Tag Archives: titanium dioxide nanoparticles

Sunscreens 2020 and the Environmental Working Group (EWG)

There must be some sweet satisfaction or perhaps it’s better described as relief for the Environmental Working Group (EWG) now that sunscreens with metallic (zinc oxide and/or titanium dioxide) nanoparticles are gaining wide acceptance. (More about the history and politics EWG and metallic nanoparticles at the end of this posting.)

This acceptance has happened alongside growing concerns about oxybenzone, a sunscreen ingredient that EWG has long warned against. Oxybenzone has been banned from use in Hawaii due to environmental concerns (see my July 6, 2018 posting; scroll down about 40% of the way for specifics about Hawaii). Also, it is one of the common sunscreen ingredients for which the US Food and Drug Administration (FDA) is completing a safety review.

Today, zinc oxide and titanium dioxide metallic nanoparticles are being called minerals, as in, “mineral-based” sunscreens. They are categorized as physical sunscreens as opposed to chemical sunscreens.

I believe the most recent sunscreen posting here was my 2018 update (uly 6, 2018 posting) so the topic is overdue for some attention here. From a May 21, 2020 EWG news release (received via email),

As states reopen and Americans leave their homes to venture outside, it’s important for them to remember to protect their skin from the sun’s harmful rays. Today the Environmental Working Group released its 14th annual Guide to Sunscreens.  

This year researchers rated the safety and efficacy of more than 1,300 SPF products – including sunscreens, moisturizers and lip balms – and found that only 25 percent offer adequate protection and do not contain worrisome ingredients such as oxybenzone, a potential hormone-disrupting chemical that is readily absorbed by the body.

Despite a delay in finalizing rules that would make all sunscreens on U.S. store shelves safer, the Food and Drug Administration, the agency that governs sunscreen safety, is completing tests that highlight concerns with common sunscreen ingredients. Last year, the agency published two studies showing that, with just a single application, six commonly used chemical active ingredients, including oxybenzone, are readily absorbed through the skin and could be detected in our bodies at levels that could cause harm.

“It’s quite concerning,” said Nneka Leiba, EWG’s vice president of Healthy Living science. “Those studies don’t prove whether the sunscreens are unsafe, but they do highlight problems with how these products are regulated.”

“EWG has been advocating for the FDA to review these chemical ingredients for 14 years,” Leiba said. “We slather these ingredients on our skin, but these chemicals haven’t been adequately tested. This is just one example of the backward nature of product regulation in the U.S.”

Oxybenzone remains a commonly used active ingredient, found in more than 40 percent of the non-mineral sunscreens in this year’s guide. Oxybenzone is allergenic and a potential endocrine disruptor, and has been detected in human breast milk, amniotic fluid, urine and blood.

According to EWG’s assessment, fewer than half of the products in this year’s guide contain active ingredients that the FDA has proposed are safe and effective.

“Based on the best current science and toxicology data, we continue to recommend sunscreens with the mineral active ingredients zinc dioxide and titanium dioxide, because they are the only two ingredients the FDA recognized as safe or effective in their proposed draft rules,” said Carla Burns, an EWG research and database analyst who manages the updates to the sunscreen guide.

Most people select sunscreen products based on their SPF, or sunburn protection factor, and mistakenly assume that bigger numbers offer better protection. According to the FDA, higher SPF values have not been shown to provide additional clinical benefit and may give users a false sense of protection. This may lead to overexposure to UVA rays that increase the risk of long-term skin damage and cancer. The FDA has proposed limiting SPF claims to 60+.

EWG continues to hone our recommendations by strengthening the criteria for assessing sunscreens, which are based on the latest findings in the scientific literature and commissioned tests of sunscreen product efficacy. This year EWG made changes to our methodology in order to strengthen our requirement that products provide the highest level of UVA protection.

“Our understanding of the dangers associated with UVA exposure is increasing, and they are of great concern,” said Burns. “Sunburn during early life, especially childhood, is very dangerous and a risk factor for all skin cancers, but especially melanoma. Babies and young children are especially vulnerable to sun damage. Just a few blistering sunburns early in life can double a person’s risk of developing melanoma later in life.”

EWG researchers found 180 sunscreens that meet our criteria for safety and efficacy and would likely meet the proposed FDA standards. Even the biggest brands now provide mineral options for consumers.  

Even for Americans continuing to follow stay-at-home orders, wearing an SPF product may still be important. If you’re sitting by a window, UVA and UVB rays can penetrate the glass.  

It is important to remember that sunscreen is only one part of a sun safety routine. People should also protect their skin by covering up with clothing, hats and sunglasses. And sunscreen must be reapplied at least every two hours to stay effective.

EWG’s Guide to Sunscreens helps consumers find products that get high ratings for providing adequate broad-spectrum protection and that are made with ingredients that pose fewer health concerns.

The new guide also includes lists of:

Here are more quick tips for choosing better sunscreens:

  • Check your products in EWG’s sunscreen database and avoid those with harmful ingredients.
  • Avoid products with oxybenzone. This chemical penetrates the skin, gets into the bloodstream and can affect normal hormone activities.
  • Steer clear of products with SPF higher than 50+. High SPF values do not necessarily provide increased UVA protection and may fool you into thinking you are safe from sun damage.
  • Avoid sprays. These popular products pose inhalation concerns, and they may not provide a thick and uniform coating on the skin.
  • Stay away from retinyl palmitate. Government studies link the use of retinyl palmitate, a form of vitamin A, to the formation of skin tumors and lesions when it is applied to sun-exposed skin.
  • Avoid intense sun exposure during the peak hours of 10 a.m. to 4 p.m.

Shoppers on the go can download EWG’s Healthy Living app to get ratings and safety information on sunscreens and other personal care products. Also be sure to check out EWG’s sunscreen label decoder.

One caveat, these EWG-recommended products might not be found in Canadian stores or your favourite product may not have been reviewed for inclusion, as a product to be sought out or avoided, in their database. For example, I use a sunscreen that isn’t listed in the database, although at least a few other of the company’s sunscreen products are. On the plus side, my sunscreen doesn’t include oxybenzone or retinyl palmitate as ingredients.

