Trace element investigations in urinary stones: A preliminary pilot case in Basilicata (Southern Italy)

The role of trace elements in the lithogenesis of urinary stones is still debated. However, it is generally appreciated that urinary stones are one of the most common health problems in the world and are strongly associated with environmental factors. It is important to highlight that urinary stones containing trace elements could be considered a marker of environmental pollution.A large set of urinary stones (48), collected among the Basilicata (southern Italy) inhabitants, was analysed by AAS and ICP for the content of specific chemical elements that were either involved in the crystallisation process of kidney stones (Ca, Mg, K, Zn, Fe, Cu, and Mn) or which were potentially toxic (Pb, Cr).Three main findings emerge from the results:(1)Most urinary stones had high concentrations of elements such as K, Cu and Mg and a low content of Fe when compared to the results of previous studies.(2)Significant amounts were found in inorganic phases (calcium oxalate and phosphates), whereas only the Zn content was high in organic phases (uric acid and cystine).(3)Among calcium-based stones, those that were calcium phosphate contained greater amounts of trace elements than those that were calcium-oxalate. Among the calcium oxalate stones, weddellite retained more trace elements than whewellite.Furthermore, the results showed that the concentrations of Zn, Cu, Fe, Pb and Cr were greater than that of ingested from a standard diet. Consequently, varying amounts of these elements may have been attributed to their enrichment in the diet of the inhabitants of polluted areas.