According to a report by the Central Ground Water Authority, Delhi’s groundwater has very high salt content. One in four groundwater samples taken from the capital city was found to have very high electrical conductivity (EC), and more than 25% of the water samples analysed in Delhi are saline.

This is second after Rajasthan, where 30% of the samples were found saline.

How does excess salt water cause kidney problems?

The national electrical conductivity average is 6%, which indicates a conductivity greater than 3,000 micro siemens per centimeter. The acceptable range of electrical conductivity for groundwater is between 750 and 3,000 units at 25 degrees Celsius.

However, when the EC exceeds 3,000 units, it becomes unfit for drinking, causing a number of diseases including kidney-related problems.

Dr Mohit Khirbat, Nephrology Consultant at CK Birla Hospital, Gurugram, said, “Salt (sodium) is one of the major components of fluid balance in the body. If you consume more salt, your body will retain more water to dilute the salt concentration. This can increase your blood pressure, which has a negative impact on your kidneys.”

High sodium intake can cause the body to retain water, which can increase blood volume and blood pressure.

Over time, this increased pressure can damage the blood vessels of the kidneys, reducing their ability to filter waste effectively.

“Excess salt intake increases the amount of calcium in the urine, which can combine with oxalate or phosphate to form kidney stones. These can block the urinary tract and cause severe pain and kidney damage,” says Dr Sanjeev Gulati, Executive Director, Nephrology & Kidney Transplant, Fortis Escorts, Okhla Road, New Delhi.

When salt intake in the body becomes excessive, it potentially leads to chronic kidney disease, in which the kidneys have to work hard to filter out excess sodium.

Are there more cases of kidney problems in Delhi?

According to Dr Khirbat, the prevalence of kidney problems in Delhi is much higher than in other regions of the country.

He said, “The quality of drinking water in Delhi and its surrounding areas may deteriorate. In some places, water may contain high levels of heavy metals and minerals, which may increase the risk of kidney problems.”

Apart from water, lifestyle choices such as long working hours, unhealthy diet and high stress are leading to high blood pressure, diabetes and obesity in Delhi — which are risk factors for kidney problems.

Air pollution has always “had a negative impact on health.” “Pollutants destroy kidney cells, which affects kidney function, leading to chronic kidney disease,” Dr. Khirbat said.

Delay in diagnosis is also due to lack of awareness about its signs and symptoms.

According to Dr Gulati, one of the reasons for the high salt content in Delhi’s groundwater is wastewater from industries, particularly those engaged in mining, chemical production or salt extraction, which can introduce high levels of salt into groundwater systems.