Why You're Exhausted After Coming Home From a Crowd | Purifying Your Space With Incense and Fresh Air
"When I get home from a crowded place, exhaustion hits me all at once."
"I haven't really done anything, and yet the moment I walk through the door, I'm completely drained."
At times like this, you may have heard that "putting a houseplant in the room cleans the air." This theory actually has a surprising backstory.
The Surprising Backstory Behind the "Houseplants Purify the Air" Theory
The idea that houseplants have an air-purifying effect spread from NASA's Clean Air Study, published in 1989. But that research was conducted in a sealed experimental chamber, a special environment very different from the size and ventilation conditions of an actual home or office. So the simplified claim "put a houseplant in the room and the air gets clean" is now generally considered to involve some misunderstanding. Having plants around isn't a bad thing in itself, but rather than expecting too much from them alone, it's closer to reality to think of them as one factor to combine with others, like ventilation and scent.
Solid Research: How Forest Scent Supports Immunity
On the other hand, there is fascinating research out of Japan on the relationship between scent and mind-body wellbeing. A research team at Nippon Medical School was the first in the world to demonstrate that 3 days of forest bathing increases the anti-cancer proteins released by NK (natural killer) cells, which attack cancer cells and other threats in the body. This is thought to happen because phytoncide, the scent compound released by trees, calms the brain through the olfactory nerve and balances the autonomic nervous system, suppressing stress hormone release and, as a result, boosting NK cell activity. The idea that scent works on your autonomic nervous system and immune system isn't an exaggeration at all — it's backed by concrete research like this.
A Japanese Tradition of "Purifying a Space"
The idea of resetting your mind with something after returning from a crowd has also long existed in Japanese life. Many people have likely felt their mind settle while walking through the scent of incense along a shrine's approach path. The custom of burning incense to purify a space took root in Japan alongside the arrival of Buddhism, and has been passed down to the present as wisdom for switching both a space and a state of mind through scent.
Steps to Reset Crowd Fatigue
Bring In a "Transition Scent" After Coming Home
Building a routine of wrapping yourself in a favorite scent the moment you open your front door makes it easier to switch from "outside time" to "home time."
Ventilate to Refresh the Air
Opening a window to refresh the air right after coming home also serves as a visual cue to help reset your mindset.
Create a Window of Time Cut Off From Information
Setting your phone aside for even just 10–15 minutes after coming home, and deliberately creating a quiet stretch of time, makes it easier to recover from sensory overload.
Reset With Scent
FUUKA's Reset Series includes No.10 Clean Energy, made to sit with the heaviness in the air after coming home from a crowd. Spreading it through your entryway or room helps mark the transition from "outside" to "home."
Summary
- The NASA study behind the "houseplants purify the air" theory was conducted in a sealed lab, under conditions very different from real life
- NK cell activation from forest bathing has been demonstrated by Japanese research, so scent's effect on the autonomic nervous system and immune system is well supported
- The custom of burning incense to purify a space is a long-established culture of switching mindset through scent
- Bringing in scent, ventilating, and carving out a window free of information after coming home are all steps you can take
References: Points regarding the experimental conditions of NASA's Clean Air Study, and Nippon Medical School's research on forest bathing and NK cell activation.