Researchers analyzed data on pollution, weather, tree cover (the amount of land covered by trees), and how concentrations of four different air pollutants affect human health for every single county in the lower 48 states. In addition to the live-saving stats above, they found that urban areas see the greatest benefit from trees’ ability to trap and absorb air pollutants while producing nice, clean oxygen. “Urban areas account for only 3% of total land use in the US, but they see almost 66% of the health benefits of all trees,” says David Nowak, PhD, study author and project leader with the USDA Forest Service. Why? Simply because there are more people there to feel the effects of the pollution reduction. That probably explains why New York County (which encompasses o-so-crowded Manhattan) saw the biggest benefit of all. You can get in on the pollution-reducing action by volunteering to plant trees in your area at arborday.org. MORE: The Very Cool Way Nature Naturally Boosts Your Happiness
