Weathered Coal Deposits and Balkan Endemic Nephropathy

The correlation between the geographic occurrence of Balkan endemic nephropathy (BEN) and low rank Pliocene lignites is striking. Comparison of mass spectra of methanol extracts from lignite samples collected in the vicinity of two endemic villages, with mass spectra of methanol extracts higher grade coals, shows the presence of many more potentially nephrotoxic compounds, and much higher total organic concentrations in the lignite extracts. The Pliocene lignite composition is dominated by highly functional aromatic compounds not found in the other coal samples. The geologic history of the endemic regions helps to explain the high concentrations of highly functional aromatic compounds found in the low grade lignites in this region. The Pliocene lignite area, and associated endemic villages in Bulgaria, Romania, Serbia, and Croatia, occur on the margins of the Balkan Peninsula's major Tertiary basins. The young age and lack of deep burial or tectonic effects on the lignites have resulted in the incomplete coalification of the original peats.