Yes, the ISS has some protection from being in low Earth orbit. But the rate of cosmic ray strikes is still high enough to pose a health risk, so the areas on I

Yes, the ISS has some protection from being in low Earth orbit. But the rate of cosmic ray strikes is still high enough to pose a health risk, so the areas on ISS where astronauts spend most of their time have additional shielding. The material most often used for shielding is polyethylene because it performs better in terms of secondary emissions - heavy elements like lead emit showers of secondary particles when struck by cosmic rays and have to be very thick to contain the secondaries, which is far too heavy to put into space. Once away from low Earth orbit the shielding on a spacecraft becomes very expensive in terms of size and weight, even when it is the lighter weight polyethylene material.