Hi CEE community,

Please join us this Thursday, January 25 at 3:30 in More Hall room 225 for this week’s water seminar where Professor Becca Neumann will present on how mercury pollution resulting from gold mining has impacted ecosystem and human health in the Amazon. See the abstract for her talk below!

Destructive Gold Mining and Mercury Contamination in the Amazon

Abstract

The Amazon forest is a dominant terrestrial carbon sink and the home of ~1.5 million indigenous people in 385 ethnic groups. Conserving the Amazon rainforest is crucial for both Earth system functioning and for protecting the rights and well-being of Indigenous people. Unfortunately, climate change and deforestation are simultaneously leading to warmer temperatures, droughts, fires, and forest losses, with negative impacts on human and ecosystem health.

An exponentially growing driver of deforestation in the Amazon is unregulated alluvial gold mining that involves slash-and-burn land-clearing, sediment extraction, and the use of mercury to amalgamate gold flecks from fine sediment. When the mercury-gold amalgam is heated, mercury vaporizes. In the atmosphere, mercury travels into and is deposited within the landscape, contaminating water, soils, plants, animals, and people. Mercury is a neurotoxin known to affect human health, animal behavior, and photosynthetic and transpiration capabilities of vegetation. The methylated form of mercury bioaccumulates in organisms.

We hypothesize that atmospheric deposition of mercury across the landscape reduces forest productivity, animal well-being and behavior, and indigenous health. Importantly, this hypothesis, if correct, indicates that, via mercury emissions, gold mining affects intact forests far beyond the location in which gold is extracted.   In addition, mercury is dispersed through food webs and faunal movements which can be extensive in the case of migratory fish, mammals, birds and many volant invertebrates. The functioning of intact and currently protected forest at a large scale  is at risk, with consequences for carbon and water budgets, Amazon-climate feedbacks, forest resilience to climate change, health of terrestrial and aquatic food webs, indigenous Hg exposure, and, potentially, indigenous lifestyles.

Data from initial efforts focused on clarifying the spatial footprint of mercury and identifying its ecosystem impacts in a Peruvian mining hotspot will be presented.