My current research interests at the fate, transport, and transformation of trace metals and metalloids in aquatic and terrestrial ecosystems and wildlife, with particular focus on mercury. The scope of research involves field work and development of analytical methodologies for studies of trace metal speciation and bioavailability in the environment. Recently, I have been developing new passive sampling approaches with Diffusive Gradients in Thin-films devices to identify the bioavailable fraction of toxic and trace metals for risk assessment. The focus of recent research seeks to identify: (i) the biogeochemical cycling of mercury and how impacts affect the bioavailability and bioaccumulation into aquatic organisms, (ii) biomarkers for human exposure assessment of metals, and (iii) the transfer of bioavailable trace metals in soils to crops. Currently, I am coordinator/partner in projects on mercury pollution in Colombia and Brazil to evaluate the environmental and health impact of artisanal and small-scale gold mining in the wetlands of northern Colombia, the Amazon basin and Pantanal.