Kilauea erupted on Wednesday after a break of several months. Volcanologists described the eruption as "dynamic" High levels of volcanic gases are the main cause for concern, the USGS said.
When sulfur dioxide is released at the summit, it reacts in the atmosphere, creating a visible fog, so-called volcanic smog. It can lead to respiratory problems in humans and animals and also affect plants. The volcanic eruption can also cause a phenomenon called "pele's hair" – very fine, hard lava fibers that can irritate the skin.