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 steven-gilbert-2Toxicologist Steven G. Gilbert, PhD, DABT, a regular guest who is helping us understand the toxicity of common chemicals we may be frequently exposed to. Dr. Gilbert is Director and Founder of the Institute of Neurotoxicology and author of A Small Dose of Toxicology- The Health Effects of Common Chemicals.He received his Ph.D. in Toxicology in 1986 from the University of Rochester, Rochester, NY, is a Diplomat of American Board of Toxicology, and an Affiliate Professor in the Department of Environmental and Occupational Health Sciences, University of Washington. His research has focused on neurobehavioral effects of low-level exposure to lead and mercury on the developing nervous system. Dr. Gilbert has an extensive website about toxicology called Toxipedia, which includes a suite of sites that put scientific information in the context of history, society, and culture.









Host: Debra Lynn Dadd
Guest: Steven G. Gilbert, PhD, DABT

Date of Broadcast: July 28, 2014

DEBRA: Hi, I’m Debra Lynn Dadd, and this is Toxic Free Talk Radio, where we talk about how to thrive in a toxic world, and live toxic-free. It is July 28, 2014, a beautiful summer day here in Clearwater, Florida.

Today, we’re going to talk about nanoparticles. I know everybody has heard of nanoparticles, but I bet a lot of people don’t know what they are. Today, I’m having our toxicologist, I want to say my resident toxicologist because he’s been on so many times, Dr. Steven Gilbert, Ph.D. from Toxipedia. And he has his own website,, and he’s the author of a book called A Small Dose of Toxicology.

Hello, Dr. Gilbert.

STEVEN GILBERT: Hi, Debra. It’s good to speak to you today.

DEBRA: Nice to speak with you too. So as long as we’re talking about A Small Dose of Toxicology, why don’t we start out with you telling us about your translation project? Tell us more about A Small Dose of Toxicology as a book. It’s been translated into many languages. Tell us about your new translation.

STEVEN GILBERT: So we’re working A Small Dose of Toxicology as an introductory toxicology text. It’s free on the web. It’s That’s So you can download that or any chapter of the book as you like.

It was recently translated in the Chinese. So it’s now published in China. And we have hopes that it will be an introductory text for people to learn more about toxicology and the issues in China.

Our latest effort is to translate the book into Arabic. There are over 400-million Arabic speakers in the world. And we have a great toxicologist that’s in the West Bank (and a novelist) that’s willing to translate the book.

Then we started an Indiegogo website to try to raise funds to complete this project. So we’re looking to raise not a lot of money, but quite a bit of money at the same time. It’s $14,000 to get the book translated. And it will be available for free on our website published by Healthy World Press as a free e-book in Arabic.

So, we’re very hopeful we’ll get that project done in the next 6 to 12 months and have it out there on the web where we’re going to put it up.

The first chapter is almost done. We completed the translation. It’s under review right now. So we’ll be posting it chapter by chapter in Arabic as the chapters become done.

So, I’m very excited about this project.

We also have our […] on the history poster. I’ve looked at the history of toxicology, and it’s translated in Arabic and Chinese as well as 10 other languages.

So, we’re working very hard to make toxicology (which really is an international issue) and help people understand a little about the health effects of chemicals around the world.

DEBRA: I will say that this is an excellent book. Anybody who hasn’t already downloaded it for free—and I’ve been talking about it on show after show—if you haven’t already downloaded it, please do because its’ an excellent book. It talks about the basics of toxicology in language that anyone can understand.

This is not a dry, uninteresting chemistry book. This is living toxicology. It’s about what’s happening right now. It’s about understanding how toxic chemicals interact in your body. It’s about gaining the ability to tell what’s toxic and what’s not.

And so this is just the basics well-explained, and you can have it for free. So go download this book, everybody who’s listening.

STEVEN GILBERT: Thank you very much. You can learn more about it right on the front page of Toxipedia, and learn how you can support our efforts to translate it into Arabic.

DEBRA: That’s

STEVEN GILBERT: I’ve actually been to Gaza twice on humanitarian issues, and it’s really painful to see what’s happening over there right now in Gaza. It’s a really, very unique place. The people are wonderful. I’m hoping that this book will also help them in their issues there.

DEBRA: So let’s talk about nanoparticles.

