ASU nanoparticle expert uses research to move society past fear

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February 14, 2017

Newly named Regents’ Professor Paul Westerhoff is part of an initiative to harness the tiny specs to purify water

When people find out there are invisible particles in their food or water, they become alarmed.

Arizona State University professor Paul Westerhoff has dedicated his career to producing research that answers people’s questions and moves them past fear.

“The things I do are not from a scare-mongering point of view, but trying to answer objective engineering questions,” said Westerhoff, a professor of in the School of Sustainable Engineering and the Built Environment at ASU.

Westerhoff, an environmental engineer, has been named one of three Regents’ Professors for the 2016-2017 academic year. Regents’ Professor is the highest faculty honor and is conferred on full professors who have made remarkable achievements that have brought them national attention and international distinction.

An expert in nanoparticles, Westerhoff started working on the tiny specks even before they had a name. As a graduate student, he worked on water filtration.

“At that time we talked about these things called ‘sub-micron particles,’ which we couldn’t measure very well but we did a bunch of experiments with them anyway,” he said.

A few years later, when the term “nano” was becoming popular, he realized he had already done it.

“So I put in my first proposal, and it got funded because I was one of the first people who had data!”

Now, he focuses on using nanoparticles to treat and purify water, an interest that was piqued by a hydrology class he took as an undergraduate.

“I understand water,” he said. “I like fishing and swimming and kayaking, and I can go to a river and not only understand the hydrology. But I know why the water is a certain color. And I know where it came from. And I know all the fish that live in it.”

From his first studies, he saw the trajectory of public perception about invisible and unknown substances in the environment, and how that could influence his research.

“In the environmental world, initially it’s like the world’s going to end. But what I’ve learned is that these things move through predictable trends,” he said, using as an example “Silent Spring,” a 1962 book by conservationist Rachel Carson that documented the effects of the use of pesticides, including DDT.

“It’s in this early stage that people are scared, while the agriculture industry and pesticide industry responded by saying that they save millions of lives. In the first few years there’s a lot of uncertainty,” he said.

“Then researchers come along and help reduce that uncertainty.

“Then there’s another phase where politics come in, and there are cost decisions and people think about regulations and finding alternatives,” he said.

“We still find DDT in the environment, but it’s regulated and people really aren’t scared of it. It’s like a 20-year cycle.”

Westerhoff said the key is to know which phase is coming next.

“As a researcher you want to be focusing on what will be the important question to answer in three to five years, before people even know it’s a question,” he said.

“In nano, we were ahead of the game in thinking, ‘Maybe this isn’t so bad, maybe we can use it.’”

Now he’s deputy director of the Nanotechnology Enabled Water Treatment Systems Center, which is focused on developing compact, mobile, off-grid systems that can provide clean water to millions of people who lack it.

Many of Westerhoff’s research projects have been funded by agencies such as the National Science Foundation and the Environmental Protection Agency, but he also works with water utilities, non-governmental organizations and industry partners.

“Industry wants to know the answers to things. It’s moved out of the scientific ‘what if’ toward reality,” he said. “They all have agendas and as long as you understand their agendas, they ask interesting questions.”

“As a researcher you want to be focusing on what will be the important question to answer in three to five years, before people even know it’s a question.”

— Regents’ Professor Paul Westerhoff

Westerhoff was commissioned by the environmental activist group Friends of the Earth to see whether there were nanoparticles in powdered infant formula after the manufacturer declined to reveal whether there were.

His lab found needle-shaped nanoparticles in the formula.

“In Europe, there’s a warning on their use in cosmetics but yet they’re in infant formula,” he said.

They discovered the nanoparticles did not dissolve in either water or saliva, but when they put them in stomach fluid, they dissolved instantly.

“They did it to deliver calcium to the gut very efficiently, so they didn’t have to use as much,” he said of the manufacturer. Friends of Earth was concerned that the formula labels didn’t disclose the presences of nanoparticles.

“That’s an example of where one group sees something as a risk to society but a company sees it as a benefit.”

