Cedar trees are behind most of pollen allergies in Japan, after a reforestation programme following World War Two covered many of the countrys hillsides with the pollen-rich trees.

• 在日本，雪松是导致很多人出现花粉过敏症状的罪魁祸首。二战后，日本进行了一项重新造林计划，使得很多地方均种满了这种可以产生大量花粉的树木。