Nanoengineered Nanoparticles in Consumer Goods

Through regulation, all players win and nobody loses.

Preface

Proceeding with the approach initiated in my article "The Roots of Nano-Fear Decoded", I will address in this article other nanotoxicology topic: consumer goods containing nanoengineered nanoparticles. Later on, I will attempt to point out ways and propose solutions in order fight and prevent nanotoxicity.


Introduction

This theme is vast.

It has been developed numerous, responsible and meritorious studies in the field of scientific research in nanotoxicology. However, the need for knowledge in this field is enormous. What has been done is too little when compared with what is still needed.

Since there is a large gap in scientific knowledge concerning nanotoxicology and nanotoxicity, the emergence of new nanoengineered nanoparticles introduced many and new questions and challenges regarding the risks and benefits:

• To the living organisms (including Humans);
• And to the environment.

The nanoscale size of those nanoparticles, associated with their highly increased surface area available for reactions allows them to penetrate the biological structures, enventually interfering with their normal function. Of course, this interference, when occurs may be nanotoxic or beneficial. 

Scientifically evidence-based proofs are the only way to demonstrate the nanotoxicological or benefical effets of each specific nanoengineered nanoparticle, for each specific set of physiological conditions.

Nanoengineered Nanoparticles in Consumer Goods

There are consumer goods being sold as commercial products containing nanoengineered nanoparticles in their composition.

Regarding the possible toxic, harmless or beneficial effect of these nanoparticles to users, the information available to the general public is, in some cases absent or poor and vague.

These consumer products fall into several categories, regarding the use by consumers and the intended purposes.

However, there is a group of consumer goods already introduced into the commercial channels that has been a particular target of debate: cosmetics, sunscreens and personal care products. Follow some examples: 

• Deodorants;
• Soaps;
• Toothpastes;
• Shampoos;
• Hair conditioners;
• Sunscreens;
• Anti-wrinkle creams;
• Lipsticks;
• Blushes;
• Eye shadows; 
• Nail polishes;
• Perfumes;
• After-shave lotions.

At this point, I want to express my personal opinion on this subject (and I want to make my position clear): the presence of nanoengineered nanoparticles in consumer goods is not necessarily harmful, as has been published in a sensationalist way in non-specialized press (especially in a minority of non-specialized press).

I even admit that a significant percentage (or even the most) of these manufacturers have conducted tests in their laboratories in order to ascertain the nanotoxicity or the beneficial effects of these nanoengineered nanoparticles and the results have confirmed its safety. it is common to hear in television ads a phrase like "after tests conducted in our laboratories ...".

I even admit that a significant percentage (or even the most) of these manufacturers has contracted independent external laboratories to carry out tests in order to determine the nanotoxicity or the beneficial effects of these nanoengineered nanoparticles and the results have confirmed its safety. It is also common to hear in television ads a phrase like "after tests conducted by independent laboratories highly accredited ...".

However, given the poor and vague (or totally nonexistent) information provided to consumers about the safety of these nanoengineered nanoparticles in some products and given the noise made by some non-specialized media, the climate of suspicion and fear was installed in a few layers of populations.

Therefore, two questions arise:

• How can consumers rely on the laboratory test results?
• How can consumers rely on the quality of these products?

In my personal opinion, there is only one answer: through regulation.

These products will inevitably need to be tested in the laboratory, being these tests closely monitored by regulatory authorities.

If the different tests are supervised by regulators and the results are approved, then consumers can use these products safely and confidently.

If the different tests - monitored by regulators - are disapproved, then the products must be removed immediately from the market. These manufacturers must reformulate their not approved consumer goods, in order to improve them to the point of being beneficial for consumers. Again, new tests, once approved, will give credibility and confidence to their use by consumers.

Thereby, through regulation, ends the climate of suspicion and fear regarding the introduction of nanotoxic nanoengineered nanoparticles into the skin of consumers and into the environment.

