Tokyo: Something in the Air

Japan’s weather is turning warmer, the plum trees are in blossom – and Tokyo’s allergy clinics are filling up with people suffering from runny noses and bloodshot eyes.

Tokyo is known for many things: the Imperial Palace gardens, cherry trees in the springtime, super-crowded commuter trains. But it has a more dubious distinction. It is also the world capital for allergies, especially hay fever, known to the Japanese as pollen sickness.

Of course this is no secret to the bulk of the people living here, especially the estimated 6 or 7 million who are prone to pollen allergies (based on general rule that 15- 20 percent of the Japanese population suffers from hay fever).

Residents know that when the plum trees start to bloom in early March it is time to stock up on antihistamine tablets, eye drops, herbal medicines and face masks. Those most susceptible to pollen may avail themselves of allergy shots and other more exotic remedies.

One might wonder why an affliction usually associated with rural areas should affect the world’s largest urban conglomeration. The answer goes back to the years just before and just after World War II ended. In that hardscrabble time, people denuded the forests of the nearby mountains to make charcoal to keep warm and cook food.

In the 1950s and 1960s the Japanese government undertook a successful reforestation program, planting millions of cedar trees, a cheap, fast-growing native tree and a prodigious pollen producer. Unlike in the U.S, where ragweed and grasses are the main pollen source, cedar and cypress trees cause the most suffering in Japan.

It was expected that these trees would be cut to produce timber, but Japan has found it more economical to import lumber from the U.S. and Canada, so they have been left standing. Now 40 to 50 years of age, they have reached their pollen-producing peak, pumping literally tons of the irritant into the atmosphere.

The pollen season for plum trees peaks in late February, but just as it dies down, the pollination of the cypress trees begins to kick in. So for those who suffer from both pollens, there is an unbroken period of sneezing and sniffling through the end of April.

Ironically, Tokyo’s urban nature compounds the problem, since the pollen particles fall on asphalt or on the roofs of buildings rather than being absorbed in the soil. Here they are picked up and blown around in little invisible eddies and whirlwinds.

The inexorable march of suburbia to the west also has eliminated many of the farms and windbreaks that once helped keep much of the pollen from reaching the city. But now suburban Tokyo extends to the very foothills of the mountains.

The forest agency, which had earlier planted 4.5 million hectares of cedar trees, now proposes to cut them down and reseed the areas with broadleaf trees that produce less pollen. The goal is to halve the number of cedar trees by 2017.

Much of the impetus for this expensive program comes from Tokyo Governor Shintaro Ishihara, who famously suffered a severe bout of hay fever in 2005, a particularly bad year when the pollen count soared some 4,000 percent over the previous year.

Hay fever is even thought to have a measurable impact on Japan’s economy, both in a negative and a positive way. The Dai-Ichi Life Insurance Research Institute estimates that the economy lost about US$3 billion due to absenteeism in the memorable hay fever year of 2005. On the other hand, Dai-Ichi Life also estimates that Japanese spend more than $6 billion a year on hay fever prevention products, such as eye drops and face masks.

In recent years the hay fever season has merged with the yellow dust peril to aggravate the woes of allergy sufferers. Yellow dust is the term for dust that originates in the Gobi desert of China’s Inner Mongolia province and other parts of Central Asia and is blown east in prevailing winds, blanketing Korea and Japan.

When it settles, cities are bathed in a kind of yellow haze similar to smog, and the dust particles get into everything. Television weather reports plot the approaching dust and recommend that people refrain from hanging washed clothes out of doors. In more extreme cases, the yellow dust can cut visibility to the point where airports close temporarily.

This being Japan, various exotic remedies have been proposed over the years to lessen the burden on the nasal system from all this junk in the air. One pharmaceutical company touts an olive leaf extraction as a way alleviating hay fever symptoms without causing side effects such as drowsiness.

An institute associated with the Ministry of Agriculture, Forestry and Fisheries says eating a new kind of genetically engineered rice may help. The rice is said to produce an amino acid that mimics the cedar pollen and helps produce immunities.

However, the Health Labor and Welfare Ministry has been slow to classify the engineered rice as a safe food, disappointing many sufferers who had hoped it would be available by now.

This time of year newspapers also carry stories filled with tips on how to prevent or at least ease the symptoms of hay fever. They all seem to boil down to the same piece of advice: wear a good face mask or stay indoors.