How is particulates or ultra-fine dust actually created?
particulatesespecially ultrafine dust, does not occur in nature. particulates is produced by friction, combustion processes and chemical reactions when nitrogen dioxide reacts to form secondary particulates . It is therefore possible that the particulate matter value of an exhaust measurement is inconspicuous, but secondary particulates is formed with a time lag.
Increasingly improved combustion processes tend to produce smaller particulates or ultra-fine dust in favor of a reduction in coarse fine dust.
"For example, high-pressure direct injection engines cause significantly more particulates (ultrafine dust) than conventional engines did, because the fuel is already broken down into ultrafine particles before combustion. This lays a foundation for the emission of ultrafine dust," says Frank Hoferecht, an expert for particulates from ETE EmTechEngineering GmbH - the first spin-off from the DBFZ Deutsches Biomasseforschungszentrum gemeinnützige GmbH.
Not to be neglected are the fine dusts produced by tire and brake abrasion during vehicle use. "This is also the case with modern electric vehicles," adds Frank Hoferecht.
particulates, ultrafine dust, nanoparticles: What are the differences?
particulates is not the same as particulates. It is important to look closely here. The amount of particulates is usually measured in µg/m³ (micrograms per cubic meter). This ignores the fact that particles with a size of 10 µm (PM10) - also known as coarse fine dust - and PM1 have a volume ratio of approx. 1: 1,000. Accordingly, a particle PM10 weighs about 1,000 times more than a particle PM1 at the same density. For PM0.1 (ultrafine dust), the factor is even 1: 1,000,000 compared to PM10. Thus, for one particle PM10 there are one million particles PM0.1 (ultrafine dust) with the same quantity µg/m³.
This results in a potential misinterpretation: Usually, the measured value to particulates PM10 also includes all smaller particles (i.e. also PM2.5, PM1 and even ultrafine dust). In practice, however, there are several problems:
- Differentiated statements about the various particles cannot be made. For example, if the number of PM10 particles has been reduced, there may still be considerably more fine dust particles in the air. Therefore, PM1 should be measured separately in addition to PM2.5. Furthermore, it is advisable to record the number of particles and not just the mass. Although this makes no difference to scientists, it clarifies the effect for laypersons.
- Although current sensors measure according to the principle that all smaller fine dusts are also counted, for technical reasons they cannot fully detect the smallest particles. This is particularly the case with inexpensive measuring devices. Often, according to the manufacturer's data sheet, only a maximum of 10 percent of the smaller particles are detected.
- Thus, statements that filters reduce the proportion of fine dust particles cannot be made across the board without also conducting separate studies in the coarse fine dust, particulates (PM2.5) and ultra-fine dust range (PM1; PM0.1 and below).
How dangerous are nanoparticles?
Over 95 percent of the lung surface consists of thin alveolar tissue. The delicate tissue of the alveoli enables the efficient exchange of oxygen and carbon dioxide with the blood. It also provides a tissue barrier, only 1 micrometer thin, that prevents larger particles from entering. Smaller particles, such as nanoparticles measuring less than 20 nanometers, nevertheless pass through and can distribute themselves in the organism much better than larger microparticles. The smaller the particles, the more reactive they are. This is due to the surface-to-volume ratio. Via the bloodstream, the particles reach all organs such as lymph nodes, spleen, bone marrow, placenta, liver, kidney, heart or even the brain. When we breathe in ultrafine dust and nanoparticles, they penetrate deep into the body and can cause health effects here.
While biodegradable materials are diluted by mixing with body fluids and dissolve over time, biodegradable materials settle in tissues and cells. This becomes dangerous when such biodegradable nanoparticles contain transition metals and/or their oxides, for example zinc, cadmium, copper or silver. These metal ions are released in the organism and can, under certain circumstances, have a toxic (poisonous) effect. In addition to the size and composition, the shape of the nanoparticles is also decisive in their effect. For example, fibrous particles are characterized by aerodynamic properties that can penetrate even deeper into the lungs and deposit there more effectively than spherical particles with the same mass. Fibrous nanoparticles occur, for example, in asbestos or in carbon nanotubes.
Through so-called endocytosis, a cellular transport process, metal-containing nanoparticles overcome the cell membrane and thus gain access to every body cell. At a pH of 4 to 5, even poorly soluble metal oxides are readily soluble. If the substances dissolve inside the cell, metal concentrations arise that the cell can hardly defend against. The cell reacts with stress and inflammatory reactions, and cell death can also be a possible consequence.
Possible effects & impending health risks from nanoparticles
Nanoparticles are often not recognized by the natural cleansing cells of the immune system, the macrophages. This enables the ultrafine particles to penetrate membranes and mucous membranes. Thus, they can accumulate on the lung tissue or enter the blood via the lungs. The deposited nanodust can trigger both acute effects such as cardiac arrhythmias and long-term effects on the lungs.