Regulation will put an end to all doubts that perhaps exist: everything will be crystal clear and transparent with regard to this subject. Through regulation, all players win and nobody loses. I highlight here some of the many advantages:

• Citizens are reassured and start to consume these products with confidence;
• This sector is no longer subject to debate and its credibility rises to an even higher level;
• Regulatory authorities demonstrate once again that they are actively monitoring the toxicity risks of society and respond positively and in accordance;
• The nano-fear decreases significantly, walking this way to fade (if additional measures are taken in other fields).

Personally, I admit that these nanoengineered nanoparticles are quite beneficial. But there is nothing like demonstrating this fact to consumers around the world, with the guarantee of the accuracy of regulatory authorities.


"The Wonders and Worries of NANOTECHNOLOGY" Video

On February 7, 2012 was published on YouTube a video titled "The Wonders and Worries of NANOTECHNOLOGY". This great video was directed and produced jointly by:

• Nanoscale Informal Science Education Network (NISE Net); 
• National Science Foundation (NSF);
• www.whatisnano.org.

This video is simply a "must". "The Wonders and Worries of NANOTECHNOLOGY" is a short video (4 min. and 33 sec.) which aims (according to its co-directors and co-producers - and I agree) to aid in the discussion of the societal and ethical implications of nanotechnology.

In my opinion is well worth watching this video several times, due to the extremely important message that transmits. In order to present a practical example of real life, face creams and skin care products as a whole are referred. The video also focuses on promoting debate of the societal and ethical implication of nanotechnology. As the narrator states, "whenever a new technology emerges, it is necessary to evaluate the risks against the benefits".

Some of The Main Types of Nanoengineered Nanoparticles Reported as Nanotoxic

Some of the main types of nanoengineered nanoparticles reported as toxic are (among others) fullerenes, carbon nanotubes (CNTs), inorganic nanoparticles, organic nanoparticles and quantum dots (QDs).

Introduction

Following up the approach initiated in my article "The Roots of Nano-Fear Decoded", and continuing with the approach taken in my previous article - "Indicators of Nanotoxicity" - I will now address another nanotoxicity topic: some of the main types of nanoengineered nanoparticles reported as nanotoxic. Later on, I will attempt to point out ways and propose solutions in order fight and prevent nanotoxicity.

Some of the main types of nanoengineered nanoparticles reported as toxic are (among others):

• Fullerenes; 
• Carbon nanotubes (CNTs);
• Inorganic nanoparticles;
• Organic nanoparticles;
• Quantum dots (QDs).

Fullerenes

Fullerenes are nanoparticles in the form of spherical cages containing 28 to 100+ carbon atoms.

The most studied fullerene contains 60 carbon atoms. This particular type of fullerene is a hollow sphere and its atomic arrangement consists of pentagons and hexagons of carbon interconnected.

The fullerenes show the capability of being subjected to extreme pressures and regain its original shape when pressure is no longer applied - something equal or identical to resilience, I would say.

When the fullerenes are not modified, these molecules do not react with each other.

However, when fullerenes are engineered, some specific carbon atoms may be replaced by other atoms. Consequently, the nanoengineered fullerenes show the capacity of establishing bonds with other molecule. The physical result obtained is a material hard and elastic at the same time.



Carbon nanotubes

Carbon nanotubes (CTNs) are hollow cylinders consisting of a crystalline form of carbon molecules arranged into a hexagonal network of carbon atoms. CNTs can have diameters around 0.7 nm.

Regarding the CNTs length, this can vary between a few nanometres to several millimetres. Each end of a CTN can be opened or closed by a fullerene half-molecule. 

Regarding the complexity of the CNTs wall, there are two main groups of CTNs. These CNTs can have:

• A wall consisting of a single layer: Single-Walled Carbon NanoTubes (SWCNTs);
• A wall consisting of several layers: Multi-Walled Carbon NanoTubes (MWCNTs). MWCNTs can also be perceived as a coaxial arrangement of carbon cylinders of increasing diameters having a common axis.

The diameter of MWCNTs can reach values such as 20 nm. MWCNTs are chemically and thermally very stable. The nanofabrication of MWCNTs normally requires the presence of metals. The presence of these metals (e.g. Co, Fe, Ni, and Mo) can play a significant role on the toxicity of these MWCNTs.

