Central Water Commission (CWC), recently disclosed that water samples from approximately two-thirds of the country’s major rivers are polluted with one or more heavy metals. According to the report, these alarming levels of contamination surpass the safety standards laid down by the Bureau of Indian Standards. Only one-third of the water quality stations indicated safe levels whereas a noticeable 65% were identified being tainted by heavy metals.
What Constitutes Heavy Metals?
Heavy metals are natural elements with a high atomic weight and a density at least five times greater than water. They cannot be avoided completely in drinking water and small trace amounts are essential for maintaining good health. However, if they are present beyond their safe limits, they can be associated with numerous disorders.
Long-term exposure to such heavy metals may lead to physical, muscular, and neurological degenerative processes that mimic diseases like Alzheimer’s, Parkinson’s, muscular dystrophy, and multiple sclerosis. The study carried out by CWC was confined to surface water excluding the groundwater contamination.
Dominant Contaminants in the Water
Iron emerged as the most common contaminant exceeding the safe limits across the country. Arsenic and zinc, classified as toxic metals, surprisingly were always found within acceptable levels. Arsenic contamination, a significant environmental issue, affects groundwater predominantly.
Other major contaminants found in the collected samples include lead, nickel, chromium, cadmium, and copper.
Seasonal Influence on Water Contamination
The contaminant levels in water bodies vary with the seasons. Therefore, in this study, the water samples were collected during three different seasons: Non-Monsoon and Monsoon.
Non-Monsoon Period encounter lead, cadmium, nickel, chromium, and copper contamination more frequently. Meanwhile, during the Monsoon Period, iron, lead, chromium, and copper often exceeded the ‘tolerance limits’.
Reasons Behind Surface Water Contamination
The primary sources of heavy metal pollution are mining, milling, plating, and surface finishing industries. These industries discharge a variety of toxic metals into the environment contributing to the pollution.
Population growth, together with the boom in agricultural and industrial activities also play a significant role in the contamination of surface water.
Quick Facts
| Fact | Details |
|---|---|
| Percentage of water quality stations reporting contamination | 65% |
| Most common contaminant | Iron |
| Toxic metals within safe limits | Arsenic and Zinc |
| Main sources of heavy metal pollution | Mining, milling, plating, and surface finishing industries |
The Upshot
Given the grave situation, it’s high time that we focus on managing and restricting the factors contributing to water contamination. It’s crucial to understand the potential harm to our health and well-being if these rising contamination levels are not controlled effectively.