To sum up the situation with sunscreens containing metallic nanoparticles (minerals), they are considered to be relatively safe but should new research emerge that designation could change. In effect, all we can do is our best with the information at hand.

History and politics of metallic nanoparticles in sunscreens

In 2009 it was a bit of a shock when the EWG released a report recommending the use of sunscreens with metallic nanoparticles in the list of ingredients. From my July 9, 2009 posting,

The EWG (Environmental Working Group) is, according to Maynard [as of 20202: Dr. Andrew Maynard is a scientist and author, Associate Director of Faculty in the ASU {Arizona State University} School for the Future of Innovation in Society, also the director of the ASU Risk Innovation Lab, and leader of the Risk Innovation Nexus], not usually friendly to industry and they had this to say about their own predisposition prior to reviewing the data (from EWG),

When we began our sunscreen investigation at the Environmental Working Group, our researchers thought we would ultimately recommend against micronized and nano-sized zinc oxide and titanium dioxide sunscreens. After all, no one has taken a more expansive and critical look than EWG at the use of nanoparticles in cosmetics and sunscreens, including the lack of definitive safety data and consumer information on these common new ingredients, and few substances more dramatically highlight gaps in our system of public health protections than the raw materials used in the burgeoning field of nanotechnology. But many months and nearly 400 peer-reviewed studies later, we find ourselves drawing a different conclusion, and recommending some sunscreens that may contain nano-sized ingredients.

My understanding is that after this report, the EWG was somewhat ostracized by collegial organizations. Friends of the Earth (FoE) and the ETC Group both of which issued reports that were published after the EWG report and were highly critical of ‘nano sunscreens’.

The ETC Group did not continue its anti nanosunscreen campaign for long (I saw only one report) but FoE (in particular the Australian arm of the organization) more than made up for that withdrawal and to sad effect. My February 9, 2012 post title was this: Unintended consequences: Australians not using sunscreens to avoid nanoparticles?

An Australian government survey found that 13% of Australians were not using any sunscreen due to fears about nanoparticles. In a country with the highest incidence of skin cancer in the world and, which spent untold millions over decades getting people to cover up in the sun, it was devastating news.

FoE immediately withdrew all their anti nanosunscreen materials in Australia from circulation while firing broadsides at the government. The organization’s focus on sunscreens with metallic nanoparticles has diminished since 2012.

Research

I have difficulty trusting materials from FoE and you can see why here in this July 26, 2011 posting (Misunderstanding the data or a failure to research? Georgia Straight article about nanoparticles). In it, I analyze Alex Roslin’s profoundly problematic article about metallic nanoparticles and other engineered nanoparticles. All of Roslin’s article was based on research and materials produced by FoE which misrepresented some of the research. Roslin would have realized that if he had bothered to do any research for himself.

EWG impressed me mightily with their refusal to set aside or dismiss the research disputing their initial assumption that metallic nanoparticles in sunscreens were hazardous. (BTW, there is one instance where metallic nanoparticles in sunscreens are of concern. My October 13, 2013 posting about anatase and rutile forms of titanium dioxide at the nanoscale features research on that issue.)

EWG’s Wikipedia entry

Whoever and however many are maintaining this page, they don’t like EWG at all,

The accuracy of EWG reports and statements have been criticized, as has its funding by the organic food industry[2][3][4][5] Its warnings have been labeled “alarmist”, “scaremongering” and “misleading”.[6][7][8] Despite the questionable status of its work, EWG has been influential.[9]

This is the third paragraph in the Introduction. At its very best, the information is neutral, otherwise, it’s much like that third paragraph.

Even John D. Rockeller’s entry is more flattering and he was known as the ‘most hated man in America’ as this show description on the Public Broadcasting Service (PBS) website makes clear,

American Experience

The Rockefellers Chapter One

Clip: Season 13 Episode 1 | 9m 37s

John D. Rockefeller was the world’s first billionaire and the most hated man in America. Watch the epic story of the man who monopolized oil.

Fun in the sun

Have fun in the sun this summer. There’s EWG’s sunscreen database, the tips listed in the news release, and EWG also has a webpage where they describe their methodology for how they assess sunscreens. It gets a little technical (for me anyway) but it should answer any further safety questions you might have after reading this post.

It may require a bit of ingenuity given the concerns over COVID-19 but I’m constantly amazed at the inventiveness with which so many people have met this pandemic. (This June 15, 2020 Canadian Broadcasting Corporation article by Sheena Goodyear features a family that created a machine that won the 2020 Rube Goldberg Bar of Soap Video challenge. The article includes an embedded video of the winning machine in action.)

Norwegian Institute for Water Research (NIVA) releases study on silver and titanium nanomaterials in wastewater

It turns out that silver and titanium nanomaterials (e.g. silver nanoparticles washed out of athletic clothing) in wastewater may have ‘negative’ and ‘positive’ effects on freshwater and marine life depending on the species.

A November 18, 2019 news item on Nanowerk provides an introduction to the research (Note: Links have been removed),

You may not always think about it when you do your laundry or flush the toilet; but whatever you eat, wear or apply on your skin ends up in wastewater and eventually reaches the environment. The use of nanoparticles in consumer products like textiles, foods and personal care products is increasing.

What is so special about nanoparticles, is their tiny size: One nanometer is one billionth of a meter. The small size gives nanoparticles unique and novel properties compared to their bigger counterparts and may for example reach locations that bigger particles cannot reach.
Further, pristine nanoparticles behave differently from nanoparticles in the environment. In the environment, nanoparticles are transformed by interacting and forming aggregates with other particles, elements or solids, and thereby obtain other physicochemical properties.

The transformation of these tiny particles in wastewater treatment processes and their effect on freshwater and marine organisms, have largely been unknown.
Increased mortality of marine crustaceans.

In a study (“Ecotoxicological Effects of Transformed Silver and Titanium Dioxide Nanoparticles in the Effluent from a Lab-Scale Wastewater Treatment System”) conducted at the Norwegian Institute for Water Research (NIVA), Anastasia Georgantzopoulou and colleagues from NIVA and SINTEF investigated how silver and titanium dioxide nanoparticles behave in wastewater treatment plants, and how marine and freshwater organisms are affected by them.

