A study by scientists at Harvard T.H. Chan School of Public Health and Brigham and Women?s Hospital in Boston, USA found women with the highest levels of vegetation, or greenness, near their homes had a 12 percent lower death rate compared to women with the lowest levels of vegetation near their homes. The researchers examined greenness around the homes of 108,630 women over a period from 2000 to 2008. The result of the study was published in the latest edition of the journal Environmental Health Perspectives.
The researchers found the biggest differences in death rates from kidney disease, respiratory disease, and cancer. They also explored how an environment with trees, shrubs, and plants might lower mortality rates. The study showed that improved mental health and social engagement are the strongest factors, while increased physical activity and reduced air pollution also contribute.
?It is important to know that trees and plants provide health benefits in our communities, as well as beauty,? said Dr. Linda Birnbaum, Director of National Institute of Environmental Health Sciences (NIEHS) ?The finding of reduced mortality suggests that vegetation may be important to health in a broad range of ways.?
The researchers mapped home locations and used high resolution satellite imagery to determine the level of vegetation within 250 meters and 1,250 meters of homes.
The scientists consistently found lower mortality rates in women as levels of trees and plants increased around their homes. This trend was seen for separate causes of death and when all causes were combined. When researchers compared women in the areas with highest greenness to women in the lowest, they found a 41 percent lower death rate for kidney disease, 34 percent lower death rate for respiratory disease, and 13 percent lower death rate for cancer in the greenest areas.
?The ability to examine vegetation in relatively fine detail around so many homes, while also considering the characteristics of the individual participants, is a major strength of this study,? said Dr. Bonnie Joubert, NIEHS scientific program director overseeing the study. ?This builds on prior studies showing the health benefits of greenness that used community-level or regional data.?
The scientists also looked at characteristics that can otherwise contribute to mortality risk, such as age, race, ethnicity, smoking, and socioeconomic status. This enabled them to be more confident that vegetation plays a role in reduced mortality, rather than these factors. If participants moved or the vegetation near their homes changed during the study, the scientists took those changes into account in their study.
Source: US National Institute of Health