It is considered that a CNT having the dimensions 20 nm width x 2.000 nm length may have 100 x more surface area than a spherical nanoparticle with a diameter of 20 nm. Under specific conditions, this can interpreted as an indicator of high toxicity of the CNTs.

On the other hand, CNTs show a great tendency to agglomerate. This fact may be a cause for a significant reduction of the total area of CNTs capable of interacting with Human cells or their components.


Inorganic Nanoparticles

Inorganic nanoparticles are frequently insoluble or show a poor solubility. Inorganic nanoparticles can be composed of pure metals or various inorganic alloys.

Among the inorganic nanoparticles, nano-titanium dioxide (nano-TiO2) is one of the most studied due to their nanotoxic effects.


Organic Nanoparticles

Organic nanoparticles are also frequently insoluble or show a poor solubility. Organic nanoparticles can be composed of various organic substances. These various organic substances are commonly insoluble polymers. Different organic radicals can be grafted to these insoluble polymers.However, organic nanoparticles can also be materials involving entrapment, encapsulation or surface adsorption of a bioactive substance.


Quantum Dots

Quantum dots (QDs) are nanoengineered nanoparticles.

The main properties of QDs are:

• High photostability;
• Strong light absorbance;
• Excitation by single-wavelength;
• Size-tunable emission.

Due to their physical properties, QDs are considered semiconductor nanocrystals.

QDs are usually composed of a core of a semiconductor material enclosed in a shell of another semiconductor material with a larger spectral band-gap. 

A typical QD has a diameter ranging from 2 to 8 nm.

QDs are extremely diversified. Therefore, the toxicity of QDs requires to be carefully characterized individually for each type of QD.

Indicators of Nanotoxicity

Despite being presented here some of the indicators of nanotoxicity of nanoparticles, there is still a wide gap of knowledge in regard to this specific topic and nanotoxicology as a whole. However, in spite of the wide gap of knowledge, many worthy efforts and a whole series of hard work in this field are underway already. Nevertheless, many challenges are still waiting to be overcome.

Preface

In the alignment of my article "The Roots of Nano-Fear Decoded", and preceding the approach taken in my previous article - "Nanotoxicity in Humans" - I will now address a nanotoxicity overview, dedicated to indicators of nanotoxicity. Later on, I will attempt to point out ways and propose solutions in order fight and prevent nanotoxicity.


Introduction

Traditionally, in toxicological studies carried out at macroscale or bulkscale, the toxic effects are normally correlated to the quantity of toxic product to which individuals are exposed.

This rule of the thumb means that "the greater the mass of toxic substance absorbed, the greater the toxic effect on individuals exposed".


Specific Surface

However, in the case of nanotoxic nanoengineered nanoparticles, once again the macroscale rules don’t apply. It has been demonstrated that the measured nanotoxic effects are not linked to the mass of the nanotoxic nanoengineered nanoparticles.

Several studies find a reasonable correlation between the specific surface of a nanotoxic nanoengineered nanoparticle and its nanotoxic effects.


Several Additional Parameters

On the other hand, several parameters can additionally contribute to the nanotoxicity of nanotoxic nanoengineered nanoparticles. Furthermore, with the currently limited existing scientific knowledge regarding nanotoxicity and nanotoxicology, it is extremely complex to weight the relative impact of each of these factors in order to predict accurately the toxicity of a new nanotoxic nanoengineered nanoparticle under study.

The published scientific literature links the observed nanotoxic effects of nanotoxic nanoengineered nanoparticles to a wide range of different chemical and physical parameters, such as, for example:

• Number of nanotoxic nanoengineered nanoparticles;
• Size of nanotoxic nanoengineered nanoparticles;
• Shape of nanotoxic nanoengineered nanoparticles;
• Surface charge of nanotoxic nanoengineered nanoparticles;
• Crystalline structure of nanotoxic nanoengineered nanoparticles;
• Concentration of nanotoxic nanoengineered nanoparticles;
• Porosity of nanotoxic nanoengineered nanoparticles;
• Electrostatic attraction potential of nanotoxic nanoengineered nanoparticles;
• Degree of agglomeration of the nanotoxic nanoengineered nanoparticles;
• Hydrophilic/hydrophobic behaviour of nanotoxic nanoengineered nanoparticles;
• Synthesis method employed on the nanotoxic nanoengineered nanoparticles;
• Post-synthesis modifications of nanotoxic nanoengineered nanoparticles.

