The National Academies Press has written that the World Health Organization (WHO) has defined health as “a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity.” This definition serves as a reminder that
redefining the view of environmental health and the natural environment requires many shifts in thinking, along with a willingness to pursue a diversity of approaches. Advances in the field of environmental health have taught us much about human health hazards, such as considerations that air pollution can cause respiratory disease, heavy metals can cause neurotoxicity, and global climate change is likely to fuel the spread of infectious diseases.
In a news release on Jan. 16, 2013, the US Forest Service has reported, Tree and human health may be linked. Evidence has been increasing from multiple scientific fields that exposure to the natural environment can improve human health. In a new study by the U.S. Forest Service, the presence of trees was found to be associated with human health. Researchers have discovered in an analysis of 18 years of data from 1,296 counties in 15 states, that Americans living in areas infested by the emerald ash borer, a beetle that kills ash trees, suffered from an additional 15,000 deaths from cardiovascular disease and 6,000 more deaths from lower respiratory disease in comparison to uninfected areas.
Geoffrey Donovan, a research forester at the Forest Service’s Pacific Northwest Research Station, has said, “There’s a natural tendency to see our findings and conclude that, surely, the higher mortality rates are because of some confounding variable, like income or education, and not the loss of trees. But we saw the same pattern repeated over and over in counties with very different demographic makeups.” However, although this study has demonstrated the association between loss of trees and human mortality from cardiovascular and lower respiratory disease, it did not prove there is a causal link.
The reason for the association has not yet been determined.