The cells in the nose and throat that trap dust particles are called goblet cells. Goblet cells are specialized epithelial cells that produce mucus, a thick, viscous fluid that helps to protect the respiratory tract from harmful substances. Mucus contains a variety of proteins, including mucins, which are responsible for the sticky nature of mucus. Dust particles and other foreign objects become trapped in the mucus, which is then swept away by the cilia, tiny hair-like structures that line the respiratory tract.