Hello, I am Yoshi Tanaka of NILS Japanese language school.
I think some of you have seen Japanese wearing white masks in this season.
It is said that 40% of Japnaese living in metropolitan area suffer from kafunsho (花粉症), a kind of hay fever caused by the pollen from cedar trees. From March to may, many Japanese white masks made of gauze when they go out. Some even wear glasses and hats to protect themselves from pollen, which causes various uncomfortable symptoms such as a runny nose, headaches, and itchy eyes. They say that more people have started suffering from kafunsho in the last 20 years because the cedars planted in the mountains around Japan after the war have been neglected, are overgrown, and create more pollen. When floating pollen in the air mixes with dust and exhaust from automobiles, it causes kafunsho.

April 3rd News, from NILS Japanese language school.