Hay fever season has arrived in Japan, presenting sufferers with an added challenge amid the coronavirus pandemic as rubbing itchy eyes and wiping runny noses may increase the risk of viral infection, while opening doors and windows to improve ventilation could add to the amount of pollen coming indoors.
As of Sunday, the cedar pollen season had started in 34 of Japan's 47 prefectures stretching from the Kyushu region in the southwest to the Tokyo metropolitan area, triggered by a rise in temperatures, according to Weathernews Inc.
The allergy-causing pollen is expected to begin dispersing in the Tohoku region in the northeast as well as the Hokuriku area in central Japan later this month, it said.
Pollen from Japanese cypress will start tormenting hay-fever sufferers in late March, while people allergic to birch-tree pollen will feel the effects in Hokkaido, the country's northernmost main island, in late April.
The amount of pollen to be released this year is predicted to be lower than the 10-year average between 2011 and 2020 but higher than last year, when it was significantly lower nationwide, according to the private weather information service based in Chiba, east of Tokyo.
Among Japan's 47 prefectures, all but Hokkaido, Aomori and Okinawa are expected to see higher cedar pollen counts compared with the previous year, Weathernews said. In the southern island prefecture, cedar and cypress trees are rare.
In Toyama, Ishikawa, Fukui, Gifu, Aichi, Hiroshima and Oita, in particular, where last year's pollen emissions amounted to only a third of the level in an average year, the amount of cedar pollen is forecast to be more than double that for 2020.
According to major drugstore chain Welcia, sales of oral medicine to ease hay fever symptoms have been picking up faster than in an average year, with the purchasing peak moving up from March.
Daily necessities provider S.T. Corp. has published tips on its website for hay-fever sufferers amid the pandemic. It encourages people to look down when they cough or sneeze and to disinfect their hands as quickly as possible to help curb the spread of the coronavirus.
The company also recommends wearing glasses, which it says is an effective measure against both hay fever and viral infection.
