Thanks to the fast changing technology that makes PCs obsolete quickly, private firms and even public sector units are selling off their old hardware instead of upgrading them.

In auctions, old hardware is available at dirt cheap prices.

In Power Finance Corporation’s auction held last year, the minimum price for 29 computers, six colour TVs and 24 printers was Rs 30,000. On an average, the cost of each item came to less than Rs 500 and the cost per kg was between Rs 20 and Rs 50.

Each item, when broken up, can fetch several times the amount paid for it.

According to a study done by NGO Toxic Links, the most valuable parts of an old computer are the circuit board and the monitor. Monitors contain a large amount of copper yoke besides a printed circuit board and a picture tube. The plastic casing, the cathode ray tube, copper yoke and plates are removed first. These tubes are then used for manufacturing picture tubes for black and white televisions which are used by local brands. Circuit boards Printed circuit boards contain heavy metals such as antimony, gold, silver, chromium, zinc, lead, tin and copper.

Retrieving metals from circuit boards is a hazardous activity, states the NGO’s report, Scrapping the Hi-Tech Myth — Computer Waste in India. Often, these components are burnt, leading to emission of dangerous gases. ‘‘During our visits, we found that the workers were using only bare hands putting them at grave risk,’’ said Papiya Sarkar, a volunteer with Toxic Links.

What is as dangerous as burning is the acid wash given to the motherboard. A mixture of hydrochloric and nitric acids is applied with an iron brush to retrieve various metals. Copper, the most abundant metal inside a computer, is found in various parts. Apart from the copper yoke in the picture tube, it can be retrieved from transformers, circuit tray and condensers.

The copper so retrieved is sold to smelters and the process of removal — which is by burning the metal in the open — puts the labourers involved at risk. An interesting fact is that a single component can move to various dealers who specialise in the extraction of only one particular metal.

Environmentalists say that while a complete ban on the import of electronic waste has to be imposed, a safe method of handling waste generated within the country has to be found out.

‘‘While computer manufacturers have to work at making their products toxic free, electronic waste has to be included in the list of products whose import is banned under the Basel convention,’’ says Toxic Links director Ravi Agarwal.

A recommendation by the Central Pollution Control Board to make it compulsory for those importing e-waste to register their import at ports is pending with the Ministry of Environment and Forests, say officials.