Final Comments

Despite being presented here some of the indicators of nanotoxicity of nanoparticles, there is still a wide gap of knowledge in regard to this specific topic and nanotoxicology as a whole.

However, in spite of the wide gap of knowledge, many worthy efforts and a whole series of hard work in this field are underway already. 

Nevertheless, many challenges are still waiting to be overcome.

Nanotoxicity in Humans

Routes for entry of nanotoxic nanoengineered nanoparticles into the Human body. Destinations of nanotoxic nanoengineered nanoparticles, after entering the Human body.

Preface

Following my article "The Roots of Nano-Fear Decoded", I start here an attempt to approach nanotoxicology and nanotoxicity. Later on, I will attempt to point out ways and propose solutions in order fight and prevent nanotoxicity.



Introduction

As I wrote in "Nanopollution Revised", addressing nanopollution without addressing nanotoxicology is (theoretically and practically) an artificial effort, I would say. Nanopollution is present in the environment, which in turn affects the biosphere (including Humans). The biosphere is exposed to the nanotoxicity and thereby contaminates the environment. There is therefore a circle inseparable. However, due to space limitations, this article will try to address the nanotoxicology and nanotoxicity.

Of course, what I write is in line with the way I understand this issue in the present.

Not all nanoparticles are nanotoxic. In my personal opinion, naturally occurring nanoparticles are not toxic. I can possibly consider some exceptions - if supported by scientific evidence (e.g. nanotoxic natural occurring nanoparticles released in forest fires). However, unfortunately not all forest fires are of natural origin. Nature has already demonstrated many times that knows how to ensure balance and harmony rather than the Mankind knows how. The Mankind must increasingly learn the lessons that nature has to teach us all.

Furthermore, even though some exceptions as valid, it does not seem to me that the nanotoxicity of naturally occurring nanoparticles has meaning when compared with the nanotoxicity (under study) on some nanoengineered nanoparticles.

Moreover, I believe that not all nanoengineered nanoparticles are toxic. In other words, I believe that:

• Only a part of them are nanotoxic;
• Some are harmless to the health;
• And others are beneficial to the health.

Of course that my personal opinion has to be demonstrated scientifically, based on evidences.

Nanotoxicity obviously affects all living beings (including of course Humans). I will focus this article on some aspects of nanotoxicity in Humans, caused by the nanoengineered nanoparticles which are nanotoxic.


Routes For Entry of Nanotoxic Nanoengineered Nanoparticles Into The Human Body

Generally, nanotoxic nanoengineered nanoparticles can enter into the Human body through incidental and/or involuntary episodes. These incidental and/or involuntary episodes may be associated with a lack of knowledge by Humans. Therefore, through episodes of incidental and involuntary nature, the nanoparticles can enter the human body via (not necessarily in that order):

• Inhalation;
• Cutaneous;
• Ingestion;
• Other.

As an example, Humans can:

• Inhale incidentally and/or involuntarily air contaminated with nanotoxic nanoengineered nanoparticles;
• Incorporate into their bodies incidentally and/or involuntarily, through their skin (via cutaneous respiration) air contaminated with nanotoxic nanoengineered nanoparticles;
• Eat incidentally and/or involuntarily food contaminated with nanotoxic nanoengineered nanoparticles; 
• Drink incidentally and/or involuntarily water and consumer drinks contaminated with nanotoxic nanoengineered nanoparticles.

Destinations of Nanotoxic Nanoengineered Nanoparticles, After Entering The Human Body

After entering the Human body, nanotoxic nanoengineered nanoparticles can undergo different fates:

1. Can be totally or partially excreted;
2. Can be totally or partially metabolized;
3. Can be totally or partially cumulated into cells, tissues and organs.

