Educated guess #1 - more toxins + less oxygen = bad for your brain, body and adds distraction (can you study/focus when you have health issues?) Educated guess

Educated guess #1 - more toxins + less oxygen = bad for your brain, body and adds distraction (can you study/focus when you have health issues?) Educated guess #2 - less pollution = better environment, country side and/or nature rich + less stress