Nasal hair, or Nose hair is the hair in the nose. Ault humans have hairs in the anterior nasal passage. These hairs act as a fibrous filter for inhaled particles. Diffusion of ultra fine particles to the nasal hair occurs mostly for particles < 5 nm. Nasal hair has important implications for the health of the human body because a lack of nasal hair could invite the transport of potentially harmful particles into the respiratory system.