Urinary stones as a novel matrix for human biomonitoring of toxic and essential elements

Abstract

Monitoring of body burden of toxic elements is usually based on analysis of concentration of particular elements in blood, urine and/or hair. Analysis of these matrices, however, predominantly reflects short- or medium-term exposure to trace elements or pollutants. In this work, urinary stones were investigated as a matrix for monitoring long-term exposure to toxic and essential elements. A total of 431 samples of urinary calculi were subjected to mineralogical and elemental analysis by infrared spectroscopy and inductively coupled plasma mass spectrometry. The effect of mineralogical composition of the stones and other parameters such as sex, age and geographical location on contents of trace and minor elements is presented. Our results demonstrate the applicability of such approach and confirm that the analysis of urinary calculi can be helpful in providing complementary information on human exposure to trace metals and their excretion. Analysis of whewellite stones (calcium oxalate monohydrate) with content of phosphorus <0.6 % has been proved to be a promising tool for biomonitoring of trace and minor elements.

The key role of major and trace elements in the formation of five common urinary stones

“…Figure 1a and e presents the result of the correlation analysis for the CO, CA, UA, mixed CO and CA, and the mixed CO and UA stone groups, respectively. In the case of the CO stone group, Ca and Na exhibit a positive correlation (r = 0.48), likely attributed to their closely matched ionic radius (116 pm for Ca and 144 pm for Na) [54], This similarity enables Na to substitute for Ca in various rock-forming minerals, such as plagioclase feldspar (sodium-calcium feldspar series NaAl3Si3O8-CaAl2Si2O8) and pyroxene [55,56]. Ca shows a strong positive correlation with Zn (r = 0.66) in the CO stone group, suggesting that these elements may undergo thermodynamically favorable substitution processes or are easily absorbed into the oxalate crystal structure [41].…”

The crucial contribution of X-ray fluorescence spectroscopy in medicine

“…Highlighting the presence or the absence of some elements in biological tissues may be of great interest in medicine in the sense that it can help in diagnosis [25][26][27][28][29][30][31][32]. Indeed, the presence of lead may indicate a diagnosis of saturnism [33] while accumulation of copper may be related to Wilson's disease [34].…”