He’s also seen the evolution of how scientific research is portrayed in the media. In 2008, he supervised a doctoral student on a research project that studied the use of nanosilver in socks to eliminate stinky feet. They wanted to know: Did the particles wash out of the socks and into the water supply? The answer was yes.

Journalists jumped all over the story. One headline read, “Toxic socks?”

“We kept telling them the amount of silver is very small and won’t affect anything. None of them got it, and everything they wrote was over the top,” Westerhoff said. “They don’t want to hear that ‘everything is safe, there’s no problem.’ They want to hear ‘there’s nanoparticles in donuts.’ “

In 2015, Westerhoff was named an Outstanding Doctoral Mentor by ASU’s Graduate College. His former students said he is able to deftly balance the guidance that students crave with the independence they need to cultivate.

Troy Benn, who worked with Westerhoff on the nanosilver paper and is now an engineer in Montana, said: “For a young kid it was a little bit shocking because you do all your research in a lab and you don’t talk to anyone outside, and all of a sudden people are asking you what you did.

“Paul’s good at knowing how much guidance each student needs because they’re all unique.”

Kyle Doudrick, who was a graduate student at ASU from 2008 to 2013, said that even with the enormous workload of a full professor, including travel, plus the administrative duties of a vice provost, Westerhoff found time to meet weekly with the students he advised.

“It was a good balance of managing but also letting you find yourself in your independence but not so hands off that you had no idea what’s going on,” said Doudrick, who is now an assistant professor in the Department of Civil and Environmental Engineering and Earth Sciences at the University of Notre Dame.

“The research I did was on nitrate as a contaminant in water,” he said. “He wasn’t the expert but what he was good at was making the student the expert, and that’s the whole purpose of the PhD, is to become an expert at something.”

Even now, Westerhoff teaches ASU 101, the required, one-credit course that all first-time freshmen take.

“I ask them why they want to be engineers, and about half have a life story of something they want to solve. They have a deep passion.

“And if you don’t hear that until you see them in grad school, you’ve lost touch with what motivates people.”

Top photo: Newly named Regents’ Professor Paul Westerhoff spends part of every week supervising students in the hydrology lab where his students work in ISTB4. Photo by Anya Magnuson/ASU Now

Mary Beth Faller

Mary Beth Faller

reporter , ASU Now


US EPA Issues Final Nano Reporting Rule Under TSCA

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As part of continued efforts to ensure a more comprehensive understanding of nanoscale materials in commerce, the US Environmental Protection Agency (EPA) has issued a final regulation requiring one-time reporting and recordkeeping of existing exposure and health and safety information on nanoscale chemical substances in commerce pursuant to its authority under Section 8(a) of the Toxic Substances Control Act (TSCA).

This rule requires companies that manufacture (including import) or process certain chemical substances already in commerce as nanoscale materials notify EPA of certain information, including:

  • specific chemical identity;
  • production volume;
  • methods of manufacture;
  • processing, use, exposure and release information; and
  • available health and safety data.

EPA seeks to facilitate innovation while ensuring safety of the substances. The information collection is not intended to conclude that nanoscale materials will to cause harm to human health or the environment. Rather, EPA will use the information gathered to determine if any further action under TSCA, including additional information collection, is needed.

EPA proposed and took comment on this rule. Persons who manufacture or process a reportable chemical substance during the three years prior to the final effective date of this rule must report to EPA within a year of the rule’s publication.

Further information, including the final rule and a fact sheet, is available on the EPA website.

ACS News Service Weekly PressPac: The impact of anti-odor clothing on the environment

ACS News Service Weekly PressPac: March 30, 2016 (CLICK HERE)

The impact of anti-odor clothing on the environment

Potential Environmental Impacts and Antimicrobial Efficacy of Silver- and Nanosilver-Containing Textiles
Environmental Science & Technology

Anti-odor athletic clothes containing silver nanoparticles have gained a foothold among exercise buffs, but questions have arisen over how safe and effective they are. Now scientists report in ACS’ journal Environmental Science & Technologythat silver nanoparticles and coatings do wash off of commercially available garments in the laundry but at negligible levels. They also found that even low concentrations of silver on clothing kept microbes at bay.

Thanks to their antimicrobial properties, silver nanoparticles are found in an increasing array of products such as food packaging, bandages and textiles. At the same time, scientists have been studying the possible effects silver nanoparticles might have on the environment and human health. Studies have shown that the particles can be toxic, but their safety is dependent on a number of factors such as size and dose. Few studies, however, have examined both their effectiveness in products and their potential for harm. Paul K. Westerhoff and colleagues wanted to see how the design of antimicrobial clothes affects how well they stand up to washing and their potential to leach silver into the environment.

The researchers tested commercial athletic shirts in which the silver nanoparticles were incorporated in one of four different ways. Washing the shirts released a range of silver concentrations, depending on how the nanoparticles were attached. But overall, the resulting toxicity of the wastewater due to its silver content was negligible to zebrafish embryos — a model animal used in toxicity studies. And after washing, the shirts still retained their antimicrobial effect even if their remaining metal concentration was low. The researchers also say, however, that the remaining silver will leach out over time when the clothes are discarded in landfills. They recommend keeping the initial metal concentration in these products low to help reduce their environmental impact while still maintaining their ability to fight off microbes.

The authors acknowledge funding from the U.S. Environmental Protection Agency.

Nanoparticles in foods raise safety questions – These microadditives enhance color, flavor and freshness. But what do they do in the body?

from SCIENCENEWS – read full article


Nanoparticles in foods raise safety questions

These microadditives enhance color, flavor and freshness. But what do they do in the body?

1:28PM, OCTOBER 16, 2015

NOSHING ON NANO  Nanoparticles can make foods like jawbreaker candies brighter and creamier and keep them fresh longer. But researchers are still in the dark about what the tiny additives do once inside our bodies.


It seemed like a small thing when Paul Westerhoff’s 8-year-old son appeared, with his tongue and lips coated bright white. The boy had just polished off a giant Gobstopper, a confectionery made of sugary, melt-in-the-mouth layers. Curious about the white coating, Westerhoff, an environmental engineer, pored over the jawbreaker’s contents and discovered just how incredibly small the matter was.

Among the Gobstopper’s ingredients were submicroscopic particles of titanium dioxide, a substance commonly added to plastics, paint, cosmetics and sunscreen. At the time, Westerhoff’s lab group at Arizona State University was actively tracking the fate of such particles in municipal wastewater systems across the nation.

Titanium dioxide is also a food additive approved by the U.S. Food and Drug Administration. Ground to teensy particles measuring just tens of billionths of a meter in size — much smaller than a cell or most viruses — titanium dioxide nanoparticles are frequently added to foods to whiten or brighten color.

Weeks after his son’s candy-coated encounter, Westerhoff went to the supermarket, pulled more than 100 products off the shelves and analyzed their contents. His findings, published in 2012 in Environmental Science & Technology, show that many processed foods contain titanium dioxide, much of it in the form of nanoparticles. Candies, cookies, powdered doughnuts and icing were among the products with the highest levels. Titanium dioxide is also found in cheese, cereal and Greek yogurt.

“I began to question why we care about things in the environment — at a few micrograms per liter in water — if we’re freely ingesting these materials,” Westerhoff says.

Titanium dioxide isn’t the only nanoingredient added to food. Various other materials, reduced to the nanoscale, are sprinkled into food or packaging to enhance color, flavor and freshness. A dash of nano will smooth or thicken liquids or extend the shelf life of some products. Scientists have designed nano-sized capsules to slip beneficial nutrients, such as omega-3 fish oil, into juice or mayonnaise, without the fishy taste.

Story continues after diagram

Food scientists aren’t stopping there. They are downsizing the structure of a wide array of ingredients with bold plans to help tackle obesity, malnutrition and other health issues (see “Nanocreativity,” below).

But as scientists cook up ways to create heart-healthy mayo and fat-fighting ice cream, some are also considering the potential risks that might accompany the would-be benefits. Because of their small size, ingested nanoparticles may interact with cells or behave differently than their bulkier counter-parts. So far, less-than-perfect laboratory studies offer contradictory results.

Researchers, including those developing nanofoods, say more information is needed on the ingredients’ potential impacts. Current studies, limited to mice or lab dishes, often analyze megadoses of particles far beyond what any normal diet would include. Scientists need a better handle on what happens when people nosh on nanolaced foods daily, taking in small doses at a time, says Ohio State University pathologist James Waldman. He and others are devising tests to find out.

A pinch of nano

Over the last two decades, nano-sized components — smaller than 100 nanometers — have found their way into a wide range of products: clothing, electronics and cosmetics as well as food. But people have been exposed to, and have inevitably ingested, nanoparticles for much longer, says Andrew Maynard, director of the Arizona State University Risk Innovation Lab in Tempe. Since prehistoric times, people have been consuming nanoparticles found in natural foods such as milk (casein micelles, for example, are nano-sized particles that help calves readily digest their mother’s milk). Nanoparticles also creep into the food supply from environmental sources. Burning wood, oil and coal; wildfires; volcanic activity; and crashing of ocean waves release ultrasmall particles of metal, carbon or silica into the atmosphere and into the food chain.

Even with this long history of nanoparticle exposure, Maynard says, it’s highly unlikely that people had been eating the kinds of particles added to foods today. The distinction is important, he says. “Our bodies have always been exposed to nanoparticles, but they’re now being exposed to different types. We just need to make sure that our bodies can deal with the ones we’re putting in food.”What makes particles different today is not only their size, but also their specificity. The amino acids and proteins that coat a nanoparticle determine its shape and surface properties, which can enhance or reduce the particle’s propensity to bind to certain molecules. By fine-tuning surface features, scientists can control where or how quicklynanoparticles release their contents.

So far, only a few nanoingredients are added directly to foods or packaging: Titanium dioxide, silicon dioxide and zinc oxide are the most common. Larger versions of these ingredients have been used in food and medicines for decades and are considered “generally recognized as safe” by the FDA, which requires that any substance added to food be evaluated for safety.

Unexpected interactions

Scientists have developed numerous ways to test the safety of substances that go into food, but most of the tests were designed decades ago, before ingredients began to go nano. Titanium dioxide, for example, was evaluated in the late 1960s, using particles larger than 100 nanometers. Human cells were exposed to the substance to test for toxic effects and to work out how much of it can be safely consumed.

But those safety tests may not apply to some nano-substances. Size and surface features can improve or impair a nanoparticle’s ability to enter cells. Some nanoparticles — including those considered safe by the FDA — interact with cells in odd or unexpected ways, according to several recent studies.

One study, published in April in the journal Small, examined the effects of silicon dioxide, titanium dioxide and zinc oxide on cells taken from the human intestinal lining. At high doses — higher than most people would ordinarily consume — all three nanoparticle types damaged DNA, proteins and lipids in the cells. Zinc oxide proved to be the most toxic. Lower levels of exposure to nanozinc oxide impaired certain proteins, such as those that help cells repair DNA damage; higher levels of the substance led to cell death.

Though it’s not yet clear if nanoparticles of these types would have toxic effects in the human gut, Gretchen Mahler of Binghamton University in New York says the findings show the difficulty of classifying a particular type of nanoparticle as toxic or safe. Many studies, she says, expose cells to very high levels of nanoparticles, focusing on the effects of a few large exposures or looking for signs of extreme cellular stress or cell death. She questions whether those safety tests are appropriate for nanomaterials.

Mahler’s lab group aims to pin down nanoparticles’ more subtle effects on the intestine using amounts that a person might consume in a single meal or day. Rather than just examining whether the cells exposed to nanoparticles are alive or dead, she evaluates whether they function the same way as unexposed cells.

