1 research outputs found
Mercury Pollution in Amapá, Brazil: Mercury Amalgamation in Artisanal and Small-Scale Gold Mining or Land-Cover and Land-Use Changes?
Mercury (Hg) poses
a public health
burden in the Amazon and worldwide. Although usually attributed to
Hg used in artisanal and small-scale gold mining (ASGM), the primary
source of elevated Hg in Amazonian aquatic ecosystems is contested
since there have not been tools to differentiate between Hg from ASGM
and Hg from other sources such as increased soil erosion associated
with land-cover and land-use change. To directly assess Hg contamination
from ASGM, stable Hg isotope analyses were applied to sediment cores,
surface sediments, and soils from two aquatic ecosystems in Amapá,
Brazil, one downstream of ASGM activities and one isolated from ASGM.
Downstream of the ASGM sites, the Hg isotope data is consistent with
elevated Hg coming dominantly from increased erosion of soils and
not from Hg used during gold extraction. Although these two sources
represent different pathways of contamination to downstream ecosystems,
ASGM may contribute to both land-cover and land-use change and local
contamination of soils. Accordingly, these findings demonstrate that
in some regions of the Amazon effective Hg mitigation strategies need
to address land-use practices in addition to ASGM