STEVEN GILBERT: Well, nanoparticles, that’s a big subject—or a small subject depending on how you look at it.

DEBRA: Well, why don’t you start by telling us exactly what a nanoparticle is?

STEVEN GILBERT: The definition of nanotechnology is the understanding and control—I want to emphasize the understanding and control—of matter. So it’s really talking about controlling matter to atomic level. And so, nanotechnology is the understanding control of matter with dimensions of approximately between 1 and 100-nanometers, where unique phenomena enable [noble] applications.

One thing about the size, let’s get a little more perspective on the size, a sheet of paper is about 100,000 nanometers. So you can imagine that sheet of paper and dividing it up to 100,000 times. A strand of human DNA is about 2.5-nanometers in diameter.

So, this is one of the concerning things, nanoparticles of the size and dimensions of DNA, so that some of the particles can travel in and out of cells, it tends to interact with DNA. And this is what has toxicologists worried about potential health effects.

A human hair is about 80,000 to 100,000 nanometers. So you can then just take a piece of hair and dividing it up 100,000 times. There are over 25 million nanometers in an inch. And this is another important factor. A single gold atom is about a third of a nanometer. So, you really can manipulate matter at the atomic level.

And of course, the definition of nanometer is a millionth of a millimeter to a billionth of a meter. So you’re talking about a very small material. And the unique thing about nanoparticles is their physical and chemical properties change. For example, a tee which is usually white, at a nano scale, it becomes clear. This has very important implications for things like sunscreen.

DEBRA: Let’s just relate this to a real consumer product right now. So sunscreen, let’s talk about it. A lot of people are putting sunscreen on their body. And titanium dioxide itself is one thing, but then when it’s at a smaller size, so that it’s not white, but it’s just clear (you don’t turn white when you put on your sunscreen) how does that change?

STEVEN GILBERT: That is why people like it.

DEBRA: That is why people like it. So tell us how that is different. When you put it on your skin, what happens that’s different?

STEVEN GILBERT: The concern is the titanium and zinc oxide […] So most sunscreens, the idea of sunscreens is protect against ultraviolet radiation. And there are UVA and UVA, ultraviolet radiation. And the nanoparticles are used to reflect the light. There are also chemicals that can be added that absorb some of the energy from the light.

So nanoparticles are great in that sense in that the small size reflect the light well. It becomes transparent so it doesn’t show up white on your nose which is good. They have a large surface area ratio, so if you apply chemicals […] in sunscreen, you have more surface area for these chemicals.

So they’re effective products. They’re very efficacious. They work well. The concern is that these nanomaterials, are they absorbed through, for example, a scratch in the skin. A baby’s skin is a little bit different, so you have to be concerned about absorbing these nanoparticles into the skin. And this is something that’s still being studied.

A lot of implications are they’re not. But then you have to ask, are these things washed off into the environment?

Ecologically, what happens to these nanoparticles as they end up in the environment?

So there are many different aspects to this—in skin breaks, if there’s a rash, something like that, is there more absorption of the nanomaterials and nanoparticles into the body that way? Do they bioaccumulate? What are the effects in wildlife? So there are many different aspects.

And by and large, we’ve just charged ahead and started using these products, in my view, without adequate study.

As a cosmetic, the FDA could declare these chemicals as new chemical entities. So a nano-sized titanium would be declared a new chemical entity, so it would require more testing. Food and Drug Administration elected not to do that.

Particles of a nano-size titanium, it’s not a different physiochemical properties. It’s still considered titanium.

So this was a great deal for the manufacturers that use these materials, but I think they deserve really closed [screening] and making sure we know what we’re doing with these nanomaterails.

DEBRA: If you make a chemical or mineral like titanium dioxide, if you make something into a smaller size, does that make it more toxic?

STEVEN GILBERT: There’s potential for that because it crosses the cellular barriers more quickly. For example, something like silver nanomaterial is a bacterial size that’s designed to kill bacteria. So it’s very effective at that, at killing bacteria.

So, they do interact with biological properties. But the question is, “Are they potentially hazardous?”

This is particularly true for developing organism. Toxicology is built on those responses. And once […] exposure, then what might be the response? How does your immune system respond to this? Does it potentially cause cancer later in life? What are the issues that might be relevant to nanomaterials and nanoparticles?

