What happens if we stay too long in the subway?

Antton Racca

This video has been trending in Belgium

The video opens with a straightforward question: What happens if you spend hours—perhaps even whole days—underground in the metro? To find out, the creator undertakes an extended immersion in the Paris network. He first explains that the metro is a closed environment, poorly ventilated and constantly flooded with passengers, making it an ideal laboratory for studying air pollution, noise, artificial light and their combined effects on the human body.

Equipped with portable sensors, the participants measure fine particles (PM10 and PM2.5) that mainly come from the trains’ mechanical braking. The readings often exceed the limits recommended by the WHO, especially during rush hour. The expert interviewed points out that, over the long term, these particles irritate the airways, worsen asthma and increase the risk of cardiovascular disease. Although a normal daily commute is safe for most passengers, prolonged exposure—such as that faced by maintenance workers or subway musicians—poses a genuine public-health problem.

Noise pollution is another drawback. Levels sometimes approach 100 dB when trains pull into cramped stations. According to the audiologist consulted, such racket induces auditory fatigue comparable to a rock concert and hastens hearing loss. Earplugs or noise-canceling headsets are therefore recommended for employees who spend the whole day on the platforms.

Next comes the issue of circadian rhythm. Deprived of natural light, the body struggles to regulate melatonin production. After only a few hours, volunteers report fatigue, irritability and difficulty concentrating. The neurochronobiologist interviewed reminds us that the light–dark cycle is a key synchronizer of our internal clock; spending too much time under neon lighting, without sunlight, disrupts sleep and can promote chronic stress.

The experiment also highlights the psychological dimension. In sparsely populated cars or transfer corridors, a sense of confinement sets in. Crowds, odors and close quarters trigger spikes in cortisol, the stress hormone. Sociologists note that some homeless people literally live underground; their mental health deteriorates even faster because they lack access to daylight, cleaner outdoor air or a calming social environment.

The video concludes that spending several hours in the metro from time to time is not disastrous, but continuous exposure quickly exacts a physiological toll: fine particles, high decibels, a disturbed body clock and mental overload make for a risky cocktail. To mitigate the effects, the advice is to vary one’s modes of transport, avoid the most enclosed platforms, step outside for fresh air regularly, choose newer trains with better ventilation and, when possible, shift travel times to off-peak hours

Share Video

¿Do you like What happens if we stay too long in the subway?? Share it with your people...

Playlist