Exposure to treated wastewater did not have any adverse effects on the freshwater crustacean Daphnia magna. (Photo: NIVA)

A November 18, 2019 NIVA press release, which originated the news item, fills in the details,

The researchers made a laboratory-scale wastewater treatment plant, using sludge from a wastewater treatment plant in Norway. They added environmentally relevant concentrations of silver (Ag) and titanium dioxide (TiO2) nanoparticles over a 5-week period and used the treated wastewater to assess the effects of transformed nanoparticles on freshwater and marine organisms, as well as on gill cells from rainbow trout.

The experiment demonstrated contrasting effects on the two crustacean species. For the marine copepod (Tisbe battagliai), mortality increased by 20-45%, whereas exposure to ttreated wastewater did not have any adverse effects on the freshwater crustacean (Daphnia magna).

“These differences are probably due, at least partly, to the two species’ different feeding habits, in combination with the fact that the nanoparticles showed a strong association to solids present in the wastewater”, Georgantzopoulou says, and explains:

“Daphnia magna is an organism that filters water for food, whereas the marine copepod feeds on bottom surfaces – like effluent solids that have settled out from the water. The bottom feeding crustacean is therefore more likely to ingest nanoparticles, and thereby be affected by solid-associated nanoparticles”. 

Effects on algal species

Nanoparticle-containing treated wastewater also affected algal growth, but the two algae species did not have a common response: The marine algae (Skeletonema pseudocostatum) responded with a 20-40 % growth inhibition, while the algal growth of the freshwater algae (Raphidocelis subcapitata) was actually stimulated, by a 40 % increase, accompanied by increased cell aggregation. The latter is probably some kind of a defense mechanism, aiming to decrease the surface area exposed to toxic particles.

“The results from our study indicate that algal responses to the treated wastewater exposure are species-dependent. This is possibly due to differences in algal cell size, surface area, and cell wall composition”, the NIVA researcher explains.

Increased permeability of fish gill cells

The researchers also found effects of silver and titanium nanoparticles on fish gill cells using an in vitro gill cell line model. As large amounts of water are passing through the gills, and they constitute a barrier to the external environment, this organ is highly exposed to water-borne contaminants, including nanoparticles.

“Exposure to nanoparticle-containing wastewater lead to an increase in reactive oxygen species, a group of molecules that can easily react with and damage cells. This was followed by increased permeability of the gill cells, leading to a compromised barrier function”, Georgantzopoulou says.

“However, the concentrations of silver and titanium nanoparticles in the treated wastewater were too low to fully account for the effects on cell permeability alone. The wastewater effluent is a complex mixture of materials, and the permeability response is probably caused by a combination of the presence of nanoparticles and other stressors”, Georgantzopoulou adds.

Wastewater treatment-transformation of nanoparticles

“We carried out this study on wastewater treatment plant-transformed nanoparticles, and compared them to pristine nanoparticles, as the former is more relevant to what is actually happening in the environment. The increased toxicity of the transformed nanomaterials observed in the study indicates that the effects cannot be predicted by assessing the effects of nanomaterials in their pristine form and highlights the importance of understanding their behavior, environmental transformation and interaction with organisms. Future studies should take nanoparticle transformation into account and focus on a more relevant experimental exposure conditions incorporating transformed nanoparticles in more long-term impact studies to provide a better understanding of their potential impacts”, Georgantzopoulou concludes.

Here’s a link to and a citation for the paper,

Ecotoxicological Effects of Transformed Silver and Titanium Dioxide Nanoparticles in the Effluent from a Lab-Scale Wastewater Treatment System by Anastasia Georgantzopoulou, Patricia Almeida Carvalho, Christian Vogelsang, Mengstab Tilahun, Kuria Ndungu, Andy M. Booth, Kevin V. Thomas, Ailbhe Macken. Environ. Sci. Technol. 2018, 52, 16, 9431-9441 DOI: https://doi.org/10.1021/acs.est.8b01663 Publication Date:July 26, 2018 Copyright © 2018 American Chemical Society

This paper is behind a paywall.

Algae outbreaks (dead zones) in wetlands and waterways

It’s been over seven years since I first started writing about Duke University’s  Center for the Environmental Implications of Nanotechnology and mesocosms (miniature ecosystems) and the impact that nanoparticles may have on plants and water (see August 11, 2011 posting). Since then, their focus has shifted from silver nanoparticles and their impact on plants, fish, bacteria, etc. to a more general examination of metallic nanoparticles and water. A June 25, 2018 news item on ScienceDaily announces some of their latest work,

The last 10 years have seen a surge in the use of tiny substances called nanomaterials in agrochemicals like pesticides and fungicides. The idea is to provide more disease protection and better yields for crops, while decreasing the amount of toxins sprayed on agricultural fields.

But when combined with nutrient runoff from fertilized cropland and manure-filled pastures, these “nanopesticides” could also mean more toxic algae outbreaks for nearby streams, lakes and wetlands, a new study finds.

A June 25, 2018 Duke University news release (also on EurekAlert) by Robin A. Smith, which originated the news item, provides more detail,

Too small to see with all but the most powerful microscopes, engineered nanomaterials are substances manufactured to be less than 100 nanometers in diameter, many times smaller than a hair’s breadth.

Their nano-scale gives them different chemical and physical properties from their bulk counterparts, including more surface area for reactions and interactions.

Those interactions could intensify harmful algal blooms in wetlands, according to experiments led by Marie Simonin, a postdoctoral associate with biology professor Emily Bernhardt at Duke University.

Carbon nanotubes and teeny tiny particles of silver, titanium dioxide and other metals are already added to hundreds of commercial products to make everything from faster, lighter electronics, self-cleaning fabrics, and smarter food packaging that can monitor food for spoilage. They are also used on farms for slow- or controlled-release plant fertilizers and pesticides and more targeted delivery, and because they are effective at lower doses than conventional products.

These and other applications have generated tremendous interest and investment in nanomaterials. However the potential risks to human health or the environment aren’t fully understood, Simonin said.

Most of the 260,000 to 309,000 metric tons of nanomaterials produced worldwide each year are eventually disposed in landfills, according to a previous study. But of the remainder, up to 80,400 metric tons per year are released into soils, and up to 29,200 metric tons end up in natural bodies of water.

