The Ingestion Pathway
As already mentioned, particles float in the atmosphere and are carried mostly by the wind. The smaller their mass, the longer their stay in the air, and the farther they can travel. In the long run, however, they all fall to the ground, and their fall can take place on fruits, vegetables and cereals, where they become part not only of our food but also of that of the animals destined to become our food and of their products. So, those particles are ingested, but most of the times we don't notice.
With an increasing frequency, micro- and nanoparticles are deliberately added to food, drugs and even chewing gums, toothpaste and accessories like toothbrushes and interdental floss, that is, something which is not food but which enters the mouth. Food industries add other inorganic material to the organic food in order to increase some properties (conservation, nutritional, aesthetic, or just commercial purposes). But there is the possibility of another contamination coming from the industrial processes of the food preparation, and that comes by using tools which can release something in the food.
In any case, pollutants and additives are regularly ingested by mostly unaware people. From the qualitative point of view, the biological effects induced by those particles are in no way different
Advances in Nanopathology: From Vaccines to Food
Antonietta Morena Gatti and Stefano Montanari
Copyright © 2021 Jenny Stanford Publishing Pte. Ltd.
ISBN 978-981-4877-29-9 (Hardcover), 978-1-003-05622-5 (eBook) w w w. j e n ny sta nf o rd. co m from the environmental pollution’s ones, the only visible difference when observed through an electron microscope being the shape and composition consistency of engineered particles as compared to those produced as a random side effect by sources like, for instance, waste incinerators.
The vast majority of those ingested particles are eliminated mixed with faeces, but part of them touch the walls of the stomach or of the intestines and stay there long enough to be captured by the tissue and, eventually, negotiate it.
The main difference between ingested and inhaled particles is size. While only the finer particles can overcome the barriers of the upper respiratory tract and then those of the progressive narrowing of the bronchial diameter, ingestion offers a much wider passage. So, particles of virtually any size can be found in all the digestive system, and some of them, even as big as a few tens of microns, can be detected in the stomach’s and the intestine’s wall thickness. Part of them, especially those with a smaller size which are not stopped and kept in the digestive system's walls, enter the bloodstream, like the ones coming from the lungs. Inflammatory conditions, no matter how originated, make the intestine wall particularly permeable to the passage of particles, triggering a vicious circle: particles cause inflammation, and inflammation opens the way to larger and larger particles with a stronger and stronger inflammatory effect.
‘Der Mensh ist was er isst', which, translated into English, is ‘Man is what he eats.' The sentence belongs to Ludwig Feuerbach and, nowadays as when it was written, keeps being largely misunderstood. Actually, the nineteenth-century German philosopher did not mean anything having to do with food science, but if we take those words in their unintended sense, we can find a lot of truth in them. Man depends on food much more than is generally believed, since food is not a simple fuel for our engine meant to give it the energy necessary to keep our organism alive but is an extremely refined mixture of treasure and poison.
‘One-third of what we eat serves to keep us alive. Two-thirds, to keep doctors alive.' The sentence sounds like an aphorism just written but, in fact, can be read in an ancient Egyptian papyrus. From that, we can draw many conclusions, the first of which is that, in the millennia passed since, we have not made great progress.
This book, and, more in particular, this chapter, are not intended as a text of dietetics, and what will be discussed in its pages is only the more or less deliberately planned and more or less known content of particles in what we eat. Some brief mention of other pollutants will be given because, as everything concerning toxicology and as has been said more than once in these pages, poisons do not just add up arithmetically their actions but often those deleterious actions are mutually synergistic, and their results may be totally unexpected.
We said that particles fall everywhere, including vegetables. It is only obvious that, at least in most cases, what is found on the surface of those vegetables can be easily enough washed away, but the particular conformation of certain products does not allow the operation to be successful. Broccoli and cauliflowers, for example, have a very rough surface in whose recesses dust creeps and it is practically impossible to get rid of it, no matter how carefully we wash them. Many cereals such as wheat are ground without having been previously washed, and dust becomes inevitably part of the flour. In addition, flour is rather often polluted by the particles produced by grinding operations and, in particular, by the wear of the machinery used. As a personal experience, we found grain polluted by waste, as it was illegally transported in trucks which, in their previous trip, had contained urban and industrial debris: an operation repeated innumerable times (Figs. 5.1 and 5.2).
Figure 5.1 Polluted corn. The particles which can be seen in the low-magnification electron microscopy image were attached to the grain kernels recovered from a truck which, before transporting grain, had transported waste of unknown origin. The presence of titanium could only be explained by knowing what the truck had transported before.
Figure 5.2 Pollution detected in a truck carrying corn. In the truck transporting grain after transporting waste, micro- and nanosized particles with the most varied compositions were detected. Not knowing the type of waste, it is impossible to establish what their origin was. Given the composition, it is not unlikely that at least part of the load was made of incinerator ash. Although it is forbidden to use a truck to transport waste and food, the practice is quite widespread.
