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Barrett PM, Hull EA, King CE, Burkart K, Ott KA, Ryan JN, Gawel JE, Neumann RB. Increased exposure of plankton to arsenic in contaminated weakly-stratified lakes. Sci Total Environ 2018; 625:1606-1614. [PMID: 29996457 PMCID: PMC6044462 DOI: 10.1016/j.scitotenv.2017.12.336] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [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: 09/20/2017] [Revised: 12/28/2017] [Accepted: 12/29/2017] [Indexed: 05/05/2023]
Abstract
Arsenic, a priority Superfund contaminant and carcinogen, is a legacy pollutant impacting aquatic ecosystems in urban lakes downwind of the former ASARCO copper smelter in Ruston, WA, now a Superfund site. We examined the mobility of arsenic from contaminated sediments and arsenic bioaccumulation in phytoplankton and zooplankton in lakes with varying mixing regimes. In lakes with strong seasonal thermal stratification, high aqueous arsenic concentrations were limited to anoxic bottom waters that formed during summer stratification, and arsenic concentrations were low in oxic surface waters. However, in weakly-stratified lakes, the entire water column, including the fully oxic surface waters, had elevated concentrations of arsenic (up to 30μgL-1) during the summer. We found enhanced trophic transfer of arsenic through the base of the aquatic food web in weakly-stratified lakes; plankton in these lakes accumulated up to an order of magnitude more arsenic on multiple sampling days than plankton in stratified lakes with similar levels of contamination. We posit that greater bioaccumulation in weakly-stratified lakes was due to elevated arsenic in oxic waters. Aquatic life primarily inhabits oxic waters and in the oxic water column of weakly-stratified lakes arsenic was speciated as arsenate, which is readily taken up by phytoplankton because of its structural similarities to phosphate. Our study indicates that mobilization of arsenic from lake sediments into overlying oxic water columns in weakly-stratified lakes leads to increased arsenic exposure and uptake at the base of the aquatic food web.
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Affiliation(s)
- P M Barrett
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA 98195, United States.
| | - E A Hull
- Environmental Science and Studies, School of Interdisciplinary Arts and Sciences, University of Washington Tacoma, Tacoma, WA 98402, United States
| | - C E King
- Environmental Science and Studies, School of Interdisciplinary Arts and Sciences, University of Washington Tacoma, Tacoma, WA 98402, United States
| | - K Burkart
- Environmental Science and Studies, School of Interdisciplinary Arts and Sciences, University of Washington Tacoma, Tacoma, WA 98402, United States
| | - K A Ott
- Civil, Environmental, and Architectural Engineering, University of Colorado Boulder, CO 80309, United States
| | - J N Ryan
- Civil, Environmental, and Architectural Engineering, University of Colorado Boulder, CO 80309, United States
| | - J E Gawel
- Environmental Science and Studies, School of Interdisciplinary Arts and Sciences, University of Washington Tacoma, Tacoma, WA 98402, United States
| | - R B Neumann
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA 98195, United States
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Abudalo RA, Ryan JN, Harvey RW, Metge DW, Landkamer L. Influence of organic matter on the transport of Cryptosporidium parvum oocysts in a ferric oxyhydroxide-coated quartz sand saturated porous medium. Water Res 2010; 44:1104-1113. [PMID: 19853880 DOI: 10.1016/j.watres.2009.09.039] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2009] [Revised: 09/08/2009] [Accepted: 09/17/2009] [Indexed: 05/28/2023]
Abstract
To assess the effect of organic matter on the transport of Cryptosporidium parvum oocysts in a geochemically heterogeneous saturated porous medium, we measured the breakthrough and collision efficiencies of oocysts as a function of dissolved organic matter concentration in a flow-through column containing ferric oxyhydroxide-coated sand. We characterized the surface properties of the oocysts and ferric oxyhydroxide-coated sand using microelectrophoresis and streaming potential, respectively, and the amount of organic matter adsorbed on the ferric oxyhydroxide-coated sand as a function of the concentration of dissolved organic matter (a fulvic acid isolated from Florida Everglades water). The dissolved organic matter had no significant effect on the zeta potential of the oocysts. Low concentrations of dissolved organic matter were responsible for reversing the charge of the ferric oxyhydroxide-coated sand surface from positive to negative. The charge reversal and accumulation of negative charge on the ferric oxyhydroxide-coated sand led to increases in oocyst breakthrough and decreases in oocyst collision efficiency with increasing dissolved organic matter concentration. The increase in dissolved organic matter concentration from 0 to 20mg L(-1) resulted in a two-fold decrease in the collision efficiency.