“And these emerging contaminants don’t end up in water bodies alone,” Simonin said. “They probably co-occur with nutrient runoff. There are likely multiple stressors interacting.”

Algae outbreaks already plague polluted waters worldwide, said Steven Anderson, a research analyst in the Bernhardt Lab at Duke and one of the authors of the research.

Nitrogen and phosphorous pollution makes its way into wetlands and waterways in the form of agricultural runoff and untreated wastewater. The excessive nutrients cause algae to grow out of control, creating a thick mat of green scum or slime on the surface of the water that blocks sunlight from reaching other plants.

These nutrient-fueled “blooms” eventually reduce oxygen levels to the point where fish and other organisms can’t survive, creating dead zones in the water. Some algal blooms also release toxins that can make pets and people who swallow them sick.

To find out how the combined effects of nutrient runoff and nanoparticle contamination would affect this process, called eutrophication, the researchers set up 18 separate 250-liter tanks with sandy sloped bottoms to mimic small wetlands.

Each open-air tank was filled with water, soil and a variety of wetland plants and animals such as waterweed and mosquitofish.

Over the course of the nine-month experiment, some tanks got a weekly dose of algae-promoting nitrates and phosphates like those found in fertilizers, some tanks got nanoparticles — either copper or gold — and some tanks got both.

Along the way the researchers monitored water chemistry, plant and algae growth and metabolism, and nanoparticle accumulation in plant tissues.

“The results were surprising,” Simonin said. The nanoparticles had tiny effects individually, but when added together with nutrients, even low concentrations of gold and copper nanoparticles used in fungicides and other products turned the once-clear water a murky pea soup color, its surface covered with bright green smelly mats of floating algae.

Over the course of the experiment, big algal blooms were more than three times more frequent and more persistent in tanks where nanoparticles and nutrients were added together than where nutrients were added alone. The algae overgrowths also reduced dissolved oxygen in the water.

It’s not clear yet how nanoparticle exposure shifts the delicate balance between plants and algae as they compete for nutrients and other resources. But the results suggest that nanoparticles and other “metal-based synthetic chemicals may be playing an under-appreciated role in the global trends of increasing eutrophication,” the researchers said.

Here’s a link to and a citation for the paper,

Engineered nanoparticles interact with nutrients to intensify eutrophication in a wetland ecosystem experiment by Marie Simonin, Benjamin P. Colman, Steven M. Anderson, Ryan S. King, Matthew T. Ruis, Astrid Avellan, Christina M. Bergemann, Brittany G. Perrotta, Nicholas K. Geitner, Mengchi Ho, Belen de la Barrera, Jason M. Unrine, Gregory V. Lowry, Curtis J. Richardson, Mark R. Wiesner, Emily S. Bernhardt. Ecological Applications, 2018; DOI: 10.1002/eap.1742 First published: 25 June 2018

This paper is behind a paywall.

What helps you may hurt you (titanium dioxide nanoparticles and orthopedic implants)

From a Sept. 16, 2017 news item on Nanotechnology Now,

Researchers from the Mayo Clinic have proposed that negative cellular responses to titanium-based nanoparticles released from metal implants interfere in bone formation and resorption at the site of repair, resulting in implant loosening and joint pain. [emphasis mine]Their review of recent scientific evidence and call for further research to characterize the biological, physical, and chemical interactions between titanium dioxide nanoparticles and bone-forming cells is published in BioResearch Open Access, a peer-reviewed open access journal from Mary Ann Liebert, Inc., publishers. The article is available free on theBioResearch Open Access website.

A Sept. 14, 2017 Mary Anne Liebert (Publishing) news release, which originated the news item,  mentions the authors,

Jie Yao, Eric Lewallen, PhD, David Lewallen, MD, Andre van Wijnen, PhD, and colleagues from the Mayo Clinic, Rochester, MN and Second Affiliated Hospital of Soochow University, China, coauthored the article entitled “Local Cellular Responses to Titanium Dioxide from Orthopedic Implants The authors examined the results of recently published studies of titanium-based implants, focusing on the direct and indirect effects of titanium dioxide nanoparticles on the viability and behavior of multiple bone-related cell types. They discuss the impact of particle size, aggregation, structure, and the specific extracellular and intracellular (if taken up by the cells) effects of titanium particle exposure.

“The adverse effects of metallic orthopedic particles generated from implants are of significant clinical interest given the large number of procedures carried out each year. This article reviews our current understanding of the clinical issues and highlights areas for future research,” says BioResearch Open Access Editor Jane Taylor, PhD, MRC Centre for Regenerative Medicine, University of Edinburgh, Scotland.

Before getting to the abstract, here’s a link to and a citation for the paper,

Local Cellular Responses to Titanium Dioxide from Orthopedic Implants by Yao, Jie J.; Lewallen, Eric A.; Trousdale, William H.; Xu, Wei; Thaler, Roman; Salib, Christopher G.; Reina, Nicolas; Abdel, Matthew P.; Lewallen, David G.; and van Wijnenm, Andre J.. BioResearch Open Access. July 2017, 6(1): 94-103. https://doi.org/10.1089/biores.2017.0017 Published July 1, 2017

This paper is open access.

Findings on oral exposure to nanoscale titanium dioxide

It’s been a while since I’ve run a piece on health concerns and nanoparticles. The nanoparticles in question are titanium dioxide and the concerns centre on oral exposure to them according to a Jan. 24, 2017 news item on Nanowerk,

Researchers from INRA [French National Institute for Agricultural Research] and their partners have studied the effects of oral exposure to titanium dioxide, an additive (E171) commonly used in foodstuffs, especially confectionary. They have shown for the first time that E171 crosses the intestinal barrier in animals and reaches other parts of the body.

Immune system disorders linked to the absorption of the nanoscale fraction of E171 particles were observed. The researchers also showed that chronic oral exposure to the additive spontaneously induced preneoplastic lesions in the colon, a non-malignant stage of carcinogenesis, in 40% of exposed animals.

