Years ago, my drawing room used to be taken over by 10 or 12 sparrows every morning. They flitted around making noisy conversation as I quietly sipped my tea. I took them for granted and they me. They seemed quite at home, coming close to me to peck on the crumbs of biscuits that fell on the floor.

Then about 15 years ago, fewer and fewer birds started showing up. And then gradually, there was none.

I discovered, much to my shock, that the sparrows started disappearing when mobile phones began making inroads. Calcutta was the first city in India to launch these phones in the mid-1990s.

I tried to find out why the sparrows started vanishing with the advent of mobile phones. Some sort of radiation was surely affecting them.

All mobile phones come with a tiny booklet in small print, which no one bothers to read. The phones emit radio waves. The unit of measurement of this is known as Specific Absorption Rate or SAR.

Tests for SAR are conducted using standardised methods with the phone transmitting at its highest certified power through all frequency bands.

There are differences between the SAR levels of various phone models and they are supposed to meet the relevant safety guidelines for exposure to radio waves. In truth, however, they seldom do.

There is a plethora of Indian and Chinese mobile phone models in the market today. They are downright dangerous and can lead to cancer and other diseases.

This is because countries that have adopted the SAR limit recommended by the International Commission on Non-Ionising Radiation Protection have set the limit at 2 Watts/kg for every 10 grams of tissue. This means it is safe if the radio emissions are 2 Watts/kg for every 10 grams of your skin that is exposed. Till about a few years ago, only the European Union, Japan, Brazil and New Zealand had joined. Subsequently, Canada, the US and other countries followed suit.

In India, mobile phone manufacturers follow no such safety rules. I am not talking about the multinational brands. Nokia, Sony Ericsson, Research In Motion (the makers of BlackBerry), Motorola, Samsung and, of course, Apples’s iPhone mention their SAR limits and even give you advice about safety instructions. But the problem is nobody reads them.

Remember, you are doing this at your own peril and this could seriously damage your health, especially if you are one of those who are constantly on the mobile phone. The iPhone 3G S has the minimum SAR limit at 0.78 Watts/kg. It is the least dangerous.

Precautions: So what precautions should you take?

• Never buy a mobile phone that has a SAR limit of more that 2 Watts/kg.

• If you have a pacemaker, always keep your phone at least 8 inches away from the machine. Use the ear opposite the pacemaker to make and receive calls.

• Do not carry your phone in your breast pocket.

• When you are in a clinic, turn off all wireless connections. Hospitals and healthcare facilities use equipment that could interfere with external radio frequency.

•Mobile phones are not intrinsically safe devices. Do not use them in the presence of gas fumes, life support and weapons systems.

• Always switch off your phone at petrol pumps. Most of you may know this, but I have noticed that no one ever does so.

• Some mobile phones have flashing lights. These can cause epileptic fits or blackouts.

• While using a mobile phone, if you experience any disorientation, loss of awareness, convulsions or any involuntary movements, stop using it immediately.

• Last and most important, avoid long conversations on a mobile phone. Speak for about 20 minutes and then give a gap and call again.

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