Protecting Indigenous territories in the Amazon supports human health

Protecting Indigenous territories in areas of the Amazon rainforest with high levels of forest cover may help reduce the number of cases of several diseases (including malaria and respiratory conditions) in the surrounding areas. The results, from an analysis published in Communications Earth & Environment, highlight the importance of legal protection for Indigenous territories in the Amazon, and the complex role they play in human health.

There are an estimated 2.7 million Indigenous people living in the Amazon, predominantly in Indigenous territories (ITs), which constitute approximately 2.4 million of the roughly 7 million square kilometres the Amazon covers. A growing body of evidence has shown that ITs are linked to decreased deforestation and biodiversity loss, but we do not currently understand the relationship between ITs and human health.

Julia Barreto and colleagues investigated how the number of cases of zoonotic and fire-related diseases between 2000 and 2019 was affected by the presence of ITs, using data from administrative regions in the nine countries the Amazon spans. For each region, their analysis combined the number of cases of 21 diseases, the forest fire rate, the forest cover and fragmentation percentages, and the percentage coverage of ITs. The authors found that the condition of a region's forest was a key factor in how the presence of an IT affected the rates of disease. In regions with more than 45% forest cover containing an IT, there was a reduction in the number of cases of both fire-related diseases (such as pneumonia) and zoonotic diseases (such as malaria). However, for regions with low forest cover or highly fragmented forests, the effect was lessened, or even reversed.

The authors argue that their work shows that ITs may help protect human health in both the IT itself and the surrounding area, but only if high levels of forest cover are maintained. They link this potential protective effect to increased pollution absorption by trees, reduced human-animal contact, and increased biodiversity within ITs. The authors also note that the effect was more pronounced when ITs were legally protected, emphasising the importance both of maintaining Amazonian forests and of protecting Amazonian ITs' legal status.