Environ Monit Assess. 2026 May 18;198(6):599. doi: 10.1007/s10661-026-15455-2.
ABSTRACT
Surges in gold prices coupled with socio-economic factors have increased small- and medium-scale gold mining in Guyana, which drives the emission of large quantities of mercury (Hg) into the atmosphere. Given the distribution of Hg through the atmosphere, reliable and affordable measurement of concentrations in the air is vital. Moss bags and Hg passive air samplers (MerPAS) were deployed to measure atmospheric Hg around a gold mine in Mahdia, Guyana over a 90-day period as well as a separate 2-day period that encompassed a periodic burn of Hg-gold amalgam (typically 2-h). Mercury in moss and MerPAS were positively correlated over both deployment periods, but Hg concentrations measured during the 2-day event were several-fold higher in both moss and MerPAS compared with the 90-day deployment. Using the 2-day deployment as an estimate of atmospheric Hg, Hg air concentrations around the burning station exceeded 100,000 ng m-3 averaged over a 48-h period, and moss Hg concentrations were greater than 250,000 ng g-1 around the burning station, although Hg concentrations in both media decreased rapidly with distance. There was no relationship between Hg in moss and soil Hg at the sampling sites; Hg in soil was instead positively associated with soil organic matter content. Overall, our study shows that Hg concentrations in air at artisanal gold mines in Guyana can exceed international health guidelines of 100,000 ng m-3 averaged over a 48-h period and that moss provides reliable estimates of relative Hg concentrations in air over both short-term and long-term exposures.
PMID:42144486 | DOI:10.1007/s10661-026-15455-2
