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

[highplainsdem]

https://www.bbc.com/future/article/20260515-the-1950s-blunder-which-causes-mass-hay-fever-in-japan

-snip-

During the war, oil and gas shortages led Japan to turn to the nation's most abundant natural resource – forests – as a source of fuel for home and industry. The result was widespread deforestation of natural forests, with the mountains around major cities like Tokyo, Osaka and Kobe completely stripped bare of trees.

-snip-

Aiming for rapid reforestation, the government chose to plant reams of only two different native, fast-growing evergreen species that could quickly reforest landscapes and provide wood for future use in construction: the Japanese cedar, sugi, and the Japanese cypress, hinoki.

Today, these hinoki and sugi plantation forests still cover around 10 million hectares (25 million acres) – a fifth of Japan's entire land area.

The problem is, sugi and hinoki trees also produce large amounts of lightweight pollen which can easily drift into cities. It's this pollen, often released all at once from the monoculture plantations, that is responsible for most seasonal allergies in Japan. The issue has become all the worse since these trees release ever more pollen after maturing at 30 years of age – now the case for nearly all of them.

-snip-

An estimated 43% of the Japanese population have hay fever, compared to 26% in the UK and 12-18% in the US. That's why so many wear masks

Much more at the link.

[liberalla]

1. Wow... Interesting!

And there's no easy fix, I bet...

[nuxvomica]

2. Monocultures always seem to be a problem

Whether ecological, like this one, or in energy (fossil fuels), technology (AI), or, of course, society. "Diversity is strength" can be said of just about anything.

[GenThePerservering]

3. Every spring we struggle with cedar pollen

and it's only one of a number of trees (alder fluff is bad, too) - it must get really bad in Japan!