CPCB reports heavy metal contamination in Delhi, uranium levels 3rd highest in country, Pg4

Key Highlights:

• CPCB's annual report reveals severe heavy metal contamination in Delhi's groundwater.
• Delhi has some of India's highest levels of uranium, lead, nitrate, fluoride, and salinity-related indicators.
• 9.3% of Delhi's groundwater samples exceeded BIS limits for lead during the pre-monsoon season.
• Delhi ranks third highest in uranium contamination after Punjab and Haryana, with 13-15% exceeding permissible limits.
• Electrical Conductivity (EC) and salinity are major groundwater stress points in Delhi.

Detailed Insights:

• Lead contamination poses significant health risks, especially for children's cognitive development and kidney function.
• Uranium contamination is linked to kidney damage and carcinogenic risks, with the northwestern belt identified as a hotspot.
• Nitrate exceedances are primarily due to anthropogenic sources like agricultural practices and improper waste disposal.
• High fluoride concentrations are predominantly geogenic, meaning they occur naturally in the groundwater.
• Elevated Electrical Conductivity (EC) indicates high levels of total dissolved solids and salinity, a major concern in arid regions.
• Delhi's groundwater shows significant alkali and salinity hazards, indicated by high Sodium Adsorption Ratio (SAR) and Residual Sodium Carbonate (RSC) values.
• Saline facies in Delhi's groundwater, particularly NaCl-type water, contribute to the overall contamination.
• Groundwater contamination in Delhi intensified from 2024 to 2025, with increased exceedances in EC, nitrate, fluoride, and uranium.

Key Concepts Involved:

• Heavy Metals: Toxic metallic elements that can contaminate water and soil, posing health risks.
• Electrical Conductivity (EC): A measure of the amount of dissolved salts and minerals in water.
• Anthropogenic Sources: Environmental pollution and pollutants originating from human activity.