Near-surface wetland sediments as a source of arsenic elease to ground water in Asia
Tens of millions of people in south and southeast Asia routinely consume ground water that has unsafe arsenic levels. Using hydrologic and (bio)geochemical measurements, the researchers show that on the minimally disturbed Mekong delta of Cambodia, arsenic is released from near-surface, river-derived sediments and transported, on a centennial timescale, through the underlying aquifer back to the river.