Aplicación del análisis exploratorio de datos (AED) al contenido de arsénico en las aguas termales de la Isla de Ischia (sur de Italia)

Abstract

The island of Ischia belongs to the active volcanic area of Naples. It is formed by quaternary volcanic rocks and it presents an intense hydrothermal activity. Exploratory data analysis (EDA) techniques based on the box-plot and class selection were applied to the analysis of As content and parameters in situ of thermal groundwater of the Ischia. The EDA applied to small sets of data, like in this case, it is an effective method to capture the empirical data distribution and the outliers, and to define appropriate intervals for the geochemical mapping. The As has been found in 86% of the aquifer points samples; in these points the value of the mean concentration of As (175.7 ppb) exceeds WHO recommended value (10 ppb) and limit set by the European and Italian legislation (98/83/CE and DM 471, respectively)