Immunity seesaw Although allergies are caused by physiological factors, adverse environmental factors can make an allergy much worse. Chiang Bor-luen points out that nitric oxide, carbon monoxide, sulfur dioxide, and other waste gases emitted by motor vehicles and factories can harm the respiratory tract and aggravate a preexisting allergy.
免疫蹺蹺板過敏雖然是體質因素，但惡化的外在環境，則讓過敏疾病有增無減，雪上加霜，空氣污染正是其中的罪魁禍首。江伯倫指出，一氧化氮、一氧化碳及二氧化硫等汽機車或工廠排放出來的廢氣，都會對呼吸道造成刺激，讓過敏更加嚴重。