White, but not pure
Even the snow on Aconcagua Mountain in the Andes is polluted with PCBs. An international team of researchers detected low concentrations of these toxic, carcinogenic chlorine compounds in samples taken from America's highest mountain. The snow samples taken at an altitude of 6200 metres are among the highest traces found anywhere in the world of these substances, which have been banned since 2001. In particular, the samples contained more persistent compounds like hexachlorobiphenyl (PCB 138) and heptachlorobiphenyl (PCB 180). Mountain ranges could be a natural trap for persistent organic pollutants that are transported by the atmosphere all over the world, say the scientists from IIQAB in Barcelona (Now IDAEA), the UFZ in Leipzig and the University of Concepcion in Chile, writing in the journal Environmental Chemistry Letters. According to the researchers, these findings highlight the need to investigate further the role of mountains in the spread of these pollutants and...