But particles fall also on the soil, thus interfering with the growth of plants, and as a matter of fact, this kind of pollution makes organic food, at least as seen from this point of view and disregarding the rest, not particularly different from non-organic, since there is no way to protect crops. Paradoxically, at least if the point of view is only that of the pollutants fallen from the sky, the plants grown in a greenhouse are cleaner and, therefore, healthier than those grown outdoor.
Particles - for example, silver, it being a component of some pesticides - can also be found in fodder for livestock, and that pollutant ends up in their tissues, that is, finally, their meat.
In many cases, fallen or purposely administered particles alter the microflora and microfauna of the soil by changing its chemical characteristics (e.g. through corrosion and the introduction of foreign chemical elements), including pH. This causes the implementation of a selection of the microorganisms to the detriment of the balance necessary for the conservation of the crops.
It must be added that, sooner or later, particles and chemical elements reach the groundwater, a phenomenon which can reach an imposing size below certain landfills. It is important to realise that, as a matter of fact and as already mentioned, purifying an aquifer is technically impossible. One can only stop immediately to pollute and wait for the water contained in the groundwater to be replaced by another which is clean. The phenomenon can take decades but only if the landfill responsible for pollution disappears. Otherwise, the pollution can remain virtually forever.
Non even oceans, lakes and rivers are saved. In addition to the falling dust and directly discharged urban and industrial waste, water contains huge quantities of particles arriving through rivers, and, therefore, even of very distant origin. Unfortunately, those particles, along with other pollutants, can be found in the fish and clams we eat.
Once we had a chance to analyse an organic cabbage which proved to be polluted by fine basalt dust The area where that vegetable had been grown was situated on the slopes of Mount Etna (Italy), a volcano which was erupting at the time of collection, so people like us living more than a 1000 km away could ingest those pollutants by eating that cabbage.
Similar events can very frequently happen with flour, a commodity which is often imported from far away, and in most circumstances the buyer does not know anything about the conditions under which the wheat had been cultivated. So, bread, pasta, cookies, cakes and all other flour products can carry a pollution which is unsuspected.
In a study we published in 2009, we showed the results obtained by analysing flour-based foods taken from different countries and continents. In 40% of cases we found them polluted by inorganic micro- and nanoparticles.
The pollution of the flour could have come from various, different sources: from environmental situations where the cereal had grown, from polluted soil or from processing residues, often caused by mechanical metal organs which are worn and whose residues inevitably end up in the flour .
Since the flour is imported from countries which can be very far from those where it is processed, it happens to find products polluted by particles which can come from far countries, even from different continents.
One of the current uses of vegetables, not rarely mixed with waste, is as (lignocellulosic) biomasses to be either burned directly in order to generate energy, or to be fermented, thus producing a mixture of gases (carbon monoxide and dioxide, nitrogen oxides, volatile organic compounds whose composition depends on what takes part in the reaction, etc.) which is used as fuel under the name of ‘biogas’. The residue of direct combustion is a mix of different ashes which can be used as an additive for fertilizers (in spite of its content of heavy metals, polycyclic aromatic hydrocarbons, chlorobenzenes and other pollutants), while the solid and slurry residue of fermentation called compost is often used as an improver for the quality of soil. The collection we made of plants of chamomile, dandelion and ears of corn in an area over which compost had been spread showed how those vegetables were severely malformed (Fig. 5.3).
Figure 5.3 Malformed plants. The images represent a malformed chamomile and a malformed dandelion collected in an area polluted by biogas plant compost.
Under the 16th European Biosolid & Organic Resources Conferences (Leeds, UK 14-16 November 2011) a seminar was held, entitled ‘Botulism and Other Scares: How Do We Reassure the Public on the Safety of Recycled Organic Wastes’. In that circumstance, Professor Henge Bohnel of the University of Gottingen (Germany) reported that Clostridium spores responsible, inter alia, for botulism and tetanus are present in the territories treated with that kind of compost.
There are cases where vegetables currently used as food are polluted on purpose with particulate matter. Polished rice treated with paraffin and then dusted with talc is an example. It should be recalled that talc, when ingested, is a carcinogen to the stomach and that one of its pollutants is asbestos and another is uranium (Fig. 5.4) .
Figure 5.4 Talc. It is a common practice to sprinkle talcum powder on children, especially after washing them. Talc also enters several adult health products. Talc is a mineral reduced to very fine dust down to the size of nanoparticles. Like any other powder, talc can also be easily inhaled and breathed and, as it is not biodegradable, is a potential cause of nanopathologies. The analysis we carried out shows that talc contains thorium and uranium as well as elements such as lanthanum, praseodymium, cerium and neodymium.