DEBRA: And we don’t know those yet. So we’ll talk more about nanoparticles when we come back. My guest today is toxicologist, Dr. Steven Gilbert. And his website is, many wonderful things there, including your free copy of A Small Dose of Toxicology.

I’m Debra Lynn Dadd. This is Toxic Free Talk Radio, and we’ll be right back.


DEBRA: You’re listening to Toxic Free Talk Radio. I’m Debra Lynn Dadd. My guest today is toxicologist, Dr. Steven Gilbert.

He’s at where you can download a free copy of his book, A Small Dose of Toxicology.

So Dr. Gilbert, let’s see. What shall we talk about next with nanoparticles?

STEVEN GILBERT: I think a little bit of history is…

DEBRA: Yes, tell us some history because this is not a new thing.

STEVEN GILBERT: It’s not! You’re really right. If you look back historically, one of the first examples of nanomaterial was […] Rome about 300 A.D. And this has […] glass.

So if you look at a glass straight on, it looks opaque and green. But if you shine light in it, it turns red and glows. And this is due to the nanomaterials of gold and silver that are being incorporated into the glass.

In the 1600’s or 1500’s, stained glass windows in European cathedrals contained nanoparticles—gold, chloride and other metals that made the glass really a unique color.

Damascus saber swords, those high-quality swords, […] they’re known for their sharp edges, they’re really related to carbon nanotubes and the nanowires. They discovered this by looking at it with SCAN electron microscope.

So the whole field really didn’t get started up until 1936 right before World War II with field emission microscopes that were developed. These developments were essential to really understand and manipulate matter at the atomic level.

Another […] was Richard Feynman. Your listeners might have heard of him. He’s a […] physicist. He wrote a paper called There’s Plenty of Room at the Bottom and gave one of the first lectures, I think it was in 1959, in technology at atomic scales that have predicted a lot of these scanning electron microscopes built in ’81.

In 1985, […] the buckyballs were discovered at Rice University. This is really a big deal because nanoparticles and nanomaterial, you can store different types of chemicals inside these buckyballs.

And then in 1986, atomic force microscopes—you can see the things really start picking up from the 80’s with the discovery of different materials, and really, the technology to manipulate these.

In 1991 was carbon nanotubes. Carbon nanotubes had a huge impact on materials, the way the materials are used now has carbon fiber in them. Just for example, I just read over the weekend that the Tour de France, the […] bicycle race in France, just ended. But one of the issues has been the bicycles are carbon fiber. And these carbon fibers, they’re a lot of nanotubes, instead of bending in a crash, the spikes shatter.

So they’re very strong and they’re very lightweight. That’s what carbon nanotubes are all about. But they also have some undesirable properties. They don’t then absorb some of the collision. Bicycle race injuries seem to be more severe.

So that’s just one of the implications or the side implications of nanomaterials.

In carbon nanotubes, we fly in them in airplanes, the new Boeing 787. Tennis rackets, all kinds of materials are starting to use carbon nanotube materials.

DEBRA: What exactly is a carbon nanotube?

STEVEN GILBERT: Carbon nanotube is you roll a carbon very thin—like one atom. You can make it a little bit thicker if you likem, but then you roll them up using atomic force instruments. The roll makes them very strong, very lightweight, and you can transfer electricity through them. They have a lot of really interesting properties.

A concern though, from a health perspective, is related to asbestos. Nanotubes have very sharp edges and look a lot like asbestos fibers. So we know from experience that asbestos inhaled can cause mesothelioma, a fatal lung cancer.

So, the concern was if carbon nanotubes would be a potential hazard with […] workers that are responsible for sanding, for grinding, for making nanomaterial up. So this is a worker-related injury. And that’s by and large an issue across the board with nanomaterials. There are worker issues that we need to be concerned about.

DEBRA: Do nanoparticles exist in nature, or are we making particle sizes that are just only manmade?

STEVEN GILBERT: There’s a lot more of them, but they do exist in nature. They’re naturally-occurring. And our […], some of them.

For example, diesel exhaust out of trucks will have a lot of nanomaterial in them. And this is particularly a concern from around ports, from a lot of train and truck traffic going in and out of it. And this becomes an environmental […] People living near the port are exposed to these nanomaterial.

