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1.
J Infect Dis ; 227(1): 141-150, 2022 12 28.
Artigo em Inglês | MEDLINE | ID: mdl-35994504

RESUMO

BACKGROUND: A third dose of measles-mumps-rubella vaccine (MMR3) is recommended in mumps outbreak scenarios, but the immune response and the need for widespread use of MMR3 remain uncertain. Herein, we characterized measles-specific immune responses to MMR3 in a cohort of 232 healthy subjects. METHODS: Serum and peripheral blood mononuclear cells (PBMCs) were sampled at day 0 and day 28 after MMR3. Measles-specific binding and neutralizing antibodies were quantified in sera by enzyme-linked immunosorbent assay and a microneutralization assay, respectively. PBMCs were stimulated with inactivated measles virus, and the release of cytokines/chemokines was assessed by a multiplex assay. Demographic variables of subjects were examined for potential correlations with immune outcomes. RESULTS: Of the study participants, 95.69% and 100% were seropositive at day 0 and day 28, respectively. Antibody avidity significantly increased from 38.08% at day 0 to 42.8% at day 28 (P = .00026). Neutralizing antibodies were significantly enhanced, from 928.7 at day 0 to 1289.64 mIU/mL at day 28 (P = .0001). Meanwhile, cytokine/chemokine responses remained largely unchanged. Body mass index was significantly correlated with the levels of inflammatory cytokines/chemokines. CONCLUSIONS: Measles-specific humoral immune responses, but not cellular responses, were enhanced after MMR3 receipt, extending current understanding of immune responses to MMR3 and supporting MMR3 administration to seronegative or high-risk individuals.


Assuntos
Sarampo , Caxumba , Rubéola (Sarampo Alemão) , Humanos , Vacina contra Sarampo-Caxumba-Rubéola , Imunidade Humoral , Índice de Massa Corporal , Leucócitos Mononucleares , Anticorpos Antivirais , Sarampo/prevenção & controle , Anticorpos Neutralizantes , Caxumba/prevenção & controle , Citocinas , Quimiocinas , Rubéola (Sarampo Alemão)/prevenção & controle , Vacina contra Sarampo
2.
Clin Infect Dis ; 73(7): e1754-e1757, 2021 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-33313656

RESUMO

Treatment options for Achromobacter xylosoxidans are limited. Eight cystic fibrosis patients with A. xylosoxidans were treated with 12 cefiderocol courses. Pretreatment in vitro resistance was seen in 3 of 8 cases. Clinical response occurred after 11 of 12 treatment courses. However, microbiologic relapse was observed after 11 of 12 treatment courses, notably without emergence of resistance.


Assuntos
Achromobacter denitrificans , Fibrose Cística , Infecções por Bactérias Gram-Negativas , Adulto , Antibacterianos/uso terapêutico , Cefalosporinas , Criança , Fibrose Cística/complicações , Fibrose Cística/tratamento farmacológico , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Humanos , Cefiderocol
3.
Environ Sci Technol ; 54(8): 4829-4839, 2020 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-32250106

RESUMO

Mixing of acid mine drainage (AMD) and hydraulic fracturing flowback fluids (HFFF) could represent an efficient management practice to simultaneously manage two complex energy wastewater streams while reducing freshwater resource consumption. AMD discharges offer generally high sulfate concentrations, especially from the bituminous coal region of Pennsylvania; unconventional Marcellus shale gas wells generally yield HFFF enriched in alkaline earth metals such as Sr and Ba, known to cause scaling issues in oil and gas (O&G) production. Mixing the two waters can precipitate HFFF-Ba and -Sr with AMD-SO4, therefore removing them from solution. Four AMD discharges and HFFF from two unconventional Marcellus shale gas wells were characterized and mixed in batch reactors for 14 days. Ba could be completely removed from solution within 1 day of mixing in the form BaxSr1-xSO4 and no further significant precipitation occurred after 2 days. Total removal efficiencies of Ba + Sr + SO4 and the proportion of Ba and Sr in BaxSr1-xSO4 depended upon the Ba/Sr ratio in the initial HFFF. A geochemical model was calibrated from batch reactor data and used to identify optimum AMD-HFFF mixing ratios that maximize total removal efficiencies (Ba + Sr + SO4) for reuse in O&G development. Increasing Ba/Sr ratios can enhance total removal efficiency but decrease the efficiency of Ra removal. Thus, treatment objectives and intended beneficial reuse need to be identified prior to optimizing the treatment of HFFF with AMD.


