Context:
High levels of heavy metals, particularly cadmium (Cd) and lead (Pb), were detected in fish from the Cauvery River. Regular or excessive consumption of contaminated fish may pose carcinogenic and non-carcinogenic health risks to humans, affecting neurological and renal health.
About the Cauvery River
- Significance: One of South India’s most sacred rivers, called the “Dakshina Ganga.”
- Origin: Brahmagiri Hills, Western Ghats, Karnataka.
- Length & Flow: 765 km southeast through Karnataka and Tamil Nadu; forms fertile plains and several waterfalls.
- Tributaries: Kabini, Hemavati, Noyil, Amaravati, Bhavani.
- Mouth: Bay of Bengal south of Cuddalore, forming the Cauvery Delta, known as the “Garden of Southern India.”
- Major Dams: Krishnaraja Sagar, Mettur, and Grand Anicut (2nd century AD).
About Heavy Metals
- Definition: Metallic elements with high atomic weight and density, toxic when accumulated in organisms.
- Common Examples: Lead (Pb), Cadmium (Cd), Chromium (Cr), Mercury (Hg), Copper (Cu).
- Sources in Cauvery: Industrial effluents (textiles, electroplating), agricultural runoff, untreated urban sewage.
Key Findings of the Study
- Metals Analyzed: Chromium (Cr), Cadmium (Cd), Copper (Cu), Lead (Pb), Zinc (Zn).
- Primary Contaminants: Cadmium and lead exceeded safety thresholds in several fish species.
- Variation: Levels differed across sites and fish species, indicating combined natural and human-induced sources.
- Health Risks: Long-term exposure may cause:
- Neurological disorders
- Kidney damage
- Carcinogenic effects