My concern about the nanomaterial, as I’ve mentioned before, they have a large surface volume ratio to their size, so they have very large surface volume, and other materials can be stuck on the surface of these nanomaterial like polyaromatic hydrocarbons. Can they coat that nanomaterial? You inhale those things in your lungs, and then it can be distributed throughout the body.

Nanomaterials are also natural. They can be sea spray, for example, along the ocean waters. Volcanoes will produce nanomaterials and nanoparticles, I should say.

So they’re both naturally occurring. But as usual, with humans, we tend to exaggerate some phenomenon, so now, we’re making all kinds of new and unique […] There’s no natural process that created carbon nanotubes. This is an entirely manufactured material.

Although we have silver, it’s not […] We’re making them and putting them in a whole host of products now.

DEBRA: It seems like this is something that is more difficult to identify than some other toxic things. You can smell formaldehyde, for example, if you know what formaldehyde smells like. You could identify it. But how would one identify that they’re being exposed to a nanoparticle?

STEVEN GILBERT: You raised a really interesting point, Debra. There are no going rules and regulations that says that a manufacturer has to show the product has been demonstrated or acknowledged there’s nanomaterial in a product. So that’s not required.

The FDA just […] start thinking about this our talk today. On June 24th, the FDA came up with some new guidelines around nanomaterials in cosmetics. I should just […] your time if I can find the quote from the…

DEBRA: Actually, we need to go to break in about 20 seconds. How many nanoseconds is that? So you can find it during the break, and we’ll come back and talk about that.

STEVEN GILBERT: That would be great.

DEBRA: Today, we’re talking about nanoparticles with Dr. Steven Gilbert. His website is You’re listening to Toxic Free Talk Radio. I’m Debra Lynn Dadd, and we’ll go to break and come back, and find out what Dr. Gilbert would like to tell us. We’ll be right back.


DEBRA: You’re listening to Toxic Free Talk Radio. I’m Debra Lynn Dadd, and my guest today is Dr. Steven Gilbert. His website is That’s T-O-X-I-P-E-D-I-A dot-org, and you can go download a free copy of his very excellent book, A Small Dose of Toxicology.

So Dr. Gilbert, did you find what you were looking for?

STEVEN GILBERT: I did. Before I go there, I just want to mention one other thing. There’s a great [book] called Prey by Michael Crichton that has nanotechnology, nanoparticles as the theme of the book. So if your listeners are looking for a good summer read, it’s Prey by Michael Crichton.

DEBRA: is that P-R-A-Y or P-R-E-Y?


DEBRA: Aha! Okay, good. Thank you.

STEVEN GILBERT: It’s a fun book. It’s a fun read. I recommend that.

So I think we’re talking a little about consumer products. And I just want to mention, when we talk more about that, particularly, related to silver, for example, one of the products is a bear, a little cuddly bear for your infant. And the product has nanosilver particles in it. It’s […] said that it’s clinically proven to be safer because it has killed bacteria, so you don’t have […] growing on your fuzzy bear.

Now, the problem with that is what do kids do? They stuck on their ears of the bear, they mouth the bear. So there’s a possibility that a kid is absorbing silver nanoparticles, and one of the potential consequences of oral exposure to nanoparticles.

So you might think that these products are all tested before they’re put on the market. That’s not the case.

Let me just read this quote from the Consumer Product Safety Commission. The first part of it sounds good. “The potential safety and health risks of nanomaterials that has another compound that are incorporated into consumer products can be assessed under existing CPSC Statutes Regulations and Guidelines.”

There’s a catch.

“Neither Consumer Product Safety Act nor the Federal Hazardous Substances Act requires the pre-marked registration or approval of products.”

So none actually require the pre-marked registration approval, thus it is usually not until a product has been distributed in commerce that the CPSC would evaluate the product for potential risks to the public.

So my view, we have some of the stuffs backwards where these products are not tested before they’re on the market. And then we decide if there’s any potential harm with that.

Another example of silver materials, silver particles is they’re used in socks to kill the bacteria on the feet. But the problem with this is what happens when your feet have cracks in them, things like that, and all these materials are being absorbed into you, they’re being exposed to your feet.

