Having greater tree cover around watersheds may protect children in rural areas from diarrhoea - the second leading cause of death for infants under the age of five, a global study on 300,000 children has found.
The study, published in the journal Nature Communicators, is the first to quantify the connection between watershed quality and individual health outcomes of children at the global scale. Diarrhoeal disease is the second leading cause of death for children under the age of five. According to the World Health Organisation (WHO), 361,000 children die of diarrhoeal disease every year because of poor access to clean water, sanitation and hygiene.
Researchers, including those from University of Vermont (UVM) in the US, found that a 30 per cent increase in upstream tree cover in rural watersheds would have a comparable effect to improved water sanitation, such as the addition of indoor plumbing or toilets. "This suggests that protecting watersheds, in the right circumstances, can double as a public health investment.
This shows, very clearly, how 'natural infrastructure' can directly support human health and welfare," said Brendan Fisher of UVM. The research is the first to use a massive new database that will enable "big data" approaches to study links between human health and the environment, globally. The database features 30 years of USAID demographic and health surveys, with 150 variables for 500,000 households, including spatial data on the environment.
"We are not saying trees are more important than toilets and indoor plumbing. But these findings clearly show that forests and other natural systems can complement traditional water sanitation systems, and help compensate for a lack of infrastructure," said Diego Herrera, postdoctoral researcher at UVM. Looking at all of these diverse households in all these different countries, we find the healthier your watershed upstream, the less likely your kids are to get this potentially fatal disease, researchers said.