Measuring Particulate Matter: What Radioactive Fallout Has to Do with Fine Dust
Russia recently presented the Kinzhal hypersonic missile, which can potentially be equipped with a nuclear warhead. The USA and other countries likewise regularly conduct missile or even nuclear tests — to demonstrate their destructive potential and thereby deter adversaries.
All of this happens in the background and is not perceived by the general public as a direct threat. Actually using a nuclear warhead seemed, people thought, a realistically distant prospect. Given recent events in Ukraine, the launch of a nuclear-armed long-range missile — one that is theoretically even unstoppable, like the Russian Kinzhal missile — or the threat of nuclear war now feels closer than the current generation has ever experienced. We want to assess this catastrophic doomsday scenario in terms of the potential dangers that could come from the air. We explain here what happens in the event of a nuclear explosion and what effects nuclear fallout and radioactively contaminated particulate matter can have.
What happens when an atomic bomb detonates?
A nuclear explosion occurs in six phases.
- Immediately after the explosion there is a flash of light. It is so bright that it can irreparably damage the retina and cause blindness.
- This is followed by an immediate heat wave that instantly vaporizes everything in the immediate vicinity.
- At the same time, all-penetrating nuclear radiation is released, with fatal consequences for organic life.
- Next comes a fireball of destruction — the actual explosion. This explosion devastates all infrastructure within a radius of 2 to 10 km around the blast. This zone is called the severe damage zone.
- The blast wave that follows has an even larger radius; traveling at several thousand kilometers per hour, it is fast enough to sweep away and destroy anything not built from solid reinforced concrete.
- Finally, nuclear fallout occurs — the settling of explosion debris, radioactive material and radioactive dust particles.
All of this happens very quickly — within a matter of seconds. A very sobering yet informative tool is the NUKEMAP simulator by Alex Wellerstein, which calculates the detonation radius for various nuclear weapons.
What is "nuclear fallout"?
Nuclear fallout — radioactive dust and debris — occurs after a nuclear weapon detonation or a reactor accident. The radioactivity of the dust particles carries significant radiation well beyond the immediate radius of the explosion.
The radioactive dust released by the explosion rises into the upper regions of the atmosphere and spreads across the various layers. Depending on wind and climatic conditions, it can be carried over many hundreds of kilometers. This dust can then become "fallout" in two ways: it can act as a condensation nucleus for water droplets, which then fall to Earth together with rain and are absorbed by plants and living beings. More critical — because it is invisible yet potentially deadly — is the dust itself, which slowly settles and falls to the ground, though wind can repeatedly stir it up and carry it further. The nuclear-contaminated dust, or particulate matter, is then inhaled with the air. These particles immediately damage the lungs and can cause burns or tumors. Radioactive particulate matter can also penetrate deeper into the body via the alveoli and cause further harm there.
How can you protect yourself from nuclear fallout and measure the effects of particulate matter?
Nuclear fallout can also occur far away from the nuclear explosion itself. The weather and wind direction should therefore be monitored to identify and avoid critical zones. Within these fallout zones, food should no longer be grown (at least for a certain period). Nothing that grows unprotected outdoors should be consumed either.
Respiratory masks such as FFP2 or FFP3 masks help against nuclear-contaminated particulate matter. They provide very good protection against particulate matter and thus also against radioactive particulate matter. The masks must be replaced at short intervals, since radioactive material accumulates on them.
Particulate matter also penetrates indoors through closed windows, since these are often not completely sealed. In the event of suspected nuclear fallout, it is therefore recommended to wear a high-quality protective mask indoors as well. Ideally, the particulate matter level in the room should be monitored. Even the smallest amounts of particulate matter can carry a large radiation dose.
As a rule, dust particles larger than PM 10 do not penetrate closed windows, since they settle to the ground quickly. The smaller the particles — for example PM 2.5 [particles smaller than 2.5 µm] or PM 1 [particles smaller than 1 µm] — the longer they remain suspended in the air and the more dangerous they can become.
Measuring particulate matter – with the air-Q air quality meter
With a particulate matter meter like the air-Q, you can check the components of your indoor air. The air-Q measures particulate matter using an infrared laser. This measuring method allows particulate matter of different sizes to be cleanly separated and captured. The sensor used therefore offers particularly high measurement accuracy.
