We basically breathe out toxins and co2. Everyone knows breathing in too much co2 can be dangerous. This is another reason why we should all strongly oppose all forms of tyrannical forced mask-wearing (outside of medical professionals in a surgery room). Mindful conscious breathing has many benefits, but we are seeing many people harmed physically and mentally due to being forced to wear masks against their will. No matter how many times they repeat their lies it’ll still never make it true. Crucial knowledge like this is hidden from us for a reason.