Geoscience themed issue: editorial

I am honored to serve as guest editor for the Environmental Science: Processes & Impacts themed issue on geoscience. Geology, and especially the field of geochemistry, has become inextricably linked to the environmental sciences, and has evolved over the past few decades to view earth in a much more holistic fashion. Earth scientists recognize that anthropogenic activities in one of the “spheres” (lithosphere, hydrosphere, biosphere, and atmosphere) have profound and in many cases unexpected consequences in the others. For example the need for energy extraction from the lithosphere comes with a significant environmental cost that affects all the other earth compartments.

Compiled in this special issue are eight papers that examine some of these processes that occur at the interface between earth and environmental sciences and are comprised of six original research articles, one Critical Review, and one Frontier paper. Hakala's Frontier paper (DOI: 10.1039/C4EM00140K) discusses the challenges facing geochemists that utilize isotopic tools used to delineate between naturally occurring methane in groundwater and methane contamination arising from the hydraulic fracturing of shale gas. The Critical Review contribution from Minor et al. (DOI: 10.1039/C4EM00062E) examines the evolving field of dissolved organic matter (DOM) isolation and characterization by both spectroscopy and mass spectrometry. DOM is further investigated by Langlois et al. (DOI: 10.1039/C4EM00138A), who observed the curious role of two herbicides in enhancing the photobleaching of DOM by sunlight. McKee and co-investigators (DOI: 10.1039/C4EM00075G) studied quinones, a key component of DOM, to provide an explanation for the conversion of labile peptides into recalcitrant adducts through an abiotic pathway. Processes at the interfaces between the microbial biosphere, lithosphere, and hydrosphere are investigated in two papers. Tang and co-workers (DOI: 10.1039/C4EM00077C) show that microbially produced manganese oxides can convert relatively benign Cr(III) to its potentially more toxic oxidized forms in the presence of organic carbon and light. MacDonald et al. (DOI: 10.1039/C4EM00073K) discuss the application of voltammetry using microelectrodes in situ to study unique environments colonized by iron oxidizing bacteria. In a different study, Parsons and co-investigators (DOI: 10.1039/C4EM00127C) showed that polycyclic aromatic hydrocarbons (PAH) co-accumulate with mercury in sediments and that the ratios of specific PAH compounds can be used to infer both modern and historic sources of mercury. Finally, Massey et al. (DOI: 10.1039/C4EM00148F) demonstrate that impure aluminum alteration of the iron oxide ferrihydrite is capable of inhibiting the incorporation of uranium as determined by X-ray absorption spectroscopy.

The papers in this themed issue of Environmental Science: Processes & Impacts reflect the diversity of research problems that face earth scientists studying environmentally relevant processes today. They range the gamut from the nano- to macro-scale and tackle problems that face organic and inorganic geochemists alike. I hope you find reading this issue as interesting and intellectually stimulating as I found it rewarding compiling and editing these papers.

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