Hugh Pickens writes "The NY Times reports that although allergies and the promise of air-conditioning tend to drive people indoors this time of year, when people swap their concrete confines for a few hours in more natural surroundings — forests, parks and other places with plenty of trees — they experience increased immune function. A study of 280 healthy people in Japan, where visiting nature parks for therapeutic effect has become a popular practice called “Shinrin-yoku,” or “forest bathing" found that being among plants produced “lower concentrations of cortisol, lower pulse rate, and lower blood pressure,” among other things. Another study in 2007 showed that men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells and a third study found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air. "It is popular to decry the destruction of tropical rainforests—citing the wonder drugs that may eventually be found there," writes Botanist Joan Maloof. "Meanwhile, closer to home, we may have medicines of our own lurking right beneath our noses. Perhaps someday, when your physician asks you to “take a deep breath,” it will be the old-growth air that he or she is referring to.""