Assuntos
Rádio (Elemento) , Poluentes Químicos da Água/análise , Região dos Apalaches , Bário , Gás Natural , Pennsylvania , Estrôncio , Sulfatos , Águas Residuárias
4.
Environ Sci Technol ; 53(17): 10295-10302, 2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-31429285

RESUMO

Radium measurements in high total dissolved solids (TDS) fluids from oil and gas extraction can have unfavorable precision and accuracy, in part because these high-level impurities incur attenuation. γ spectroscopy is often recommended for determining radium activities in these fluids, but even this method can produce a range of reported activities for the same sample. To reduce measurement duration and to maintain or improve accuracy, we propose a method to rapidly assess both 226Ra and 228Ra and to account for the self-attenuation of γ rays in high-TDS oil and gas fluids when they are monitored by a well detector. In this work, comparisons between a NaCl-only and a multi-cation-chloride synthetic brine spiked with known amounts of 226Ra and 228Ra indicated that both the TDS concentration and the type of TDS (i.e., Na only vs Na-Mg-Ba-Ca-Sr) influenced self-attenuation in well-detector γ spectroscopy, thus highlighting the need to correct for this TDS-influenced self-attenuation. Radium activities can be underestimated if the correction is not applied. For instance, 226Ra activities could be ∼40% lower in a sample when measured directly at the 186 keV energy level if the attenuation of the high TDS of the fluid is not considered. We also showed that using a NaCl-only brine to match the matrix of high-TDS oil and gas brines is inadequate to produce accurate measurements, rather, the full set of cations should be included.


Assuntos
Rádio (Elemento) , Poluentes Radioativos da Água , Raios gama , Análise Espectral , Água
5.
Environ Sci Technol ; 52(3): 955-962, 2018 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-29300469

RESUMO

In Pennsylvania, Appalachian oil and gas wastewaters (OGW) are permitted for release to surface waters after some treatment by centralized waste treatment (CWT) facilities. While this practice was largely discontinued in 2011 for unconventional Marcellus OGW at facilities permitted to release high salinity effluents, it continues for conventional OGW. This study aimed to evaluate the environmental implications of the policy allowing the disposal of conventional OGW. We collected stream sediments from three disposal sites receiving treated OGW between 2014 and 2017 and measured 228Ra, 226Ra, and their decay products, 228Th and 210Pb, respectively. We consistently found elevated activities of 228Ra and 226Ra in stream sediments in the vicinity of the outfall (total Ra = 90-25,000 Bq/kg) compared to upstream sediments (20-80 Bq/kg). In 2015 and 2017, 228Th/228Ra activity ratios in sediments from two disposal sites were relatively low (0.2-0.7), indicating that a portion of the Ra has accumulated in the sediments in recent (<3) years, when no unconventional Marcellus OGW was reportedly discharged. 228Ra/226Ra activity ratios were also higher than what would be expected solely from disposal of low 228Ra/226Ra Marcellus OGW. Based on these variations, we concluded that recent disposal of treated conventional OGW is the source of high Ra in stream sediments at CWT facility disposal sites. Consequently, policies pertaining to the disposal of only unconventional fluids are not adequate in preventing radioactive contamination in sediments at disposal sites, and the permission to release treated Ra-rich conventional OGW through CWT facilities should be reconsidered.


