Japan will Cut Pollen Emissions by 50% to Combat Hay Fever

40% of the Japanese population are estimated to be impacted by hay fever.

Tue 30 May 23


Japan has launched a policy to counter the rising incidence of hay fever caused by pollen from cedar and cypress trees. The policy aims to decrease pollen emissions by 50% over 30 years.

Hay fever, with symptoms of a runny nose, sneezing, and itchy eyes, is estimated to afflict more than 40% of the Japanese population.

Hay fever, which presents symptoms such as a runny nose, sneezing, and itchy eyes, affects 40% of the Japanese population.

To tackle this health issue, the government has a two-pronged plan: one, to reduce the area of planted cedar by roughly 20% over the next decade, escalating the tree-cutting rate from the current 50,000 hectares per year to 70,000 hectares.

Two, to substitute over 90% of the young cedar trees with species that generate less pollen over the coming decade.

The policy will also address medical treatment, with the government committing to boost the annual production of immunotherapy medicines.

This will expand the capacity to cater to one million people’s needs, a leap from the present capacity of 250,000.

“It’s crucial to keep a strong focus on the issue and steadily implement policies as this isn’t a problem that can be solved instantly,” Prime Minister Fumio Kishida stated at a hay fever ministerial meeting on Tuesday.

The proposed measures are anticipated to be included in the annual economic policy blueprint, slated for completion in June.

The surge of cedar trees in Japan can be traced back to the post-World War II economic boom when large-scale reforestation efforts were undertaken.

Although official data is lacking, a survey conducted by a group of ear, nose, and throat specialists suggests that hay fever prevalence in Japan has steadily risen from 19.6% in 1998 to 42.5% in 2019.

The government plans to use supercomputers and artificial intelligence to refine the accuracy of pollen forecasts. Furthermore, the Japan Meteorological Agency’s information services are set to be improved.

The government also pledged to encourage home builders to use more timber from domestic cedar trees and urged the business community to promote remote working to reduce pollen exposure.

A large number of cedar trees were planted during the period of rapid economic growth after the end of World War II for reforestation.

Scientists may have cracked the code on pollen

Last month, researchers pinpointed the gene that deprives Japanese cedar trees of their ability to produce pollen, carving out a future no one could suffer from hay fever.

Scientists from Niigata University, the Forestry and Forest Products Research Institute have presented the achievement at a conference of the Japanese Society of Breeding.

According to findings, a single base sequence constituting the gene determines whether pollen is released. If a method known as genome editing is used to modify the target gene, cedar trees free from pollen could be bred efficiently.

“Only one of all the cedar’s more than 10 billion bases has turned out to be a deciding factor behind the presence of pollen,” said Hiroyuki Kakui, a specially appointed assistant professor of thremmatology at the university.

“Using genome editing can remove pollen from cedar that is useful as construction material.”

One in every 5,000 cedar trees undergoes a genetic mutation so as not to produce pollen.

The team of researchers thus compared the DNA of more than one cedar. The results showed the gene called TKPR1 works aggressively in male flowers, and one of the gene’s 1,002 bases decides whether pollen can be generated.

Applying the normal TKPR1 gene from cedar into a pollen-free thale cress in a test resulted in pollen production. At the same time, the base’s control rendered it impossible to release pollen, according to the researchers.


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