Beware Of Watching Television, You May Be Singed

Modern electronic domestic appliances like the mixer/grinder, hairdryer, washing machine, microwave oven, television, video cassette recorder and personal computer might have reduced the drudgery for housewives, but they could prove to be a major health hazard.

The electromagnetic field created while these gadgets are in use could inflict thermal injury by radiation and flow of current through the human body.

This was the subject of discussion in one of the technical sessions of the on-going International Conference on Electromagnetic Interference and Compatibility here yesterday.

The debate was set in motion by NP Francis of the Army Centre for Electromagnetics, Mhow ( Madhya Pradesh), who underlined the health hazards from electromagnetic fields. These fields have been keeping human beings in an invisible cage of electromagnetic wave and pulses, he said.

 

Stating that the effect from these radiations on health are certainly the most complicated and difficult to understand, Francis noted that in most domestic appliances a controlled environment is created to reduce radiation by putting up shields, gaskets and the like.

While in the European Economic Area strict mandatory standards have been laid down, in India there was urgent need to analyse the problem in the correct perspective and formulate standards and lay down strict regulations for domestic electronic appliances. Of all the domestic gadgets, Francis said, the microwave oven, television and personal computer were the largest contributor to radiation (electromagnetic interference).

Exposure to microwave, Francis said, causes changes in the tissues of liver and bone-marrow. For microwaves of frequency 2450 MHz, which were the ones in common use in India, the surface absorption rate becomes more than 8 Watts per kg with depth penetration equal or less than 0.9 mm.

The International Non-Ionizing Radiation Committee has recommended that the peak energy absorption rate in any 0.1 kg of an internal organ or tissue in the head or trunk averaged over a period of six minutes should not exceed 10 Watts per kg.

Dealing with radiation flowing from the visual display terminals (VDT) of TV and PCs, Francis said a person viewing a TV or working on a PC receives radiation causing flow of electricity through his or her body. The flow of electricity is associated with the generation of heat and human body can radiate heat. If heat radiated is not equal to heat generated, then the body tissue gets heated. This damages the human body.

Francis conceded that radiation is more from the back and the side of the VDT (visual display terminals of TV/PC) than from the front. However, it has been found that women working for more than 20 hours per week or being exposed to radiations for the same period with PCs, have the possibility of getting malborn babies or suffer from miscarriage.

Use of room heaters and electric blankets, according to the defence scientist, could also result in brain and breast cancer or leukaemia. This is because when sleeping in the dark, secretion of a hormone called melatonin becomes effective. In light or under electromagnetic (EM) fields, this secretion of melatonin stops. This leads to cancer or leukaemia. Francis advises people to sleep in dark without using electric blanket or heater.

Dealing with electrostatic discharge (ESD) in homes, Francis says human body is good for the generation of static electricity. When a person moves over a floor covered with synthetic carpet, charges are transferred between the floor and non-conducting soles of the shoes. Charge at the soles and the floor are opposite in nature. As soon as charges develop at the soles, opposite charges start growing at the feet i.e. inside human body. More the person moves on the synthetic carpet, the larger is the amount of charge.

If the charged man touches a conductor, stored charges are discharged to the ground through his hand. Static charges generate voltage. If the voltage due to this stored energy rises up to 15 kv, a man can feel this discharge and shock current apparently causes damage to human organ.

Electromagnetic field created while using domestic gadgets like the microwave oven, washing machine, television or computers could inflict thermal injury by radiation and flow of current through human body, say scientists.