Published on August 1, 2022
Ahmedabad: A study carried out on the coast of Gujarat indicated that various heavy metals, salinity, nitrate, and carbonate/carbon trioxide can be found in both seawater and groundwater. The ecological risk index (ERI) was found to be higher for the study area compared to the areas focused on in Kerala and Tamil Nadu coasts.
Some districts including Bhavnagar and Valsad were found to be more vulnerable to the phenomenon due to metal concentration in water, the study said.
The paper ‘Seawater intrusion decreases the metal toxicity but increases the ecological risk and degree of treatment for coastal groundwater: An Indian perspective’ was published recently in Elsevier journal Environment Pollution. The authors include Chandrashekhar Bhagat and Pranab Kumar Mohapatra from IIT-Gandhinagar; Manish Kumar from University of Petroleum and Energy Studies, Uttarakhand; Jurgen Mahlknecht from Applied Science University, Bahrain; and Rouya Hdeib from Tecnologico de Monterrey, Mexico.
For the study, the researchers collected 56 samples of groundwater and 56 samples of seawater from the same site for comparison. The study covered Gulf of Khambhat, South Gujarat, and Saurashtra coasts from Valsad in the east to Gir-Somnath on the west. The study found distribution of contaminants including nitrate, fluoride, zinc, nickel, copper, lead, iron, manganese, cadmium, chromium, cobalt, and strontium.
At several locations, the concentration was found to be more than the acceptable standards set by the World Health Organization (WHO).
“Iron was found to have the highest concentration among the metals, followed by zinc and chromium,” said a researcher. “Bhavnagar and Surat districts were found to have high concentration of iron, whereas zinc was found in high concentration in Valsad and Navsari.
The concentration was found to be significantly higher than in the southwestern coast of India in previous studies.” The researcher added: “Regular and sustained exposure to heavy metals both through consumption and skin contact can cause various health problems including cancer.”
The researcher went on to say: “Thus, regular checks are very important to ensure that the quality of water is good.”