The fascinating and controversial world of nanotechnology has undoubtedly brought numerous innovations and advantages to multiple sectors of applied science and, consequently, to our daily lives. However, the potential medium- and long-term impacts on our health are still unknown and remain the subject of extensive scientific research by all relevant regulatory agencies. Let’s analyze the current state of nanotechnology together.
What are the properties of nanoparticles?
As the name suggests, nanoparticles have nanometric dimensions. This peculiarity grants them specific characteristics:
- Unique intrinsic properties: Optical, mechanical, magnetic, conduction, and absorption properties can be very different from those of the same substances on a larger scale.
- Cellular penetration: They can cross cell membranes and, in theory, be transported anywhere, thereby interacting with biological systems and accumulating in various tissues.
- High surface-to-volume ratio: This gives nanoparticles a high capacity for reactivity and catalysis, making them potentially very disruptive to the sophisticated and highly regulated chemical reactions that occur within our bodies.
Where can nanoparticles be found?
If we look closely, nanoparticles can be found everywhere: in combustion fumes, technological devices, cosmetics, yarns, household furnishings, packaging, and medicines. Currently, more than 500 products contain nanomaterials among their ingredients or components, with which we can come into contact through inhalation, dermal absorption, and ingestion. Examples include:
- Sweets and candies are made more appealing by the food coloring E171 (titanium dioxide). In addition to being linked to intestinal inflammation, it can be contaminated by about 3% pure titanium, whose toxicity is under significant suspicion.
- Kitchen utensils are coated with a nanometric layer of synthetic or metallic origin to give them a characteristic appearance or a “natural stone” finish. If this coating is cut or scratched, it can become a source of nanoparticles that are then ingested through food, causing intestinal inflammation.
- Indirect production: Some nanoparticles are produced indirectly by natural phenomena such as lightning, eruptions, and fires. Others are man-made through industrial processes, thermal power plants, incinerators, and road traffic, contributing as a whole to air pollution and various lung pathologies.
Are nanoparticles safe or dangerous?
Given the many sectors and situations in which nanoparticles are present, studies on the possible risks associated with them are continuous and increasingly in-depth. Let’s look at a few.
The EPA and Nanoparticles
The EPA (U.S. Environmental Protection Agency) is monitoring the sustainability of many nanomaterials, determining potential exposure and concentration limits throughout the entire life cycle of products—from extraction or synthesis to disposal. Materials under the magnifying glass include:
- Carbon nanotubes found in vehicles, electronic circuits, and flat-screen televisions;
- Cerium oxide nanoparticles, used as an additive for fuels and medical supplies;
- Titanium dioxide and zinc nanoparticles, key ingredients in cosmetics, sunscreens, food preservatives, and paints;
- Silver nanoparticles found in textiles and packaging;
- Iron nanoparticles used in optics and wastewater purification.
The SUN Project
Another program aiming to contribute to the knowledge of potential risks that nanomaterials might pose to health and the environment is the European SUN project (Sustainable Nanotechnologies Project). Coordinated by Professor Antonio Marcomini of Ca’ Foscari University of Venice, 100 scientists from 25 research institutions and industries across 12 European countries are analyzing the risks of nanoparticles from production to disposal. Among the nanomaterials analyzed are carbon nanotubes, silver nanoparticles, titanium dioxide, pigments, and silica anti-caking agents. The 140 scientific articles produced have been instrumental in developing guidelines for safer products and manufacturing processes.
The intervention of the “Que Choisir” association
In 2018, the French consumer association Que Choisir exposed 9 companies for failing to declare the presence of nanoparticles in their products. Undeclared traces of nanoparticles—such as titanium dioxide, silica, iron and zinc oxides, and carbon black—were detected in 87% of the food products and 39% of the cosmetics analyzed. A notable example was Mars’ famous M&M’s peanut candies: 35% of the titanium dioxide was found to consist of nanoparticles.
EU-OSHA and Legislative Provisions
Further reflection is needed regarding the risks for those who produce or are exposed to nanomaterials, for which there are not yet legislative exposure limits, only reference values. EU-OSHA (European Agency for Safety and Health at Work) recently updated its information sheet, focusing on nanomaterials manufactured in the workplace. The topics addressed range from detailed information on regulations and health risks to advice on preventing and mitigating worker exposure.
What are the benefits of nanoparticles?
The unique characteristics of nanoparticles listed earlier are essential for them to provide the significant benefits for which they were studied and synthesized:
- Oncology: Interaction with cancer cells to amplify signals in MRI or CT scans has allowed for a substantial step forward in early cancer diagnosis.
- Targeted Therapy: The ability to be transported in the bloodstream, directing a drug selectively toward the tissue to be treated, allows nanoparticles to reduce the quantity of medication required while slashing side effects.
- Metabolism: Trace elements, fundamental for the efficiency of many biochemical reactions underlying our metabolism, can be delivered in nanoparticle form to improve absorption.
Certainly, nanoparticles, nanomaterials, and nanotechnology in general represent the future—provided that this evolution goes hand in hand with a full awareness of the limits necessary for the safety of the environment and humanity. At Nanomnia, we work with biocompatible and biodegradable nano- and microparticles, ensuring no side effects for humans or animals and leaving no residues in the environment.
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