Japan is gripped by mass allergies. A 1950s project is to blame

> A 1950s project is to blame

Half-way through the article: "When the sugi and hinoki forests were first planted in the 1950s and 60s, they weren't meant to stand forever. At the time, it was assumed they would be gradually cut down and replanted over time, as had been the case before the war. But as Japan's economy boomed in the late 60s and 70s, major cities like Kobe and Tokyo grew rapidly, and it ended up being cheaper to import wood from other countries such as Malaysia and Indonesia."

As often in environmental health, the cost-benefit ratio is calculated after the exposure is widespread, i.e. too late.

>Every year, an area is selectively clear-cut, removing sugi, hinoki but also other invasive species like bamboo. Broadleaf trees are left, and with more sun coming through to the ground, they grow back, along with other new seedlings either planted by staff or brought by birds or animals.

In other parts of the world, some plantation -> forest projects don't remove trees but instead pull them over and leave them as logs with exposed roots. This provides new habitats for various plants and animals around the logs and the gap in the canopy. I'm curious if they've explored the impacts that approach would have.

Hmm, most German forests are also vast monoculture 'tree farms' and have been for the last 250 years (also caused by large scale deforestation in the centuries before). In the Ore Mountains we also have those yellow clouds of pollen coming off spruce trees every few years, covering everything with a thin yellow dust layer, yet I'm not aware that the number of people with pollen allergies is exceptionally high (oth, maybe it was 200 years ago and by now the population has become immune, or maybe the tree pollen in Japan is just more aggressive...).

I was surprised to not find anything about possible cures or treatments in the article.

I had bad allergies myself in my teenage years - unable to sleep for weeks - I finally sought help. The western medicine offers protein shots (similar treatment as to food allergies) but I heard good things about acupuncture. First, I was very skeptical about how needles could "help" with allergies. But about 2 months into the treatment (two sessions per week) the pollen season started. The air felt "heavy to breathe" but to my surprise I was not effected that year at all. After finishing the whole treatment I was allergy free for many years. Now I sometimes feel it on bad days with clouds of pollen hanging in humid air. My uneducated guess is, that my acupuncture treatment I received over 2 decades ago "wears off".

I wonder if others experienced similar or if I was a statistical outlier to a well shaped Gauss curve?

I was surprised to read that our allergies evolve, though perhaps I shouldn't have been. When I lived in the midwest of the USA, I hated mowing the lawn so much. I became a gunked-up mess with my sinuses packed with snot, regardless of antihistamines and (new at the time) allergy meds that presaged our present treatments.

I'd lived in the Bay Area for one or two months before a neighbor in my apartment complex knocked to ask if it was standard to not have an air conditioner in the residence (something that had surprised me as well). She said that keeping the windows open was aggravating her allergies and it was the first moment that I realized I could breathe easily through my nose. I don't know what grows where I grew up that isn't here, but getting away from it really changed my quality of life.

Severe allergies can be so intrusive that I'd consider moving out of the country if I was in the situation described in this article. But I only think that because I've experienced the effect of changing regions and experiencing a radically different outcome. If someone grew up with this being normal, they might never consider getting away. I certainly didn't think it could be better or worse if I lived someplace else.

Hmm, I'm also wondering about studies about overly sanitized environments for children being correlated with higher allergy rates.

I guess poking around for a good representative study, it's actually low diversity of microbial exposure, not "cleaning" per-se that is correlated - e.g this is one reason why households with dogs have lower allergy rates. A monoculture of certain tree species also implies less microbial diversity.

“Arboreal sexism” is a similar phenomenon:

We prefer male trees in cities since they do not produce fruit that drop on the streets. The result is a much higher pollen load.

Interesting. I noticed that many people have hay fever in Japan, but I always just assumed it was genetic or something. I wonder if living there for a long time will make you more sensitive to pollen

Allergies are weird. I definitely became more sensitive to hay fever after a gastric bypass.

I have a friend who for no apparent reason developed strong allergies in their sixties. Particularly to goats milk.

So much so that they will not go to a restaurant that has goat milk products (e.g.: halloumi cheese) in their kitchen due to one too many visits to the hospital emergency ward.

While in Japan, I heard an urban legend that, it typically takes 5 accumulated years for a foreigner to acquire hay fever in Japan.

The Melbourne epidemic thunderstorm asthma event 2016: an investigation of environmental triggers, effect on health services, and patient risk factors

https://www.thelancet.com/journals/lanplh/article/PIIS2542-5...

I first read about this in The Emptiness of Japanese Affluence by Gavin McCormick. Really good read.

Japan being 68% forest is an astounding stat.

It wasn't smoke – it was AISLOP

Doesn't pollen also have to do with the "gender" of the trees? In gendered trees, male trees emit pollen and female trees intercept pollen. Not all species of trees are gendered (dioecious) but various are. If reforestation uses male trees at the expense of female, then pollen count will be higher.

Urban developers who make the mistake of using male trees, because they don't drop fruit/berries/seed pods, will make the residents suffer pollen. Sugi and hinoki apparently are not gendered -- they're monoecious.

The article makes the argument "there is a lot of pollen" and separately "there exist monoculture forests / tree farms" in Japan.

But what it doesn't do is:

1. Argue that the pollen is worse because of monoculture relative to polyculture forests (we could mix sugi and hinoki and...I assume net pollen would be the same?)

2. Argue that lots of pollen leads to more allergies. I mean, you might think that higher levels of exposure in childhood would lead to *fewer* people with allergies. So maybe a lack of forests in the past --> lots of people with allergies today? Why are the Japanese so allergic?

This article is bad and the author should feel bad.

estimated 43% of the population --wow

I think its the same in Germany no? Heuschnupfen is something that got worse over the time and if i remember correct is as well related with some reforest project..

This article could have been summarized in three paragraphs.

I'm really hating this trend of diluting content by giving useless testimonials, random anecdotes and delaying the resolution of the subject as much as possible.

What about nuclear bombs? No effects from nuking cities?

Only two types of tree? Even in the 1970's surely that should have been cause for concern.

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> which is already arriving earlier in Japan due to climate change

They couldn’t help but put in ideological bs.