Why is the Dragon Boat Festival poisonous?

Explain the reason why the Dragon Boat Festival is so heavy. . . Some people say it's a hot summer and a bad day. In the pre-Qin period, it was generally believed that May was a poisonous month and the fifth was an evil day. Midsummer in Lu's Spring and Autumn Annals stipulates that people should abstain from sex and fast in May. "Xia Zheng Xiao" records: "Store medicine this day to get rid of poisonous gas." It is recorded in "Da Dai Li" that "the livestock orchid takes a bath on May 5", and there are many legends that the fifth day is the taboo day for bathing to exorcise evil spirits. So in May, there are five poisons. . . Actually, there is no scientific research literature. . . Just say it. It can be seen that this day has been an unlucky day since the pre-Qin period. In this way, it is logical to insert calamus and mugwort leaves to exorcise ghosts, smoke atractylodes rhizome and angelica dahurica and drink realgar wine to avoid the epidemic on this day.