Nanoparticles could be a big problem
Nanotechnology was supposed to revolutionize the world, making us healthier and producing cleaner energy. But it’s starting to look more like a nightmare.
Nanomaterials—tiny particles as little as 1/100,000 the width of a human hair—have quietly been used since the 1990s in hundreds of everyday products, everything from food to baby bottles, pills, beer cans, computer keyboards, skin creams, shampoo, and clothes.
But after years of virtually unregulated use, scientists are now starting to say the most commonly used nanoproducts could be harming our health and the environment.
One of the most widespread nanoproducts is titanium dioxide. More than 5,000 tonnes of it are produced worldwide each year for use in food, toothpaste, cosmetics, paint, and paper (as a colouring agent), in medication and vitamin capsules (as a nonmedicinal filler), and in most sunscreens (for its anti-UV properties).
In food, titanium-dioxide nanoparticles are used as a whitener and brightener in confectionary products, cheeses, and sauces. Other nanoparticles are employed in flavourings and “nutritional” additives, and to reduce fat content in “health” foods.
In the journal Cancer Research in 2009, environmental-health professor Robert Schiestl coauthored the first comprehensive study of how titanium-dioxide nanoparticles affect the genes of live animals. Mice in his study suffered DNA and chromosomal damage after drinking water with the nanoparticles for five days.
“It should be removed from food and drugs, and there’s definitely no reason for it in cosmetic products,” said cancer specialist Schiestl, who is also a professor of pathology and radiation oncology at UCLA’s school of medicine.
“The study shows effects [from the nanoparticles] on all kinds of genetic endpoints,” Schiestl told the Georgia Straight in a phone interview from his office. “All those are precursor effects of cancer. It’s a wake-up call to do something.”
After Schiestl’s study came out, he said, he started getting calls from nervous people saying they had discovered titanium dioxide was listed as a nonmedicinal ingredient in their prescription medication. “They wanted to know how to get it out,” he said. “I said, ”˜I don’t know how to get it out.’ ”
Schiestl’s study is cited by groups like Greenpeace and Friends of the Earth in their calls for a moratorium on nanomaterials in food and consumer products.
“They were thought to be safe. Our study shows a lot of harm,” Schiestl said.
Nanoparticles can be harmful because they are so tiny they can pass deep into the skin, lungs, and blood. They are made by burning or crushing regular substances like titanium, silver, or iron until they turn into an ultrafine dust, which is used as a coating on, or ingredient in, various products.
Schiestl is now studying two other common nanoparticles, zinc oxide and cadmium oxide, and he has found they also cause DNA and chromosomal damage in mice.
Yet two years after Schiestl’s first study, titanium dioxide and other nanoparticles remain virtually unregulated in Canada and the U.S. Products containing nanoparticles still don’t have to be labelled, and manufacturers don’t have to prove they are safe for health or the environment.
In fact, only a small fraction of the hundreds of nanomaterials on the market have been studied to see if they are safe.
“The public has had little or no say on this. It’s mostly industry guiding government to make sure this material isn’t regulated,” said Ian Illuminato, a nanotech expert with Friends of the Earth, speaking from his home office in Victoria.
“Consumers aren’t given the right to avoid this. We think it’s dangerous and shouldn’t be in contact with the public and the environment,” he said.
Meanwhile, the number of products using nanomaterials worldwide has shot up sixfold in just a couple of years, from 212 in 2006 to more than 1,300 in 2011, according to a report in March by the Washington, D.C.–based Project on Emerging Nanotechnologies.
Those numbers are based on self-reporting by industry, and the real numbers are thought to be much higher. A Canadian government survey in 2009 found 1,600 nanoproducts available here, according to a report in December from the ETC Group, an Ottawa-based nonprofit that studies technology.
Nanotech is worth big money. More than $250 billion of nano-enabled products were produced globally in 2009, according to Lux Research, a Boston-based technology consultancy. That figure is expected to rise 10-fold, to $2.5 trillion, by 2015.
Lux Research estimated in 2006 that one-sixth of manufactured output would be based on nanotechnology by 2014.
Nanotech already appears to be affecting people’s health. In 2009, two Chinese factory workers died and another five were seriously injured in a plant that made paint containing nanoparticles.
The seven young female workers developed lung disease and rashes on their face and arms. Nanoparticles were found deep in the workers’ lungs.
“These cases arouse concern that long-term exposure to some nanoparticles without protective measures may be related to serious damage to human lungs,” wrote Chinese medical researchers in a 2009 study on the incident in the European Respiratory Journal.
When inhaled, some types of nanoparticles have been shown to act like asbestos, inflaming lung tissue and leading to cancer. In 2009, the World Health Organization’s International Agency for Cancer Research declared titanium dioxide to be “possibly carcinogenic to humans” after studies found that inhaling it in nanoparticle form caused rats to develop lung cancer and mice to suffer organ damage.
Nanoparticles can also hurt the skin. All those nanoparticles in skin creams and sunscreens may be behind a rise in eczema rates in the developed world, according to a 2009 study in the journal Experimental Biology and Medicine. The study found that titanium-dioxide nanoparticles caused mice to develop eczema. The nanoparticles “can play a significant role in the initiation and/or progression of skin diseases”, the study said.
Schiestl said nanoparticles could also be helping to fuel a rise in the rates of some cancers. He wouldn’t make a link with any specific kind of cancer, but data from the U.S. National Cancer Institute show that kidney and renal-pelvis cancer rates rose 24 percent between 2000 and 2007 in the U.S., while the rates for melanoma of the skin went up 29 percent and thyroid cancer rose 54 percent.
Schiestl said workers who deal with nanoparticles could be the most affected. That concern prompted the International Union of Food, Farm, and Hotel Workers to call in 2007 for a moratorium on commercial uses of nanotechnology in food and agriculture.
But despite all the health risks, we may already have run out of time to determine many of nanotech’s health impacts, Schiestl said.
“Nanomaterial is so ubiquitous that it would be very difficult to do an epidemiological study because there would be no control group of people who don’t use it.”
What happens when nanoparticles get out into the environment in wastewater or when products are thrown out?
Nanosilver is the most common nanomaterial on the market. Its extraordinary antimicrobial properties have earned it a place in a huge variety of products, including baby pacifiers, toothpaste, condoms, clothes, and cutting boards.
Virginia Walker, a biology professor at Queen’s University in Kingston, Ontario, decided to study nanosilver one day after a grad student said her mother had bought a new washing machine that doused clothes with silver nanoparticles to clean them better.
It sounded intriguing, Walker recalled thinking, but what would happen if nanosilver in the laundry water wound up in the environment? “What would it do to the bacterial communities out there?” she wondered.
On a whim, Walker decided to study the question. She figured the nanosilver would probably have no impact on beneficial microbes in the environment because any toxicity would be diluted.
“I did the experiment almost as a lark, not expecting to find anything,” she said by phone. “I hoped I would not find anything.”
In fact, Walker found that nanosilver was “highly toxic” to soil bacteria. It was especially toxic to one kind of nitrogen-fixing bacterium that is important to plant growth.
“If you had anything that was sensitive to nanoparticles, the last thing you would want is to have this microbe affected,” Walker said in a phone interview from her office.
The study prompted Walker to do more studies on nanoparticles. In one study now being reviewed for publication, one of her students found that mice exposed to nanoparticles developed skeletal abnormalities.
“People should have their eyes open. There are so many different nanoparticles, and the consequences of their use could be grave. We know almost nothing about these things,” Walker said.
Other scientists have raised concerns about nanosilver too. Some clothes makers now put it in socks and shirts, promising it will help control body odour. In a 2008 study in the Washington, D.C.–based journal Environmental Science and Technology, researchers took nanosilver-laced socks and washed them in water. They found the socks released up to half of their nanosilver into the water.
“If you start releasing ionic silver, it is detrimental to all aquatic biota. Once the silver ions get into the gills of fish, it’s a pretty efficient killer,” said study coauthor Troy Benn, a graduate student at Arizona State University, in a ScienceDaily.com story in 2008.
“I’ve spoken with a lot of people who don’t necessarily know what nanotechnology is, but they are out there buying products with nanoparticles in them.”
And what about the promise that nanotech could produce cleaner energy? The idea was that nanoparticles could make solar panels more efficient, be used as fuel additives to improve gas mileage, and make lighter cars and planes.
Most of the promised efficiency gains haven’t materialized, according to a 2010 report from Friends of the Earth. And it turns out that making nanomaterial is itself a huge energy guzzler.
A kilogram of carbon nanotubes—a nanoparticle used in cancer treatment and to strengthen sports equipment—requires an estimated 167 barrels of oil to produce, the Friends of the Earth report said.
Carbon nanotubes are “one of the most energy intensive materials known to humankind”, said a 2010 report to a symposium of the U.S.–based Institute of Electrical and Electronics Engineers.
That report said many nanoproducts may remain profitable despite their high energy cost only because of enormous government subsidies to the nanotech industry—$1.6 billion from the U.S. government last year.
But despite all this, regulation of nanotech remains glacially slow. The European Parliament voted nearly unanimously to recommend that nanoproducts be banned from food in 2009. But the European Commission rejected that recommendation last year, agreeing only that it may require labels on food containing nanomaterials. It will also require labels on cosmetics containing some nanoingredients starting in 2014.
Canada and the U.S. have yet to go even that far. At Health Canada, which regulates nanotechnology, a web page dealing with nanoproducts hasn’t been amended in four years and contains outdated information.
Health Canada spokesman Stéphane Shank did not return calls.
They used to say small is beautiful. But that was before small got scary.