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Affiliation(s)
- R A Abudalo
- 428 UCB, Department of Civil, Environmental, and Architectural Engineering, University of Colorado, Boulder, CO 80309, USA.
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Pang L, Nowostawska U, Ryan JN, Williamson WM, Walshe G, Hunter KA. Modifying the surface charge of pathogen-sized microspheres for studying pathogen transport in groundwater. J Environ Qual 2009; 38:2210-7. [PMID: 19875776 DOI: 10.2134/jeq2008.0451] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Consuming pathogen-contaminated groundwater has caused many waterborne disease worldwide. Microspheres are often used as pathogen surrogates because they can be made similar to pathogens in terms of their sizes, buoyant densities, and shapes. Laboratory studies have, however, shown that the surface charges of microspheres are very different from those of pathogens of comparable sizes, and that their attenuation and transport behaviors differ significantly to those of the pathogens mimicked. Thus, for microspheres to be better surrogates, their surface charges need to be modified. We have demonstrated that the surface charge of a microorganism can be closely mimicked by microspheres covalently coated with a protein that has a similar pHPZC to the microorganism. Using MS2 bacteriophage to test our concept, 20 nm carboxylated microspheres were covalently coated with casein. Zeta potentials as a function of pH were determined for purified MS2, casein, and uncoated and coated microspheres. The uncoated microspheres were significantly more negatively charged than MS2. The coated microspheres displayed zeta potentials and a pHPZC value similar to MS2. The modified surface charge on the microspheres was stable for at least 4 mo. Using the concept developed from this study, surrogates for many specific pathogens of concern can be developed, and the results can be corrected with pathogen die-off determined independently in the laboratory. Protein-coated microspheres could provide a new and alternative approach to investigate pathogen transport in groundwater. Future research is required to validate the surrogates' resemblances to pathogens in terms of their attenuation and transport behaviors in groundwater.
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Affiliation(s)
- L Pang
- Institute of Environmental Science & Research Ltd., P.O. Box 29181, Christchurch, New Zealand.
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Abudalo RA, Bogatsu YG, Ryan JN, Harvey RW, Metge DW, Elimelech M. Effect of ferric oxyhydroxide grain coatings on the transport of bacteriophage PRD1 and Cryptosporidium parvum oocysts in saturated porous media. Environ Sci Technol 2005; 39:6412-9. [PMID: 16190194 DOI: 10.1021/es050159h] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
To test the effect of geochemical heterogeneity on microorganism transport in saturated porous media, we measured the removal of two microorganisms, the bacteriophage PRD1 and oocysts of the protozoan parasite Cryptosporidium parvum, in flow-through columns of quartz sand coated by different amounts of a ferric oxyhydroxide. The experiments were conducted over ranges of ferric oxyhydroxide coating fraction of lambda = 0-0.12 for PRD1 and from lambda = 0-0.32 for the oocysts at pH 5.6-5.8 and 10(-4) M ionic strength. To determine the effect of pH on the transport of the oocysts, experiments were also conducted over a pH range of 5.7-10.0 at a coating fraction of lambda = 0.04. Collision (attachment) efficiencies increased as the fraction of ferric oxyhydroxide coated quartz sand increased, from alpha = 0.0071 to 0.13 over lambda = 0-0.12 for PRD1 and from alpha = 0.059 to 0.75 over lambda = 0-0.32 for the oocysts. Increasing the pH from 5.7 to 10.0 resulted in a decrease in the oocyst collision efficiency as the pH exceeded the expected point of zero charge of the ferric oxyhydroxide coatings. The collision efficiencies correlated very well with the fraction of quartz sand coated by the ferric oxyhydroxide for PRD1 but not as well for the oocysts.
