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.

South Asia's well-water is widely polluted with arsenic, but no one has located the source. A study on the Mekong River finds that contamination begins in pond sediments, and is spread by groundwater flow to wells.

Geological map pinpoints fresh areas of contamination in Asia.

The present investigation deals with the analysis of physico-chemical characteristics, concentration of heavy metals and textural analysis of sediments in Poovar estuary of Kerala during the period 2004-2005. Three sampling stations were selected and sediments were collected for the study.

Water quality of lake normall get contaminated every where by accumulaton of sediments, human waste, silt, organic matter, industrial waste but in India different type of religious activities (idol immersion) are taking place every year, to which other countries are not concerned. The water bodies selected for the study are Upper and Lower Lakes of Bhopal, Madhya Pradesh.

The coastal and marine nitrogen cycle occupies a complex, central role within the biogeochemical cycles. Human interventions in the earth system have risen to unprecedented levels, strongly influencing the global nitrogen cycle. The nitrogen cycle in the open ocean compared to coastal ecosystems appears to have remained unharmed, although recent observations have shown increasing anthropogenic influence.

The South Asian rivers show a discharge weighted average NO3-N of 2 mg/l and average sediment-bound N, that is mostly organic, of 0.2%. The reported global average for the uncontaminated river system is of the order of about 0.028 mg/l (NO3-N). Hence, our freshwater aquatic systems can no longer be considered natural, at least with respect to nitrogen transport.

Martin Kennedy and colleagues searched the Australian outback for clues to the transition out of Snowball Earth. The answer, as it turns out, was much closer to home.