Explained Snippets | Sulphur dioxide, heavy metals: How copper smelting pollutes

The main pollutants are released by the process of smelting. Most copper ores are sulphur-based and smelting releases sulphur dioxide, an air pollutant known to have many harmful effects.

By: Express News Service | New Delhi | Published: May 28, 2018 5:54:00 am
Explained Snippets | Sulphur dioxide, heavy metals: How copper smelting pollutes Smoke rises from vehicles set on fire during protests in Tuticorin. (Express Photo)

Protests OVER the expansion of a Sterlite Copper smelting plant in Tuticorin, Tamil Nadu, which led to police firing that killed 13 people, have been over pollution concerns. How do copper and smelting of the metal pollute? Dr Purnendu Bose of the environmental engineering faculty in IIT Kanpur explains that copper, while an essential nutrient, is toxic to animals and humans in high concentrations. The main pollutants are released by the process of smelting. Most copper ores are sulphur-based and smelting releases sulphur dioxide, an air pollutant known to have many harmful effects. Sometimes, depending on the quality of the ore, the concentration of sulphur dioxide is so high that industries are forced to convert it into sulphuric acid, which itself is a water contaminant. The other byproduct of smelting is slag, the waste matter separated from metals. This slag may leach heavy metals (arsenic, cadmium, lead or mercury depending on the composition of the ore) into groundwater reservoirs. Water which has a high heavy metal content is very toxic to humans. Slag may also increase the concentration of other, less harmful salts in water resources, which may change the taste of water. The proper disposal of these byproducts can restrict the pollution caused by these factors to within the limits permitted by the government and other regulatory bodies. —Promit Chakroborty

***

Telling Numbers

Regional parties earned Rs 321 crore, spent Rs 435 crore in a year, SP shares highest

Regional parties declared an income of Rs 321.03 crore and an expenditure of Rs 435.38 crore in 2016-17, according to an analysis of their audited accounts by the Association for Democratic Reforms. Of India’s 48 regional parties, the audited accounts of 32 were available on the Election Commission website, an ADR report said. The Samajwadi Party led on both counts, accounting for one-fourth of all income by regional parties and one-third of their expenditure.

***

Tip for Reading List

Leg Exercise Keeps Brain Healthy

New research shows that neurological health depends as much on signals sent by the body’s large leg muscles to the brain as it does on directives from the brain to the muscles. Published in Frontiers in Neuroscience, the study fundamentally alters brain and nervous system medicine — giving doctors new clues as to why patients with neurological diseases often rapidly decline when their movement becomes limited. The study involved restricting mice from using their hind legs, but not their front legs, over a period of 28 days. At the end, the researchers examined an area of the brain called the sub-ventricular zone. Limiting physical activity decreased the number of neural stem cells by 70% compared to a control group of mice. Further, neurons and specialised cells called oligodendrocytes didn’t fully mature when exercise was severely reduced. The research shows that using the legs, particularly in weight-bearing exercise, sends signals to the brain that are vital for the production of healthy neural cells, essential for the brain and nervous system. The research has a range of potential implications. For example, missions to send astronauts into space for long periods should keep in mind that gravity and load-bearing exercise play an important role in maintaining health, say the researchers. —Source: EurekAlert press release

For all the latest Explained News, download Indian Express App

Advertisement
Advertisement
Advertisement
Advertisement
Advertisement