Health Effects of Inhaled NanomaterialsEPA Grant Number: R831714
Title: Health Effects of Inhaled Nanomaterials
Investigators: Pinkerton, Kent E. , Guo, Ting
Institution: University of California - Davis
EPA Project Officer: Hahn, Intaek
Project Period: July 1, 2004 through June 30, 2007
Project Amount: $334,998
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: Exploratory Research - Human Health , Health , Safer Chemicals , Nanotechnology , Health Effects
The potential health impact of engineered nanomaterials is unknown. Nanomaterials are particles less than 100 nm in diameter. It is anticipated there will be an exponential increase in the commercial use of these materials in society as carbon nanotubes, nanowires, and silicon/metal alkoxides. This use will lead to a concomitant increase in exposure of the general population to nanomaterials in products and the environment through incidental introduction to the soil, water and air. Little is known what the environmental fate of these particles will be. Epidemiological and toxicological studies on the effects of particulate air pollution support the premise that ultrafine or nanosize particles cause pulmonary inflammation as well as systemic effects. Therefore, we propose to test the hypothesis that inhaled nanomaterials cause respiratory effects in the form of oxidative stress and inflammation. We further propose such events will lead to release of pro-inflammatory cytokines as well as other mediators to induce cell proliferation and alterations in the normal cellular milieu of the airways and alveoli of the lungs. We will test whether these health impacts of nanomaterials on the respiratory system are driven in large measure by (1) particle size, (2) particle composition and/or (3) trace contaminants associated with the manufacturing process of nanomaterials.
These studies will be done at the Center for Health and the Environment, and the Department of Chemistry, University of California, Davis. Nanomaterials will be obtained from commercial sources as well as generated in our laboratories at the University of California, Davis. To study the health effects of nanomaterials, a novel exposure system will be used to generate aerosols of these materials requiring only small quantities (100 mg) for short-term inhalation in rodents. Exposures will take place for up to 3 consecutive days, with exposures being 6 hours/day. Exposures will use specific types of carbon nanotubes (single-walled, bundled and multiwalled) of known size and composition. Ultrafine titanium dioxide (TiO2) and ultrafine carbon black (CB) will also be aerosolized to compare their potential health effects to these various forms of nanotubes in the respiratory tract. Cellular, biochemical and histological assays will be measured in the respiratory tract to determine potential changes due to nanoparticle exposure. These measures include indicators of oxidative stress, inflammation, cell injury and repair and metabolic change. The role of metal contaminants (present in catalysts used in the manufacturing process) will be studied using nanotube preparations with these trace metals/contaminants removed.
(1) Characterization of aerosolized nanotubes, ultrafine TiO2. and CB under environmentally relevant conditions found in the workplace. (2) The influence of uniquely distinct forms of nanotubes to produce health effects in the respiratory system. (3) The impact of trace metals associated with nanotubes to enhance/cause health effects due to inhalation.