Assuntos
Rádio (Elemento) , Águas Residuárias , Região dos Apalaches , Pennsylvania , Rios
6.
Environ Sci Technol ; 52(18): 10883-10892, 2018 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-30179464

RESUMO

For several decades, high-salinity water brought to the surface during oil and gas (O&G) production has been treated and discharged to waterways under National Pollutant Discharge Elimination System (NPDES) permits. In Pennsylvania, USA, a portion of the treated O&G wastewater discharged to streams from 2008 to 2011 originated from unconventional (Marcellus) wells. We collected freshwater mussels, Elliptio dilatata and Elliptio complanata, both upstream and downstream of a NPDES-permitted facility, and for comparison, we also collected mussels from the Juniata and Delaware Rivers that have no reported O&G discharge. We observed changes in both the Sr/Cashell and 87Sr/86Srshell in shell samples collected downstream of the facility that corresponded to the time period of greatest Marcellus wastewater disposal (2009-2011). Importantly, the changes in Sr/Cashell and 87Sr/86Srshell shifted toward values characteristic of O&G wastewater produced from the Marcellus Formation. Conversely, shells collected upstream of the discharge and from waterways without treatment facilities showed lower variability and no trend in either Sr/Cashell or 87Sr/86Srshell with time (2008-2015). These findings suggest that (1) freshwater mussels may be used to monitor changes in water chemistry through time and help identify specific pollutant sources and (2) O&G contaminants likely bioaccumulated in areas of surface water disposal.


Assuntos
Bivalves , Poluentes Químicos da Água , Animais , Delaware , Água Doce , Metais , Pennsylvania , Águas Residuárias
7.
Proc Natl Acad Sci U S A ; 112(43): 13184-9, 2015 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-26460018

RESUMO

Hundreds of organic chemicals are used during natural gas extraction via high-volume hydraulic fracturing (HVHF). However, it is unclear whether these chemicals, injected into deep shale horizons, reach shallow groundwater aquifers and affect local water quality, either from those deep HVHF injection sites or from the surface or shallow subsurface. Here, we report detectable levels of organic compounds in shallow groundwater samples from private residential wells overlying the Marcellus Shale in northeastern Pennsylvania. Analyses of purgeable and extractable organic compounds from 64 groundwater samples revealed trace levels of volatile organic compounds, well below the Environmental Protection Agency's maximum contaminant levels, and low levels of both gasoline range (0-8 ppb) and diesel range organic compounds (DRO; 0-157 ppb). A compound-specific analysis revealed the presence of bis(2-ethylhexyl) phthalate, which is a disclosed HVHF additive, that was notably absent in a representative geogenic water sample and field blanks. Pairing these analyses with (i) inorganic chemical fingerprinting of deep saline groundwater, (ii) characteristic noble gas isotopes, and (iii) spatial relationships between active shale gas extraction wells and wells with disclosed environmental health and safety violations, we differentiate between a chemical signature associated with naturally occurring saline groundwater and one associated with alternative anthropogenic routes from the surface (e.g., accidental spills or leaks). The data support a transport mechanism of DRO to groundwater via accidental release of fracturing fluid chemicals derived from the surface rather than subsurface flow of these fluids from the underlying shale formation.


Assuntos
Gasolina/análise , Água Subterrânea/química , Indústria de Petróleo e Gás , Compostos Orgânicos/análise , Poluentes Químicos da Água/análise , Cromatografia Gasosa-Espectrometria de Massas
8.
Environ Sci Technol ; 51(15): 8851-8860, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28699344

RESUMO

Combining horizontal drilling with high volume hydraulic fracturing has increased extraction of hydrocarbons from low-permeability oil and gas (O&G) formations across the United States; accompanied by increased wastewater production. Surface water discharges of O&G wastewater by centralized waste treatment (CWT) plants pose risks to aquatic and human health. We evaluated the impact of surface water disposal of O&G wastewater from CWT plants upstream of the Conemaugh River Lake (dam controlled reservoir) in western Pennsylvania. Regulatory compliance data were collected to calculate annual contaminant loads (Ba, Cl, total dissolved solids (TDS)) to document historical industrial activity. In this study, two CWT plants 10 and 19 km upstream of a reservoir left geochemical signatures in sediments and porewaters corresponding to peak industrial activity that occurred 5 to 10 years earlier. Sediment cores were sectioned for the collection of paired samples of sediment and porewater, and analyzed for analytes to identify unconventional O&G wastewater disposal. Sediment layers corresponding to the years of maximum O&G wastewater disposal contained higher concentrations of salts, alkaline earth metals, and organic chemicals. Isotopic ratios of 226Ra/228Ra and 87Sr/86Sr identified that peak concentrations of Ra and Sr were likely sourced from wastewaters that originated from the Marcellus Shale formation.


Assuntos
Campos de Petróleo e Gás , Águas Residuárias , Poluentes Químicos da Água/análise , Pennsylvania , Rios , Água
9.
J Clin Apher ; 32(6): 567-570, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27709659

RESUMO

HIV complicates the diagnostic and therapeutic approaches to idiopathic thrombotic thrombocytopenic purpura (TTP), prompting debate in the literature regarding the benefit of plasma exchange versus simple plasma infusion. Herein we present a case of HIV-TTP, initially treated conservatively with plasma infusion but because of progressive neurologic decline, required urgent plasma exchange for resolution of hematologic derangements and neurologic sequelae. Based on the available literature, there appears to be a spectrum of HIV-associated TTP disorders. Patients with advanced HIV disease and opportunistic infections who present with thrombotic microangiopathy tend to respond to simple plasma infusion, while patients with less progressive HIV disease tend to behave like those with idiopathic TTP, requiring plasma exchange rather than simple plasma infusion. This article illustrates that in patients with HIV-TTP who do not respond to plasma infusion, early escalation to plasma exchange may help avoid life-threatening complications such as seizures and even death.


Assuntos
Infecções por HIV , Troca Plasmática/métodos , Púrpura Trombocitopênica Trombótica/terapia , Púrpura Trombocitopênica Trombótica/virologia , Adulto , Feminino , Humanos , Plasma , Púrpura Trombocitopênica Trombótica/complicações
10.
Proc Natl Acad Sci U S A ; 111(39): 14076-81, 2014 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-25225410

RESUMO

Horizontal drilling and hydraulic fracturing have enhanced energy production but raised concerns about drinking-water contamination and other environmental impacts. Identifying the sources and mechanisms of contamination can help improve the environmental and economic sustainability of shale-gas extraction. We analyzed 113 and 20 samples from drinking-water wells overlying the Marcellus and Barnett Shales, respectively, examining hydrocarbon abundance and isotopic compositions (e.g., C2H6/CH4, δ(13)C-CH4) and providing, to our knowledge, the first comprehensive analyses of noble gases and their isotopes (e.g., (4)He, (20)Ne, (36)Ar) in groundwater near shale-gas wells. We addressed two questions. (i) Are elevated levels of hydrocarbon gases in drinking-water aquifers near gas wells natural or anthropogenic? (ii) If fugitive gas contamination exists, what mechanisms cause it? Against a backdrop of naturally occurring salt- and gas-rich groundwater, we identified eight discrete clusters of fugitive gas contamination, seven in Pennsylvania and one in Texas that showed increased contamination through time. Where fugitive gas contamination occurred, the relative proportions of thermogenic hydrocarbon gas (e.g., CH4, (4)He) were significantly higher (P < 0.01) and the proportions of atmospheric gases (air-saturated water; e.g., N2, (36)Ar) were significantly lower (P < 0.01) relative to background groundwater. Noble gas isotope and hydrocarbon data link four contamination clusters to gas leakage from intermediate-depth strata through failures of annulus cement, three to target production gases that seem to implicate faulty production casings, and one to an underground gas well failure. Noble gas data appear to rule out gas contamination by upward migration from depth through overlying geological strata triggered by horizontal drilling or hydraulic fracturing.


