New Delhi, March 21 (IANS) As panic and myths do the rounds after the radiation leak at Japan's quake-hit Fukushima nuclear plant, experts feel India should not worry about the radiation reaching the country's shores.

"It is very important to consider India's location in the South Asian map. It is just not possible for radiation to reach India through wind flow because of the Himalayas. Infact, India was much more in danger when the Chernobyl disaster happened in 1986," C.S. Bal, professor of nuclear medicine at the All India Institute of Medical Sciences (AIIMS), told IANS.

According to experts, radiation reaches hazardous levels when rays emitted by radioactive substances exceed defined limits.

"The harm depends on the level of radiation exposure, which is quite low as of now. Human beings are exposed to some minimum amount of radiation on a daily basis, like when somebody gets an X-ray done," said Ishita Sen, head of the nuclear medicine division at Artemis Hospital in Gurgaon.

"Inhaling smaller molecules of radioactive substance through contaminated air can cause nausea, vomiting or headache initially, but that is for areas within 10 miles (16 km) of the leaking plant," Sen told IANS.

Radiation leaks at the nuclear plant in Chernobyl, Ukraine, in 1986, left over 4,000 dead, and affected thousands of others with after-effects like cancer.

"The situation was very grave from the environmental and health perspective during the Chernobyl disaster as the containment vessel was missing. The situation is critical for Japan, but nowhere near Chernobyl," said Bal.

Japan was hit by a massive earthquake, measuring 9 on the Richter scale, March 11, triggering a tsunami along its northeastern coast, leaving over 7,000 people dead.

Experts feel that apart from the release of radioactive iodine from the crippled reactors, it is also important to note the release of cesium.

"Cesium, released in small amounts, is absorbed throughout the body - not just by the thyroid - and stays in organs, tissue and the environment much longer," T.K Joshi, director of the Centre for Occupational and Environmental Health at Lok Nayak Hospital, told IANS.

Cesium particles are usually large and heavy, and thus are less likely to reach other Asian nations, including India.

The escalating crisis due to leakage of radioactive materials from the Fukushima plant has raised health concerns, with anxious citizens stocking potassium iodide tablets as a preventive measure.

"This is a serious myth amongst people because they have been misinformed that potassium iodide can help them prepare against the radiation. Potassium iodide is not recommended until radiation levels hit the tens of thousands of microsieverts (a unit of measuring radiation)," said G.K. Rath, head of department of radiotherapy and chief of B.R. Ambedkar Institute-Rotary Cancer Hospital at AIIMS.

Rumours spread after a widely-circulated mail said "iodine pills can prevent radiation", with people rushing to stock iodine pills or liquid iodine, commonly used as an antiseptic. Iodine is also available in common iodised salt.

Radioactive iodine is released during nuclear emergencies and, if breathed in or swallowed, concentrates in the thyroid gland and increases the risk of thyroid cancer.

"It is true that potassium iodide pills reduce the risk of thyroid cancer, but then it is only for people who are very close to the nuclear reactors. These pills can also cause harm to women who are in early stages of pregnancy, if not in radiation-hit areas," said Sen.

Potassium iodide pills, according to experts, are meant to flood the thyroid with ordinary iodine in the hope that it will prevent the gland from taking in the radioactive iodine.

The World Health Organisation (WHO) too recently issued a statement saying iodine pills are "not radiation antidotes" and offer no protection against radioactive elements such as cesium.

WHO recommendations include intake of 150-mg iodine pill only for people living in radiation-hit areas.

"Taking a pill every day only encourages hyperthyroidism and may be harmful in the long run," added Sen.

Another concern is that the farm produce and vegetation at the sites close to the Fukushima plant may be contaminated.