There is an urgent need to better understand and address the potential health and safety implications of nanotechnology, the design and manipulation of materials at the molecular and atomic scale. This need is demonstrated by
Several reviews of toxicity issues of nanotechnology that highlight the lack of basic understanding of the potential risks of these novel materials (which are often called "nanomaterials").1
Documentation of more than 200 products containing nanomaterials already on the market, including at least 70 used in ways that lead directly to human exposure.2
Numerous national and international efforts to establish standards and appropriate controls for nanotechnology, including those organized by the U.S. Environmental Protection Agency, the International Standards Organization, and ASTM International, which must be informed by the best available science.
Nanotechnology is one of the most exciting fields in high technology, one that could revolutionize the way our society manufactures products, produces energy, and treats diseases. Numerous societal benefits will potentially result from the safe development of nanotechnology. Safe development and public acceptance of beneficial products will depend on a thorough investigation of the potential risks of nanomaterials.
Although the field is still in its infancy, it is growing steadily, with well over 200 products already on the market.3 This rapid growth in potential consumer, worker, and general population exposures underscores the need to institute timely control measures and ramp up research efforts to evaluate potential risks.
The few studies now available on nanomaterials give cause for concern: some nanomaterials- particularly single-walled carbon nanotubes, cadmium-selenide quantum dots, and fullerenes- have potential to damage skin, brain, and lung tissue, and to be mobile or persistent in the environment. For example, studies strongly suggest that some nanoparticles can, when inhaled, penetrate deep into the lung, where they can cause tissue damage or cross into the circulatory system. Another study has documented that after deposition in the nasal passages, nano titanium dioxide particles can be taken up by the olfactory nerve directly into brain cells, bypassing the blood-brain barrier.5 Separate studies on fish also suggest that buckyballs can be transported to the brain, with resulting oxidative damage.6
Some of these initial studies have yielded unexpected results. For example, while individual buckyballs (spheres composed of 60 carbon atoms) do not dissolve well in water, one recent study found that they can cluster together to form aggregates that are both very water-soluble and bactericidal.7 Given that bacteria constitute the bottom of the food chain, this finding raises strong concerns about ecosystem impacts.
The potential of dusts of various chemical substances to explode is well established, with numerous examples of injuries and fatalities in industrial settings. While the chemical properties and surface areas of dusts are known to be a factor in the explosivity of dusts, there have been no published studies of the explosivity of nanomaterials (even for those compounds which are known to form explosive dust clouds of micron-sized particles). Given that some physical properties of compounds in their nanomaterial state can differ from those for larger particles of those compounds, the Health and Safety Laboratory of the UK Health and Safety Executive has recommended that the explosivity of nanomaterials be made a research priority.8
The growth of products on the market means that a growing number of workers are potentially being exposed to nanomaterials. Exposure monitoring and worker protection are more complex with nanomaterials than with conventional chemicals. Improved understanding of nanomaterial toxicity, as well as improved instrumentation for monitoring and controls, are urgently required to assure workers are not being harmed by their exposures.
While industry, academic, and government scientists continue to extensively research nanotechnology's potential applications in a wide variety of fields, such as groundwater cleanup and cancer therapy, research on nanotechnology's potential health and environmental implications has fallen behind. Through the National Nanotechnology Initiative, the federal government currently spends more than $1 billion annually on nanotechnology R&D.9 Of this amount, environmental and health implications research accounted for only $8.5 million (less than 1 percent) in FY 2004.10 This funding is expected to increase to only $38.5 million (less than 4 percent) in FY 2006. 9
With increased federal funding, scientists could begin to develop an adequate understanding of the potential risks posed by nanomaterials, allowing society to address these risks while these materials are still in an early stage of development and commercialization. Doing so would help avoid repeating problems such as those that arose with asbestos, leaded gasoline and paint, and other materials that were commercially produced and widely distributed without an adequate understanding of their risks.
Accounting for funding dedicated to health and environmental implications research should not be commingled with that for health and environmental applications. For example, use of nanomaterials to enhance drug delivery to target organs is an application, as is use of nano-scale iron for groundwater remediation. Failure to distinguish between funding levels for implications research as contrasted with applications research is likely to lead to continued under-investment in the former.
In December 2004, EPA's Science Policy Council created a workgroup to "identify the issues EPA must address to ensure protection of human health and the environment as nanotechnology is developed." The workgroup, which included members from the Office of Research and Development and the Office of Prevention, Pesticides and Toxic Substances, produced the Nanotechnology White Paper in December 2005. This external review draft discusses the potential benefits of nanotechnology; outlines a plan for managing risk; makes recommendations to the EPA for generating more research on applications/implications; and calls on the agency to develop approaches to good product stewardship in the various nanotechnology industries.11
In October 2005, the National Institute for Occupational Safety and Health developed Approaches to Safe Nanotechnology: An Information Exchange with NIOSH.12 This document describes ways in which workplace exposures to nanomaterials may be harmful, provides guidance for reducing such exposures, and identifies future research needs.
APHA urges:
