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Heavy metal toxicity and water contamination

| | in Oped

Heavy metal contamination has not only impacted health and environment but the crippling effects of fluoride and arsenic toxicity is transforming to become a major public health issue today. The Government must step up its heavy metal contamination prevention and mitigation activities

For the past few years, there has been a concerning spike in the levels of heavy metals in our daily lives. The contamination of drinking water with these harmful heavy metals is one of the most serious issues, as no amount of efforts so far have been able to rein in the growing levels of heavy metals in water.

The major hazardous metals of concern for India in terms of their environmental load and health effects are: Lead, mercury, chromium, cadmium, copper and aluminum. Their source is mostly anthropogenic — industrial activity and vehicles. Natural causes like seepage from rocks, volcanic activity and forest fires can also be the contributing factors.

In general, heavy metal toxicity can cause chronic degenerative diseases — the symptoms being mental disorders, pain in muscle and joints, gastro-intestinal disorders, vision problems, chronic fatigue, and susceptibility to fungal infections. Sometimes the symptoms are vague and difficult to diagnose at early stage. Geno-toxicity and cancers can also occur.

Industrial workers and populations living near the polluting industry are more susceptible and have to be monitored for the effects of sustained exposure to heavy metals. Additionally, malnourished people and pregnant women are also extremely vulnerable.

The issue of heavy metal contamination has not only impacted health and environment but the crippling effects of fluoride and arsenic toxicity due to non-availability of safe water for drinking and farming, is transforming to become a major public health issue in India today.

Heavy metals are also dangerous because they tend to bioaccumulate. Bioaccumulation is a condition in which the concentration of a chemical in a biological organism increases over time, compared to the chemical’s concentration in the environment.

Compounds accumulate in living beings any time they are taken up and stored faster than they are broken down that is, metabolised or excreted. Heavy metals can enter a water supply by industrial and consumer waste, or even from acidic rain breaking down soils and releasing heavy metals into streams, lakes, rivers, and groundwater.

Off late, India has seen a spurt in health cases pertaining to physical, muscular, and neurological degenerative diseases that resemble Alzheimer’s, Parkinson’s disease, muscular dystrophy, and multiple sclerosis.

Given this disturbing background, it is essential for the Government to step up its heavy metal contamination prevention and mitigation activity so that the growing concern of heavy metal poisoning in the country can effectively be addressed.

For instance, a new low cost and safe method for removing chromium-6, a highly toxic heavy metal, from wastewater has been developed by a group of scientists from India and Ethiopia. The method uses water hyacinth, a weed known for its ability to spread rapidly over water bodies. It is used for cleansing polluted water bodies owing to its remarkable capacity of absorbing pollutants.

As per this method, water hyacinth is made into a powder and then mixed with water containing chromium-6. The powder is allowed to settle down and gradually the water above the powdered area starts showing lower levels of chromium-6 as compared to other parts of the water body where the powder has not been applied.

This because water hyacinth particles attract chromium, which then gets ‘stuck’ to it, thereby leaving water chromium ‘free’. For every litre of water, only 0.04 grams of powdered water hyacinth is required to reduce the amount of chromium-6 to ‘safer’ levels over a period of 30 minutes. It was also found that acidic water further encouraged the ‘sticking’ or adsorption of chromium-6 particles to the powdered water hyacinth.

The Government must encourage researches, such as the water hyacinth powder model, to remove extremely hazardous elements from industrial waste before it becomes dangerous to the humans and the environment.

It is also essential that physico-chemical, as well bioremediation solutions, should be applied immediately to reduce the environment and public health load, preferably at the site of generation.

While large industries are mandated to set up and operate their own effluent treatment plants, how well these plants work, or whether they work at all is anybody’s guess. This dismal state of affairs must be dispensed urgently. Focus must be put on ensuring that the plants not only operate efficiently but also with due concentration on handling the heavy metals.

On the other hand, common effluent treatment facilities can be considered for smaller industries, provided they are maintained properly. To ensure accountability and proper functioning of these plants, the Government must set up a supervisory team comprising of representatives of industry employees, Government officials and representatives of the local population in the area.

This will guarantee that in the best interests of health and ecology, the supervisory team will prevail upon the industry management to keep the effluent treatment plant working in perfect order. There is also a need to check the pollution occurring from items such as medical devices containing mercury and compact fluorescent  bulbs.

(The writer is an environmental journalist)

 
 
 
 
 
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