Can we consider a natural environment always of high quality and adequate to protect population from potential risks of health threats?

The question posed in the title arise because the current knowledge suggests that there are important, both beneficial and adverse, relationships between natural environment and human health. The human body obtains metals and metalloids from diet, some of which are derived from local foodstuffs and municipal water supplies, and it is therefore plausible that areas characterized by various types of bedrock and superficial materials, upon which food is grown and water drained, provide different availabilities of trace elements. The present study aimed at elucidating whether the degree of human exposure to trace elements is subject to changes in local environmental factors. This hypothesis was tested analyzing nineteen trace element (Al, As, Ba, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Pb, Rb, Sb, Se, Sr, U, V and Zn) by inductively coupled mass spectrometry (ICP-MS) in 376 samples of human scalp hair collected from children (11-14 years old) of both genders, living in ten towns (Adrano, Belpasso, Biancavilla, Castiglione di Sicilia, Maletto, Nicolosi, Pedara, Trecastagni, Sant’Alfio and Zafferana Etnea), located around the volcanic area of Mt. Etna (Sicily), and comparing the obtained results with those (215 samples) from children living in areas of Sicily characterized by a different geological setting (Palermo, Mistretta and Caltagirone). As, U and V showed much higher concentrations at the volcanic site whereas Sr was particularly more abundant at the reference site. Linear Discriminant Analysis (LDA) indicated an Etna factor, made up of V and U, and a second factor, concerning the reference site, characterized by Sr and Ni. Significant spatial differences in element concentrations were also observed among the three different sectors of Mt. Etna area. Natural environmental factors do influence exposure to and intake of trace elements in humans. Young people living in the Mt. Etna area are naturally exposed to enhanced intakes of some metals (V, Mn, U) and non-metals (e.g., As) than individuals of the same age residing in other areas of Sicily. The present study also confirms that hair is suitable for screening to identify long-term exposure of entire groups of people to abnormal concentrations of trace elements in natural sources.