[Metal content and trace elements in groundwater supply of the island of El Hierro (Canary Islands, Spain).].

Objective: Volcanic eruptions are a natural source of substances potentially dangerous to human health. The island of El Hierro (Canary Islands, Spain) suffered a marine volcanic eruption in 2012, making it necessary to monitor the levels of certain elements that can alter the quality of groundwater supply. The objective of this work was to determine the content of metals and trace elements in the groundwater supply of the Isla del Hierro and to check if they met the quality parameters established in Spanish legislation.