Vog (volcanic fog) can envelop the island of Hawaiʻi when Kilauea Volcano is active. Since the termination of volcanic activity in September 2018, the vog has largely disappeared on the west side of the island. The gas plumes of the Kīlauea Volcano create a blanket of vog which the dominant trade winds mostly deflect toward the Kona coast on the west side of the island of Hawaiʻi. Vog contains chemicals that can damage the environment and the health of plants, humans, and other animals. Most of the aerosols are acidic and of a size where they can remain in the lungs to damage them and impair function. Flu-like symptoms and general lethargy are reported, and are especially pronounced in people with respiratory conditions.