A tropical fig tree may be the missing link in tracking mercury pollution from small-scale gold mines across the Global South.
Erin Blakemore reports for The Washington Post.
In short:
- A new study finds that Ficus insipida, a common wild fig tree, can capture historical mercury pollution in its growth rings, acting as a natural pollution logbook.
- Researchers found strong correlations between mercury levels in tree rings and local air pollution near gold mines in Peru, especially after mining intensified in the 2000s.
- Unlike expensive or short-term pollution monitoring, trees offer a cheap, widespread, and long-term way to measure mercury exposure across tropical regions.
Key quote:
“We’re trying to reduce emissions … to do that, we need to be able to measure it, to see the impact over time. This really offers a method that can be employed throughout the Global South to understand changes in mercury over time, as well as spatial indicators of mercury."
— Jacqueline Gerson, a study author and assistant professor of biological and environmental engineering, Cornell University
Why this matters:
Mercury, a powerful neurotoxin, is one of the most dangerous substances unleashed by artisanal gold mining, a booming industry across the Global South. The health toll is staggering: Mercury exposure is tied to neurological damage, immune system problems, and birth defects. But tracking this invisible threat, especially in remote forested areas, has been a logistical and financial nightmare. Now, scientists say these fig trees, with roots in Indigenous and tropical ecosystems, can do what million-dollar monitoring networks often can’t: quietly and affordably map mercury pollution across time and space.
Read more: After decades of decreases, mercury rises in Great Lakes wildlife