Nanotoxic nanoengineered nanoparticles can be excreted, for example:

• Through the kidneys, during the blood filtration in which the nanotoxic nanoengineered nanoparticles are to be a product of excretion (a constituent of the urine);
• Through the intestines, during the formation of faeces and excreted through the anus;
• Through the sweat glands in order to be excreted in sweat during perspiration;
• Through the lungs (after venous blood having executed gas exchanges with the lung alveoli) being released into the environment during the exhalation.

Nanotoxic nanoengineered nanoparticles can be metabolized: 

• In the liver; 
• In the spleen.

Nanotoxic nanoengineered nanoparticles can circulate in the blood stream and lymphatic vessels. Through this path, they can travel around the entire Human body and eventually accumulate into diverse organs (e.g. brain cells).

Insoluble or low solubility nanotoxic nanoengineered nanoparticles in biological fluids are a great cause for concern.

Some insoluble or low solubility nanotoxic nanoengineered nanoparticles can pass through the several defence mechanisms of the Human body. Thus, these insoluble or low solubility nanotoxic nanoengineered nanoparticles can then be transported through the body in insoluble form. Therefore, some insoluble or low solubility nanotoxic nanoengineered nanoparticles can pass to the bloodstream (blood vessels and/or lymphatic vessels) after passing through the respiratory membranes (pulmonary alveoli, through gas exchanges) and/or gastrointestinal membranes. These insoluble or low solubility nanotoxic nanoengineered nanoparticles are then distributed to various organs and eventually can accumulate at specific locations. 

Other insoluble or low solubility nanotoxic nanoengineered nanoparticles find a direct shortcut to the brain: after inhalation, travel along the olfactory nerves and penetrate directly into the brain neurons.


Final Comment

Given my personal belief that nanotoxicity of nanoparticles is practically caused only by nanotoxic nanoengineered nanoparticles, nanotoxicology and nanotoxicity are relatively new subjects that emerged after the appearance of nanofabrication.

Fighting & Preventing Nanopollution

Although there is much to be done, the fight against nanopollution and its prevention are not exactly in the phase zero. At a given moment, we will see players competing with each other to see who implements the "best of the best practices". This momentum will be highly beneficial to strengthen and implement to a large extension the fight against nanopollution and its prevention. The environment and the people in the world will benefit greatly from this great spiral of sustainability.

Introduction

Following my article "The Roots of Nano-Fear Decoded", and after I have addressed briefly the issue of "Nanopollution Revised", I start here an attempt to point out ways and propose solutions which I believe will help to combat effectively nanopollution.

An effective combat against nanopollution brings in the long term, several benefits:

• Improvement of the quality of the environment;
• Improvement of the quality of the biosphere;
• Improvement of the public health;
• A strong contribution to the dissipation of fear.

I identify three major groups of actions to combat effectively nanopollution:

1. Strategic planning of actions to be implemented immediately or as soon as possible;
2. Preventive actions against the increase in nanopollution;
3. Actions to combat the nanopollution that already exists or to minimize the current levels of nanopollution to levels without great impact. 

Regarding point one, strategy, planning and strategic planning are obvious. If small actions need often a strategic planning, what to say about the combat against nanopollution?

Regarding points two and three, it is, at least to me, hard to separate both issues. The reason is that there is a lot to do. The need for effective measures is so huge, that in practice, each measure can be implemented for preventive purposes and also adapted for combating the nanopollution that already exists (or to minimize the current levels of nanopollution to levels without great impact).

Besides, I believe that it is just impossible to implement points two and three through a sequential way. It would not make sense. Therefore, these two points must be implemented simultaneously.


