Tracking the ecological impact of nanotechnology
Scientists are still uncovering the potential uses for nanotechnology. Just this month, researchers have reported on nanotechnology’s potential to eradicate cancer cells and blood diseases, desalinate seawater on the go and convert environmental energy waste to hydrogen fuel. With new research arising daily, it seems nanotechnology could have many applications in medicine and alternative energy.
Take, for example, the recent development of skin care products laced with nanomaterials. As described in a press release earlier this month, gold nanoshells, which with other nanomaterial products are currently banned by the Food and Drug Administration while awaiting a safety ruling, could be used to treat melanoma:
[G]old nanoshells can be engineered to absorb specific wavelengths of light. If the wavelength of light unique to a particular type of gold nanoshell is used on it, the particle generates heat. In one animal study done at MD Anderson Cancer Center in Houston, investigators joined gold nanoshells with a molecule which homes to melanoma. When these gold nanoshells are injected into mice harboring melanoma, the nanoshells accumulate in the cancerous tissue. When mice are illuminated with the proper wavelength of light, their tumors, laden with gold nanoshells, heat up and are effectively killed. The surrounding tissue, which lacks targeted gold nanoshells, is unharmed.
However, the side effects and environmental impact of these altered materials remain under-researched. In general, introducing a new material into the environment—engineered or not—will affect ecosystems. Omowunmi Sadik, director of Binghampton University’s Center for Advanced Sensors and Environmental Systems, cites the example of silver nanoparticles, which are used to coat materials ranging from cookware to laundry liquids. Socks that are laced with silver nanoparticles for their antibacterial and deodorant properties are eventually washed in the laundry, and some of the particles are flushed into waterways.
The biggest problem with these tiny particles—they range in size from 1 to 100 nanometers—is locating them in water, soil and the atmosphere. Current methods of analyzing nanoparticles rely on bulky, hard-to-move microscopes that are unable to provide information on the toxicity of the materials. Sadik and colleagues, with support from the U.S. Environmental Protection Agency, are designing and testing sensors that could replace these microscopes as the primary means for detecting nanoparticles in the environment.
The researchers designed a membrane composed of cyclodextrin, a compound with a molecular structure resembling a tiny cup. The material would be able to not only monitor nanoparticle levels but capture those and other pollutants as well. As Sadik says in a press release:
Society has a duty to not only consider the positive sides of science and technology but also the not-so-desirable sides of technology itself. We need to think not just about how to make these nanoparticles but also about their impact on human health and the environment. We need to understand the chemical transformation of these materials in the ecosystem so we can take action to prevent unnecessary exposure.