Assuntos
Gases Nobres/análise , Campos de Petróleo e Gás , Poluentes Químicos da Água/análise , Abastecimento de Água/análise , Poços de Água/análise , Meio Ambiente , Monitoramento Ambiental , Água Subterrânea , Humanos , Modelos Teóricos , Pennsylvania , Texas , Poluição Química da Água
13.
Proc Natl Acad Sci U S A ; 110(28): 11250-5, 2013 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-23798404

RESUMO

Horizontal drilling and hydraulic fracturing are transforming energy production, but their potential environmental effects remain controversial. We analyzed 141 drinking water wells across the Appalachian Plateaus physiographic province of northeastern Pennsylvania, examining natural gas concentrations and isotopic signatures with proximity to shale gas wells. Methane was detected in 82% of drinking water samples, with average concentrations six times higher for homes <1 km from natural gas wells (P = 0.0006). Ethane was 23 times higher in homes <1 km from gas wells (P = 0.0013); propane was detected in 10 water wells, all within approximately 1 km distance (P = 0.01). Of three factors previously proposed to influence gas concentrations in shallow groundwater (distances to gas wells, valley bottoms, and the Appalachian Structural Front, a proxy for tectonic deformation), distance to gas wells was highly significant for methane concentrations (P = 0.007; multiple regression), whereas distances to valley bottoms and the Appalachian Structural Front were not significant (P = 0.27 and P = 0.11, respectively). Distance to gas wells was also the most significant factor for Pearson and Spearman correlation analyses (P < 0.01). For ethane concentrations, distance to gas wells was the only statistically significant factor (P < 0.005). Isotopic signatures (δ(13)C-CH4, δ(13)C-C2H6, and δ(2)H-CH4), hydrocarbon ratios (methane to ethane and propane), and the ratio of the noble gas (4)He to CH4 in groundwater were characteristic of a thermally postmature Marcellus-like source in some cases. Overall, our data suggest that some homeowners living <1 km from gas wells have drinking water contaminated with stray gases.

14.
Environ Sci Technol ; 49(3): 1955-63, 2015 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-25587644

RESUMO

The expansion of unconventional shale gas and hydraulic fracturing has increased the volume of the oil and gas wastewater (OGW) generated in the U.S. Here we demonstrate that OGW from Marcellus and Fayetteville hydraulic fracturing flowback fluids and Appalachian conventional produced waters is characterized by high chloride, bromide, iodide (up to 56 mg/L), and ammonium (up to 420 mg/L). Br/Cl ratios were consistent for all Appalachian brines, which reflect an origin from a common parent brine, while the I/Cl and NH4/Cl ratios varied among brines from different geological formations, reflecting geogenic processes. There were no differences in halides and ammonium concentrations between OGW originating from hydraulic fracturing and conventional oil and gas operations. Analysis of discharged effluents from three brine treatment sites in Pennsylvania and a spill site in West Virginia show elevated levels of halides (iodide up to 28 mg/L) and ammonium (12 to 106 mg/L) that mimic the composition of OGW and mix conservatively in downstream surface waters. Bromide, iodide, and ammonium in surface waters can impact stream ecosystems and promote the formation of toxic brominated-, iodinated-, and nitrogen disinfection byproducts during chlorination at downstream drinking water treatment plants. Our findings indicate that discharge and accidental spills of OGW to waterways pose risks to both human health and the environment.


Assuntos
Compostos de Amônio/análise , Brometos/análise , Fraturamento Hidráulico , Iodetos/análise , Águas Residuárias/análise , Poluentes Químicos da Água/análise , Meio Ambiente , Resíduos Industriais/análise , Petróleo , Estados Unidos
15.
Proc Natl Acad Sci U S A ; 109(30): 11961-6, 2012 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-22778445

RESUMO

The debate surrounding the safety of shale gas development in the Appalachian Basin has generated increased awareness of drinking water quality in rural communities. Concerns include the potential for migration of stray gas, metal-rich formation brines, and hydraulic fracturing and/or flowback fluids to drinking water aquifers. A critical question common to these environmental risks is the hydraulic connectivity between the shale gas formations and the overlying shallow drinking water aquifers. We present geochemical evidence from northeastern Pennsylvania showing that pathways, unrelated to recent drilling activities, exist in some locations between deep underlying formations and shallow drinking water aquifers. Integration of chemical data (Br, Cl, Na, Ba, Sr, and Li) and isotopic ratios ((87)Sr/(86)Sr, (2)H/H, (18)O/(16)O, and (228)Ra/(226)Ra) from this and previous studies in 426 shallow groundwater samples and 83 northern Appalachian brine samples suggest that mixing relationships between shallow ground water and a deep formation brine causes groundwater salinization in some locations. The strong geochemical fingerprint in the salinized (Cl > 20 mg/L) groundwater sampled from the Alluvium, Catskill, and Lock Haven aquifers suggests possible migration of Marcellus brine through naturally occurring pathways. The occurrences of saline water do not correlate with the location of shale-gas wells and are consistent with reported data before rapid shale-gas development in the region; however, the presence of these fluids suggests conductive pathways and specific geostructural and/or hydrodynamic regimes in northeastern Pennsylvania that are at increased risk for contamination of shallow drinking water resources, particularly by fugitive gases, because of natural hydraulic connections to deeper formations.


Assuntos
Fenômenos Geológicos , Água Subterrânea/química , Sais/química , Movimentos da Água , Poluentes Químicos da Água/análise , Abastecimento de Água/análise , Cromatografia por Troca Iônica , Isótopos/análise , Espectrometria de Massas , Pennsylvania , Rádio (Elemento)/análise , Isótopos de Estrôncio/análise
16.
Environ Sci Technol ; 48(15): 8334-48, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24606408

RESUMO

The rapid rise of shale gas development through horizontal drilling and high volume hydraulic fracturing has expanded the extraction of hydrocarbon resources in the U.S. The rise of shale gas development has triggered an intense public debate regarding the potential environmental and human health effects from hydraulic fracturing. This paper provides a critical review of the potential risks that shale gas operations pose to water resources, with an emphasis on case studies mostly from the U.S. Four potential risks for water resources are identified: (1) the contamination of shallow aquifers with fugitive hydrocarbon gases (i.e., stray gas contamination), which can also potentially lead to the salinization of shallow groundwater through leaking natural gas wells and subsurface flow; (2) the contamination of surface water and shallow groundwater from spills, leaks, and/or the disposal of inadequately treated shale gas wastewater; (3) the accumulation of toxic and radioactive elements in soil or stream sediments near disposal or spill sites; and (4) the overextraction of water resources for high-volume hydraulic fracturing that could induce water shortages or conflicts with other water users, particularly in water-scarce areas. Analysis of published data (through January 2014) reveals evidence for stray gas contamination, surface water impacts in areas of intensive shale gas development, and the accumulation of radium isotopes in some disposal and spill sites. The direct contamination of shallow groundwater from hydraulic fracturing fluids and deep formation waters by hydraulic fracturing itself, however, remains controversial.


Assuntos
Indústrias Extrativas e de Processamento , Gás Natural , Recursos Hídricos , Meio Ambiente , Água Doce , Água Subterrânea , Humanos , Risco , Estados Unidos , Águas Residuárias , Poluição da Água
17.
Environ Sci Technol ; 48(2): 1334-42, 2014 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-24367969

RESUMO

Wastewaters generated during hydraulic fracturing of the Marcellus Shale typically contain high concentrations of salts, naturally occurring radioactive material (NORM), and metals, such as barium, that pose environmental and public health risks upon inadequate treatment and disposal. In addition, fresh water scarcity in dry regions or during periods of drought could limit shale gas development. This paper explores the possibility of using alternative water sources and their impact on NORM levels through blending acid mine drainage (AMD) effluent with recycled hydraulic fracturing flowback fluids (HFFFs). We conducted a series of laboratory experiments in which the chemistry and NORM of different mix proportions of AMD and HFFF were examined after reacting for 48 h. The experimental data combined with geochemical modeling and X-ray diffraction analysis suggest that several ions, including sulfate, iron, barium, strontium, and a large portion of radium (60-100%), precipitated into newly formed solids composed mainly of Sr barite within the first ∼ 10 h of mixing. The results imply that blending AMD and HFFF could be an effective management practice for both remediation of the high NORM in the Marcellus HFFF wastewater and beneficial utilization of AMD that is currently contaminating waterways in northeastern U.S.A.


