark CJ, Siegel HG, De Vera GAD, Li Y, Brenneis RJ, Cox AJ, Ryan EC, Sumner AJ, Deziel NC, Saiers JE, Plata DL. Groundwaters in Northeastern Pennsylvania near intense hydraulic fracturing activities exhibit few organic chemical impacts. Environ Sci Process Impacts 2022; 24:252-264. [PMID: 35018906 DOI: 10.1039/d1em00124h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Horizontal drilling with hydraulic fracturing (HDHF) relies on the use of anthropogenic organic chemicals in proximity to residential areas, raising concern for groundwater contamination. Here, we extensively characterized organic contaminants in 94 domestic groundwater sites in Northeastern Pennsylvania after ten years of activity in the region. All analyzed volatile and semi-volatile compounds were below recommended United States Environmental Protection Agency maximum contaminant levels, and integrated concentrations across two volatility ranges, gasoline range organic compounds (GRO) and diesel range organic compounds (DRO), were low (0.13 ± 0.06 to 2.2 ± 0.7 ppb and 5.2-101.6 ppb, respectively). Following dozens of correlation analyses with distance-to-well metrics and inter-chemical indicator correlations, no statistically significant correlations were found except: (1) GRO levels were higher within 2 km of violations and (2) correlation between DRO and a few inorganic species (e.g., Ba and Sr) and methane. The correlation of DRO with inorganic species suggests a potential high salinity source, whereas elevated GRO may result from nearby safety violations. Highest-concentration DRO samples contained bis-2-ethylhexyl phthalate and N,N-dimethyltetradecylamine. Nevertheless, the overall low rate of contamination for the analytes could be explained by a spatially-resolved hydrogeologic model, where estimated transport distances from gas wells over the relevant timeframes were short relative to the distance to the nearest groundwater wells. Together, the observations and modeled results suggest a low probability of systematic groundwater organic contamination in the region.
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Affiliation(s)
- Boya Xiong
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
| | - Mario A Soriano
- School of the Environment, Yale University, New Haven, Connecticut, USA
| | | | - Nicholas Hoffman
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
| | - Cassandra J Clark
- Department of Environmental Health Sciences, School of Public Health, Yale University, New Haven, Connecticut, USA
| | - Helen G Siegel
- School of the Environment, Yale University, New Haven, Connecticut, USA
| | - Glen Andrew D De Vera
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
| | - Yunpo Li
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
| | - Rebecca J Brenneis
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
| | - Austin J Cox
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
| | - Emma C Ryan
- Department of Environmental Health Sciences, School of Public Health, Yale University, New Haven, Connecticut, USA
- Tufts University, Department of Public Health and Community Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Andrew J Sumner
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
| | - Nicole C Deziel
- Department of Environmental Health Sciences, School of Public Health, Yale University, New Haven, Connecticut, USA
| | - James E Saiers
- School of the Environment, Yale University, New Haven, Connecticut, USA
| | - Desiree L Plata
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
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11
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Clark CJ, Xiong B, Soriano MA, Gutchess K, Siegel HG, Ryan EC, Johnson NP, Cassell K, Elliott EG, Li Y, Cox AJ, Bugher N, Glist L, Brenneis RJ, Sorrentino KM, Plano J, Ma X, Warren JL, Plata DL, Saiers JE, Deziel NC. Assessing Unconventional Oil and Gas Exposure in the Appalachian Basin: Comparison of Exposure Surrogates and Residential Drinking Water Measurements. Environ Sci Technol 2022; 56:1091-1103. [PMID: 34982938 PMCID: PMC10259677 DOI: 10.1021/acs.est.1c05081] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Health studies report associations between metrics of residential proximity to unconventional oil and gas (UOG) development and adverse health endpoints. We investigated whether exposure through household groundwater is captured by existing metrics and a newly developed metric incorporating groundwater flow paths. We compared metrics with detection frequencies/concentrations of 64 organic and inorganic UOG-related chemicals/groups in residential groundwater from 255 homes (Pennsylvania n = 94 and Ohio n = 161). Twenty-seven chemicals were detected in ≥20% of water samples at concentrations generally below U.S. Environmental Protection Agency standards. In Pennsylvania, two organic chemicals/groups had reduced odds of detection with increasing distance to the nearest well: 1,2-dichloroethene and benzene (Odds Ratio [OR]: 0.46, 95% confidence interval [CI]: 0.23-0.93) and m- and p-xylene (OR: 0.28, 95% CI: 0.10-0.80); results were consistent across metrics. In Ohio, the odds of detecting toluene increased with increasing distance to the nearest well (OR: 1.48, 95% CI: 1.12-1.95), also consistent across metrics. Correlations between inorganic chemicals and metrics were limited (all |ρ| ≤ 0.28). Limited associations between metrics and chemicals may indicate that UOG-related water contamination occurs rarely/episodically, more complex metrics may be needed to capture drinking water exposure, and/or spatial metrics in health studies may better reflect exposure to other stressors.
