Breath in the damp thick oxygen filled air with lots of negative ions. In fact, experts say that once negative ions reach our bloodstreams, they produce biochemical reactions that increase levels of serotonin in our bodies, hence helping to relieve stress and alleviate depression. When I am close to nature and I breathe in the fresh air and feel the dampness of the forest, when I hear the sound of water flowing and the leaves rustling, accompanied by birdsong, I feel at home.