Strategic Planning of Actions to be Implemented Immediately or as Soon as Possible

A strategic planning of actions to be implemented immediately or as soon as possible requires, at least, the following issues (not necessarily by this order):

• An intense, serious, comprehensive and constructive debate. The problem of nanopollution is relatively new. The approach to combat nanopollution requires new ideas, new concepts, new practices, new scientific and technological approaches. A discussion with the participation of players from different areas of expertise, under the auspices of a constructive atmosphere, may be the embryo of an effective strategy;
• The definition of a chain of strategies and priorities to be implemented. Since there is much to be done (in both prevention and combat), it is essential to set priorities;
• Definition of geographical areas of highest priority;
• Definition which environmental media (air, water, soil) should be the subject of top priority;
• Regulation. To my knowledge, regulation is already underway. It is necessary to continue, be strengthened, extended to all countries, be object of international consensus.

Preventive Actions Against The Increase in Nanopollution And Actions to Combat The Nanopollution That Already Exists or to Minimize The Current Levels of Nanopollution to Levels Without Great Impact

Preventive measures and actions to combat nanopollution require, at least, the following issues (not necessarily by this order):

• The creation of a whole awareness and culture of best practices always under the auspices of an absolute transparency and high sense of responsibility. All people (actors and civil society) must be clearly and responsibly informed, using an accessible language and calling for positive and constructive actions. To hide the reality no longer results (did it ever worked?). Media campaigns must be created, targeting different audiences, carefully planned in order to be both transparent and calling for positive actions;
• R&D. Since nanopollution is closely related to nanotoxicology, will be very useful that R&D covers the two aspects. Follow some aspects I consider important, among many others:
• Intensive studies on nanocharacterization. I have to write this very clearly: nanoegineered nanoparticles are not necessarily nanopollutants. Some may be nanopollutants to the environment, others may be harmless to the environment and some may even be beneficial to the environment. Only intensive and detailed studies of nanocharacterization can demonstrate the degree of dangerousness (or the degree of benefit) of each nanoengineered nanoparticle to the environment, based on scientific evidence;
• Verification of traceability. Much R&D is required as well as a whole platform of collaborative organizations and individuals in order to implement an effective verification of traceability of the nanoengineered nanoparticles which are harmful to the environment;
• R&D of key-technologies to fight effectively, in a clean and safe way the nanopollutants that are already contaminating the environment and biosphere. I would not be surprised at all if it is demonstrated that nanotechnology may offer the best means to combat and prevent nanopollution;
• R&D with the aim of all nanoengineered nanoparticles nanofabricated are biodegradable;
• Practices related to risk. Practices related to risk necessarily involve the following three aspects (among many others): risk monitoring, risk detection and risk assessment. My proposal goes to the creation of a network of nanopollution observatories. I do not mean "a network watchdogs". Rather, I refer to observatories operated by highly qualified professionals, equipped with sophisticated computer technology, databases, GPS technology and operating with the aid of satellites. I mean observatories linked to external probes and sensors placed at critical locations, providing these observatories with real-time data. Therefore, these nanopollution observatories will operate with real-time risk monitoring, risk detection and risk assessment. This modus operandi, as I describe here, will allow the ability to send automatic warnings (or alerts) to the operating teams. The automatic warnings (or alerts) may be scaled in warning (or alert) levels, linked to pre-established protocols of measures to be triggered accordingly - all these observatories linked on a whole network;
• Regulation. Once again, I believe that regulation has a role here which is crucial, fundamental and decisive: without regulation is simply not possible to carry out the prevention or combating nanopollution. The rules must be very clearly defined, with no gaps and no room for bad and/or ineffective practices. Unfortunately, regulation does not fall from a tree like a mature fruit. This concept is even more valid for new technologies and challenges. The regulation is built in stages, gradually, as the information arrives, is analyzed and conclusions are taken, matured and consolidated. New unforeseen situations arise and the cycle tends to repeat itself. Regulation must take into account all matters discussed above and many others. Some aspects must be considered more important, others less important. Since nanopollution affects the environment on a planetary scale, regulations must also require the participation and consensus of all countries. Regulations to combat and prevent nanopollution must involve experts and players from various sectors around the world, working in a collaborative context with the aim of building a better environment on a global scale. All countries must provide real-time data (not periodically) to a multinational organization to monitor compliance or infringement of the rules established. Measures must be studied to be applied in case of any country violating these regulations. Sanctions must be applied to infringing countries; 
• Change of change of mindset, attitudes, habits and practices:
• Education of professionals in the industry in changing processes and practices that facilitate the fight against nanopollution and its prevention. Once again, a whole wide culture of best practices needs to be strengthened, intensified, generalized and adopted as the best and the wisest option;
• Education of populations in changing habits and practices that facilitate the fight against nanopollution and its prevention.