In a series of experiments, Mahler set out to see what happens in the gut after a steady stream of small doses, the kind you’d get if you were eating nanoparticle-enriched foods daily. Working with scientists at Cornell University and the U.S. Department of Agriculture, she developed a three-dimensional model of the intestinal tract, composed of the various cells that line the human gut. The scientists tracked the effects of polystyrene nanoparticles on the cells and on the intestinal linings of live chickens. Though polystyrene, a polymer, is not used in food products, Mahler says the particles were ideal for testing because they can fluoresce, making them easy to track once swallowed.

The results, published in 2012 in Nature Nanotechnology, showed that small doses of the polystyrene nanoparticles created changes in the fingerlike projections that cover the surfaces of the intestine-lining cells. These tiny structures, called villi, are important for absorbing nutrients. After initial ingestion of nanoparticles, iron absorption dropped by almost 50 percent. But in chickens fed over a period of two weeks, iron absorption rose about 200 percent. Over time, the villi became larger, allowing more iron to enter the bloodstream.

Mahler’s lab used the same approach to study how nanoparticles of titanium dioxide and silicon dioxide influence nutrient absorption in human cells in the lab. Preliminary results from the studies, presented in March at the Society of Toxicology annual meeting in San Diego, indicate that titanium dioxide nanoparticles in the gut change the way iron is absorbed, and silicon dioxide nanoparticles alter zinc absorption. Mahler’s group is working to piece together the mechanism by which these nanoparticles disrupt absorption in the small intestine.

Down the hatch

Most studies of nanoparticles in food focus on the gastrointestinal tract — the mouth, esophagus, stomach and intestines. Waldman’s group at Ohio State is tracking the fate of nanoparticles once they’re swallowed to see if they travel beyond the gut. In February, the researchers showed that nanoparticles force-fed to mice can reach the liver, kidneys, lungs, brain and spleen. Details were published in the International Journal of Nanomedicine.

“Particles are getting into the bloodstream, and once they’re there, they can go to any other organ,” Waldman says.

Fluorescent nanoparticles (green) force-fed to mice found their way beyond the stomach (top) to the kidneys (center) and brain (bottom).


The findings were not entirely a surprise, he says. In earlier research, in animals fed different types of nanoparticles, the particles were later detected in organs. But previous studies relied only on crude methods, removing organs and digesting them in acid to look for the tiny particles.To see where nanoparticles accumulate in live animals, Waldman’s group created a nanoparticle filled with quantum dots that fluoresce (SN: 7/11/15, p. 22). Working with Ohio State chemist Prabir Dutta, Waldman’s group designed particles with outer shells nearly identical to a food-grade nanosilicon dioxide. Because the surface of the particle is what interacts with a cell, the scientists buried the fluorescent molecules inside the silica shell. By doing so, they could ensure that it was silicon dioxide — not the fluorescent tag — interacting with the cell.

The method allowed the scientists to see where the material goes once it enters the body and then count the number of particles actually absorbed. Waldman says that knowing the path that tiny nanoparticles take is essential for settling questions about their potential risk and impact on human health. Scientists need to know, for example, if a particle will be absorbed into the bloodstream and where it will travel. They also need to know if it will stay or be cleared.

Waldman’s group plans to incorporate the fluorescent nanoparticles into the mice’s chow so they consume them regularly in their food. Every few weeks, the scientists will run tests to see where the particles accumulate and assess the animals’ tissues for inflammatory responses and nanoparticle-associated injury. The study will include newly pregnant animals to determine if the particles from food reach cells in the developing fetus.

Chew on this

The FDA has not erected new hoops for food manufacturers that use nanoparticles. Requests to use a food ingredient at the nanometer scale are subject to the same safety requirements applied to other food additives, according to FDA press officer Megan McSeveney. Manufacturers must demonstrate that the substance is safe under the conditions of its intended use.

In June 2014, the agency issued guidelines that go only as far as advising manufacturers to consult with the government before launching nanotechnology products.

