New research published this week, in which Cambodia was used as the case study, has found that deforestation is associated with an increased risk of several major causes of childhood morbidity and mortality.

The study, published earlier this month in the UK-based journal Lancet Planetary Health, found that deforestation was linked to increased incidences of diarrhoea, fever and acute respiratory infection in children. That was based on analysis of data from 35,547 households from the Cambodia Demographic Health Surveys.

The data was used to investigate the relationship between health and protected areas that have been deforested in Cambodia between 2005 and 2014.

Researchers found that a 10 percent hike in the loss of dense forest was estimated to be associated with an increase of 14.1 percent in the incidence of diarrhoea in children younger than 5 years old per household.

“Cambodia is an interesting case study for several reasons,” said Thomas Pienkowski, with the National University of Singapore and the main author of the study.

“It has experienced substantial health gains in the last 15 years . . . However, it has also simultaneously experienced relatively high rates of environmental changes, including extensive deforestation.”

Trucks drive through a deforested area in 2014, removing unwanted materials from the Lower Sesan II dam construction site in Stung Treng's Sesan district. Pha Lina

Researchers are still trying to figure out how exactly diarrhoea, fever and acute respiratory infections are linked to deforestation, Pienkowski said.

“That’s a complex question, and one that we don’t yet really know the full answer to,” he said. “There are multiple ways that deforestation can affect these health outcomes.”

For example, he said, some studies have shown that when forests are cleared, the local environment warms. That can create habitats that are more suitable for mosquito breeding, which could elevate the risk of malaria.

Rainwater may also run off from deforested areas more quickly than forested areas, which might wash animal and human faeces into the water that people use for drinking.

“These are just a few hypothesised links between deforestation and health,” he said.

Pienkowski said this study may offer new ways of meeting joint public health and environmental objectives, and could contribute toward meeting Sustainable Development Goals.

“However, in the same breath, we are still unsure about how protected areas might be associated with health; more research in this area is required,” he said.

Officials from the ministries of health and environment could not be reached for comment.