Science time: Radiation talk

Electromagnetic pollution - a biohazard

Is the air really as calm as we see it or does it hold some invisible demon in its folds?

The environment in which we live and the pace with which we are advancing our technology ensures our constant interaction with electromagnetic radiation. Since it is inevitable to be out of its path, it would be beneficial to be aware of the biological effects of exposure to such radiation.

Physically, there are two types of eelectromagnetic radiation - Ionizing (X-rays, g-rays, neutrons, b-rays and a-rays) and Non-Ionizing (extremely low frequency, radiofrequency and microwaves). It is the latter type that we encounter in our daily lives.

Until about a century ago, the sole source of human exposure to electromagnetic radiation was atmospheric electricity and geomagnetism. Various human activities involving the use of electromagnetic fields have now led to widespread presence of fields of low frequency in the environment - the main sources being electricity distribution systems, household electrical appliances, radiofrequency heaters, television broadcasting waves, radars and portable radio-transmitters.

Now since the living body is electrochemical in nature, any force that alters the normal electrochemical phenomena occurring in humans will affect the physiology of the body. The effects depend on the age, sex and pre-existing stress conditions of the exposed individual, besides the srength and duration of the exposure.

Exposure from high voltage power lines can cause lymphoma and leukemia. Electrical workers, in addition, are also prone to pancreatic cancer too. The tumor promotion action is attributed to the alteration in the immune defence system as well as in the enzymatic functioning in the body.
Prolonged exposure to extremely low frequency fields can cause hormonal imbalances, due to which growth might be affected.

Secondary effects: Stress, inflammatory responses, heating of the tissues on the surface or deep within the body, production of new, unwanted proteins or change in protein quantity.
Effects of chronic or occupational exposure: Reduced metabolic heat production, lowered skin temperature, altered vasomotor thresholds and augmented sweating rates.

Keeping in mind the hazards of continuous exposure, certain safety standards have been prescribed in terms of the Specific Absorption Rate (SAR), restrictive limits being the human resonance frequency of 30-300 MegaHertz.

Some specialists think it is high time we shelled out large sums on making major changes in the designs, operation and use of electric systems. Efforts are on to investigate more vigorously the multidimensional aspects of electromagnetic pollutants and find ways to strike a balance between minimizing of radiation and technological progress. Devices like Trifield meters have been introduced to measure the levels in houses.

Nevertheless, as long as radiation cannot be out of our way, we have to be careful not to fall into the arms of its hazards by indiscriminate and ignorant use of technology.

- Nivedita M Shori