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Affiliation(s)
- Cassandra J Clark
- Yale School of Public Health, Department of Environmental Health Sciences, 60 College Street, New Haven, Connecticut 06510, United States
| | - Boya Xiong
- Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, Parsons Laboratory, 15 Vassar Street, Cambridge, Massachusetts 02139, United States
- University of Minnesota, Department of Civil, Environmental and Geo-Engineering, 500 Pillsbury Dr. SE, Minneapolis, Minnesota 55455, United States
| | - Mario A Soriano
- Yale School of the Environment, 195 Prospect Street, New Haven, Connecticut 06511, United States
| | - Kristina Gutchess
- Yale School of the Environment, 195 Prospect Street, New Haven, Connecticut 06511, United States
| | - Helen G Siegel
- Yale School of the Environment, 195 Prospect Street, New Haven, Connecticut 06511, United States
| | - Emma C Ryan
- Tufts University, Department of Public Health and Community Medicine, 136 Harrison Avenue, Boston, Massachusetts 02111, United States
| | - Nicholaus P Johnson
- Yale School of Public Health, Department of Environmental Health Sciences, 60 College Street, New Haven, Connecticut 06510, United States
| | - Kelsie Cassell
- Yale School of Public Health, Department of Epidemiology of Microbial Diseases, 60 College Street, New Haven, Connecticut 06510, United States
| | - Elise G Elliott
- Yale School of Public Health, Department of Environmental Health Sciences, 60 College Street, New Haven, Connecticut 06510, United States
- Harvard T.H. Chan School of Public Health, Department of Environmental Health, Boston, Massachusetts 02115, USA
- Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Yunpo Li
- Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, Parsons Laboratory, 15 Vassar Street, Cambridge, Massachusetts 02139, United States
| | - Austin J Cox
- Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, Parsons Laboratory, 15 Vassar Street, Cambridge, Massachusetts 02139, United States
| | - Nicolette Bugher
- Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, Parsons Laboratory, 15 Vassar Street, Cambridge, Massachusetts 02139, United States
| | - Lukas Glist
- Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, Parsons Laboratory, 15 Vassar Street, Cambridge, Massachusetts 02139, United States
| | - Rebecca J Brenneis
- Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, Parsons Laboratory, 15 Vassar Street, Cambridge, Massachusetts 02139, United States
| | - Keli M Sorrentino
- Center for Perinatal, Pediatric and Environmental Epidemiology, Yale University Schools of Public Health and Medicine, 1 Church Street, New Haven, Connecticut 06510, United States
| | - Julie Plano
- Center for Perinatal, Pediatric and Environmental Epidemiology, Yale University Schools of Public Health and Medicine, 1 Church Street, New Haven, Connecticut 06510, United States
| | - Xiaomei Ma
- Yale School of Public Health, Department of Chronic Disease Epidemiology, 60 College Street, New Haven, Connecticut 06510, United States
| | - Joshua L Warren
- Yale School of Public Health, Department of Biostatistics, 60 College Street, New Haven, Connecticut 06510, United States
| | - Desiree L Plata
- Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, Parsons Laboratory, 15 Vassar Street, Cambridge, Massachusetts 02139, United States
| | - James E Saiers
- Yale School of the Environment, 195 Prospect Street, New Haven, Connecticut 06511, United States
| | - Nicole C Deziel
- Yale School of Public Health, Department of Environmental Health Sciences, 60 College Street, New Haven, Connecticut 06510, United States
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12
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Li Y, Thelemaque NA, Siegel HG, Clark CJ, Ryan EC, Brenneis RJ, Gutchess KM, Soriano MA, Xiong B, Deziel NC, Saiers JE, Plata DL. Groundwater Methane in Northeastern Pennsylvania Attributable to Thermogenic Sources and Hydrogeomorphologic Migration Pathways. Environ Sci Technol 2021; 55:16413-16422. [PMID: 34874708 DOI: 10.1021/acs.est.1c05272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Conflicting evidence exists as to whether or not unconventional oil and gas (UOG) development has enhanced methane transport into groundwater aquifers over the past 15 years. In this study, recent groundwater samples were collected from 90 domestic wells and 4 springs in Northeastern Pennsylvania located above the Marcellus Shale after more than a decade of UOG development. No statistically significant correlations were observed between the groundwater methane level and various UOG geospatial metrics, including proximity to UOG wells and well violations, as well as the number of UOG wells and violations within particular radii. The δ13C and methane-to-higher chain hydrocarbon signatures suggested that the elevated methane levels were not attributable to UOG development nor could they be explained by using simple biogenic-thermogenic end-member mixing models. Instead, groundwater methane levels were significantly correlated with geochemical water type and topographical location. Comparing a subset of contemporary methane measurements to their co-located pre-drilling records (n = 64 at 49 distinct locations) did not indicate systematic increases in methane concentration but did reveal several cases of elevated concentration (n = 12) across a spectrum of topographies. Multiple lines of evidence suggested that the high-concentration groundwater methane could have originated from shallow thermogenic methane that migrated upward into groundwater aquifers with Appalachian Basin brine.
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Affiliation(s)
- Yunpo Li
- Department of Civil and Environmental Engineering, Parsons Laboratory, Massachusetts Institute of Technology, 15 Vassar Street, Cambridge, Massachusetts 02139, United States
| | - Nathalie A Thelemaque
- Department of Civil and Environmental Engineering, Parsons Laboratory, Massachusetts Institute of Technology, 15 Vassar Street, Cambridge, Massachusetts 02139, United States
- Civil and Environmental Engineering, The University of Washington, 3760 East Stevens Way Northeast, Seattle, Washington 98195, United States
| | - Helen G Siegel
- The School of the Environment, Yale University, 195 Prospect Street, New Haven, Connecticut 06511, United States
| | - Cassandra J Clark
- Yale School of Public Health, Department of Environmental Health Sciences, Yale University, 60 College Street, New Haven, Connecticut 06512, United States
| | - Emma C Ryan
- Yale School of Public Health, Department of Environmental Health Sciences, Yale University, 60 College Street, New Haven, Connecticut 06512, United States
- Department of Public Health and Community Medicine, Tufts University, 136 Harrison Avenue, Boston, Massachusetts 02111, United States
| | - Rebecca J Brenneis
- Department of Civil and Environmental Engineering, Parsons Laboratory, Massachusetts Institute of Technology, 15 Vassar Street, Cambridge, Massachusetts 02139, United States
| | - Kristina M Gutchess
- The School of the Environment, Yale University, 195 Prospect Street, New Haven, Connecticut 06511, United States
| | - Mario A Soriano
- The School of the Environment, Yale University, 195 Prospect Street, New Haven, Connecticut 06511, United States
| | - Boya Xiong
- Department of Civil and Environmental Engineering, Parsons Laboratory, Massachusetts Institute of Technology, 15 Vassar Street, Cambridge, Massachusetts 02139, United States
- Department of Civil, Environmental and Geo-Engineering, University of Minnesota, 500 Pillsbury Dr. SE, Minneapolis, Minnesota 55455, United States
| | - Nicole C Deziel
- Yale School of Public Health, Department of Environmental Health Sciences, Yale University, 60 College Street, New Haven, Connecticut 06512, United States
| | - James E Saiers
- The School of the Environment, Yale University, 195 Prospect Street, New Haven, Connecticut 06511, United States
| | - Desiree L Plata
- Department of Civil and Environmental Engineering, Parsons Laboratory, Massachusetts Institute of Technology, 15 Vassar Street, Cambridge, Massachusetts 02139, United States
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13
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Clark CJ, Warren JL, Kadan-Lottick N, Ma X, Bell ML, Saiers JE, Deziel NC. Community concern and government response: Identifying socio-economic and demographic predictors of oil and gas complaints and drinking water impairments in Pennsylvania. Energy Res Soc Sci 2021; 76:102070. [PMID: 34123731 PMCID: PMC8192069 DOI: 10.1016/j.erss.2021.102070] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Oil and gas development has led to environmental hazards and community concerns, particularly in relation to water supply issues. Filing complaints with state agencies enables citizens to register concerns and seek investigations. We evaluated associations between county-level socio-economic and demographic factors, oil and gas drilling, and three outcomes in Pennsylvania between 2004-2016: number of oil and gas complaints filed, and both the number and proportion of state investigations of water supply complaints yielding a confirmed water supply impairment (i.e., "positive determination"). We used hierarchical Bayesian Poisson and binomial regression analyses. From 2004-2016, 9,404 oil and gas-related complaints were filed, of which 4,099 were water supply complaints. Of those, 3,906 received investigations, and 215 yielded positive determinations. We observed a 47% increase in complaints filed per $10,000 increase in annual median household income (MHI) (Rate Ratio [RR]: 1.47, 95% credible interval [CI]: 1.09-1.96) and an 18% increase per 1% increase in educational attainment (RR: 1.18, 95% CI: 1.11-1.26). While the number of complaints filed did not vary by race/ethnicity, the odds of a complaint yielding a positive determination were 0.81 times lower in counties with a higher proportion of marginalized populations (Odds Ratio [OR]: 0.81 per 1% increase in percent Black, Asian, and Native American populations combined, 95% CI: 0.64-0.99). The odds of positive determinations were also lower in areas with higher income (OR per $10,000 increase in MHI: 0.35, 95% CI: 0.09-0.96). Our results suggest these relationships are complex and may indicate potential environmental and procedural inequities, warranting further investigation.
