Detection of engineered nanomaterials in drinking water, food, commercial products and biological samples

Project: Research project

Description

Nanotechnology has immense potential for improving human welfare. However, there is concern among scientists and the public alike about the risk of adverse health impacts of nanomaterials (NMs) exposed in manufacturing facilities, used in commercial products and released into the environment. Human exposure to chemicals, including NMs, occurs by ingestion, inhalation, or dermal contact. In the case of NM, exposure may occur due to the intact NM or elements solubilized from the NM. The degree of bioavailability is likely to be vastly different for soluble elements versus those associated with the parent NM. The parent NIH grant focuses on blood, urine, and cell-line fluids. One aspect of the requested supplement will be to add lung fluids to the overall project investigation. The second aspect is to begin to develop our outreach in research and education with local High Schools. To fully realize the potential benefits of nanotechnology, society must be convinced that this technology is safe. Beginning to educate the public on nanotechnology at the high school level will greatly facilitate the acceptance of nanotechnology. The experiments will be performed in the chemical research laboratories at Colorado School of Mines. A key to success will be that although the experiments must be reasonably simple to perform, the information obtained must be relevant to the overall project goals of the parent study. Solubility experiments with NMs using fluids that mimic lung fluids will be straightforward to perform, while still providing new and highly useful data for development of a risk framework for NMs. Both ICP-AES and ICP-MS will be used to detect and quantify Ag, Ti, and other elements in both the NMs and in solutions following dissolution studies. Changes in the physical properties (particle size and surface charge) will also be measured using dynamic light scattering. Training on the instruments to be used in the project will be provided to allow the measurements to be made by the teacher and student. These data will be analyzed to determine dissolution and aggregation rates. All data will be provided to Dr Westerhoff for incorporation into NIH reports. Procedures and results will be incorporated into educational materials for use in the high school science curriculum.

Description

Nanotechnology is rapidly resulting in the production of nanomaterials (NMs) that will be used in everything from toothpaste to pesticides, yet the research community lacks adequate techniques to measure the size and concentration of nanomaterials in even the simplest of environmental and biological samples at levels which may be relevant to human exposures. The National Nanotechnology Initiative, including NIEHS, and other organizations ranks as a top priority the need to develop methods to quantify nanomaterials in matrices including drinking water, commercial products, blood and other biological matrices. The purpose of our proposed work is two-fold: first, we aim to develop state-of-theart exposure assessment tools for nanomaterials for the international scientific, medical and regulatory community; second, we will identify and quantify the metrology gap between what exposure levels may be potentially harmful based on published toxicological data and the method detection limits that can be achieved for non-labeled commercial nanomaterials with current technology. Inorganic and carbonaceous nanomaterials are being synthesized in a wide range of sizes, shapes and with various surface coatings or functionalities. Consequently, people may soon be exposed to thousands of different types of nanomaterials in their workplace or during other daily activities. Risk assessments from these exposures are hampered by the lack of adequate detection capabilities. While electron microscopy and other techniques can image NMs in samples, they fall short of being able to quantify the size, number concentration and mass concentration of NMs which are thought to be crucial for understanding to properly assess NM exposures and effects. We hypothesize that two basic instrumentation platforms (ion coupled plasma mass spectroscopy and liquid chromatography mass spectroscopy) can be developed in conjunction with sample pretreatment methods, involving extraction, separation and or concentration of NMs from environmental and biological samples, to quantify the size, number concentration and mass concentration of the currently most widely used inorganic NMs (Ag, TiO2, Au) and carbonaceous NMs (fullerenes and functionalized fullerenes). To support this hypothesis we will exploit techniques initially developed to quantify natural aquatic colloids (i.e., NMs) and organic pollutants. Specifically, real time single particle ICP mass spectroscopy (RTSP-MS) will be used to differentiate metal or metal oxide NMs from dissolved ionic forms of the base NM material. Carbonaceous NMs will be handled in a similar fashion as organic chemicals, by pre-treating and analyzing (LC/MS) them based upon solubility and hydrophobicity characteristics. By working with a range of widely employed NMs the methods will be immediately and widely applicable. Standard operating procedures for NM analytical techniques and extraction protocols will be developed. The investigators have been working with NMs for many years, and are familiar with purchasing, characterizing, solubilizing and handling NMs. Using robust statistical approaches, the procedures (detection limits, precision, accuracy, reproducibility, recovery rate, etc) will be validated. Once validated, the pretreatment methods and analytical techniques will be used to quantify engineered nanomaterials in drinking water, food, consumer products and biological fluids (including whole blood, blood plasma, blood serum, urine and human milk). Our team has extensive experience in the analysis of manmade pollutants in these matrices. Due to a presumably low present ambient exposure to engineered NMs, except perhaps for TiO2, we do not expect to detect these types of materials in our archived samples of biological fluids or drinking waters. After testing this hypothesis, we will fortify aliquots of pools of blood, human milk and urine, respectively, with known and increasing concentrations of
StatusFinished
Effective start/end date9/30/097/31/12

Funding

  • HHS: National Institutes of Health (NIH): $1,892,623.00

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Nanostructured materials
Drinking Water
Nanotechnology
Blood
Fluids
Fullerenes
Spectroscopy
Dissolution