Drzal peers through a model of a carbon molecule. Photo by G.L. Kohuth.
In October 2010 the National Organic Standards Board recommended that engineered nanomaterials (ENMs) be banned from food that carries the U.S. Department of Agriculture’s Organic label. Health concerns raised by researchers, environmental agencies and regular citizens prompted the recommendation.
WHAT IS A NANOMATERIAL?
A nanomaterial is a material having at least one dimension 100 nanometres or less (NICNAS). To put nanomaterials into perspective, up to 10,000 could fit across a human hair. Synthetic development of nanomaterials began in the 1980s. Today thousands of ENMs are manufactured in a variety of shapes and sizes for use in a wide range of products and industrial processes. ENMs are being used to improve texture, taste, nutrition, shelf life, and safety.
WHICH PRODUCTS CONTAIN ENMs?
Clothing, sunscreens, cosmetics, sporting equipment, batteries, food packaging, dietary supplements, and electronics are some of the goods on the market that contain nanotechnology.
xGnP Exfoliated Graphite NanoPlatelets are one of the most recent advanced creations. An electrically and thermally conductive nanomaterial that has reduced flammability and barrier properties will be used for applications in the aerospace, automotive and packaging industries, said Lawrence Drzal, University Distinguished Professor of chemical engineering and materials science at MSU and director of MSU’s Composite Materials and Structure Center.
Salad dressings may also contain nanoscale oil droplets intended to slow the separation of ingredients and fruits and vegetables may carry a coating of nanoscale wax droplets. As of 2007, the National Science Foundation estimated that up to $70 billion worth of nanotechnology-enabled products were sold in the United States every year.
There haven’t been any confirmed cases of human illness or death resulting from ENMs, but researchers and environmental advocates have warned that there must be more caution around ENMs and their consequences or we could risk another asbestos disaster. Experts say that for consumers, the greatest exposure could come from products that are eaten or come into contact with the body, through things like dietary supplements, food, and personal care products.
Many sunscreens include titanium dioxide or zinc oxide nanoparticles because they block ultraviolet light while letting the sunscreen be transparent when rubbed onto the skin, according to the Environmental Working Group (EWG). There is a danger to health only if the nanomaterials penetrate the skin. The EWG suggests that the risk of ultraviolet radiation damage from not wearing sunscreen outweighs the risk of harm from nanoparticles.
Some studies have indicated that titanium dioxide and zinc oxide nanoparticles can harm algae, water fleas, and frogs, and that they can travel up the aquatic food chain. A 2009 study from the University of California, Los Angeles, found that when mice are given certain kinds of titanium dioxide nanoparticles with their drinking water for 5 days, they suffer from DNA and chromosomal damage and inflammation. Other studies have suggested that some types of both titanium dioxide and zinc oxide nanoparticles are toxic to the human brain and lung cells.
Food wise, the majority of the tests done on exposure nanoparticles have looked at exposure through inhalation or injection. There are practically no studies on ingestion, and there is little research into the effects of long-term exposure to ENMs. Manufacturers are not required to label products containing ENMs, and in some cases manufacturers only print the name of the chemical without stating whether it’s at the nanoscale or not.
Experts state that many ENMs pose challenges to researchers because of the restricted ability to detect them when they are in cells and tissues. It is difficult to image materials smaller than 50 nanometres inside the human body.
The Environmental Protection Agency announced it had given $5.5 million to different companies to support health and safety research on ENMs. The research is aimed at determining whether certain nanomaterials can leach out of products such as paints, plastics, and fabrics and whether they could become toxic to people and the environment. Researchers are looking into the emerging field of green nanotechnology as a way to make ENMs and their production processes safer for people and the environment.
A database of nanotechnology-based consumer products is available online at the NanotechProject.org.