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Affiliation(s)
- Cassandra J. Clark
- Department of Environmental Health Sciences, Yale School of Public Health, 60 College Street, New Haven CT, 06510, United States
| | - Joshua L. Warren
- Department of Biostatistics, Yale School of Public Health, 60 College Street, New Haven CT, 06510, United States
| | - Nina Kadan-Lottick
- Department of Pediatric Hematology and Oncology, Yale School of Medicine, 333 Cedar Street, New Haven CT 06510, United States
| | - Xiaomei Ma
- Department of Chronic Disease Epidemiology, Yale School of Public Health, 60 College Street, New Haven CT, 06510, United States
| | - Michelle L. Bell
- Yale School of the Environment, 195 Prospect Street, New Haven CT, 06511, United States
| | - James E. Saiers
- Yale School of the Environment, 195 Prospect Street, New Haven CT, 06511, United States
| | - Nicole C. Deziel
- Department of Environmental Health Sciences, Yale School of Public Health, 60 College Street, New Haven CT, 06510, United States
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14
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Piotrowski PK, Weggler BA, Yoxtheimer DA, Kelly CN, Barth-Naftilan E, Saiers JE, Dorman FL. Elucidating Environmental Fingerprinting Mechanisms of Unconventional Gas Development through Hydrocarbon Analysis. Anal Chem 2018; 90:5466-5473. [PMID: 29580048 DOI: 10.1021/acs.analchem.8b00822] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hydraulic fracturing is an increasingly common technique for the extraction of natural gas entrapped in shale formations. This technique has been highly criticized due to the possibility of environmental contamination, underscoring the need for method development to identify chemical factors that could be utilized in point-source identification of environmental contamination events. Here, we utilize comprehensive two-dimensional gas chromatography (GC × GC) coupled to high-resolution time-of-flight (HRT) mass spectrometry, which offers a unique instrumental combination allowing for petroleomics hydrocarbon fingerprinting. Four flowback fluids from Marcellus shale gas wells in geographic proximity were analyzed for differentiating factors that could be exploited in environmental forensics investigations of shale gas impacts. Kendrick mass defect (KMD) plots of these flowback fluids illustrated well-to-well differences in heteroatomic substituted hydrocarbons, while GC × GC separations showed variance in cyclic hydrocarbons and polyaromatic hydrocarbons among the four wells. Additionally, generating plots that combine GC × GC separation with KMD established a novel data-rich visualization technique that further differentiated the samples.
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Affiliation(s)
- Paulina K Piotrowski
- Department of Chemistry , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | - Benedikt A Weggler
- Department of Biochemistry and Molecular Biology , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | - David A Yoxtheimer
- Marcellus Center for Outreach and Research , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | - Christina N Kelly
- Life Science and Chemical Analysis , LECO Corporation , Saint Joseph , Michigan 49085 , United States
| | - Erica Barth-Naftilan
- Yale School of Forestry & Environmental Studies , Yale University , New Haven , Connecticut 06520 , United States
| | - James E Saiers
- Yale School of Forestry & Environmental Studies , Yale University , New Haven , Connecticut 06520 , United States
| | - Frank L Dorman
- Department of Biochemistry and Molecular Biology , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
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15
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Patterson LA, Konschnik KE, Wiseman H, Fargione J, Maloney KO, Kiesecker J, Nicot JP, Baruch-Mordo S, Entrekin S, Trainor A, Saiers JE. Unconventional Oil and Gas Spills: Risks, Mitigation Priorities, and State Reporting Requirements. Environ Sci Technol 2017; 51:2563-2573. [PMID: 28220696 DOI: 10.1021/acs.est.6b05749] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Rapid growth in unconventional oil and gas (UOG) has produced jobs, revenue, and energy, but also concerns over spills and environmental risks. We assessed spill data from 2005 to 2014 at 31 481 UOG wells in Colorado, New Mexico, North Dakota, and Pennsylvania. We found 2-16% of wells reported a spill each year. Median spill volumes ranged from 0.5 m3 in Pennsylvania to 4.9 m3 in New Mexico; the largest spills exceeded 100 m3. Seventy-five to 94% of spills occurred within the first three years of well life when wells were drilled, completed, and had their largest production volumes. Across all four states, 50% of spills were related to storage and moving fluids via flowlines. Reporting rates varied by state, affecting spill rates and requiring extensive time and effort getting data into a usable format. Enhanced and standardized regulatory requirements for reporting spills could improve the accuracy and speed of analyses to identify and prevent spill risks and mitigate potential environmental damage. Transparency for data sharing and analysis will be increasingly important as UOG development expands. We designed an interactive spills data visualization tool ( http://snappartnership.net/groups/hydraulic-fracturing/webapp/spills.html ) to illustrate the value of having standardized, public data.
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Affiliation(s)
- Lauren A Patterson
- Nicholas Institute for Environmental Policy Solutions, Duke University , 2111 Campus Drive, Durham North Carolina 27708, United States
| | - Katherine E Konschnik
- Environmental Policy Initiative, Harvard Law School , #4123 Wasserstein Hall, Cambridge, Massachusetts 02138, United States
| | - Hannah Wiseman
- Florida State University College of Law , 424 W. Jefferson Street, Tallahassee, Florida 32306, United States
| | - Joseph Fargione
- The Nature Conservancy, 1101 West River Parkway, Suite 200, Minneapolis, Minnesota 55415, United States
| | - Kelly O Maloney
- U.S. Geological Survey, Leetown Science Center, Kearnevsville, West Virginia 25430, United States
| | - Joseph Kiesecker
- The Nature Conservancy, Global Lands Team, 117 E. Mountain Avenue, Suite 201, Fort Collins, Colorado 80524, United States
| | - Jean-Philippe Nicot
- Bureau of Economic Geology, Jackson School of Geosciences, The University of Texas at Austin , 10100 Burnet Road, Building 130, Austin, Texas 78758, United States
| | - Sharon Baruch-Mordo
- The Nature Conservancy, Global Lands Team, 117 E. Mountain Avenue, Suite 201, Fort Collins, Colorado 80524, United States
| | - Sally Entrekin
- Department of Biology, University of Central Arkansas , 201 Donaghey Avenue, Conway, Arkansas 72035, United States
| | - Anne Trainor
- The Nature Conservancy, African Program, University of Cincinnati, Department of Biological Sciences , 820G Rieveschl Hall, Cincinnati, Ohio 45221, United States
| | - James E Saiers
- School of Forestry and Environmental Studies, Yale University , 195 Prospect St., New Haven, Connecticut 06511, United States
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16
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Maloney KO, Baruch-Mordo S, Patterson LA, Nicot JP, Entrekin SA, Fargione JE, Kiesecker JM, Konschnik KE, Ryan JN, Trainor AM, Saiers JE, Wiseman HJ. Unconventional oil and gas spills: Materials, volumes, and risks to surface waters in four states of the U.S. Sci Total Environ 2017; 581-582:369-377. [PMID: 28043701 DOI: 10.1016/j.scitotenv.2016.12.142] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 12/19/2016] [Accepted: 12/20/2016] [Indexed: 05/02/2023]
Abstract
Extraction of oil and gas from unconventional sources, such as shale, has dramatically increased over the past ten years, raising the potential for spills or releases of chemicals, waste materials, and oil and gas. We analyzed spill data associated with unconventional wells from Colorado, New Mexico, North Dakota and Pennsylvania from 2005 to 2014, where we defined unconventional wells as horizontally drilled into an unconventional formation. We identified materials spilled by state and for each material we summarized frequency, volumes and spill rates. We evaluated the environmental risk of spills by calculating distance to the nearest stream and compared these distances to existing setback regulations. Finally, we summarized relative importance to drinking water in watersheds where spills occurred. Across all four states, we identified 21,300 unconventional wells and 6622 reported spills. The number of horizontal well bores increased sharply beginning in the late 2000s; spill rates also increased for all states except PA where the rate initially increased, reached a maximum in 2009 and then decreased. Wastewater, crude oil, drilling waste, and hydraulic fracturing fluid were the materials most often spilled; spilled volumes of these materials largely ranged from 100 to 10,000L. Across all states, the average distance of spills to a stream was highest in New Mexico (1379m), followed by Colorado (747m), North Dakota (598m) and then Pennsylvania (268m), and 7.0, 13.3, and 20.4% of spills occurred within existing surface water setback regulations of 30.5, 61.0, and 91.4m, respectively. Pennsylvania spills occurred in watersheds with a higher relative importance to drinking water than the other three states. Results from this study can inform risk assessments by providing improved input parameters on volume and rates of materials spilled, and guide regulations and the management policy of spills.
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Affiliation(s)
- Kelly O Maloney
- U.S. Geological Survey, Leetown Science Center, 11649 Leetown Rd., Kearneysville, WV 25430, United States.
| | - Sharon Baruch-Mordo
- The Nature Conservancy, Global Lands Team, 117 E. Mountain Avenue, Suite 201, Fort Collins, CO 80524, United States
| | - Lauren A Patterson
- Nicholas Institute for Environmental Policy Solutions at Duke University, 2111 Campus Drive, Durham, NC 27708, United States
| | - Jean-Philippe Nicot
- Bureau of Economic Geology, Jackson School of Geosciences, The University of Texas at Austin, 10100 Burnet Road, Building 130, Austin, TX 78758, United States
| | - Sally A Entrekin
- Department of Biology, University of Central Arkansas, 201 Donaghey Avenue, Conway, AR 72035, United States
| | - Joseph E Fargione
- The Nature Conservancy, 1101 West River Parkway, Suite 200, Minneapolis, MN 55415, United States
| | - Joseph M Kiesecker
- The Nature Conservancy, Global Lands Team, 117 E. Mountain Avenue, Suite 201, Fort Collins, CO 80524, United States
| | - Kate E Konschnik
- Environmental Policy Initiative, Harvard Law School, #4123 Wasserstein Hall, Cambridge, MA 02138, United States
| | - Joseph N Ryan
- Department of Civil, Environmental and Architectural Engineering, University of Colorado Boulder, UCB 607, Boulder, CO 80309, United States
| | - Anne M Trainor
- The Nature Conservancy, Africa Program, 820G Rieveschl Hall, Cincinnati, OH 45221, United States
| | - James E Saiers
- School of Forestry and Environmental Studies, Yale University, 195 Prospect St., New Haven, CT 06511, United States
| | - Hannah J Wiseman
- Florida State University College of Law, 425 W. Jefferson Street, Tallahassee, FL 32306, United States
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17
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Mohanty SK, Saiers JE, Ryan JN. Colloid Mobilization in a Fractured Soil: Effect of Pore-Water Exchange between Preferential Flow Paths and Soil Matrix. Environ Sci Technol 2016; 50:2310-2317. [PMID: 26829659 DOI: 10.1021/acs.est.5b04767] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Exchange of water and solutes between contaminated soil matrix and bulk solution in preferential flow paths has been shown to contribute to the long-term release of dissolved contaminants in the subsurface, but whether and how this exchange can affect the release of colloids in a soil are unclear. To examine this, we applied rainfall solutions of different ionic strength on an intact soil core and compared the resulting changes in effluent colloid concentration through multiple sampling ports. The exchange of water between soil matrix and the preferential flow paths leading to each port was characterized on the basis of the bromide (conservative tracer) breakthrough time at the port. At individual ports, two rainfalls of a certain ionic strength mobilized different amounts of colloids when the soil was pre-exposed to a solution of lower or higher ionic strength. This result indicates that colloid mobilization depended on rainfall solution history, which is referred as colloid mobilization hysteresis. The extent of hysteresis was increased with increases in exchange of pore water and solutes between preferential flow paths and matrix. The results indicate that the soil matrix exchanged the old water from the previous infiltration with new infiltrating water during successive infiltration and changed the pore water chemistry in the preferential flow paths, which in turn affected the release of soil colloids. Therefore, rainfall solution history and soil heterogeneity must be considered to assess colloid mobilization in the subsurface. These findings have implications for the release of colloids, colloid-associated contaminants, and pathogens from soils.
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Affiliation(s)
- Sanjay K Mohanty
- Civil, Environmental and Architectural Engineering, University of Colorado , Boulder, Colorado 80309, United States
| | - James E Saiers
- Yale School of Forestry and Environmental Studies, Yale University , New Haven, Connecticut 06511, United States
| | - Joseph N Ryan
- Civil, Environmental and Architectural Engineering, University of Colorado , Boulder, Colorado 80309, United States
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18
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Bouda M, Caplan JS, Saiers JE. Box-Counting Dimension Revisited: Presenting an Efficient Method of Minimizing Quantization Error and an Assessment of the Self-Similarity of Structural Root Systems. Front Plant Sci 2016; 7:149. [PMID: 26925073 PMCID: PMC4758026 DOI: 10.3389/fpls.2016.00149] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 01/28/2016] [Indexed: 05/27/2023]
Abstract
Fractal dimension (FD), estimated by box-counting, is a metric used to characterize plant anatomical complexity or space-filling characteristic for a variety of purposes. The vast majority of published studies fail to evaluate the assumption of statistical self-similarity, which underpins the validity of the procedure. The box-counting procedure is also subject to error arising from arbitrary grid placement, known as quantization error (QE), which is strictly positive and varies as a function of scale, making it problematic for the procedure's slope estimation step. Previous studies either ignore QE or employ inefficient brute-force grid translations to reduce it. The goals of this study were to characterize the effect of QE due to translation and rotation on FD estimates, to provide an efficient method of reducing QE, and to evaluate the assumption of statistical self-similarity of coarse root datasets typical of those used in recent trait studies. Coarse root systems of 36 shrubs were digitized in 3D and subjected to box-counts. A pattern search algorithm was used to minimize QE by optimizing grid placement and its efficiency was compared to the brute force method. The degree of statistical self-similarity was evaluated using linear regression residuals and local slope estimates. QE, due to both grid position and orientation, was a significant source of error in FD estimates, but pattern search provided an efficient means of minimizing it. Pattern search had higher initial computational cost but converged on lower error values more efficiently than the commonly employed brute force method. Our representations of coarse root system digitizations did not exhibit details over a sufficient range of scales to be considered statistically self-similar and informatively approximated as fractals, suggesting a lack of sufficient ramification of the coarse root systems for reiteration to be thought of as a dominant force in their development. FD estimates did not characterize the scaling of our digitizations well: the scaling exponent was a function of scale. Our findings serve as a caution against applying FD under the assumption of statistical self-similarity without rigorously evaluating it first.