Moreover, E171 was found to accelerate the development of lesions previously induced for experimental purposes. While the findings show that the additive plays a role in initiating and promoting the early stages of colorectal carcinogenesis, they cannot be extrapolated to humans or more advanced stages of the disease. [emphasis mine]

A Jan. 20, 2017 IINRA press release, which originated the news item,  provides more detail about European use of titanium dioxide as a food additive and about the research,

Present in many products including cosmetics, sunscreens, paint and building materials, titanium dioxide (or TiO2), known as E171 in Europe, is also widely used as an additive in the food industry to whiten or give opacity to products. It is commonly found in sweets, chocolate products, biscuits, chewing gum and food supplements, as well as in toothpaste and pharmaceutical products. Composed of micro- and nanoparticles, E171 is nevertheless not labelled a “nanomaterial”, since it does not contain more than 50% of nanoparticles (in general it contains from 10-40%). The International Agency for Research on Cancer (IARC) evaluated the risk of exposure to titanium dioxide by inhalation (occupational exposure), resulting in a Group 2B classification, reserved for potential carcinogens for humans.

Today, oral exposure to E171 is a concern, especially in children who tend to eat a lot of sweets. INRA researchers studied the product as a whole (that is, its mixed composition of micro- and nanoparticules), and have also evaluated the effect of the nanoscale particle fraction alone, by comparing it to a model nanoparticle.

Titanium dioxide crosses the intestinal barrier and passes into the bloodstream

The researchers exposed rats orally to a dose of 10mg of E171 per kilogram of body weight per day, similar to the exposure humans experience through food consumption (data from European Food Safety Agency, September 20162). They showed for the first time in vivo that titanium dioxide is absorbed by the intestine and passes into the bloodstream. Indeed, the researchers found titanium dioxide particles in the animals’ livers.

Titanium dioxide alters intestinal and systemic immune response

Titanium dioxide nanoparticles were present in the lining of the small intestine and in the colon, and entered the nuclei of the immune cells of Peyer’s patches, which induce immune response in the intestine. The researchers showed an imbalance in immune response, ranging from a defect in the production of cytokines in Peyer’s patches to the development of micro-inflammation in colon mucosa. In the spleen, representative of systemic immunity, exposure to E171 increases the capacity of immune cells to produce pro-inflammatory cytokines when they are activated in vitro.

Chronic oral exposure to titanium dioxide plays a role in initiating and promoting early stages of colorectal carcinogenesis

The researchers exposed rats to regular oral doses of titanium dioxide through drinking water for 100 days. In a group of rats previously treated with an experimental carcinogen, exposure to TiO2 led to an increase in the size of preneoplastic lesions. In a group of healthy rats exposed to E171, four out of eleven spontaneously developed preneoplastic lesions in the intestinal epithelium. Non-exposed animals presented no anomalies at the end of the 100-day study. These results indicate that E171 both initiates and promotes the early stages of colorectal carcinogenesis in animals.

These studies show for the first time that the additive E171 is a source of titanium dioxide nanoparticles in the intestine and the entire body, with consequences for both immune function and the development of preneoplastic lesions in the colon. These first findings justify a carcinogenesis study carried out under OECD [Organization for Economic Cooperation and Development] guidelines to continue observations at a later stage of cancer. They provide new data for evaluating the risks of the E171 additive in humans.

These studies were carried out within the framework of the Nanogut project, financed by the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) within the French national programme for research related to the environment, health and the workplace (PNR EST) and coordinated by INRA. Sarah Bettini’s university thesis contract was financed by the French laboratory of excellence LabEx SERENADE.

Here’s a link to and a citation for the paper,

Food-grade TiO2 impairs intestinal and systemic immune homeostasis, initiates preneoplastic lesions and promotes aberrant crypt development in the rat colon by Sarah Bettini, Elisa Boutet-Robinet, Christel Cartier, Christine Coméra, Eric Gaultier, Jacques Dupuy, Nathalie Naud, Sylviane Taché, Patrick Grysan, Solenn Reguer, Nathalie Thieriet, Matthieu Réfrégiers, Dominique Thiaudière, Jean-Pierre Cravedi, Marie Carrière, Jean-Nicolas Audinot, Fabrice H. Pierre, Laurence Guzylack-Piriou, & Eric Houdeau. Scientific Reports 7, Article number: 40373 (2017) doi:10.1038/srep40373 Published online: 20 January 2017

This paper is open access.

The research is concerning but they don’t want to draw any conclusions yet, which explains the recommendation for further research.

Nanosunscreen in swimming pools

Thanks to Lynn L. Bergeson’s Sept. 21, 2016 posting for information about the US Environmental Protection Agency’s (EPA) research into what happens to the nanoparticles when your nanosunscreen washes off into a swimming pool. Bergeson’s post points to an Aug. 15, 2016 EPA blog posting by Susanna Blair,

… It’s not surprising that sunscreens are detected in pool water (after all, some is bound to wash off when we take a dip), but certain sunscreens have also been widely detected in our ecosystems and in our wastewater. So how is our sunscreen ending up in our environment and what are the impacts?

Well, EPA researchers are working to better understand this issue, specifically investigating sunscreens that contain engineered nanomaterials and how they might change when exposed to the chemicals in pool water [open access paper but you need to register for free] … But before I delve into that, let’s talk a bit about sunscreen chemistry and nanomaterials….

Blair goes on to provide a good brief description of  nanosunscreens before moving onto her main topic,

Many sunscreens contain titanium dioxide (TiO2) because it absorbs UV radiation, preventing it from damaging our skin. But titanium dioxide decomposes into other molecules when in the presence of water and UV radiation. This is important because one of the new molecules produced is called a singlet oxygen reactive oxygen species. These reactive oxygen species have been shown to cause extensive cell damage and even cell death in plants and animals. To shield skin from reactive oxygen species, titanium dioxide engineered nanomaterials are often coated with other materials such as aluminum hydroxide (Al(OH)3).

EPA researchers are testing to see whether swimming pool water degrades the aluminum hydroxide coating, and if the extent of this degradation is enough to allow the production of potentially harmful reactive oxygen species. In this study, the coated titanium dioxide engineered nanomaterials were exposed to pool water for time intervals ranging from 45 minutes to 14 days, followed by imaging using an electron microscope.  Results show that after 3 days, pool water caused the aluminum hydroxide coating to degrade, which can reduce the coating’s protective properties and increase the potential toxicity.  To be clear, even with degraded coating, the toxicity measured from the coated titanium dioxide, was significantly less [emphasis mine] than the uncoated material. So in the short-term – in the amount of time one might wear sunscreen before bathing and washing it off — these sunscreens still provide life-saving protection against UV radiation. However, the sunscreen chemicals will remain in the environment considerably longer, and continue to degrade as they are exposed to other things.

