In the test tube at left, exposed to sunlight, single-walled carbon nanotubes have settled out of solution; at right is a control sample that was not exposed to light. (Photograph from study)
By David Funkhouser
A new study has found sunlight may help break down carbon nanotubes—but also suggests the products of the photochemical reaction could be toxic to aquatic organisms.
“This study is one of the first to address whether [carbon nanotubes] undergo reactions in the environment,” said environmental engineer Chad Jafvert of Purdue University, one of the researchers. He said exposure to sunlight seems to produce highly reactive oxygen molecules that could degrade the carbon nanotubes; but those same molecules also are known to damage cells and DNA.
The results mirror the complexity of the effort to understand how manufactured nanoparticles—materials measured in billionths of a meter—might affect the environment and human health.
The growing use of nanomaterials in hundreds of industrial and consumer products, and their huge potential in medicine, electronics, energy and other fields, have lent urgency to that effort. Scientists are concerned about what happens to these substances when workers and consumers are exposed to them, and when they enter the environment.
Because of their tiny size, the materials can take on extraordinary properties. Carbon nanotubes, for instance, can be lighter and stronger than steel and are already used to make bicycles, tennis racquets, car bumpers and other products.
When Wisconsin lawmaker Terese Berceau first learned about nanomaterials a few years ago, she found there were many nano-based products on the market, but little research into their possible health effects. “The horse was already out of the barn,” she said, but she found it hard to get anyone interested. “It is a difficult subject to get people feeling that, ‘Geez, we should do something now.’ ”
But she worked at it, and her concern has paid off. The Wisconsin legislature just set up a study committee to gather information about nanotechnology and consider the policy implications. Berceau hopes that will lead to a registry, so health and environmental officials can track how the materials are being used, and how manufacturers and researchers are disposing of them.
Wisconsin is one of the first states to undertake this effort. Nano-enhanced consumer, environmental and health products have spawned a red-hot industry. Across the country, the use of nanomaterials—substances manufactured on a tiny scale, measured in billionths of a meter—is largely unmonitored and unregulated. Nanotechnology manipulates matter on a near-atomic scale in order to develop nanomaterials with surprising new properties, such as strength and super-conductivity. The results have ranged from super-strong sunscreen and bicycle frames to life-saving drugs.
“If we’ve learned anything from the BP oil spill [in the Gulf of Mexico], it’s that you should have a plan, that you shouldn’t just hope that nothing bad happens. You should have a plan so you don’t have serious consequences for public or environmental health,” Berceau said.
By David Funkhouser
New Haven Independent (originally posted July 29, 2010)
You may already be carrying quantum dots, carbon nanotubes and nano-silver around in your pocket: They’re all around us, part of a new industrial revolution that feeds a market for products like cell phones and bug-repellent clothing that could reach $2.6 trillion worldwide by 2015.
The federal government is trying to drive this runaway train with one hand on the throttle and another on the brakes. One agency is calling for a greater push to get nano-based products to market, while another says the government needs to put more emphasis on developing health and environmental standards.
A new General Accounting Office study laments the lack of information about the properties of nanomaterials and their potential risks and toxicity to the environment and human health. The report urges the federal Environmental Protection Agency (EPA) to move ahead with plans to gather information about how nanomaterials are being used in manufacturing, and to treat nanomaterials as essentially new chemicals that would require more extensive analysis than materials already in use.
By David Funkhouser — June 23, 2010
Nanotechnology may be an “emerging” science, but we’re already slathering its products on our skin, wearing them to go hiking and ingesting them in medicines and food. With more than 1,000 consumer items using nanomaterials already out there, a new California study urges government to take action to find out which ones might be dangerous and start getting them under control.
“We must determine the toxicity of molecules and nano particles before the public and workforce are exposed; otherwise citizens become experimental subjects,” said Carl Cranor, a professor at the University of California at Riverside and a member of the study’s science advisory panel.
The report, prepared by the University of California/San Francisco’s Program on Reproductive Health and the Environment, recommends that state agencies try to speed up the regulatory process, and look at whether they can act under existing policies to put curbs on some materials, rather than waiting for new legislation.
By David Funkhouser — June 8, 2010
A Connecticut company that makes a line of what it labels “green” products for auto and marine use says it has just the thing for cleaning up the Gulf oil spill: A nanotech-based, biodegradable oil dispersant.
But a number of scientists and environmental groups are warning that the firm’s marine oil dispersant relies on nanoparticles in an untested formulation that could cause more harm than good.
Green Earth Technologies’ oil dispersant uses a detergent based on plant-based oils and other unspecified compounds.
Stamford-based Green Earth Technologies defends its products as harmless, and says a protest letter sent to the U.S. Environmental Protection Agency by environmental groups has unfairly characterized the company’s dispersant. The EPA, which has been flooded by suggestions for using various products, has basically told the company to get in line along with other companies proposing Gulf solutions.
“This company may be right on, we don’t know that,” said Penny Vlahos, assistant professor of marine science and chemistry at the University of Connecticut at Avery Point in Groton. “It’s good someone is asking questions, and it’s good they have to defend themselves.”
Millions of gallons of oil have gushed into the sea in the seven weeks since the Deepwater Horizon oil rig exploded in the Gulf of Mexico, uncorking a well a mile below the surface. Efforts to fight the spill have included spreading more than a million gallons of oil dispersant.
Vlahos and two UConn colleagues are just back from a one-day conference in Baton Rouge at which 200 scientists in ocean and coastal research consulted with federal officials engaged in the oil cleanup. Vlahos described the Gulf crisis as “a bit of a feeding frenzy” for companies trying to promote their products and techniques for environmental cleanup.