So food scientists who are developing futuristic applications are scrambling to assess the safety of their downsized substances. At the University of Massachusetts Amherst, food scientist David Julian McClements is creating nanoparticles using natural ingredients, such as casein micelles from milk or plant proteins, to encapsulate everything from vitamins and antioxidants to omega-3 fatty acids and probiotics.

Once they create a new particle, McClements and colleagues run a gamut of tests to see how the particle reacts in cells in the lab and in mice. Because the nanoparticles he studies are made from ingredients normally found in the human diet, the particles tend to break down during digestion in ways similar to foods. Such particles are expected to be safer than particles made of nonbiodegradable materials, such as titanium dioxide, McClements says. Still, such tests are needed before bringing new foods to the market.

Waldman and Mahler say that to realistically reflect what is happening with people, scientists need to conduct long-term studies, in both animals and people. By feeding animals low doses of a particle over several months’ time, researchers should be able to spot potential problems.

“I would study the animal’s overall health. If something specific is found, then you can zero in on that particular effect, that organ, that system,” Waldman says.

Ultimately, epidemiological studies — designed to track peoples’ intake of nanoparticle-laced foods over extended periods of time — would be most informative, the scientists say. The ideal would be to track large groups of people who consume many foods containing nanoparticles and those who eat fewer nanoparticles, monitoring their health over months or years.

Waldman says studies should include individuals with intestinal diseases and pregnant women — groups that could be more vulnerable to any potential effects. People who have inflammatory bowel disease — in which the intestinal wall is “leaky” — may be at higher risk of nanoparticles getting into circulation and reaching other tissues, he says.

Meanwhile, scientists agree that, based on studies to date, the nanofoods found on supermarket shelves are probably safe to eat — when consumed at “typical” quantities. A few nanolaced cookies probably won’t do harm.

Waldman says he doesn’t avoid eating foods containing nanoparticles. Westerhoff, whose son devoured the Gobstopper, agrees. Food nanotechnology actually makes food better, he says, “giving chocolate a smooth, creamy texture or preventing dry ingredients from clumping.”

Still, skeptical consumers, who cannot always find nanoparticles listed on ingredient labels, want to be assured that the additives are safe. While nanotechnology offers new ways of transforming the features of food, creating safer, more nutritious fare, McClements says, scientists must find ways to demonstrate the safety of new types of nanoparticles before they are brought to market. “As with any new technology, you have to be cautious about how you use it and understand what’s going on.”

This article appears in the October 31, 2015, Science News with the headline, “Noshing on nano: The tiny particles in what we eat raise big questions.”


Finalists Announced for Undergraduate Nanoscience and Nanoengineering Competition

The Center for Nano Science and Technology at the University of Notre Dame today announced the finalists for the fifth annual NDConnect undergraduate nanotechnology research competition.

The 14 finalists are: …

Joana Sipe, a senior in chemical engineering at Arizona State University. Joana is advised by Prof. Paul Westerhoff and Prof. Pierre Herckes. The title of her project is “Synthesis and lifecycle analysis of layer-by-layer silver nanoparticle coated fabrics.”

Read the complete story: by Published: October 07, 2015; Author: Heidi Deethart

Methadone In The Water: What’s The Real Risk?

link to article

Methadone In The Water: What’s The Real Risk?

Peter Chawaga - editor

By Peter Chawaga, Associate Editor, Water Online


An environmental study made headlines this spring as it drew a distinct parallel between the growing PPCP epidemic and a poisonous disinfection byproduct (DBP) making its way into drinking water. The culprit in this case is methadone, which reacts to chloramination by forming large amounts of N-Nitrosodimethylamine (NDMA), a probable human carcinogen.

Using a mass spectrometry screening procedure, a team of researchers assembled from Arizona State, the University of Colorado at Boulder, and the University of Toronto discovered the connection and published their findings in Environmental Science & Technology Letters.