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Affiliation(s)
- R A Abudalo
- Department of Civil, Environmental, and Architectural Engineering, University of Colorado, 428 UCB, Boulder, Colorado 80309, USA
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Aiken G, Haitzer M, Ryan JN, Nagy K. Interactions between dissolved organic matter and mercury in the Florida Everglades. ACTA ACUST UNITED AC 2003. [DOI: 10.1051/jp4:20030235] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Abadzic SD, Ryan JN. Particle release and permeability reduction in a natural zeolite (clinoptilolite) and sand porous medium. Environ Sci Technol 2001; 35:4502-4508. [PMID: 11757608 DOI: 10.1021/es001868s] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
To evaluate clinoptilolite, a natural zeolite, as a candidate material for a permeable reactive barrier for removal of strontium from groundwater, we investigated particle release and permeability reduction in clinoptilolite and sand porous media. In flow-through column experiments, we tested the effects of solution chemistry, grain size, and clinoptilolite pretreatment on particle release and hydraulic conductivity. Permeability reduction occurred not in the clinoptilolite itself but only in finer-grained sand down-gradient of the clinoptilolite. Solutions of high ionic strength inhibited particle release and prevented clogging. Clinoptilolite of larger grain size produced slightly less particle release and clogging. Two pretreatments of the clinoptilolite, rinsing to remove fine particles and calcining to improve strength, reduced particle release and clogging. Calcining, however, significantly reduced the strontium binding strength of the clinoptilolite.
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Affiliation(s)
- S D Abadzic
- Department of Civil, Environmental, and Architectural Engineering, University of Colorado, Boulder 80309-0428, USA
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Sun N, Elimelech M, Sun NZ, Ryan JN. A novel two-dimensional model for colloid transport in physically and geochemically heterogeneous porous media. J Contam Hydrol 2001; 49:173-199. [PMID: 11411396 DOI: 10.1016/s0169-7722(00)00193-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [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
A two-dimensional model for colloid transport in geochemically and physically heterogeneous porous media is presented. The model considers patchwise geochemical heterogeneity, which is suitable to describe the chemical variability of many surficial aquifers with ferric oxyhydroxide-coated porous matrix, as well as spatial variability of hydraulic conductivity, which results in heterogeneous flow field. The model is comprised of a transient fluid flow equation, a transient colloid transport equation, and an equation for the dynamics of colloid deposition and release. Numerical simulations were carried out with the model to investigate the colloid transport behavior in layered and randomly heterogeneous porous media. Results demonstrate that physical and geochemical heterogeneities markedly affect the colloid transport behavior. Layered physical or geochemical heterogeneity can result in distinct preferential flow paths of colloidal particles. Furthermore, the combined effect of layered physical and geochemical heterogeneity may result in enhanced or reduced preferential flow of colloids. Random distribution of physical heterogeneity (hydraulic conductivity) results in a random flow field and an irregularly distributed colloid concentration profile in the porous medium. Contrary to random physical heterogeneity, the effect of random patchwise geochemical heterogeneity on colloid transport behavior is not significant. It is mostly the mean value of geochemical heterogeneity rather than its distribution that governs the colloid transport behavior.
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Affiliation(s)
- N Sun
- Environmental Engineering Program, Department of Chemical Engineering, Yale University, P.O. Box 208286, New Haven, CT 06520-8286, USA
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Ryan JN, Gschwend PM. Effect of solution chemistry on clay colloid release from an iron oxide-coated aquifer sand. Environ Sci Technol 1994; 28:1717-1726. [PMID: 22176375 DOI: 10.1021/es00058a025] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
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Abstract
Treatment of parturient rats with 100 micrograms oestradiol/day caused a significant retardation of uterine involution and collagen breakdown. The post-partum uterus had a peroxidase activity of 180 mumol H2O2 reduced/min per uterus. Treatment with oestradiol caused an eight- to tenfold increase in this activity within 3--4 days. Treatment of rats with 4 mg cortisol/day commencing 3 days prepartum had no effect on uterine peroxidase acitvity but it blocked the oestradiol-induced increase in peroxidase. Cortisol had no effect on collagen breakdown and did not reverse the inhibition of collagen breakdown produced by oestradiol. It is postulated that the effects of oestradiol on peroxidase activity are mediated by uterine epithelial cells but that oestradiol effects on collagen breakdown may be mediated by another cell type.
