Srinagar, July 14: A new scientific study has raised concerns over heavy metal pollution in Kashmir’s freshwater ecosystems, revealing that toxic metals are entering edible water chestnuts harvested from major lakes, with the Dal Lake recording the highest contamination levels among the water bodies examined.
Published in the journal Scientific Reports, the study analysed water, sediments and different parts of water chestnut plants (Trapa natans), locally known as ‘Gaur’, collected from Dal Lake, Hokersar Wetland, Manasbal Lake and Wular Lake.
Researchers assessed the accumulation of eight heavy metals, including cadmium, chromium, copper, cobalt, iron, manganese, nickel and zinc. The findings showed that contamination levels were highest in Dal Lake, followed by Hokersar Wetland, while Manasbal and Wular lakes recorded comparatively lower levels.
The study found that water chestnut roots absorbed the highest concentration of heavy metals, indicating that polluted sediments are the primary source of contamination. Iron levels in roots reached 322.50 mg/kg, while zinc concentrations were recorded at 82.45 mg/kg.
Although edible fruits contained lower levels of contaminants, researchers detected cadmium concentrations of up to 0.11 mg/kg in water chestnuts from Dal Lake, which is significantly above the World Health Organization’s recommended limit.
The researchers warned that regular consumption of water chestnuts from highly polluted areas, particularly Dal Lake, could pose health risks due to cadmium exposure.
The study attributed the rising pollution levels to untreated sewage discharge, agricultural runoff, urban waste, houseboat waste and other human activities affecting Kashmir’s water bodies. It noted that a large portion of Srinagar’s daily sewage remains untreated and eventually enters water bodies like Dal Lake.
The analysis also found elevated levels of organic pollutants, nutrients and heavy metals in Dal Lake’s water and sediments, indicating deteriorating water quality.
However, researchers highlighted that water chestnut plants could also help in pollution control, as their ability to absorb and store heavy metals makes them potential candidates for phytoremediation.
The study recommended regular monitoring of Kashmir’s lakes and routine testing of edible aquatic plants to protect public health and preserve the region’s freshwater ecosystems.