The Great Spiral of Sustainability

Some important steps have been taken. Although there is much to be done, the fight against nanopollution and its prevention are not exactly in the phase zero. Much hard work has already been developed in various fields (including regulation, nanocharacterization, risk monitoring, risk detection, risk assessment and others).

There is one aspect here that I consider very important to highlight. There is a vast and diversified whole chain of actors related to nanoscience and nanotechnology (I do not just mean only the industry and the scientific community).

It has been triggered somewhere in this chain the implementation of a culture of best practices. It is extremely important that this culture (still in the embryonic stage) is strategically maintained and strengthened in order to gain social impact. If this culture of best practices gains social impact, it will generate a kind of chain reaction of the whole chain of actors I just described above. This process will generate a highly positive effect that will gradually raise awareness in all persons and actors in this chain.

At a given moment, we will see players competing with each other to see who implements the "best of the best practices". This momentum will be highly beneficial to strengthen and implement to a large extension the fight against nanopollution and its prevention. The environment and the people in the world will benefit greatly from this great spiral of sustainability.

Nanopollution Revised

Since naturally occurring nanoparticles are not pollutants (according to my personal opinion and of some authors), nanopollution only began after the appearance of nanofabrication of nanoengineered nanoparticles that are hazardous to the environment. Therefore, nanopollution is a considerably recent phenomenon.

Preface

In my last article ("nanopollution") I wrote about this subject briefly. After publishing the article, I reviewed some concepts. My ideas were consolidated and I believe that my perspective changed for the better. Thus, for reasons of loyalty to my readers, here are my revised concepts of nanopollution.


Introdution

Following my article "The Roots of Nano-Fear Decoded", I start here an attempt to point out ways and propose solutions in order to demystify the nano-fear.

From what I can understand, the roots of fear seem to be of the fasciculate type. In other words, there are not a "primary root" and "secondary roots". I choose to state that they all have approximately an identical importance.

Addressing nanopollution without addressing nanotoxicity is in theory and in practice an artificial effort, I'd say. Nanopollution exists in the environment and affects the biosphere (including Humans). The biosphere is exposed to nanotoxicity and, in turn contaminates the environment. We are therefore facing an indissociable circle. However, due to space limitations, this article will try to address nanopollution revised. Later I will write about combating nanopollution. Only then I will address nanotoxicity. Naturally, what I write is in line with my way of understanding this issue, in the present.

Before I start writing about nanopollution, I propose a brief analysis of pollution as a concept.


Pollution

Pollution is the introduction of contaminants in the natural environment. Pollution causes instability, several disorders, harm or discomfort to the ecosystem.

The ecosystem comprises:

• Physical systems;
• Systems of living organisms (including humans)

Pollution may involve:

• Chemicals;
• Energy in various forms (e.g. heat, noise, radiation).

The presence of pollutants in the environment is the cause pollution. Pollutants may be coming from either:

• Naturally occurring substances (or energies);
• Substances (or energy) which is strange to the environment (contaminants).

Nanopollution


I will continue to follow the same thinking regarding pollution.

Nanopollution is the introduction of nanosized contaminants in the natural environment. Nanopollution causes instability, several disorders, harm or discomfort to the ecosystem.

The ecosystem is the same, whether we are addressing pollution or nanopollution. The ecosystem comprises:

• Physical systems;
• Systems of living organisms (including humans)

The presence of nanopollutants in the environment is the cause nanopollution.


Nanoparticles

Some authors claim that the nanopollutants can be naturally occurring nanoparticles or nanoengineered nanoparticles.