Assuntos
Ácidos/química , Bário/isolamento & purificação , Mineração , Rádio (Elemento)/isolamento & purificação , Eliminação de Resíduos Líquidos , Águas Residuárias/química , Poluentes Químicos da Água/isolamento & purificação , Precipitação Química , Condutividade Elétrica , Geografia , Concentração de Íons de Hidrogênio , Cinética , Peso Molecular , Pennsylvania , Termodinâmica
18.
Proc Natl Acad Sci U S A ; 108(20): 8172-6, 2011 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-21555547

RESUMO

Directional drilling and hydraulic-fracturing technologies are dramatically increasing natural-gas extraction. In aquifers overlying the Marcellus and Utica shale formations of northeastern Pennsylvania and upstate New York, we document systematic evidence for methane contamination of drinking water associated with shale-gas extraction. In active gas-extraction areas (one or more gas wells within 1 km), average and maximum methane concentrations in drinking-water wells increased with proximity to the nearest gas well and were 19.2 and 64 mg CH(4) L(-1) (n = 26), a potential explosion hazard; in contrast, dissolved methane samples in neighboring nonextraction sites (no gas wells within 1 km) within similar geologic formations and hydrogeologic regimes averaged only 1.1 mg L(-1) (P < 0.05; n = 34). Average δ(13)C-CH(4) values of dissolved methane in shallow groundwater were significantly less negative for active than for nonactive sites (-37 ± 7‰ and -54 ± 11‰, respectively; P < 0.0001). These δ(13)C-CH(4) data, coupled with the ratios of methane-to-higher-chain hydrocarbons, and δ(2)H-CH(4) values, are consistent with deeper thermogenic methane sources such as the Marcellus and Utica shales at the active sites and matched gas geochemistry from gas wells nearby. In contrast, lower-concentration samples from shallow groundwater at nonactive sites had isotopic signatures reflecting a more biogenic or mixed biogenic/thermogenic methane source. We found no evidence for contamination of drinking-water samples with deep saline brines or fracturing fluids. We conclude that greater stewardship, data, and-possibly-regulation are needed to ensure the sustainable future of shale-gas extraction and to improve public confidence in its use.


Assuntos
Monitoramento Ambiental/métodos , Combustíveis Fósseis , Resíduos Industriais/análise , Metano/análise , Abastecimento de Água/normas , Poluentes Químicos da Água/análise , Poluição da Água/análise
20.
Sci Total Environ ; 927: 172151, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38575010

RESUMO

Legacy disposal of oil and gas produced water (OGPW) to surface water has led to radium contamination in streambed sediment creating a long-term radium source. Increased radium activities pose a potential health hazard to benthic organisms, such as freshwater mussels, as radium is capable of bioaccumulation. This project quantifies the impact of OGPW disposal on adult freshwater mussels, Eurynia dilatata, which were examined along the Allegheny River adjacent to a centralized waste treatment facility (CWT) that historically treated and then discharged OGPW. Radium isotopes (226Ra and 228Ra) were measured in streambed sediment, mussel soft tissue, and mussel hard shell collected upstream, at the outfall, 0.5 km downstream, and 5 km downstream of the CWT. Total radium activity was significantly higher (p < 0.05) in mussel tissue (mean = 3.44 ± 0.95 pCi/g), sediment (mean = 1.45 ± 0.19 pCi/g), and hard shell (mean = 0.34 ± 0.11 pCi/g) samples 0.5 km downstream than background samples collected upstream (mean = 1.27 ± 0.24; 0.91 ± 0.09; 0.10 ± 0.02 pCi/g respectively). Mussel shells displayed increased 226Ra activities up to 5 km downstream of the original discharge. Downstream soft tissue and hard shell 87Sr/86Sr ratios, as well as hard shell metal/calcium (e.g., Na/Ca; K/Ca; Mg/Ca) and 228Ra/226Ra ratios demonstrated trends towards values characteristic of Marcellus OGPW. Combined, this study demonstrates multiple lines of evidence for radium retention and bioaccumulation in freshwater mussels resulting from exposure to Marcellus OGPW.


Assuntos
Bivalves , Rádio (Elemento) , Poluentes Radioativos da Água , Animais , Poluentes Radioativos da Água/análise , Bivalves/metabolismo , Rádio (Elemento)/análise , Monitoramento de Radiação , Água Doce , Sedimentos Geológicos/química
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