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Affiliation(s)
- Martin Bouda
- Saiers Lab, School of Forestry and Environmental Studies, Yale UniversityNew Haven, CT, USA
| | - Joshua S. Caplan
- Department of Ecology, Evolution and Natural Resources, Rutgers, The State University of New JerseyNew Brunswick, NJ, USA
| | - James E. Saiers
- Saiers Lab, School of Forestry and Environmental Studies, Yale UniversityNew Haven, CT, USA
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19
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Affiliation(s)
- Peter A. Raymond
- Yale School of Forestry and Environmental Studies; New Haven Connecticut 06511 USA
| | - James E. Saiers
- Yale School of Forestry and Environmental Studies; New Haven Connecticut 06511 USA
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20
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Shih JS, Saiers JE, Anisfeld SC, Chu Z, Muehlenbachs LA, Olmstead SM. Characterization and Analysis of Liquid Waste from Marcellus Shale Gas Development. Environ Sci Technol 2015; 49:9557-65. [PMID: 26140412 DOI: 10.1021/acs.est.5b01780] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Hydraulic fracturing of shale for gas production in Pennsylvania generates large quantities of wastewater, the composition of which has been inadequately characterized. We compiled a unique data set from state-required wastewater generator reports filed in 2009-2011. The resulting data set, comprising 160 samples of flowback, produced water, and drilling wastes, analyzed for 84 different chemicals, is the most comprehensive available to date for Marcellus Shale wastewater. We analyzed the data set using the Kaplan-Meier method to deal with the high prevalence of nondetects for some analytes, and compared wastewater characteristics with permitted effluent limits and ambient monitoring limits and capacity. Major-ion concentrations suggested that most wastewater samples originated from dilution of brines, although some of our samples were more concentrated than any Marcellus brines previously reported. One problematic aspect of this wastewater was the very high concentrations of soluble constituents such as chloride, which are poorly removed by wastewater treatment plants; the vast majority of samples exceeded relevant water quality thresholds, generally by 2-3 orders of magnitude. We also examine the capacity of regional regulatory monitoring to assess and control these risks.
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Affiliation(s)
- Jhih-Shyang Shih
- †Resources for the Future, 1616 P Street NW, Washington, DC 20036, United States
| | - James E Saiers
- ‡School of Forestry and Environmental Studies, Yale University, 195 Prospect Street, New Haven, Connecticut 06511, United States
| | - Shimon C Anisfeld
- ‡School of Forestry and Environmental Studies, Yale University, 195 Prospect Street, New Haven, Connecticut 06511, United States
| | - Ziyan Chu
- †Resources for the Future, 1616 P Street NW, Washington, DC 20036, United States
| | - Lucija A Muehlenbachs
- †Resources for the Future, 1616 P Street NW, Washington, DC 20036, United States
- §Department of Economics, University of Calgary, 2500 University Dr. NW, Calgary, Alberta Canada T2N 1N4
| | - Sheila M Olmstead
- †Resources for the Future, 1616 P Street NW, Washington, DC 20036, United States
- ∥Lyndon B. Johnson School of Public Affairs, University of Texas at Austin, P.O. Box Y, Austin, Texas 78713, United States
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21
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Mohanty SK, Saiers JE, Ryan JN. Colloid Mobilization in a Fractured Soil during Dry-Wet Cycles: Role of Drying Duration and Flow Path Permeability. Environ Sci Technol 2015; 49:9100-9106. [PMID: 26134351 DOI: 10.1021/acs.est.5b00889] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In subsurface soils, colloids are mobilized by infiltrating rainwater, but the source of colloids and the process by which colloids are generated between rainfalls are not clear. We examined the effect of drying duration and the spatial variation of soil permeability on the mobilization of in situ colloids in intact soil cores (fractured and heavily weathered saprolite) during dry-wet cycles. Measuring water flux at multiple sampling ports at the core base, we found that water drained through flow paths of different permeability. The duration of antecedent drying cycles affected the amount of mobilized colloids, particularly in high-flux ports that received water from soil regions with a large number of macro- and mesopores. In these ports, the amount of mobilized colloids increased with increased drying duration up to 2.5 days. For drying durations greater than 2.5 days, the amount of mobilized colloids decreased. In contrast, increasing drying duration had a limited effect on colloid mobilization in low-flux ports, which presumably received water from soil regions with fewer macro- and mesopores. On the basis of these results, we attribute this dependence of colloid mobilization upon drying duration to colloid generation from dry pore walls and distribution of colloids in flow paths, which appear to be sensitive to the moisture content of soil after drying and flow path permeability. The results are useful for improving the understanding of colloid mobilization during fluctuating weather conditions.
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Affiliation(s)
- Sanjay K Mohanty
- †Civil, Environmental and Architectural Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | | | - Joseph N Ryan
- †Civil, Environmental and Architectural Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
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22
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Cheng T, Saiers JE. Effects of dissolved organic matter on the co-transport of mineral colloids and sorptive contaminants. J Contam Hydrol 2015; 177-178:148-157. [PMID: 25938867 DOI: 10.1016/j.jconhyd.2015.04.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 04/04/2015] [Accepted: 04/12/2015] [Indexed: 06/04/2023]
Abstract
Colloid-facilitated transport of contaminants in the vadose zone has important implications to groundwater quality, and has received considerable attention. Natural organic matter (NOM) is ubiquitous in subsurface environments, and its influence on mineral colloids and solute transport has been well documented. However, research on the influence of NOM on colloid-facilitated transport is limited. The objective of this paper is to elucidate the effects of NOM on colloid-facilitated transport of a radioactive contaminant (Cs-137) within partially-saturated sediments. Measurements made with re-packed columns reveal that Cs-137 mobility was low when mineral colloids were absent and was unaffected by the presence of NOM. The addition of mineral colloids to influent increased Cs-137 mobility, and effluent Cs-137 was dominated by the colloid-associated form. When NOM was added to systems that contained mineral colloids and Cs-137, the mobility of Cs-137 further increased. A mathematical model simulating colloid-facilitated transport showed that NOM increases Cs-137 transport by increasing colloid mobility and reducing the rate of Cs-137 adsorption to the porous medium.
