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

bbc.com

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

#111

Post by IAmBroom »

flohofwoe wrote: post #14

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, m…

Pollen can be broadly separated into airborne and not-airborne.

Ragweed pollen is light enough to be borne miles by wind. Goldenrod pollen is too heavy for that, but is sticky, and is carried on fur and feathers. Ironically, people blame the showy goldenrod blooms for allergies, although they likely have never had goldenrod pollen in their breathing passages - while lowly, hiding ragweed unleashes millions of barbed pollens spores upon their breathing passages. (Ragweed flowers are small and green - you can stare at a plant and not realize it's blooming!)

Likewise: the sap of poison ivy is strongly allergenic; the sap of maple trees almost never, due to reactivity with immune systems. Americans are likely to be exposed to both.

So, in short: there are plants that are potential allergy-sources, and others that are not.

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

#112

Post by IAmBroom »

Tade0 wrote: post #71
Terr_ wrote: post #43

Earlier quoted context omitted.

I'd like to preemptively draw a line between two different kinds of hypothesis when it comes to hygiene: 1. The immune system is not being exposed enough to wild or even infectious content, and it needs more threats to fight off. 2. ("Old Friends") The immune system is not being exposed enough to commensal or even symbiotic organisms that we co-evolved with, throwing off its calibration and tuning. I instinctively pr…

Regarding the second point: ...or parasitic. There's a hypothesis that says the incidence of allergies correlates inversely with the incidence of certain common parasites, like the tapeworm or the pinworm. Additionally, nowadays pregnant women are advised to avoid getting infected with toxoplasmosis due to the birth defects it causes, but it wasn't until the 70s when the last route of transmission was found and expla…

What if the human body's response to external influences (including parasites) is nuanced and complex?

What if the very idea of "parasite" is overly redactive: maybe there are both advantages and disadvantages of having another organism in your internal biome, in varying amounts?

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

#113

Post by IAmBroom »

timr wrote: post #11
hastily3114 wrote: post #3

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

As someone who has suffered from hay fever for my entire life, and also lived in many different locations, almost every move came with a 2-3 year reprieve from my symptoms while my body "discovered" the fun new local allergens.

Same.

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

#114

Post by IAmBroom »

mathieuh wrote: post #40
hastily3114 wrote: post #3

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

It’s known that repeated exposure to allergens can cause allergic symptoms in people previously without them. For example https://en.wikipedia.org/wiki/Bird_fancier%27s_lung https://en.wikipedia.org/wiki/Farmer%27s_lung I actually seemed to grow out of hay fever when I was in my early 20s. Perhaps coincidentally this is also around the time I developed an allergy to cannabis from overuse. Wonder if they’re related so…

Poison ivy/oak sensitivity varies with lifetime exposure. On rare occasions, it is inverse: careful exposure can sometimes lead to resistance. More commonly: you get more sensitive over your lifetime, and some "once immune" people end up catastrophically changing due to incautious exposure.

It's complicated.

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

#115

Post by [deleted] »

vikramkr wrote: post #58
niemandhier wrote: post #54

“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.

That's not actually a thing. Very few trees we plant have specific male vs female plants. One of the few that does that gets brought up in this context, ginko, tends to have male trees preferred because the fruit kind of reeks. Ginkgo fruit is also toxic so you really don't want masses of it getting washed into local waterways in ecosystems the tree isn't native to - not a great time for the local wildlife. A signifi…

[deleted]

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

#116

Post by rouvax »

> 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.

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

#117

Post by rsynnott »

lazide wrote: post #110
flakiness wrote: post #104

Earlier quoted context omitted.

Japanese sugi forests are too dense. I don't think they have the space to lay these logs down.

A historically common way to clear certain kinds of areas in the US is to drag anchor chains with giant bulldozers. May still work?

In this case they're trying to leave broadleaf trees alone, so probably not.

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

#118

Post by rsynnott »

the_af wrote: post #85
INTPenis wrote: post #59

Earlier quoted context omitted.

Yes timotej is my allergy as well. And I got it as an adult, in 2009. So 26 years without any allergies, then suddenly, one summer in Helsingborg, the air was thick with pollen. I remember the smell was like cheese doodles in the air, musty. Once I got back from an errand in the city my face was leaking, I walked to the pharmacy with blurry vision to get my first antihistamines. Ever since then every year june is a n…

Once you get sensitized, it gets worse every year, right? Since my teenage years I was mildly allergic to pollen, and now in my adulthood it seems to be getting progressively worse. Each spring is worse than the previous one, and the antihistamines do less effect (or so I subjectively feel).

Not _necessarily_. I had big problems with pollen when I was a kid, but very rarely, these days (there seems to be _something_ that causes me difficulty for a few weeks a year, but that's more or less it now).

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

#120

Post by dv_dt »

Tade0 wrote: post #71
Terr_ wrote: post #43

Earlier quoted context omitted.

I'd like to preemptively draw a line between two different kinds of hypothesis when it comes to hygiene: 1. The immune system is not being exposed enough to wild or even infectious content, and it needs more threats to fight off. 2. ("Old Friends") The immune system is not being exposed enough to commensal or even symbiotic organisms that we co-evolved with, throwing off its calibration and tuning. I instinctively pr…

Regarding the second point: ...or parasitic. There's a hypothesis that says the incidence of allergies correlates inversely with the incidence of certain common parasites, like the tapeworm or the pinworm. Additionally, nowadays pregnant women are advised to avoid getting infected with toxoplasmosis due to the birth defects it causes, but it wasn't until the 70s when the last route of transmission was found and expla…

IIRC there has been scientists looking at what substances and pathways the parasites, particularly the helminths family, might affect because the parasites have a evolutionary "motivation" to suppress immune responses, at least to some degree in the host.
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