(NHI Nanoblog) California’s Department of Toxic Substances Control is asking in-state nanotechnology companies and researchers to share how they’re keeping tabs on several nano-sized metals, as evidence continues to emerge that these substances might have long-term implications for the environment.
Late last month, the DTSC put out a request for information about nano-sized silver, zero valent iron, titanium dioxide, zinc oxide, cerium oxide and quantum dots.
Specifically, the agency wants to know what tools companies and researchers are using to analyze these materials — a key question for regulators across the country in the effort to understand the impact of the substances — over a broad range of areas, including air, water, soil, sewage sludge and urine.
Nanotechnology, which capitalizes on the often amazingly useful properties of super-small particles, is already in use in manufacturing items like bike frames, skin creams and cancer treatments. As these tiny materials hit the market, there are huge gaps in what scientists know about their properties.
Jeffrey Wong, DTSC’s chief scientist, said in an interview that his agency’s call for information — its second such request, after a similar move involving carbon nanotubes two years ago — is aimed at informing consumers. California, with its concentration of high-tech companies, is a hotbed for nanotechnology, he said, and the DTSC wants to push as much information into the public sphere as possible.
The basic question the agency is asking, Wong said, is “what do you know about your materials?”
Several of the metals, such as nanosilver and titanium dioxide, are of interest because they’re being used in consumer products. Nanosilver, for example, is used as an antibacterial agent in athletic clothing, while titanium dioxide is in some sunscreens. Wong said they’re considered safe for people, but less is known about what happens after that.
“The issue becomes, is it safe for the environment as everybody begins to use it and take a shower and washes it down the drain?” Wong said.
Some studies have shown that these materials are turning up in end-stage sewage sludge, raising questions about long-term problems.
Other materials on the list are even closer to the water supply, Wong said: zero valent iron is being used as an ingredient in efforts to clean up polluted groundwater.
“The wastewater agencies have no clue” how to measure the amount of these metals, or what to do to get them out if they do pose a hazard, Wong said.
DTSC chose these metals, and to query companies about their analytical techniques, because this inquiry doesn’t duplicate the work being done by federal agencies, such as the U.S. Environmental Protection Agency and the National Institute for Occupational Safety and Health, which are examining other parts of the nanotoxicity puzzle, Wong said.
There’s a lot of focus on toxicity — that is, whether these materials pose a threat to people, animals and the environment — but less on how to measure the substances themselves, he said.
“It seems as if nobody’s working on the analytical part, and nobody’s working on the exposure end,” Wong said.
The request is a chance for DTSC to pull the state’s “stakeholders,” including manufacturers, government agencies and universities, together to expand the information pool, Wong said. While it’s not regulation, he added, it does put those working with these nanometals on notice that the state does expect them to be cognizant of California’s environmental laws as lab discoveries move into the marketplace.
“This is a signal to them that at some point in time, we are going to ask them for a solution, because this is their responsibility,” Wong said.
