In the coming years, as a result of changes, in solar activity, radiation hazards are likely to increase for both air travelers and astronauts.

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

The Sun is currently approaching the peak of its current 11-year cycle, called Solar Cycle 24. That peak will occur in 2013, according to NASA reports.

Solar magnetic fields protect the 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

Based on past records, researchers have found that the risk of hazardous space weather is likely to rise noticeably over the next century, as compared to those of a few decades ago.

Various studies have shown that an exposure to radiation will increase health risks. Space radiation on the ground is very low but increases significantly with altitude. Exposure is considerably higher, however, over the Earth's poles, where the planet's magnetic field no longer provides a shield.