All major powers are making efforts to research and develop nanotechnology- based materials and systems for military use. Asian and European countries, with the exception of Sweden (Swedish Defence Nanotechnology Programme), do not run dedicated programs for defense nanotechnology research. Rather, they integrate several nanotechnology- related projects within their traditional defense-research structures, e.g., as materials research, electronic devices research, or bio-chemical protection research. Not so the U.S. military. Stressing continued technological superiority as its main strategic advantage, it is determined to exploit nanotechnology for future military use and it certainly wants to be No. 1 in this area. The U.S. Department of Defense (DoD) is a major investor, spending well over 30% of all federal investment dollars in nanotechnology. Of the $352m spent on nanotech by the DoD in 2005, $1m, or roughly 0.25%, went into research dealing with potential health and environmental risks. In 2006, estimated DoD nanotechnology expenditures will be $436m - but the risk-related research stays at $1m.
Building construction and operation is estimated to be a trillion dollar per year industry worldwide. And it is one that is ripe for the innovations offered by nanotechnology and nanomaterials. Already, dozens of building materials incorporate nanotechnology, from self-cleaning windows to flexible solar panels to wi-fi blocking paint. Many more are in development, including self-healing concrete, materials to block ultraviolet and infrared radiation, smog-eating coatings and light-emitting walls and ceilings. Nanotech is also starting to make the smart home a reality. Nanotech-enabled sensors are available today to monitor temperature, humidity, and airborne toxins. The nanosensor market is expected to reach $17.2 billion by 2012. Soon, inexpensive sensors will be available to monitor vibration, decay and other performance concerns in building components from structural members to appliances. Nanotechnology is also rapidly improving the batteries and wireless components used in these sensors. In the not-too-distant future, sensors will be ubiquitous in buildings, gathering data about the environment and building users. Building components will be intelligent and interactive. Nanosensors and nano building materials raise questions for building designers, builders, owners and users. What will the consequences be as buildings become increasingly intelligent and nanomaterials become an everyday part of the buildings that surround us?
Particulate nanocarriers have been praised for their advantageous drug delivery properties in the lung, such as avoidance of macrophage clearance mechanisms and long residence times. However, instilled non-biodegradable polystyrene nanospheres with small diameters and thus large surface areas have been shown to induce pulmonary inflammation. New evidence suggests that biodegradable polymeric nanoparticles designed for pulmonary drug delivery may not induce the same inflammatory response as non-biodegradable polystyrene particles of comparable size.
Carbon nanomaterials have been studied as superior sorbents for their potential environmental applications to remove pollutants such as organic pollutants, metals, fluorides and radionuclides. Most of these studies focused on the adsorption process and few dealt with the interfacial interactions of organic contaminants with carbon nanomaterials in aqueous media. However, understanding their desorption behavior as well is critical to evaluating environmental and health impacts of carbon nanomaterials. New research looks at the high adsorption capacity and reversible adsorption of PAHs (polycyclic aromatic hydrocarbons), many of which are suspected carcinogens, on CNTs. The findings imply the potential release of PAHs if PAH-adsorbed CNTs are inhaled by animals and humans, leading to a high environmental and public health risk.
A new study by Swedish researchers shows that gold nano spheres with a diameter of 7 nm, produced in a conventional laboratory surrounding, activate human antigen presenting dendritic cells (DCs) to induce proliferation of peripheral blood mononuclear cells (PBMC), mixed with either allergenic or autologous DCs. This effect was found to be due to endotoxin (lipopolysaccharide, LPS) contamination of the nanoparticles. When particles were produced in a controlled way eliminating endotoxin contamination, the activation of the DCs did not take place.
The use of nanoparticles in sunscreens is one of the most common uses of nanotechnology in consumer products. Well over 300 sunscreens on the market today contain zinc oxide or titanium oxide nanoparticles.
A new toxicological study of carbon nanotubes (CNTs) doped with nitrogen found clear differences in the toxicological aspects and biocompatibility compared to multiwalled or singlewalled CNTs, indicating that they might be more advantageous for bioapplications.
Addressing the potential hazards associated with nanomaterials requires a comprehensive approach to gaining, collecting and publishing knowledge about individual nanomaterials. Expanding MSDS (Material Safety Data Sheets) into nMSDS for nanomaterials could be a way to accomplish this.