Scientists warn that change in solar activity will increase space radiation that could be hazardous to astronauts and airline passengers in the near future.

Cosmic rays from deep space and high-energy particles from the sun are hazardous to astronauts and are likely to expose airline crews and passengers to high levels of radiation. Cosmic rays constantly hit Earth, but the solar activity is dependent on the sun's regular weather cycle.

The reports said more storms would arrive in coming months as the sun is approaches the peak of its current 11-year cycle in 2013. Researchers have expressed serious concerns over long-haul flights since the sun has been in a grand solar maximum that has already lasted longer than another other maximum in the past 9,300 years.

Solar magnetic fields protect Earth by repelling incoming galactic cosmic rays, thus limiting the damage caused. However, the period of high solar magnetic activity known as the grand solar maximum that persisted throughout the Space Age now appears to be coming to an end, and solar particle levels might start rising at the same time, according to space.com.

The recent solar storm that reached the Earth Monday has shrouded the planet with cosmic rays and high-energy particles. The National Oceanic and Atmospheric Administration earlier reported that the G3 class strong-to-severe geomagnetic storm that resulted from a Coronal Mass Ejection on the sun was active and strengthening.

Researchers based on the past record found that the risk of hazardous space weather is likely to rise noticeably over the next century from the level in recent decades.

However, it is good to be aware that one is exposed to more hazardous particles, particularly on trans-polar flights. For really frequent, lifelong fliers, it might become wise to be like workers in the radiation industry and have more-frequent and more in-depth health checks,” a NASA scientist told space.com.

Numerous studies have shown that exposure to radiation will increase health risk. Space radiation on the ground is very low, but increases significantly with altitude. At 30,000 to 40,000 feet, the typical altitude of a jetliner, exposure on a typical flight is still considered safe - less than a chest X-ray.

Exposure is considerably higher, however, over the Earth's poles, where the planet's magnetic field no longer provides a shield. And with a thousandfold rise in commercial airline flights over the North Pole in the last 10 years, exposure to radiation has become a serious concern, NASA has said.

The International Commission on Radiological Protection recommends a 1 mSv limit for the annual dose. Dosages during a flight depend on path, duration and altitude as well as on the level of solar activity. A commercial eight-hour polar flight during the 2003 Halloween SEP event would have given 70 per cent of this recommended annual limit and it is estimated that the largest known SEP event, the Carrington event of 1859, would have given 20 times the limit.

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