And when you wash the material, the silver nanoparticles, some of them will leave the socks of the fabric and get into the waste stream, get down into the sewage treatment plants, and then out into the water system. So it’s one of the consequences of silver nanoparticles from an ecological perspective.

So, I think it’s one of the huge struggles from a regulatory perspective, how to manage the explosion of nanomaterials and nanoproducts, products that use nanomaterials in our day-to-day lives.

DEBRA: But there are no regulations for them to apply.

STEVEN GILBERT: Right! It’s been a really tough struggle for that. The EPA would use the TSCA, Toxic Substance Control Act. It was passed in ’76. But we all know that that law is pretty broken, so all these materials are not well-tested. It’s very difficult for the EPA to regulate this.

Nano silver particles, they’ve tried to move it, to regulate them as pesticides, as bactericides which is really what they are.

But the advertisement for the products was that they are naturally-occurring and natural silver-based nanotechnology that’s used to reduce bacteria in these products.

Kitchen silverware, all kinds of new products that are coming out there with silver nanoparticles, and it’s reduced bacteria.

And I want to emphasize bacteria is everywhere. Our tabletops, our everything is […] bacteria. And the important thing is just use soap and water to keep it clean. Don’t use antibiotic-based products, or silver-based products for trying to reduce bacteria in the world unless there’s a real need for it. Just soap and water does a great job.

DEBRA: I agree. I had a guest on, a doctor who wrote a book called Missing Microbes. He was talking about how, because of antibiotics and antimicrobials, we’ve lost 30% of the amount of different types of microorganisms that we should have in our bodies that are helping us.

And so I could see that silver would do the same thing. It’s one of those antimicrobials.

STEVEN GILBERT: Our bodies are very finely-tuned. We’re used to a lot of different kinds of bacteria. We have a little ecosystem of bacteria inside of us. Nanomaterials and antibodies really disrupt those systems. And I think we have to be really cautious about that or minimize our exposure to antibiotics.

Particularly things like […] and triclosans, they just show not to be efficacious. And what you really need to do is keep things as clean as possible with soap and water.

DEBRA: Yes, that will do it.

STEVEN GILBERT: […] clean the house, the first thing you have to do is wash the hands.

DEBRA: Yes, you mentioned that before. I remember that. And I would also point out, I always like to say that doctors in hospitals just scrub. They scrub with hot water and soap.

STEVEN GILBERT: Yes, that’s right.

DEBRA: So, there are no antimicrobials. That does the job, and it has for many, many years, many decades, centuries.

So, should we be concerned about all nanoparticles? Don’t you think that nanoparticles are automatically bad because it’s a nanoparticle?

STEVEN GILBERT: I don’t think so. I think there are a lot of good uses for nanomaterials. There are certainly going to be—like I just had solar panels put on my house. And I’m sure those solar panels, they use nanotechnology. So, there are really some excellent uses.

I think the concern is that we overuse them. Do we really need nano silver particles in our socks, in our bears for our kids, or the blanket for the kid? I think we just have to be a little bit judicious about where we want to use nanoparticles.

They’re widely used in our phones. There’s great advantage to them. Small size is important. They use less energy. For cell phones, this is great. They have the potential to revolutionize batteries.

There are a lot of great uses for nanomaterials. I think planes is another one, light in cars. You need more carbon fiber material.

So there are a lot of important uses, but we just need to be aware and take more of a precautionary approach to when we use them and ask what our exposure is. Do we really want to be exposed to nanomaterials every time we […] like our cosmetics? How much nanomaterials do we want to use in our cosmetics?

There are some that are really useful. Maybe titanium and zinc oxide are safe and efficacious for sure. But how much do we need to use or how careful? My view is always precautionary. We should try to reduce exposure, so we can […] the materials that there are not necessary […]

DEBRA: Also, there’s a big difference between using nanoparticles in cosmetics that you’re putting on your skin, and using nanoparticles in a solar panel that’s on top of your house, in terms of one’s exposure.

And so it’s not necessarily the technology is really bad, it’s mostly overuse, as you said, or having too much use I places where it really doesn’t need to be. And that overloads our bodies. But if we can use these technologies judiciously and appropriately, then they can be beneficial.

