- In 15 states infected with emerald ash borer, an additional 15,000 people died from cardiovascular disease and 6,000 more from lower respiratory disease compared with uninfected areas of the country.
- Levels of asthma are highest where tree density is the lowest but the rate of childhood asthma is 29% lower for every 343 trees per square kilometer.
- Accounting for socioeconomic factors, residents of areas with the highest levels of greenery were three times as likely to be physically active and 40% less likely to be overweight or obese than residents living in the least green settings.
- Urban trees reduce ultraviolet (UV) radiation, especially UV-B radiation, which is known to cause skin cancer. A person standing in direct sunlight takes 20 minutes to burn. Under a tree providing 50% coverage, it takes 50 minutes to burn. Under full shade it takes 100 minutes for one to get a sunburn.