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Affiliation(s)
- Tao Cheng
- Department of Earth Sciences, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador A1B 3X5, Canada.
| | - James E Saiers
- School of Forestry & Environmental Studies, Yale University, New Haven, CT 06511, USA
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Abstract
The potential of freeze-thaw cycles to release colloids and colloid-associated contaminants into water is unknown. We examined the effect of freeze-thaw cycles on the mobilization of cesium and strontium in association with colloids in intact cores of a fractured soil, where preferential flow paths are prevalent. Two intact cores were contaminated with cesium and strontium. To mobilize colloids and metal cations sequestered in the soil cores, each core was subjected to 10 intermittent wetting events separated by 66 h pauses. During the first five pauses, the cores were dried at room temperature, and during last five pauses, the cores were subjected to 42 h of freezing followed by 24 h of thawing. In comparison to drying, freeze-thaw cycles created additional preferential flow paths through which colloids, cesium, and strontium were mobilized. The wetting events following freeze-thaw intervals mobilized about twice as many colloids as wetting events following drying at room temperature. Successive wetting events following 66 h of drying mobilized similar amounts of colloids; in contrast, successive wetting events after 66 h of freeze-thaw intervals mobilized greater amounts of colloids than the previous one. Drying and freeze-thaw treatments, respectively, increased and decreased the dissolved cesium and strontium, but both treatments increased the colloidal cesium and strontium. Overall, the freeze-thaw cycles increased the mobilization of metal contaminants primarily in association with colloids through preferential flow paths. These findings suggest that the mobilization of colloid and colloid-associated contaminants could increase when temperature variations occur around the freezing point of water. Thus, climate extremes have the potential to mobilize contaminants that have been sequestered in the vadose zone for decades.
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Affiliation(s)
- Sanjay K Mohanty
- Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder , Boulder, Colorado 80309-0428, United States
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Yang Y, Saiers JE, Barnett MO. Impact of interactions between natural organic matter and metal oxides on the desorption kinetics of uranium from heterogeneous colloidal suspensions. Environ Sci Technol 2013; 47:2661-9. [PMID: 23387874 DOI: 10.1021/es304013r] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Colloids play an important role in governing the transport of radionuclides in geologic environments. As naturally occurring colloidal suspensions are compositionally heterogeneous, the subsurface fate of radionuclides may be sensitive to interactions among different kinds of colloids. Therefore, we investigated the adsorption equilibrium and desorption kinetics of uranium (U(VI)) in experiments conducted with compositionally homogeneous suspensions of colloidal SiO(2), ZnO, hydrous ferric oxide (HFO) or humic acids (HAs) as well as heterogeneous suspensions consisting of a colloidal metal oxide and HA. We found that interactions between HAs and ZnO or HFO greatly inhibited the sorption of U onto colloids in the heterogeneous suspensions. HA-ZnO interactions enhanced the desorption of U from the heterogeneous colloidal suspensions, while the association between HA and SiO(2) or HFO inhibited U desorption. Molecular-level characterizations reveal that HFO interacted with HAs by electrostatic interactions, association with aliphatic/aromatic carbon and inner-sphere complexation with carboxyl functional groups, while SiO(2) and ZnO mainly associated with HAs by weak interactions (e.g., van der Waals interactions). The present findings indicate that interactions between HA and metal-oxide colloids can substantially influence the desorption of U(VI) from these particles, thereby potentially affecting the mobility of this radionuclide in groundwater.
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Affiliation(s)
- Yu Yang
- School of Forestry and Environmental Studies, Yale University , 195 Prospect Street, New Haven, Connecticut, 06511, USA.
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25
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Xu N, Wilson HF, Saiers JE, Entz M. Effects of crop rotation and management system on water-extractable organic matter concentration, structure, and bioavailability in a chernozemic agricultural soil. J Environ Qual 2013; 42:179-190. [PMID: 23673753 DOI: 10.2134/jeq2012.0126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Water-extractable organic matter (WEOM) in soil affects contaminant mobility and toxicity, heterotrophic production, and nutrient cycling in terrestrial and aquatic ecosystems. This study focuses on the influences of land use history and agricultural management practices on the water extractability of organic matter and nutrients from soils. Water-extractable organic matter was extracted from soils under different crop rotations (an annual rotation of wheat-pea/bean-wheat-flax or a perennial-based rotation of wheat-alfalfa-alfalfa-flax) and management systems (organic or conventional) and examined for its concentration, composition, and biodegradability. The results show that crop rotations including perennial legumes increased the concentration of water-extractable organic carbon (WEOC) and water-extractable organic nitrogen (WEON) and the biodegradability of WEOC in soil but depleted the quantity of water-extractable organic phosphorus (WEOP) and water-extractable reactive phosphorus. The 30-d incubation experiments showed that bioavailable WEOC varied from 12.5% in annual systems to 22% for perennial systems. The value of bioavailable WEOC was found to positively correlate with WEON concentrations and to negatively correlate with C:N ratio and the specific ultraviolet absorbance of WEOM. No significant treatment effect was present with the conventional and organic management practices, which suggested that WEOM, as the relatively labile pool in soil organic matter, is more responsive to the change in crop rotation than to mineral fertilizer application. Our results indicated that agricultural landscapes with contrasting crop rotations are likely to differentially affect rates of microbial cycling of organic matter leached to soil waters.
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Affiliation(s)
- James E Saiers
- Yale School of Environmental Studies, New Haven, CT, USA.
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27
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Yang Y, Saiers JE, Xu N, Minasian SG, Tyliszczak T, Kozimor SA, Shuh DK, Barnett MO. Impact of natural organic matter on uranium transport through saturated geologic materials: from molecular to column scale. Environ Sci Technol 2012; 46:5931-8. [PMID: 22533547 DOI: 10.1021/es300155j] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The risk stemming from human exposure to actinides via the groundwater track has motivated numerous studies on the transport of radionuclides within geologic environments; however, the effects of waterborne organic matter on radionuclide mobility are still poorly understood. In this study, we compared the abilities of three humic acids (HAs) (obtained through sequential extraction of a peat soil) to cotransport hexavalent uranium (U) within water-saturated sand columns. Relative breakthrough concentrations of U measured upon elution of 18 pore volumes increased from undetectable levels (<0.001) in an experiment without HAs to 0.17 to 0.55 in experiments with HAs. The strength of the HA effect on U mobility was positively correlated with the hydrophobicity of organic matter and NMR-detected content of alkyl carbon, which indicates the possible importance of hydrophobic organic matter in facilitating U transport. Carbon and uranium elemental maps collected with a scanning transmission X-ray microscope (STXM) revealed uneven microscale distribution of U. Such molecular- and column-scale data provide evidence for a critical role of hydrophobic organic matter in the association and cotransport of U by HAs. Therefore, evaluations of radionuclide transport within subsurface environments should consider the chemical characteristics of waterborne organic substances, especially hydrophobic organic matter.
