Because the various types of camp followers were seen as impoverished and homeless, they were regarded as "hinin" or non-citizens by medieval samurai, and taboos of pollution arose around them. In the Tokugawa period, this polluted status sometimes became hereditary, due to Confucian construction of the "ie" family system. At other times and places, pollution was not hereditary but was associated with jobs involving blood such as hunting, fishing, and tanning. The belief in pollution ebbed and flowed throughout the Tokugawa period, being most strictly observed in the 19th century as Tokugawa society came under increased pressure.