Blair finishes by explaining that research is continuing as the EPA researches the whole life cycle of engineered nanomaterials.

Nanotechnology in the house; a guide to what you already have

A July 4, 2016 essay by Cameron Shearer of Flinders University (Australia) on The Conversation website describes how nanotechnology can be found in our homes (Note: Links have been removed),

All kitchens have a sink, most of which are fitted with a water filter. This filter removes microbes and compounds that can give water a bad taste.

Common filter materials are activated carbon and silver nanoparticles.

Activated carbon is a special kind of carbon that’s made to have a very high surface area. This is achieved by milling it down to a very small size. Its high surface area gives more room for unwanted compounds to stick to it, removing them from water.

The antimicrobial properties of silver makes it one of the most common nanomaterials today. Silver nanoparticles kill algae and bacteria by releasing silver ions (single silver atoms) that enter into the cell wall of the organisms and become toxic.

It is so effective and fashionable that silver nanoparticles are now used to coat cutlery, surfaces, fridges, door handles, pet bowls and almost anywhere else microorganisms are unwanted.

Other nanoparticles are used to prepare heat-resistant and self-cleaning surfaces, such as floors and benchtops. By applying a thin coating containing silicon dioxide or titanium dioxide nanoparticles, a surface can become water repelling, which prevents stains (similar to how scotch guard protects fabrics).

Nanoparticle films can be so thin that they can’t be seen. The materials also have very poor heat conductivity, which means they are heat resistant.

The kitchen sink (or dishwasher) is used for washing dishes with the aid of detergents. Detergents form nanoparticles called micelles.

A micelle is formed when detergent molecules self-assemble into a sphere. The centre of this sphere is chemically similar to grease, oils and fats, which are what you want to wash off. The detergent traps oils and fats within the cavity of the sphere to separate them from water and aid dish washing.

Your medicine cabinet may include nanotechnology similar to micelles, with many pharmaceuticals using liposomes.

A liposome is an extended micelle where there is an extra interior cavity within the sphere. Making liposomes from tailored molecules allows them to carry therapeutics inside; the outside of the nanoparticle can be made to target a specific area of the body.

Shearer’s essay goes on to cover the laundry, bathroom, closets, and garage. (h/t July 5, 2016 news item on phys.org)

June 2016: time for a post on nanosunscreens—risks and perceptions

In the years since this blog began (2006), there’ve been pretty regular postings about nanosunscreens. While there are always concerns about nanoparticles and health, there has been no evidence to support a ban (personal or governmental) on nanosunscreens. A June 2016 report  by Paul FA Wright (full reference information to follow) in an Australian medical journal provides the latest insights on safety and nanosunscreens. Wright first offers a general introduction to risks and nanomaterials (Note: Links have been removed),

In reality, a one-size-fits-all approach to evaluating the potential risks and benefits of nanotechnology for human health is not possible because it is both impractical and would be misguided. There are many types of engineered nanomaterials, and not all are alike or potential hazards. Many factors should be considered when evaluating the potential risks associated with an engineered nanomaterial: the likelihood of being exposed to nanoparticles (ranging in size from 1 to 100 nanometres, about one-thousandth of the width of a human hair) that may be shed by the nanomaterial; whether there are any hotspots of potential exposure to shed nanoparticles over the whole of the nanomaterial’s life cycle; identifying who or what may be exposed; the eventual fate of the shed nanoparticles; and whether there is a likelihood of adverse biological effects arising from these exposure scenarios.1

The intrinsic toxic properties of compounds contained in the nanoparticle are also important, as well as particle size, shape, surface charge and physico-chemical characteristics, as these greatly influence their uptake by cells and the potential for subsequent biological effects. In summary, nanoparticles are more likely to have higher toxicity than bulk material if they are insoluble, penetrate biological membranes, persist in the body, or (where exposure is by inhalation) are long and fibre-like.1 Ideally, nanomaterial development should incorporate a safety-by-design approach, as there is a marketing edge for nano-enabled products with a reduced potential impact on health and the environment.1

Wright also covers some of nanotechnology’s hoped for benefits but it’s the nanosunscreen which is the main focus of this paper (Note: Links have been removed),

Public perception of the potential risks posed by nanotechnology is very different in certain regions. In Asia, where there is a very positive perception of nanotechnology, some products have been marketed as being nano-enabled to justify charging a premium price. This has resulted in at least four Asian economies adopting state-operated, user-financed product testing schemes to verify nano-related marketing claims, such as the original “nanoMark” certification system in Taiwan.4

In contrast, the negative perception of nanotechnology in some other regions may result in questionable marketing decisions; for example, reducing the levels of zinc oxide nanoparticles included as the active ingredient in sunscreens. This is despite their use in sunscreens having been extensively and repeatedly assessed for safety by regulatory authorities around the world, leading to their being widely accepted as safe to use in sunscreens and lip products.5

Wright goes on to describe the situation in Australia (Note: Links have been removed),

Weighing the potential risks and benefits of using sunscreens with UV-filtering nanoparticles is an important issue for public health in Australia, which has the highest rate of skin cancer in the world as the result of excessive UV exposure. Some consumers are concerned about using these nano-sunscreens,6 despite their many advantages over conventional organic chemical UV filters, which can cause skin irritation and allergies, need to be re-applied more frequently, and are absorbed by the skin to a much greater extent (including some with potentially endocrine-disrupting activity). Zinc oxide nanoparticles are highly suitable for use in sunscreens as a physical broad spectrum UV filter because of their UV stability, non-irritating nature, hypo-allergenicity and visible transparency, while also having a greater UV-attenuating capacity than bulk material (particles larger than 100 nm in diameter) on a per weight basis.7

Concerns about nano-sunscreens began in 2008 with a report that nanoparticles in some could bleach the painted surfaces of coated steel.8 This is a completely different exposure situation to the actual use of nano-sunscreen by people; here they are formulated to remain on the skin’s surface, which is constantly shedding its outer layer of dead cells (the stratum corneum). Many studies have shown that metal oxide nanoparticles do not readily penetrate the stratum corneum of human skin, including a hallmark Australian investigation by Gulson and co-workers of sunscreens containing only a less abundant stable isotope of zinc that allowed precise tracking of the fate of sunscreen zinc.9 The researchers found that there was little difference between nanoparticle and bulk zinc oxide sunscreens in the amount of zinc absorbed into the body after repeated skin application during beach trials. The amount absorbed was also extremely small when compared with the normal levels of zinc required as an essential mineral for human nutrition, and the rate of skin absorption was much lower than that of the more commonly used chemical UV filters.9 Animal studies generally find much higher skin absorption of zinc from dermal application of zinc oxide sunscreens than do human studies, including the meticulous studies in hairless mice conducted by the Commonwealth Scientific and Industrial Research Organisation (CSIRO) using both nanoparticle and bulk zinc oxide sunscreens that contained the less abundant stable zinc isotope.10 These researchers reported that the zinc absorbed from sunscreen was distributed throughout several major organs, but it did not alter their total zinc concentrations, and that overall zinc homeostasis was maintained.10

He then discusses titanium dioxide nanoparticles (also used in nanosunscreens, Note: Links have been removed),

The other metal oxide UV filter is titanium dioxide. Two distinct crystalline forms have been used: the photo-active anatase form and the much less photo-active rutile form,7 which is preferable for sunscreen formulations. While these insoluble nanoparticles may penetrate deeper into the stratum corneum than zinc oxide, they are also widely accepted as being safe to use in non-sprayable sunscreens.11

Investigation of their direct effects on human skin and immune cells have shown that sunscreen nanoparticles of zinc oxide and rutile titanium dioxide are as well tolerated as zinc ions and conventional organic chemical UV filters in human cell test systems.12 Synchrotron X-ray fluorescence imaging has also shown that human immune cells break down zinc oxide nanoparticles similar to those in nano-sunscreens, indicating that immune cells can handle such particles.13 Cytotoxicity occurred only at very high concentrations of zinc oxide nanoparticles, after cellular uptake and intracellular dissolution,14 and further modification of the nanoparticle surface can be used to reduce both uptake by cells and consequent cytotoxicity.15

The ongoing debate about the safety of nanoparticles in sunscreens raised concerns that they may potentially increase free radical levels in human skin during co-exposure to UV light.6 On the contrary, we have seen that zinc oxide and rutile titanium dioxide nanoparticles directly reduce the quantity of damaging free radicals in human immune cells in vitro when they are co-exposed to the more penetrating UV-A wavelengths of sunlight.16 We also identified zinc-containing nanoparticles that form immediately when dissolved zinc ions are added to cell culture media and pure serum, which suggests that they may even play a role in natural zinc transport.17

Here’s a link to and a citation for Wright’s paper,

Potential risks and benefits of nanotechnology: perceptions of risk in sunscreens by Paul FA Wright. Med J Aust 2016; 204 (10): 369-370. doi:10.5694/mja15.01128 Published June 6, 2016

This paper appears to be open access.

The situation regarding perceptions of nanosunscreens in Australia was rather unfortunate as I noted in my Feb. 9, 2012 posting about a then recent government study which showed that some Australians were avoiding all sunscreens due to fears about nanoparticles. Since then Friends of the Earth seems to have moderated its stance on nanosunscreens but there is a July 20, 2010 posting (includes links to a back-and-forth exchange between Dr. Andrew Maynard and Friends of the Earth representatives) which provides insight into the ‘debate’ prior to the 2012 ‘debacle’. For a briefer overview of the situation you could check out my Oct. 4, 2012 posting.

New model to track flow of nanomaterials through our air, earth, and water

Just how many tons of nanoparticles are making their way through the environment? Scientists at the Swiss Federal Laboratories for Materials Science and Technology (Empa) have devised a new model which could help answer that question. From a May 12, 2016 news item on phys.org,

Carbon nanotubes remain attached to materials for years while titanium dioxide and nanozinc are rapidly washed out of cosmetics and accumulate in the ground. Within the National Research Program “Opportunities and Risks of Nanomaterials” (NRP 64) a team led by Empa scientist Bernd Nowack has developed a new model to track the flow of the most important nanomaterials in the environment.

A May 12, 2016 Empa press release by Michael Hagmann, which also originated the news item, provides more detail such as an estimated tonnage for titanium dioxide nanoparticles produced annually in Europe,

How many man-made nanoparticles make their way into the air, earth or water? In order to assess these amounts, a group of researchers led by Bernd Nowack from Empa, the Swiss Federal Laboratories for Materials Science and Technology, has developed a computer model as part of the National Research Program “Opportunities and Risks of Nanomaterials” (NRP 64). “Our estimates offer the best available data at present about the environmental accumulation of nanosilver, nanozinc, nano-tinanium dioxide and carbon nanotubes”, says Nowack.

In contrast to the static calculations hitherto in use, their new, dynamic model does not just take into account the significant growth in the production and use of nanomaterials, but also makes provision for the fact that different nanomaterials are used in different applications. For example, nanozinc and nano-titanium dioxide are found primarily in cosmetics. Roughly half of these nanoparticles find their way into our waste water within the space of a year, and from there they enter into sewage sludge. Carbon nanotubes, however, are integrated into composite materials and are bound in products such as which are immobilized and are thus found for example in tennis racquets and bicycle frames. It can take over ten years before they are released, when these products end up in waste incineration or are recycled.

39,000 metric tons of nanoparticles

The researchers involved in this study come from Empa, ETH Zurich and the University of Zurich. They use an estimated annual production of nano-titanium dioxide across Europe of 39,000 metric tons – considerably more than the total for all other nanomaterials. Their model calculates how much of this enters the atmosphere, surface waters, sediments and the earth, and accumulates there. In the EU, the use of sewage sludge as fertilizer (a practice forbidden in Switzerland) means that nano-titanium dioxide today reaches an average concentration of 61 micrograms per kilo in affected soils.