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Affiliation(s)
- Yu Yang
- School of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511, USA.
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28
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Cheng T, Saiers JE. Colloid-facilitated transport of cesium in vadose-zone sediments: the importance of flow transients. Environ Sci Technol 2010; 44:7443-7449. [PMID: 20812714 DOI: 10.1021/es100391j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Colloid-sized particles are commonly detected in vadose-zone pore waters and are capable of binding chemicals with sorptive affinities for geologic materials. Published research demonstrates that colloids are capable of facilitating the transport of sorptive contaminants under conditions of steady pore water flow, when volumetric moisture content and pore water velocity are constant. Less is known about the role of colloids in governing contaminant mobility under transient-flow conditions, which are characteristic of natural vadose-zone environments. The objective of this study is to elucidate the influences of flow transients on the mobilization and transport of in situ colloids and colloid-associated contaminants. We conducted column experiments in which the mobilization of in situ colloids and (137)Cs was induced by transients associated with the drainage and imbibition of (137)Cs contaminated-sediments. Our results demonstrate that substantial quantities of in situ colloids and colloid-associated (137)Cs are mobilized as volumetric moisture content declines during porous-medium drainage and as volumetric moisture content increases during porous-medium imbibition. We also find that the colloid-effect on (137)Cs transport is sensitive to changes in pore water ionic strength. That is, the quantities of colloids mobilized and the capacity of the these colloids to bind (137)Cs decrease with increasing ionic strength, leading to a decrease of the mass of (137)Cs eluted from the columns during porous-medium drainage and imbibition.
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Affiliation(s)
- Tao Cheng
- School of Forestry and Environmental Studies, Yale University, 195 Prospect Street, New Haven, CT 06511, USA
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29
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Xu N, Saiers JE. Temperature and hydrologic controls on dissolved organic matter mobilization and transport within a forest topsoil. Environ Sci Technol 2010; 44:5423-5429. [PMID: 20552956 DOI: 10.1021/es1002296] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Variations in concentrations of dissolved organic matter (DOM) in streams and rivers reflect, in part, coupled biogeochemical and hydrological processes that govern DOM mobilization and transport through soils. We explore the effects of temperature and rainfall characteristics on the quantity and composition of DOM mobilized from laboratory columns packed with an unsaturated forest soil. Our observations demonstrate that changes in temperature and a five-month drought period affect the mass and structure of DOM mobilized during soil-water infiltration, while changes in rainfall intensity and hourly to daily changes in the frequency of rainfall affect only the mass of DOM mobilized. The spectroscopic analyses indicate that DOM mobilized at low temperature is less humified and tends to be less condensed and lower in molecular weight. The C:N ratios of effluent DOM decline with cumulative rainfall volume during successive rainfall events and decrease by an average of 36% owing to the extended drought period. A two-region model that accounts for rate-limited DOM desorption from soil-water interfaces present within inter-aggregate and intra-aggregate pore spaces closely describes the time-series data on total concentrations of DOM eluted from the soil columns during the rainfall events.
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Affiliation(s)
- Na Xu
- School of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511, USA.
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30
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Abstract
We explore the effects of colloid shape on straining kinetics by measuring the filtration of spherical and nonspherical colloids within saturated columns packed with quartz sand. Our observations demonstrate that the transport of peanut-shaped colloids matches the transport of spherical colloids with diameters equal to the minor-axis length of the peanut-shaped colloids. The straining rates of the spherical colloids vary linearly with the ratio of colloid diameter (d(p)) to sand-grain diameter (d(g)) for 0.0083 < d(p)/d(g) < 0.06. This linear relationship also quantifies the straining rates of the peanut-shaped particles provided that the particle's minor axis length is used for d(p). Results of pore-scale simulations reveal that a peanut-shaped particle adopts a preferred orientation as it approaches a pore-space constriction such that its major axis tends to align with the local flow direction. The extent of this reorientation increases with the particle's aspect ratio. Findings from this research suggest that straining is sensitive to changes in colloid shape and thatthe kinetics of this process can be approximated on the basis of measurable properties of the nonspherical colloids and porous media.
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Affiliation(s)
- Shangping Xu
- School of Environmental Studies, Yale University, New Haven, Connecticut 06511, USA
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Abstract
We constructed a numerical model of transient ground water flow and solute transport for a portion of the Biscayne Aquifer in Florida, and calibrated the model with three different combinations of data from a 193-day period: head (h) data alone, data on h and ground water discharge to a canal (q), and data on h, q, and ground water chloride concentration (C). We used each of the three calibrated models to predict h and q during a 182-day test period separate from the calibration period. All three calibrated models predicted h equally well during the test period (r = 0.95, where r = 1 indicates perfect agreement between measured and simulated values), though the model calibrated on h alone had significantly different parameter values than the other two models. Predictions of q during the test period depended on calibration methodology; models calibrated with multiple targets simulated q more accurately than the model calibrated on h alone (r = 0.79 compared to r = 0.49). Based on the results of these simulations, we conclude: (1) Post-calibration prediction is important in assessing the value of different data types in automated calibration; (2) inverse-solution uniqueness is not a requirement for accurate h predictions; (3) relatively simple models can predict with reasonable accuracy transient ground water flow in a complex aquifer, and parameters governing this prediction can be estimated by nonlinear regression methods that incorporate both h and q data; (4) addition of C data to the calibration did not improve model predictive capacity because the information in the C data was similar to that in the q data, from the perspective of model calibration (the subsurface chemical signal in question was controlled mainly by seepage of high-chloride canal water into the low-chloride ground water system).
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Affiliation(s)
- James E Saiers
- School of Forestry and Environmental Studies, Yale University, New Haven, CT 06511, USA.
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Lenhart JJ, Saiers JE. Adsorption of natural organic matter to air-water interfaces during transport through unsaturated porous media. Environ Sci Technol 2004; 38:120-126. [PMID: 14740726 DOI: 10.1021/es034409a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
To better understand how interactions with the air phase influence the movement of natural organic matter (NOM) through the vadose zone, we measured the transport of soil-humic acid (SHA) through laboratory columns packed with partially saturated sand. Our results demonstrate that sorptive reactions at air-water interfaces reduce SHA mobility and that the affinity of SHA for the air phase increases as the porewater pH declines from 8 to 3.9. SHA desorption from air-water interfaces is negligible for conditions of constant pH, but release of bound SHA occurs in response to perturbations in porewater pH. We analyzed the effluent samples collected from our laboratory columns using high-performance size-exclusion chromatography. The results of this analysis demonstrate that the SHA did not fractionate appreciably during transport through the columns, suggesting that the various components of the SHA pool (as distinguished on the basis of molecular weight) express an equal affinity for the air-water interfaces over the range of pH conditions tested. A mathematical model incorporating irreversible, second-order rate laws to simulate adsorption at air-water and solid-water interfaces closely describes the SHA breakthrough data. The mass-transfer parameters that govern this model vary in a discernible fashion with changes in porewater pH, and the parameter trends are consistent with published theories for SHA adsorption.