The study found a median methadone concentration of 23 mg/L and determined the drug was responsible for 1 to 10 percent of NDMA formation potential (FP) in most raw surface waters in which it was detected, and up to 62 percent of NDMA FP in wastewater.

“The conclusion is that pharmaceuticals, in particular methadone, are responsible for at least some of the formation of a carcinogen in drinking water,” said David Hanigan, the study’s lead PhD student. “This adds to mounting evidence that loading pharmaceuticals to our wastewater plants, which are not designed to remove them, is damaging ecosystem health and human health.”

Hanigan pointed to the unnatural phenomenon of fish feminization as an example of this damage to our ecosystem health. While he believes the water industry is aware of the presence of NDMA in water, a conclusive treatment method hasn’t been developed to combat it.

“Early indications suggest that activated carbon, pre-oxidation with ozone or chlorine dioxide, and changing primary or secondary disinfectants to free chlorine from chloramines will reduce or eliminate NDMA formation,” Hanigan said, when asked what treatment plants might do to avoid NDMA forming in the first place. But he noted that pre-oxidation and disinfectant switching can form other byproducts that may be harmful.

“Therefore my suggestion would be for plants to use activated carbon prior to disinfection,” he said. “This is, unfortunately, likely the most expensive option for most water treatment plants.  It is the only one, though, that removes organic matter rather than simply transforming it to something that is not reactive in forming NDMA.”

He may be a preeminent scholar on the risk that methadone runoff is introducing to our waters, but Hanigan remains tempered in his stance on the drug.

“Although this is carcinogen exposure that could be in part or entirely due to upstream prescription use, I still view this as relatively low risk,” he said. “Rather than think about removing methadone from physicians’ toolsets, we should work to find a way to remove methadone from water.”

Due in no small part to its attention-grabbing focus on methadone and the possibility that our water is giving us cancer, the study was seized by media outlets upon its release, including this one. Coverage resulted from PBSThe U.S. Finance Post, and a slew of scientific publications. But Hanigan feels that many readers are drawing the wrong conclusion and don’t realize the power they have to change things for the better.

“Sometimes I see people saying they are switching to bottled water, which I think really misses the point,” he said. “Whether it’s methadone, sucralose, synthetic estrogen, we are all responsible for surface water pollution with pharmaceuticals and anthropogenic chemicals, and thus are all responsible to find ways to fix these issues.”

Image credit: “weekend supply,” Mr Cumbo © 2007, used under an Attribution 2.0 Generic license:

LCnano team published ES&T Paper – Life Cycle Payback Estimates of Nanosilver Enabled Textiles under Different Silver Loading, Release, And Laundering Scenarios Informed by Literature Review



Andrea L. Hicks, Leanne M. Gilbertson, Jamila S. Yamani, Thomas L. Theis, and Julie B. Zimmerman

DOI: 10.1021/acs.est.5b01176; Environ. Sci. Technol. 2015, 49, 7529−7542

ABSTRACT: Silver was utilized throughout history to prevent the growth of bacteria in food and wounds. Recently, nanoscale silver has been applied to consumer textiles (nAg-textiles) to eliminate the prevalence of odor-causing bacteria. In turn, it is proposed that consumers will launder these items less frequently thus, reducing the life cycle impacts. While previous studies report that laundering processes are associated with the greatest environmental impacts of these textiles, there is no data available to support the proposed shift in consumer laundering behavior. Here, the results from a comprehensive literature review of nAg-textile life cycle studies are used to inform a cradle-to-grave life cycle impact assessment. Rather than assuming shifts in consumer behavior, the impact assessment is conducted in such a way that considers all laundering scenarios to elucidate the potential for reduced laundering to enable realization of a net life cycle benefit. In addition to identifying the most impactful stages of the life cycle across nine-midpoint categories, a payback period and uncertainty analysis quantifies the reduction in lifetime launderings required to recover the impacts associated with nanoenabling the textile. Reduction of nAg-textile life cycle impacts is not straightforward and depends on the impact category considered.