T. Lalith Singh

High concentration of heavy metals found in soil, ground and surface water

Study, funded as part of an Indo-Norwegian project, conducted for over 40 monthsPresence of lead at 2,000 mg/kg against an acceptable limit of 140 mg/kgLakes of Noor Mohammad, Chilan and Ura considered to be extremely contaminated

HYDERABAD: Unchecked pollution over decades has brought the residents of Katedan and surrounding areas on city suburbs into the risk zone of a contamination bomb that appears to be ticking away.

A study conducted by the National Geophysical Research Institute has found high concentration of heavy metals in soil, groundwater, surface water and sediments in areas around Katedan. Such high concentration of metals could lead to severe debilitating health hazards like damage to kidney, brain, nervous system or even affect the fertility of men.

The study, funded as part of an Indo-Norwegian project and conducted for over 40 months, found concentrations to be extremely high at some `dump sites.' Researchers found that presence of lead stood at 2,000 mg/kg against an acceptable limit of 140 mg/kg.

Chromium contamination

The arsenic presence at some sites, including those near Noor Mohammad Lake and Narsabaigunta, was found to be exceeding 400 mg/kg against Soil Quality Guidelines (SQGL) limit of 12 mg/kg. Even in residential areas, the Arsenic content was around 140 mg/kg. The team consisting of scientists from the NGRI and the Oslo-based Norwegian Geotechnical Institute, found chromium concentrations at some spots to be 877 mg/kg much beyond the SQGL limit of 64 mg/kg.

Contamination levels were also recorded for groundwater and surface water at several points in the study in which samples were drawn from 66 wells in the industrial area and 27 wells in the residential areas.

The groundwater studies revealed a maximum of 5,260 microgram per litre zinc presence at some observation points during pre-monsoon sampling, a measure far beyond the standard of a 3,000 microgram per litre.

Among others, the study teams covered the lakes of Noor Mohammad, Chilan and Ura and evaluated them to be `extremely contaminated' because of high metal concentrations. "Over the years, the fresh water environment has been degraded to the extent that it cannot support any organisms, flora or fauna," it points out.

Long-term effect

At another point, the report says Noor Mohammad Lake was `acting as a sink for the contaminants' and lake sediments were also found to be extremely contaminated with high arsenic concentrations.

"Even if dumping and discharging of effluents is totally terminated from the surface soil, contamination will remain for many more years in the subsoil and groundwater," says Pradip K. Govil NGRI Project Coordinator.

Making a risk assessment, the Indo-Norwegian Institutional Cooperation Programme-sponsored report describes the soil, surface and groundwater in the Katedan Industrial Area as a serious health risk to humans and goes on to add, "the degree of contamination has been so intense that in some parts the environment has become unsuitable for human living."