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Affiliation(s)
- John J Lenhart
- School of Forestry and Environmental Studies, Yale University, 205 Prospect Street, New Haven, Connecticut 06511, USA
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Villinski JE, Saiers JE, Conklin MH. The effects of reaction-product formation on the reductive dissolution of MnO2 by Fe(II). Environ Sci Technol 2003; 37:5589-96. [PMID: 14717168 DOI: 10.1021/es034060r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
We conducted batch-reactor experiments to measure the reductive dissolution of pyrolusite-coated (beta-MnO2) quartz by Fe(II) under conditions representative of an acid mine-drainage subsurface plume. The results reveal that reductive dissolution rates were initially rapid but declined considerably as Fe(III)(aq), a product of the reductive-dissolution reaction, was removed from solution by heterogeneous precipitation. The inhibition of reductive-dissolution was attributed to blocking of the beta-MnO2 surface sites by the Fe(III)(s) precipitate. Calculations of a simple model that accounts for the effects of Fe(III)(s) precipitate formation on reductive dissolution rates closely match temporal changes in Mn(II), Fe(II), and Fe(II) concentrations measured in 10 experiments, distinguished on the basis of the initial Fe(II)-to-Mn(IV) mole ratio and the initial Fe(III)(aq) concentration. The model-data comparisons reveal that the initial reaction rate on a clean beta-MnO2 surface exceeds the long-term reaction rate by 3 orders of magnitude, highlighting the importance of linking Fe(III) precipitation with the reductive dissolution of beta-MnO2 by Fe(II).
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Affiliation(s)
- John E Villinski
- Department of Hydrology and Water Resources, The University of Arizona, P.O. Box 210011, Tucson, Arizona 85721-0011, USA.
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Abstract
This research focuses on the effects of transients in porewater chemistry on colloid mobilization within water-saturated porous media. We develop a model that couples equations for solute transport with those for colloid release and transport. The model accounts for heterogeneity in the interaction energies between deposited colloids and the mineral grains by dividing the immobile-phase colloid population into a series of compartments. Each compartment releases colloids at a characteristic critical solute concentration, which is assigned on the basis of a piece-wise linear distribution function. We test this model against data from column experiments in which successive step-change reductions in porewater NaCl concentrations induced pulse-type releases of silica colloids from the surfaces of quartz sand. Comparison of experimental and computed results reveals that colloid release rates vary nonlinearly with the immobile-phase colloid concentration and depend on the chemical conditions under which the colloids were deposited on the quartz sand. Our work demonstrates that colloid mobilization kinetics can be quantified given knowledge of the spatiotemporal changes in porewater chemistry.
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Affiliation(s)
- John J Lenhart
- School of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511, USA
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Lenhart JJ, Saiers JE. Transport of silica colloids through unsaturated porous media: experimental results and model comparisons. Environ Sci Technol 2002; 36:769-777. [PMID: 11878396 DOI: 10.1021/es0109949] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We present results on the migration of silica colloids through laboratory columns packed with partially saturated quartz sand. The transport of the silica colloids responds to changes in the steady-state volumetric moisture content (theta) and for low theta depends on the wetting history of the sand pack prior to colloid injection. A mathematical model that incorporates a first-order rate law to simulate film straining and a second-order rate law to simulate partitioning at air-water interfaces closely describes colloid transport and mass transfer over the range of experimental conditions tested. The mass-transfer parameters of the model are sensitive to changes in both the level of water saturation and the flow rate. A semiempirical expression, based on a modification of film-straining theory, accounts for the observed variation in the first-order rate coefficient with changes in theta and average porewater velocity. Our work indicates that the presence of the air phase substantially influences porewater concentrations of mineral colloids in water-unsaturated media and that the kinetics of particle removal attributed to air-water boundaries reflects the contribution of multiple mass-transfer mechanisms.
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Affiliation(s)
- John J Lenhart
- School of Forestry and Environmental Studies, Yale University, Greeley Laboratory, New Haven, Connecticut 06511, USA
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Abstract
Data from a large-scale canal-drawdown test were used to estimate the specific yield (sy) of the Biscayne Aquifer, an unconfined limestone aquifer in southeast Florida. The drawdown test involved dropping the water level in a canal by about 30 cm and monitoring the response of hydraulic head in the surrounding aquifer. Specific yield was determined by analyzing data from the unsteady portion of the drawdown test using an analytical stream-aquifer interaction model (Zlotnik and Huang 1999). Specific yield values computed from drawdown at individual piezometers ranged from 0.050 to 0.57, most likely indicating heterogeneity of specific yield within the aquifer (small-scale variation in hydraulic conductivity may also have contributed to the differences in sy among piezometers). A value of 0.15 (our best estimate) was computed based on all drawdown data from all piezometers. We incorporated our best estimate of specific yield into a large-scale two-dimensional numerical MODFLOW-based ground water flow model and made predictions of head during a 183-day period at four wells located 337 to 2546 m from the canal. We found good agreement between observed and predicted heads, indicating our estimate of specific yield is representative of the large portion of the Biscayne Aquifer studied here. This work represents a practical and novel approach to the determination of a key hydrogeological parameter (the storage parameter needed for simulation and calculation of transient unconfined ground water flow), at a large spatial scale (a common scale for water resource modeling), for a highly transmissive limestone aquifer (in which execution of a traditional pump test would be impractical and would likely yield ambiguous results). Accurate estimates of specific yield and other hydrogeological parameters are critical for management of water supply, Everglades environmental restoration, flood control, and other issues related to the ground water hydrology of the Biscayne Aquifer.
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Affiliation(s)
- C H Bolster
- School of Forestry and Environmental Studies, Yale University, New Haven, CT 06511, USA.
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37
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Abstract
We examine how the processes of advection, dispersion, oxidation-reduction, and adsorption combine to affect the transport of chromium through columns packed with pyrolusite (beta-MnO2)-coated sand. We find that beta-MnO2 effectively oxidizes Cr(III) to Cr(VI) and that the extent of oxidation is sensitive to changes in pH, pore water velocity, and influent concentrations of Cr(III). Cr(III) oxidation rates, although initially high, decline well before the supply of beta-MnO2 is depleted, suggesting that a reaction product inhibits the conversion of Cr(III) to Cr(VI). Rate-limited reactions govern the weak adsorption of each chromium species, with Cr(III) adsorption varying directly with pH and Cr(VI) adsorption varying inversely with pH. The breakthrough data on chromium transport can be matched closely by calculations of a simple model that accounts for (1) advective-dispersive transport of Cr(III), Cr(VI), and dissolved oxygen, (2) first-order kinetics adsorption of the reduced and oxidized chromium species, and (3) nonlinear rate-limited oxidation of Cr(III) to Cr(VI). Our work supplements the limited database on the transport of redox-sensitive metals in porous media and provides a means for quantifying the coupled processes that contribute to this transport.
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Affiliation(s)
- H Guha
- Hemispheric Center for Environmental Technology, Florida International University, 10555 West Flagler Street CEAS 2100, Miami, FL 33174, USA
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