It's not a gasmask. Well it is, sort of, in reverse. It's a filtration system I designed to keep particles in the environment from further damaging my fragile body. Operation "Get Revenge on the Environment for Damaging my Fragile Body" has regrettably stalled due to- oh, you'll find this interesting! The system has the unintended side effect of reducing my radioactive decay by 90.05%! You've only been exposed to a mere yearly recommended maximum dosage!

What's the big deal? Just wear sunscreen and a hat until next year. And don't get any medical x-rays. Or talk on any cellphones. You'll be fine!