NEW YORK – Flight attendants and pilots are at the highest risk of dying from radiation-related cancers – even more than people who work with radioactive materials, according to a new study. Cosmic radiation comes from space. Only a small amount reaches the Earth's surface, but exposure is greater for people flying at high altitudes. There's been limited evidence from small studies suggesting that the exposure translates to higher cancer death rates among people who fly often – particularly pilots and flight attendants. The new study "brings important new evidence to bear on this question," two Australian radiation experts who weren't…