Grantee Research Project Results
Final Report: Fate, Transformation and Toxicity of Manufactured Nanomaterials in Drinking Water
EPA Grant Number: R831713Title: Fate, Transformation and Toxicity of Manufactured Nanomaterials in Drinking Water
Investigators: Westerhoff, Paul , Crittenden, John C. , Capco, David , Chen, Yongsheng
Institution: Arizona State University
EPA Project Officer: Hahn, Intaek
Project Period: October 1, 2004 through September 30, 2007
Project Amount: $455,000
RFA: Exploratory Research to Anticipate Future Environmental Issues: Impacts of Manufactured Nanomaterials on Human Health and the Environment (2003) RFA Text | Recipients Lists
Research Category: Nanotechnology , Human Health , Safer Chemicals
Objective:
Although the current market for nanomaterials is small and their concentration may not be high enough in the environment to cause human health or environmental problems, this market is increasing rapidly and the discharge of nanomaterials into the environment in the near future could be significant as manufacturing costs decrease and new applications are discovered. The accumulation of nanomaterials in cells may have significant environmental and human impacts. At present, however, very little is known about the fate, transport, transformation, and toxicity of these man-made nanomaterials in the environment. The objectives of this research project were to: (1) characterize the fundamental properties of nanomaterials in aquatic environments; (2) examine the interactions between nanomaterials and toxic organic pollutants and pathogens (viruses); (3) evaluate the removal efficiency of nanomaterials by drinking water unit processes; and (4) test the toxicity of nanomaterials in drinking water using the cell culture model system of the epithelium. This study considers the physical, chemical, and biological implications of nanomaterial fate and toxicity in systems that will provide insight into the potential for nanomaterials to be present and to cause health concerns in treated drinking water.
Summary/Accomplishments (Outputs/Outcomes):
Studies were conducted using several types of commercial metal oxide nanoparticles (two types of titanium dioxide, iron(III) oxide, zinc oxide, nickel oxide, and silica in powder form or liquid suspensions), functionalized quantum dots, lab-synthesized hematite nanoparticles and aqueous fullerenes (nC60). Most experiments were conducted with 10 mg/L of the nanoparticles. Among the analytical methods developed, a solid phase extraction and LC/MS method was developed to quantify C60 at ppb concentrations in complex water matrices. Aggregation studies were conducted in the presence of simple salts to compress electric double layer of the nanoparticles, to study their aggregation rates. Increasing salt concentrations lead to aggregation. CdTe quantum dots (QDs) containing carboxylic functional groups were stable in the presence of monovalent salts, but aggregated rapidly upon addition of di- or tri-valent cations (Ca, Mg, Al) that complexed with the functional groups on the quantum dots. Adding natural organic matter stabilized most nanoparticles (i.e., less aggregation). The fate of nanoparticles during drinking water “jar” tests using aluminum sulfate as a coagulant was characterized by changes in dynamic light scattering, zeta potential, scanning electron microscopy (SEM), and acid digestion followed by atomic absorption spectroscopy. Metal oxides and hematite rapidly aggregated in the presence of simple salts, local tap water, and addition of aluminum sulfate.
Trans-Epithelial Electrical Resistance (TEER) measurements have been made using Caco2 BBe (human intestinal cells) grown and maintained with Dulbecco’s Modified Eagle Medium (DMEM) supplemented with 10 percent fetal bovine serum, penicillin/streptomycin/ fungizone, and transferrin. Nanoparticles were applied to the tests in the medium. Controls were conducted without nanoparticles or with sodium azide. Aggregation within the medium was observed. Measurements included TEER, live/dead assays, confocal microscopy and SEM imaging, and quantification of passage of nanomaterials across the membrane. Nanoparticles were found to flatten down the microvilli, allowed passage of 1% to ~10% of the nanoparticles, and result in >25% decrease in TEER relative to controls only at very high nanoparticle dosages.
This study developed a novel technique to prevent aggregation of QDs by diluting the QDs in calcium/magnesium-free phosphate buffered saline, while retaining conditions on one side of the epithelial sheet to provide necessary nutrients and co-factors to the cells. Toxicity studies completed here show that the QDs purchased for these experiments caused disruption in the epithelium monolayer and cell death.
Journal Articles on this Report : 7 Displayed | Download in RIS Format
| Other project views: | All 12 publications | 7 publications in selected types | All 7 journal articles |
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Kiser MA, Westerhoff P, Benn T, Wang Y, Perez-Rivera J, Hristovski K. Titanium nanomaterial removal and release from wastewater treatment plants. Environmental Science & Technology 2009;43(17):6757-6763. |
R831713 (Final) R833322 (2008) |
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Kiser MA, Ryu H, Jang H, Hristovski K, Westerhoff P. Biosorption of nanoparticles to heterotrophic wastewater biomass. Water Research 2010;44(14):4105-4114. |
R831713 (Final) R833322 (2008) |
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Kiser MA, Ladner DA, Hristovski KD, Westerhoff PK. Nanomaterial transformation and association with fresh and freeze-dried wastewater activated sludge: implications for testing protocol and environmental fate. Environmental Science & Technology 2012;46(13):7046-7053. |
R831713 (Final) R833322 (2008) |
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Wang Y, Westerhoff P, Hristovski KD. Fate and biological effects of silver, titanium dioxide, and C60 (fullerene) nanomaterials during simulated wastewater treatment processes. Journal of Hazardous Materials 2012;201-202:16-22. |
R831713 (Final) R833322 (2008) |
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Westerhoff PK, Kiser MA, Hristovski K. Nanomaterial removal and transformation during biological wastewater treatment. Environmental Engineering Science 2013;30(3):109-117. |
R831713 (Final) R833322 (2008) |
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Zhang W, Yao Y, Chen Y. Imaging and quantifying the morphology and nanoelectrical properties of quantum dot nanoparticles interacting with DNA. Journal of Physical Chemistry C 2011;115(3):599-606. |
R831713 (Final) R833856 (Final) |
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Zhang Y, Chen Y, Westerhoff P, Crittenden J. Impact of natural organic matter and divalent cations on the stability of aqueous nanoparticles. Water Research 2009;43(17):4249-4257. |
R831713 (Final) R833856 (Final) |
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Supplemental Keywords:
fate, transport, toxicity, manufactured nanomaterials, drinking water, Health, RFA, Scientific Discipline, Water, Health Risk Assessment, Risk Assessments, Environmental Chemistry, Engineering, Chemistry, & Physics, Biochemistry, Drinking Water, community water system, health effects, toxicity, toxicokinetics, human exposure, engineered nanomaterials, environmental contaminants, fate and transport, nanotechnology, ambient particle health effects, respiratory impact, drinking water system, drinking water contaminants, other - risk assessment, cellular responses, human health risk, human health effects, particle exposure, biochemical researchRelevant Websites:
http://enpub.fulton.asu.edu/pwest/nano/Nanotechnology%20group%20front%20page.htm ExitProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.