Spring continues to advance – days with double-digit maximums are the norm (although northerly winds and single-digit days persist), small vegetable patches that looked decayed and lifeless just a few weeks ago have been hoed and are now full of promise [cue “Circle of Life”], various magnolias are in bloom (unfortunately, getting photos means sticking my camera into other people’s yards), and the weather reports include daily updates on the status of cherry blossoms.
A sudden low-pressure cell passed over Japan on the 3rd of this month, bringing typhoon-strength winds (over 25 m/second in the centre of Tokyo) and rain, and causing at least four deaths.
Another sign of spring, although this starts in late winter, is the onset of hay-fever in millions of people. (In my darker, more cynical moments, it is the Japanese allergy to nature)
Hay fever is known is Japan as kafunsho (花粉症), which literally means “pollen syndrome”. Many Japanese people are genuinely surprised to hear that hay fever exists in other countries. I am not a hay fever sufferer, and many assume that it is a uniquely Japanese problem.
The leading cause of hay fever is the cryptomeria (Cryptomeria japonica) or sugi (杉), often – incorrectly – called the Japanese cedar.
This tree was the preferred timber for construction of housing, and thousands of hectares were planted, at the expense of biodiversity, during the housing shortages after World War II. As the economy picked up and then fell, the trees became less economical to harvest compared to imported timber, and the monoculture plantation forests have been left largely unmanaged.
As trees age past 20 years, they can produce large amounts of pollen, which increase as the tree ages.
Added to this is the lack of grass in populated areas. Grass helps catch pollen once it makes contact with the ground. Concrete, asphalt and pounded clay allow fallen pollen to be taken up by the wind and blown “back into circulation”.
Furthermore, research suggests that dust and air pollution may aggravate allergic reactions to pollen, so city dwellers are more likely to develop hay fever symptoms. Nature strikes back…
There is a whole industry based around hay fever – masks (used during the cold and flu season, but hay fever season greatly increases their demand period), yoghurt (said to help increase resistance), medications and air filtering devices. Another staple of the weather report is the pollen forecast.
Governments are starting to take action. There have been proposals to cut down cryptomeria and replace them with broadleaf trees – like they were before the crytopmeria plantations.
One major proponent of this is Tokyo governor Ishihara, mostly because he started suffering from hay fever…