Knowing the degree of accumulation in the environment is only the first step in the risk assessment of nanomaterials, however. Now this data has to be compared with results of eco-toxicological tests and the statutory thresholds, says Nowack. A risk assessment has not been carried out with his new model so far. Earlier work with data from a static model showed, however, that the concentrations determined for all four nanomaterials investigated are not expected to have any impact on the environment.

But in the case of nanozinc at least, its concentration in the environment is approaching the critical level. This is why this particular nanomaterial has to be given priority in future eco-toxicological studies – even though nanozinc is produced in smaller quantities than nano-titanium dioxide. Furthermore, eco-toxicological tests have until now been carried out primarily with freshwater organisms. The researchers conclude that additional investigations using soil-dwelling organisms are a priority.

Here are links to and citations for papers featuring the work,

Dynamic Probabilistic Modeling of Environmental Emissions of Engineered Nanomaterials by Tian Yin Sun†, Nikolaus A. Bornhöft, Konrad Hungerbühler, and Bernd Nowack. Environ. Sci. Technol., 2016, 50 (9), pp 4701–4711 DOI: 10.1021/acs.est.5b05828 Publication Date (Web): April 04, 2016

Copyright © 2016 American Chemical Society

Probabilistic environmental risk assessment of five nanomaterials (nano-TiO2, nano-Ag, nano-ZnO, CNT, and fullerenes) by Claudia Coll, Dominic Notter, Fadri Gottschalk, Tianyin Sun, Claudia Som, & Bernd Nowack. Nanotoxicology Volume 10, Issue 4, 2016 pages 436-444 DOI: 10.3109/17435390.2015.1073812 Published online: 10 Nov 2015

The first paper, which is listed in Environmental Science & Technology, appears to be open access while the second paper is behind a paywall.

Open access to nanoparticles and nanocomposites

One of the major issues for developing nanotechnology-enabled products is access to nanoparticles and nanocomposites. For example, I’ve had a number of requests from entrepreneurs for suggestions as to how to access cellulose nanocrystals (CNC) so they can develop a product idea. (It’s been a few years since the last request and I hope that means it’s easier to get access to CNC.)

Regardless, access remains a problem and the European Union has devised a solution which allows open access to nanoparticles and nanocomposites through project Co-Pilot. The announcement was made in a May 10, 2016 news item on Nanowerk (Note: A link has been removed),

“What opportunities does the nanotechnology provide in general, provide nanoparticles for my products and processes?” So far, this question cannot be answered easily. Preparation and modification of nanoparticles and the further processing require special technical infrastructure and complex knowledge. For small and medium businesses the construction of this infrastructure “just on luck” is often not worth it. Even large companies shy away from the risks. As a result many good ideas just stay in the drawer.

A simple and open access to high-class infrastructure for the reliable production of small batches of functionalized nanoparticles and nanocomposites for testing could ease the way towards new nano-based products for chemical and pharmaceutical companies. The European Union has allocated funds for the construction of a number of pilot lines and open-access infrastructure within the framework of the EU project CoPilot.

A May 9, 2016 Fraunhofer-Institut für Silicatforschung press release, which originated the news item, offers greater description,

A simple and open access to high-class infrastructure for the reliable production of small batches of functionalized nanoparticles and nanocomposites for testing could ease the way towards new nano-based products for chemical and pharmaceutical companies. The European Union has allocated funds for the construction of a number of pilot lines and open-access infrastructure within the framework of the EU project CoPilot. A consortium of 13 partners from research and industry, including nanotechnology specialist TNO from the Netherlands and the Fraunhofer Institute for Silicate Research ISC from Wuerzburg, Germany as well as seven nanomaterial manufacturers, is currently setting up the pilot line in Wuerzburg. First, they establish the particle production, modification and compounding on pilot scale based on four different model systems. The approach enables maximum variability and flexibility for the pilot production of various particle systems and composites. Two further open access lines will be established at TNO in Eindhoven and at the Sueddeutsche Kunststoffzentrum SKZ in Selb.

The “nanoparticle kitchen”

Essential elements of the pilot line in Wuerzburg are the particle synthesis in batches up to 100 liters, modification and separation methods such as semi-continuous operating centrifuge and in-line analysis and techniques for the uniform and agglomeration free incorporation of nanoparticles into composites. Dr. Karl Mandel, head of Particle Technology of Fraunhofer ISC, compares the pilot line with a high-tech kitchen: “We provide the top-notch equipment and the star chefs to synthesize a nano menu à la carte as well as nanoparticles according to individual requests. Thus, companies can test their own receipts – or our existing receipts – before they practice their own cooking or set up their nano kitchen.”

In the future, the EU project offers companies a contact point if they want to try their nano idea and require enough material for sampling and estimation of future production costs. This can, on the one hand, minimize the development risk, on the other hand, it maximizes the flexibility and production safety. To give lots of companies the opportunity to influence direction and structure/formation/setup of the nanoparticle kitchen, the project partners will offer open meetings on a regular basis.

I gather Co-Pilot has been offering workshops. The next is in July 2016 according to the press release,

The next workshop in this context takes place at Fraunhofer ISC in Wuerzburg, 7h July 2016. The partners present the pilot line and the first results of the four model systems – double layered hydroxide nanoparticle polymer composites for flame inhibiting fillers, titanium dioxide nanoparticles for high refractive index composites, magnetic particles for innovative catalysts and hollow silica composites for anti-glare coatings. Interested companies can find more information about the upcoming workshop on the website of the project www.h2020copilot.eu and on the website of Fraunhofer ISC www.isc.fraunhofer.de that hosts the event.

I tracked down a tiny bit more information about the July 2016 workshop in a May 2, 2016 Co-Pilot press release,

On July 7 2016, the CoPilot project partners give an insight view of the many new functionalization and applications of tailored nanoparticles in the workshop “The Nanoparticle Kitchen – particles und functions à la carte”, taking place in Wuerzburg, Germany. Join the Fraunhofer ISC’s lab tour of the “Nanoparticle Kitchen”, listen to the presentations of research institutes and industry and discuss your ideas with experts. Nanoparticles offer many options for today’s and tomorrow’s products.

More about program and registration soon on this [CoPilot] website!

I wonder if they’re considering this open access to nanoparticles and nanocomposites approach elsewhere?