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Marcus FI, Ryan JN, Stafford MG. The reactivity of derivatives of digoxin and digitoxin as measured by the Na-K-atpase displacement assay and by radioimmunoassay. J Lab Clin Med 1975; 85:610-20. [PMID: 123547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Derivatives of digoxin and digitoxin were measured by the Na-K-ATPase displacement assay and by radioimmunoassay and the data compared with biological potency of these compounds. There was a slightly higher affinity of digoxigenin-bis-digitoxoside as compared with digoxin using digoxin-specific antiserum and considerably less affinity of digoxigenin and dihydrodigoxin than the parent compound in the same system. A similar trend was observed for the derivatives of digitoxin using digoxin-specific antiserum. The recovery on extraction of some of the derivatives of digoxin and digitoxin differed from that of the parent compounds in the ATPase assay. The potency of the derivatives of these drugs in displacing 3H ouabain also differed from the parent compoundmboth the recovery on extraction and the potency for displacing ouabain must be considered in the estimation of the contribution of the derivatives of digoxin or digitoxin to the result of Na-K-ATPase assay. Quantitative information of the metabolites of digoxin and digitoxin in normal and pathological conditions is needed to properly interpret assay data obtained either by radioimmunoassay or by ATPase assay.
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Chvapil M, Madden JW, Peacock EE, Ryan JN. Effect of 1,10-phenanthroline on acute liver injury induced by dimethylnitrosamine in the rat. Life Sci 1974; 14:1653-65. [PMID: 4276354 DOI: 10.1016/0024-3205(74)90267-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Chvapil M, Ryan JN. The pool of free proline in acute and chronic liver injury and its effect on the synthesis of collagen and globular proteins. Agents Actions 1973; 3:38-44. [PMID: 4715533 DOI: 10.1007/bf02023850] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Chvapil M, Ryan JN. Diverse effect of 1,10-phenanthroline and 2,2'-dipyridyl on the synthesis of collagen and noncollagenous proteins in in vivo and in vitro systems. Biochim Biophys Acta 1972; 273:208-11. [PMID: 5038279 DOI: 10.1016/0304-4165(72)90208-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Abstract
1. The earlier observation (Woessner, 1969) of oestradiol inhibition of collagen breakdown is confirmed and extended. Administration of 100mug of oestradiol-17beta/day to parturient rats strongly inhibits the loss of collagen from the involuting uterus. Three experiments show that this effect is due to an inhibition of collagen degradation rather than to a stimulation of collagen synthesis. 2. Uterine collagen was labelled with hydroxy[(14)C]-proline by the administration of [(14)C]proline near the end of pregnancy. By 3 days post partum, control uteri lost 83% of their collagen and 90% of their hydroxy[(14)C]proline. Uteri from oestradiol-treated rats lost only 50% of both total and labelled hydroxyproline, with no decrease in the specific radioactivity of the hydroxyproline. 3. Incorporation of [(14)C]proline into uterine collagen hydroxyproline in vivo was not affected by oestradiol treatment. 4. Urinary excretion of hydroxyproline was increased in post-partum control rats and decreased in oestradiol-treated rats. 5. An enzyme capable of cleaving 4-phenylazobenzyloxycarbonyl-l-prolyl-l-leucylglycyl- l-prolyl-d-arginine (a substrate for clostridial collagenase) increased in activity in the post-partum uterus and was unaffected by oestradiol treatment. 6. Uterine homogenates digested uterine collagen extensively at pH3.2. This digestion was unaffected by the oestradiol treatment. 7. Lysosomal fractions prepared by density-gradient centrifugation of uterine homogenates contained coincident peaks of cathepsin D activity and peptide-bound hydroxyproline. The cathepsin D and hydroxyproline contents of this peak were unaffected by oestradiol treatment.
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