Radiation at higher atmosphere is indeed an issue but one hard to control for in a aluminum plane. I'd love to see more mfg embrace electric compressors instead of bleed air for cabin pressurization to reduce the CNS issues faced by pilots, stewards and passengers due to toxic air syndrome from the contaminants aerosolized by engine-supplied bleed air into the cabin. It's so gross, so preventable, and possibly criminal as operators and manufacturers are found liable for injuries.