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“Recent advances in nanotechnology and the corresponding increase in its use in the most diverse products and in all sectors of society, has given rise to great uncertainty as to the environmental impacts that these could have in the short, medium and long term. term."
Although nanotechnology is a relatively new subject, it is essential to know the fate, behavior, disposition and toxicity of manufactured nanomaterials and their direct or indirect effects on living things.
The reality is that there is a shortage of research devoted to studying the colloidal behavior and toxicology of nanoparticles, many times due to the limitations imposed by their size. The few scientists who are dedicated to it, warn that we are facing a problem whose consequences could be at least: dire.
Nanomaterials in the environment
There is still a debate regarding the nomenclature associated with nanoscience and nanotechnology, although the definition of a nanomaterial (NM) approved by the British Standards Institution, the American Society for Testing Materials and the Scientific Committee on Health Risks, maintains that It is a material with a dimension that is below 100 nm (nanometers).
Within this group of materials, nanoparticles (NP) are materials with dimensions ranging from 1 to 100 nm and are considered particularly important (and dangerous due to their adverse effects on health), although they have always existed in our environment, from both natural and anthropogenic sources.
Nanoparticles in the air are traditionally known as ultrafine particles, while those in soil and water are called colloids and have a slightly different size range.
Natural and anthropogenic nanomaterials
In urban environments, vehicles and stationary sources of combustion that use material of fossil origin (oil, coal and / or gas), have contributed for many years to the generation of particulate material, in a wide range of sizes, including PN , amounting to more than 36% of the total particle number concentration.
In addition, there is a natural background of PN in the atmosphere, although the overall concentration in general (with exceptions such as deserts) is very low, compared to possible manufactured PN releases.
The health effects of such particles are still being investigated: the traditional PM10 (particles less than 10 microns in diameter) are PM5 and PM2.5; but below, a considerable increase in the toxicity of even finer particles has been identified.
Most of the research carried out in this field to date has focused on ultrafine particulate matter, that is, particles at the nanoscale and its effects on human health, especially at the level of the respiratory system, including oxidative stress and reactions inflammatory and fibrotic.
In aquatic systems, the generic term for nano-sized particles is colloids, and they comprise macro-molecular organic materials, such as humic and fulvic acids, proteins and peptides, as well as microscopic inorganic species.
Although dissolved species are operationally defined as those that pass through a 0.45 micron filter, this fraction also includes colloidal species whose bioavailability is very different from truly soluble ionic or organic metal species and more recent work has emphasized in the necessary separation and differentiation of the different aquatic colloids.
In soils, natural NPs (also called colloids) include clays, organic matter, iron oxides and other minerals that play an important role in biogeochemical processes and have been studied in relation to their influence on its development (pedogenesis). and its effect on structural soil behavior (scattering and crusting).
One of the fundamental factors of this type of particle is that soil colloids and other porous media can facilitate the movement of pollutants, which can be absorbed or incorporated into them and serve as transport when conditions are favorable for it (for for example, through stormwater runoff).
Much remains to be investigated
Scientists recognize that because the particles are so small and have so many ways of spreading, it is not easy to do detailed studies, much less to predict how they will behave, in order to combat this type of pollution invisible to the human eye, but extremely harmful to the health of living beings and for the ecosystem balance.
For this reason, although they remain committed to studying these tiny structures, they call on the world's communities to immediately stop burning fossil fuels, the main origin of the most harmful NPs, and to use renewable energy sources that do not poison soils, water and air.Ecoportal.net