You’re listening to Toxic Free Talk Radio. I’m Debra Lynn Dadd, and my guest today is Dr. Steven Gilbert and he’s the author of A Small Dose of Toxicology, which you can download for free at his website, And we’ll be right back


DEBRA: You’re listening to Toxic Free Talk Radio. I’m Debra Lynn Dadd, and my guest today is Dr. Steven Gilbert, a toxicologist, and the author of A Small Dose of Toxicology. You can download your free copy at And also, if you go to, you can find out about his most recent translation of this book into Arabic, and make a contribution there if you want.

How many languages has it been translated into?

STEVEN GILBERT: It’s in English, Chinese, we’re working on Arabic, and our Spanish is going to be our next one.

DEBRA: It’s a great book. It should totally be international. It’s great.

STEVEN GILBERT: Actually, it’s interesting. A German colleague has just started translating it in German on his own. I’m not sure when it will be done, but that’s also in the works.

DEBRA: Good! I think that my book, Toxic Free, is now in five languages or something like that.

STEVEN GILBERT: Wow, that’s great.

DEBRA: Yes, I’m very happy that that has happened. I’m looking at your nanoparticles page on Toxipedia, and I just want to say a few of the known health risks. In sunscreen, it’s been known to damage human colon cells, damage brain stem cells in mice, and penetrate the human skin, entering the bloodstream, posing a threat to the heart, liver and red blood cells. It can travel from mothers to unborn fetuses.

And these are things that are known health risks. There were those studies.

So it’s being used in so many products, and as we said earlier, that it’s not necessarily on the label. It’s not necessarily advertised, and not very well understood.

So in this last segment, let’s talk about how consumers can minimize their risk for nanoparticles.

STEVEN GILBERT: I think the important thing is just be aware of what products might have nanomaterials in them, and […] exposure.

And I think you mentioned too, the really important ones are sunscreens and general class of cosmetics because we’re applying them right to our skin.And [manipulation] materials that might get into the atmosphere is important if you inhale them—and in the water supply.

But I think cosmetics are probably the most important one now. They’re also used in some medicines, things like that.

So I think to try to look into some of the websites where the products might be listed. There’s a really good website called So it’s It’s tried to produce some […] So there are websites that list some of the manufacturers, some of the products with nanomaterials.

But I think the FDA is trying to get their handle on this issue. I think looking at cosmetics, and really demanding of your legislative folks to pass rules and regulations that require labeling—like how many people know that there are nanomaterials in their sunscreens? There’s titanium and zinc oxide, titanium dioxide and zinc oxide in nano scale in sunscreens. They’re not required to label them as such.

And also, as the size of the particles can be very widely—so how much control the manufacturers use over the particle size, and what chemicals might be attached to the particles, is the other really important question because of the surface area issue. There’s a greater surface area to volume ratio, so you get more exposure to any chemicals that are attached to these products. And these products, because they’re small size, they’re great carriers. They move the chemical into the cell, and you get exposure and potential hazard effects from that.

From a toxicological point of view, nanomaterials are complicated because it varies in size, the […] of the materials. They change their physiochemical properties. In my recommendation to be always on the precautionary side is try to limit exposure unless you really need it.

DEBRA: I completely agree with that on every type of toxic chemical there is, or anything that’s unknown. I think one of the biggest problems here with nanoparticles is that the health effects, we’re just starting to look at them. And so we don’t know what the health effects are. We don’t know they’re in the product.

When you were just taking about the different sizes of the nanoparticles, it suddenly occurred to me that nanoparticles are a whole range of different sizes in a range, but they’re all within this very small, infinitisemal size, but they’re not all exactly the same size.

STEVEN GILBERT: And that’s how the manufacturing process works […]. There are some people […] are calling ultra-fine particles which do not quite meet the definition of nano-size.

Remember, […] nanoparticles serve an arbitrary definition. It just said it was 1 to 100-nanometers. So if it’s 101 nanometers, a nanomaterial, there’s a wide range of concern about how the manufacturer […] size, whether they’re clumped together or not.

And really, I want to emphasize too, the occupational health issues. The World Health Organization put out a statement that people that “research, develop, manufacture, package, handle, transport, use and dispose nanomaterials will be the most exposed, and therefore, most likely to suffer any potential human health harms. As such, worker protection should be paramount with any nanomaterial oversight regime.”

