The article does imply that hay fever is a big factor when it references air polution and pollen from Japanese cedars. > Then, in the 1950s, Japan’s rapid post

The article does imply that hay fever is a big factor when it references air polution and pollen from Japanese cedars. > Then, in the 1950s, Japan’s rapid post-World War II industrialization led to rampant air pollution and booming growth of the pollen-rich Japanese cedar, which flourished due to rising ambient levels of carbon dioxide. Mask-wearing went from seasonal affectation to year-round habit.