# What needs to be changed in the structure of human lungs to be able to filter the inhaled air from heavy particles and toxic gases?

What needs to be changed in the structure of human lungs to be able to filter the inhaled air from heavy particles and toxic gases? For example, mine air can contain gases such as nitrogen ( This refers to the excessive inhalation of nitrogen - when there is too much of it in the air, it is harmful to the body ), methane, carbon monoxide, sulfur dioxide, hydrogen sulfide, nitrogen oxides, methane, hydrogen, heavy hydrocarbons, radon, ammonia and other harmful gases, as well as water vapor and dust.

Note: please do not create a special separate lung like the Astartes, the changes should concern the larynx and existing lungs and if it is considered necessary for the cardiovascular system.

Just describe in as much detail as possible these same filters from a biological point of view (how they do it and what they are). The more toxic gases you can remove from the air you breathe, the better.

• we all breathe nitrogen every single day since we are born. I think you should better define what you want to achieve with this modification of the lungs.
– L.Dutch
Nov 9, 2020 at 7:07
• Does it have to be in the lungs? I'm thinking a filter in sinus and back of throat that opens with the swallow reflex. The hard part is going to be cleaning the filter when it gets clogged. Can clean into the stomach - which is less poisonous than breathing it.
– Ash
Nov 9, 2020 at 7:31
• Okay, it fits, in a note I just meant that you don't need to create a whole separate lung, as for example was shown by the Space Marines from the Warhamer 40,000 universe. Nov 9, 2020 at 7:52
• As mentioned in your later question, reality-check and hard-science are mutually exclusive and you've not met the mandate for reality-check.
– JBH
Nov 9, 2020 at 15:54
• There is a huge variety of reasons of why the air is non-breathable. While some (like particulates) can be reasonably addressed with anatomical changes, others (like excess partial nitrogen) would require huge, potentially impossible changes in human metabolism. Nov 9, 2020 at 17:54

# Impossible

Toxic gases are in the same size as the oxygen you want to breathe: $$O_2$$ (2.99 A), $$N_2$$ (3.05 A) and $$Ar$$ (3.63 A) are all in the 3-4 Angström area and have been tested in 2018 how they passed through nano windows. $$CO_2$$, the gas you exhale, has about 3.3 Angström diameter. Researchers tested the permeability of nanowindows with the first three gases. The 2.9 Angström window did not only allow Oxygen to pass, it did pass through this window at a higher pace than through the 3.3 Angström window. They did find out that the permeation of the windows did result in an increase of the filtered for gas, but they also commented on the fact, that these nano windows "lack a high permeation rate". This makes them utterly useless for breathing applications.

Even if you could make it work with the permeation rates, the fact that $$CO_2$$ is comparable to $$Ar$$ in size would mean that you enrich the $$CO_2$$ inside the lungs, leading to suffocation.

# We can't modify humans so extensively

Remember, with today's tech, we can't modify human biology to such an extent, so... impossible.

• Is it possible to use a certain chemical reaction to neutralize the above toxic gases or screen out heavy particles? Nov 9, 2020 at 16:19
• NO, $N_2$ is an inert gas - and to get it to react we need huge setups as we use in the Haber-Bosh process. A good breathing apparatus that provides fresh air is much easier and again, we can't alter the human body that radically Nov 9, 2020 at 16:23
• Okay, but how can you get rid of mercury vapor, dust, or radon then? Nov 9, 2020 at 17:09
• Several organisms use n2 and even more co2 to make something else, just like we do with o2. There is no reason to filter out n2 and most likely there isn't reason to filter co2, but biologically converting them, either in a symbiotic relationship, via tech or by the superhuman itself is maybe not economically speaking realistic, but plausible (all that you need here). I'd still challenge why you'd want to do that. The simple solution to radon is being more resistant to cancer, as many organisms are. Mercury is a rather complex topic, worthy of a separate thread Nov 9, 2020 at 17:11
• @FrenchThompson3 No. Mercury vapor is in the same size-area as other gases! Radon too. Dust is comparatively huge, and to protect from that, we wear masks with micrometer filters. Nov 9, 2020 at 17:14