Lyric discussion by kathudson 

It's not about an apocalypse, it's about spiritual awakening. The spiritual awakening process sparks the activation of awareness and once someone have completed their spiritual awakening and they go and look back on their life before the awakening began they may see how much they were just existing in robot mode, a spiritual awakening brings them out of this robot mode and in to awareness mode which wakes them up and they start to exist with a new and positive lease of life. December 21, 2012 marks Earth’s entrance into a new stage in the evolution of human consciousness. There is a mass of "awakenings" occurring seen in highly sensitive creative individuals. They can be very outspoken and tend to go against the grain of main society and have always felt like outcasts. They are unwilling to conform to societies standards if it isn’t congruent with the way they believe things should be done. While they may attempt to go with the flow, they cannot suppress how against the “system” they really are, and simply cannot and will not accept things that do not make sense to them.

Break down:

I'm waking up to ash and dust, I wipe my brow and I sweat my rust, I'm breathing in, the chemicals. (This is in regards to the fluoride, Monsanto, GMO's etc. in our bodies. Fluoride for example calcifies the pineal gland in our brain "our third eye", blocking our path to higher consciousness)

I'm breaking in, shaping up, checking out on the prison bus. This is it, the apocalypse, whoa. (Not apocalypse end of world, but end of old world consciousness//beliefs. Starting to "wake up" entering a stage of higher consciousness, the "New Age")

I'm waking up, I feel it in my bones. Enough to make my systems blow. (Symptoms of "awakening")

Welcome to the new age, to the new age. Welcome to the new age, to the new age. (New Age: A movement drawing on both Eastern and Western spiritual and metaphysical traditions and infusing them with influences from self-help and motivational psychology, holistic health, parapsychology, consciousness research and quantum physics)

Whoa, whoa, radioactive, radioactive. Whoa, whoa, radioactive, radioactive. (Radioactivity has everything to do with energy.According to quantum physics, we are part of a vast, invisible field of energy, which contains all possible realities and responds to our thoughts and our feelings. Related to The Law of Attraction, The Law of Vibration, each frequency of vibration has a certain radiation )

I raise my flags, don my clothes, It's a revolution I suppose. We'll paint it red, to fit right in, whoa. (Realizing all the awakenings lately, in songs, media, movies, joining the new age revolution) I'm breaking in, shaping up, checking out on the prison bus. This is it, the apocalypse, whoa.

I'm waking up, I feel it in my bones. Enough to make my systems blow. Welcome to the new age, to the new age. Welcome to the new age, to the new age. Whoa, whoa, radioactive, radioactive. Whoa, whoa, radioactive, radioactive.

All systems go, sun hasn't died. Deep in my bones, straight from inside.

I'm waking up, I feel it in my bones. Enough to make my systems blow. Welcome to the new age, to the new age. Welcome to the new age, to the new age. Whoa, whoa, radioactive, radioactive. Whoa, whoa, radioactive, radioactive.

Hate to break it to you jenpen114, but this interpretation is based on unscientific dillusions that the members of Imagine Dragons don't subscribe to. It's actually about a communist revolution

" It you thought that science was certain – well, that is just an error on your part. " - Richard Feynman

I think your right about the awakening or spiritual emergence. Further I would add that term 'Radioactive' in the context of the song may refer a new consciousness about songs on the radio as opposed anything nuclear and/or being suddenly 'wired up' to the Universe. Also, the 'chemicals' he is breathing in may be drug related rather than pollutant as there is more of an eager spin and tone regarding these ' chemicals' and not negative (which may have been taken before the 'awakening'....or not, as you mentioned there can be chemicals triggered in the brain due to...

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