"The way air pollution can lead to gastrointestinal problems is quite straightforward to explain. Yet, this is almost completely unknown, even though scientific studies provide enough practical knowledge to establish potential connections.

In short, not all substances we inhale through the lungs are also expelled from the body through the lungs. This would make no sense. The lungs, like the stomach and intestines, are designed to be permeable in certain directions for certain substances.

Thus, the lungs primarily transport oxygen into the blood and CO2 from the blood back into the breathing air.

Air pollutants, such as NO2, CO, and others, which pass through the lungs and enter the bloodstream, do not necessarily leave the body in the same way.

Once dissolved in the blood, all pollutants are excreted in the most efficient way, regardless of how they entered the body. For example, ammonia inhaled is excreted through the kidneys. Other substances are converted by the liver into water-soluble substances and then excreted through the kidney or intestines.

There isn't a scientific study for every single substance's degradation pathway. However, it is proven that both the lungs and the stomach and intestines are not one-way streets and can both absorb and release substances.

Why do we sometimes have bloating after eating and sometimes not? Perhaps someone has already experienced that bloating can occur very quickly after eating. You have just had lunch at a restaurant, and bloating begins as soon as you leave the restaurant.

Everyone knows that this is caused by bacteria in the intestines, but so soon after eating, the food has not yet passed from the stomach into the intestines. This process is much slower. Such a short time is not enough for bloating to occur due to the decomposition processes of bacteria.

So, if you have bloating shortly after visiting a restaurant, it could also be because the body is currently transporting inhaled air pollutants out of the body through the intestines. This can also happen through belching. Gases from the bloodstream can also enter the stomach, then leaving the body as heartburn or belching. Whether these are decomposition processes by bacteria or previously inhaled air pollutants is hard to distinguish.

Pay attention to whether you have more frequent bloating, diarrhea, constipation, or heartburn when eating indoors or outdoors. Of course, the pollutant exposure of the entire day also plays a role here.

We have experienced that high pollutant exposures, regardless of their origin, can have a very significant impact on intestinal activity within just a few minutes or hours.

In addition to this information, there are scientific studies that have shown that NO2 can significantly reduce intestinal activity. With high exposures to NO2 and CO2, the intestines can even completely stop their activity. If this state lasts too long, parts of it can permanently die.

(Scientific studies show a possible connection between chronic intestinal diseases and air pollutants)"

Another important aspect of this perspective is as follows:

While we consume and excrete about 4 to 5.5 kg of food and liquid daily, we inhale and exhale around 11 kg of air in the same period.

Thus, in terms of mass, food only constitutes about 33% of the substances we introduce to our bodies. Yet, we are most careless with the air we breathe and often completely ignore it when considering health issues.