And I’d like to add to that, we should be doing a better job of studying the workers because […] their exposure is going to be great, and we can learn a great deal about potential health consequences of nanomaterial by studying the workers.

DEBRA: I would totally agree with that too. That’s exactly where they would be.

STEVEN GILBERT: I think that’s where the exposure would be greatest. You’ve got the greatest volume of material there, and the greatest manipulation of the product both into the atmosphere as well as in the water supply. There’s surface area around that manufacturing process.

DEBRA: I was also thinking about what you said about the nanoparticle silver washing off, and then it would go down into the water system. Would you think that some of those nanoparticles are getting into our drinking water supplies?

STEVEN GILBERT: I don’t think we looked at that. One of the challenges when you do these studies is trying to quantitate the amount of nanomaterial that’s in the medium. So trying to look for it in the water, look for it in the food, look for it in soil is challenging.

But I think that’s something we need to be spending more time on. I think one of the challenges that we should take on is quantitation of the nanomaterial in different media, so we know what our exposure is.

And silver has been used for a long time. It’s used in medicine for a long time as an antibiotic, for example. It was used […] after World War II when antibiotics got more widely used. But now, it’s coming back particularly in wound dressing. So, actually, you use silver nanomaterial in wound dressing.

And generally, people would say—or they’re convinced that silver nano exposure is not harmful for them. The application in medicine […] But still, it’s not clear exactly where all the silver nano parts that are going in the biological system.

So, there needs to be a lot more study—either animal studies or human health studies—that try to quantitate where the nanomaterial is going in our bodies.

DEBRA: So much to learn. In some ways, you and I have both been working in this field for many years in our own respective ways, in decades. And yet, I keep learning more and more, but I keep finding that there’s more and more to know. And I would say that probably, there’s a word just at the tip of the iceberg about what we know about toxics.

STEVEN GILBERT: Really, what’s discouraging to me is that we know better than this. We put asbestos and lead onto the environment to great detrimental effects to many people. Thousands of people have died from mesothelioma from asbestos exposure. Many kids have been harmed by lead exposure as well as […] chemicals.

And what we don’t need to do is add nanomaterial into that. So my view, we should have a much more robust program to study the potential ecological health effects of nanomaterials before we put them in our socks, in our shoes, in our teddy bears, and all kinds of other products.

We should have a pretty good understanding of the life cycle of these products, how they’re manufactured, where they go, […] products, how do we dispose of them, and what happens to them in the waste stream, and what happens, of course, from an ecological and human health standpoint.

DEBRA: I totally agree. There’s so much that you were talking earlier about the Consumer Product Safety Commission making a statement, and this was something that I read many, many years ago.

The Consumer Product Safety Commission is one of the first places I went when I was looking for information about toxics.

And it really is most people don’t understand that there isn’t preliminary testing, that what happens is that the Consumer Product Safety Commission can’t do anything until the product is in use, and consumers start writing to the Consumer Product Safety Commission to tell them that there’s something wrong.

And that’s just backwards. It’s just backwards.

STEVEN GILBERT: It is backwards, and we need a more precautionary approach. So we put human health, ecological health first before using some of these products. So we really go to ask, “Do we really need it?”

Do we really need antibiotics in our soap? That’s one of the great examples of that. Do we really need antibiotics in our teddy bears or nano silver particles in our teddy bears, in our socks? There are some things that you just don’t need.
[…] some nanomaterial in the washing machine. It would add a little bit of silver nanoparticle in the wash water. So do we really need to go there with some of these products?

DEBRA: No, we don’t. We don’t. Well, Dr. Gilbert, it’s been a pleasure talking to you yet again, and I’m sure that we’ll talk to you a lot more.

STEVEN GILBERT: Thanks, Debra. Have a good day.

DEBRA: You too. So you’ve been listening to You can go to Dr. Gilbert’s website, which is Get his book, A Small Dose of Toxicology. It’s absolutely free. You can also go to and find out who’s going to be on tomorrow, and this week. I always have the list of all the guests for the week.

You can also listen to this show again. You can listen to any other shows again because they are all archived.

You’re listening to Toxic Free Talk Radio. I’m Debra Lynn Dadd. Be well.


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