In the case of naturally occurring particles, however, some authors claim that these are non-polluting. Personally, I share this position. Nature produces and always produced nanoparticles. I believe that naturally occurring nanoparticles have always existed on our planet, even before there was life. Naturally occurring nanoparticles have never constituted an obstacle to that life came up our planet. These naturally occurring nanoparticles also have never been an obstacle to biological evolution of species until today.

Follow some examples of naturally occurring nanoparticles:

• Nanoparticles expelled by volcanoes, along with ash and other natural materials;
• Nanoparticles naturally occurring on the ocean spray; formed by the violent burst of waves;
• Nanoparticles naturally occurring in mineral composites;
• Nanoparticles naturally produced by living organisms.

Nature produces mechanisms for its own balance. If naturally occurring nanoparticles are produced by nature, then, not only are not pollutants as also play a necessary role in establishing the ecological equilibrium. This is my personal opinion about naturally occurring nanoparticles.

Regarding, nanoengineered nanoparticles, as I pointed out on "The Roots of Nano-Fear Decoded", nanoengineered nanoparticles are nanoparticles produced by Humans that have been specifically designed for a specific function (e.g. packaging coating, protection of radiation in sunscreens).

In the case of nanoengineered nanoparticles, I have to put this idea very clearly. Nanoegineered nanoparticles do not necessarily have to be nanopollutants: some may be nanopollutants to the environment; others may be harmless to the environment and some can even be beneficial to the environment. Only through intensive study and detailed nanocharacterization (among other scientific studies) it is possible to demonstrate - based on scientific evidence - the degree of hazard (or the degree of benefit) of each nanoengineered nanoparticle to the environment.

Still with respect to nanoengineered nanoparticles, I believe they only recently came into existence through the processes of nanofabrication.

Studies suggest that nanoparticles are, by nature, extremely reactive. This means that the nanoparticles are most commonly found clustered in groups or linked to other atoms, nanostructures, organic material or blends than in its native form. With respect to the nanoengineered particles that are pollutants to the environment, and the ones which are nanotoxic, these authors claim that, through high reactivity, the degree of hazard or toxicity is greatly reduced.


How Can The Environment Spread Nanoparticles to The Entire Biosphere?

Nanoparticles are present in the air, in the water and in the soils. All requirements for the entire biosphere is contaminated with the ubiquity of nanoparticles are gathered.

For example, nanoparticles present in the air:

• Mix with humidity also present in the air. Consequently, precipitation (e.g. rain, sleet, snow) become contaminated with nanoparticles. Precipitation reaches the soils and the open water (oceans, seas, rivers, lakes); 
• Are incorporated in plants through their by the aerial components, for the processes of photosynthesis and respiration; 
• Are incorporated in animals through respiration; 
• Contaminate food exposed to air; 
• Contaminate drinking water exposed to air; 
• Are mixed with open water (e.g. oceans, rivers, streams, creeks, lakes); 
• Are infiltrated in soils.

For example, nanoparticles present in the water:

• Pass into the atmosphere accompanying the water vapour during the evaporation of water;
• Contaminate soils (trough groundwater);
• Are absorbed by roots of aquatic plants;
• Are absorbed by aquatic animals;
• Contaminate food during the process of washing with water and when water is used to cook.

Nanoparticles present in soils:

• Pass into the atmosphere accompanying the water vapour during the evaporation of water; 
• Are absorbed by underground roots of terrestrial plants; 
• Are absorbed by underground and terrestrial animals; 
• Contaminate groundwater. 

On the other hand, nanoparticles present into plants and animals traverse the entire food chain until reach Humans.


Final Comments

There are some ideas that I want to present here:

• Since naturally occurring nanoparticles are not pollutants (according to my personal opinion and of some authors), nanopollution only began after the appearance of nanofabrication of nanoengineered nanoparticles that are hazardous to the environment. Therefore, nanopollution is a considerably recent phenomenon; 
• Regardless of the degree of risk of nanoengineered nanoparticles (pollutants, harmless or beneficial), they are present in the environment and human beings are exposed to them.