Potential health effects from nanoparticles:
- Chronic lung disease & increased likelihood of lung tumors.
- Increase in inflammatory markers in the blood
- increased tendency to blood clotting
- increased risk of cardiac arrhythmia and heart attack
- Allergies & eczema (e.g. hay fever, elevated IgE antibodies against common allergens)
- local inflammatory reactions (fibrosing/scarring changes in the lungs)
Large population studies show that the effects of ultrafine dusts and nanoparticles are particularly evident in children, who experience increased respiratory infections.
How is particulates deposited?
particulates has a tendency to agglomerate, i.e. to accumulate. This is caused by van der Waals interactions, which ensure that particles attract each other at the molecular level. This is why fine dust particles have a tendency to bind together. Ultrafine dusts and fine dusts easily attach to dust that is similar in substance. The accumulations (agglomerates) thus formed over time are eventually so heavy that they fall to the ground. This effect can be accelerated by high humidity or rain.
If large particles (dust and coarse dust) are removed from the air, particulates and ultrafine dust particles remain. Due to their size and the lower van der Waals forces of these particles, they meet much less frequently and therefore adhere to each other less often. Dust and coarse dust have been filtered out of the air over the years by ever-improving filter technology in vehicle exhaust systems. What remains are the fine and ultrafine dusts whose occurrence cannot be reduced by filter technology.
"According to the latest studies, smaller fine dust particles and ultra-fine dust remain in the air for a very long time, in some cases indefinitely, because they do not fall to the ground," argues Hoferecht of ETE EmTechEngineering GmbH. There is thus a danger from very small fine dust particles that has so far been underestimated.
The latest studies show that especially small fine dust particles are much more harmful than large fine dust particles, as they penetrate the alveoli into the bloodstream and also into human cells. There, they can cause inflammatory reactions that can lead to cancer. The incidence of disease and mortality, especially in large cities and conurbations, is increasing dramatically 1.
Nanoparticles & pollutants from laser printers and copiers
Nanoparticles such as ultrafine dust are not only released into the air by traffic exhaust. Another source of air pollutants is technical equipment such as laser printers and copiers. It is estimated that more than one billion laser printers and copiers worldwide emit a mix of fine dusts, nanoparticles and pollutants unfiltered, thus polluting the air that humans and animals breathe. The emissions contain metallic as well as carbon nanoparticles from the toners, which enter the body with every breath. The nanoparticles can be deposited in the lungs, in the blood and in all organs and cells reached and trigger cell-damaging oxidative stress, inflammations or even genotoxic effects.
Typical symptoms of nanoparticle exposure from laser printers
Do you often have to deal with laser printers, fax/copier machines or toner dust - for example in the office or at your home workplace? Then you should pay attention to possible effects. Observe your health as well as your well-being in the vicinity of the devices. Do the following symptoms occur frequently?
- Cold symptoms such as sneezing, runny nose, cough, sore throat, asthma or chronic bronchitis (COPD).
- Red, itchy, burning eyes
Reddened skin, itching, pustules, especially in the unclothed area such as the face, décolleté or on the hands - Headache or pain in the musculoskeletal system, especially in the muscles
- Inflammation of the bladder or prostate
- Concentration, memory and word-finding disorders
- Exhaustion, burnout or depression
Do you notice the symptoms regularly in contact with the devices and do the complaints subside when you are on vacation, for example, and therefore not in the vicinity of the devices? Furthermore, do the symptoms intensify when the devices run more or when there is less ventilation? Then the toner or the emissions from the devices could be the cause of your complaints.
How to reduce impact from laser printers & copiers?
- Prefer to print with an inkjet printer (ink, instead of toner)
- Always use a filter for laser printers (toner-based printing systems).
- If possible, place laser printers and copiers in separate rooms. Ideally, this room should have its own supply and exhaust air that is not coupled with the central air conditioning system for supply and exhaust air.
- Check the air quality with an air meter such as the air-Q.
Tip: nano-Control, the international foundation for healthy indoor air, advises companies, schools, daycare centers, authorities and organizations. In doing so, the foundation shows concrete measures and developments on how safe printing is possible.
particulates reliably detect with the air-Q air meter
The air analyzer air-Q can particulates detect different particle sizes. With the sensitive air measuring device, you can detect all three different sizes PM₁, PM₂,₅ and PM₁₀ in real time via sensors. If the fine dust value or the limit values of other air pollutants are exceeded, the air-Q sounds an alarm. Using the intuitive traffic light system, you can see via the LED lights whether and how the air quality is changing. The tables and charts in the web browser or in our air-Q web app show a detailed development of the measured values.
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