@article {2919,
	title = {Aquifer-Scale Observations of Iron Redox Transformations in Arsenic-Impacted Environments to Predict Future Contamination},
	journal = {Environmental Science \& Technology Letters},
	volume = {7},
	year = {2020},
	month = {Aug-12-2020},
	pages = {916 - 922},
	abstract = {Iron oxides control the mobility of a host of contaminants in aquifer systems, and the microbial reduction of iron oxides in the subsurface is linked to high levels of arsenic in groundwater that affects greater than 150 million people globally. Paired observations of groundwater and solid-phase aquifer composition are critical to understand spatial and temporal trends in contamination and effectively manage changing water resources, yet field-representative mineralogical data are sparse across redox gradients relevant to arsenic contamination. We characterize iron mineralogy using X-ray absorption spectroscopy across a natural gradient of groundwater arsenic contamination in Vietnam. Hierarchical cluster analysis classifies sediments into meaningful groups delineating weathering and redox changes, diagnostic of depositional history, in this first direct characterization of redox transformations in the field. Notably, these groupings reveal a signature of iron minerals undergoing active reduction before the onset of arsenic contamination in groundwater. Pleistocene sediments undergoing postdepositional reduction may be more extensive than previously recognized due to previous misclassification. By upscaling to similar environments in South and Southeast Asia via multinomial logistic regression modeling, we show that active iron reduction, and therefore susceptibility to future arsenic contamination, is more widely distributed in presumably pristine aquifers than anticipated.},
	keywords = {BANGLADESH, BENGAL BASIN, groundwater, PLEISTOCENE AQUIFER, POLLUTION, RELEASE, RIVER DELTA, Sediment, TRANSPORT, VIETNAM},
	issn = {2328-8930},
	doi = {10.1021/acs.estlett.0c0067210.1021/acs.estlett.0c00672.s00110.1021/acs.estlett.0c00672.s00210.1021/acs.estlett.0c00672.s00310.1021/acs.estlett.0c00672.s004},
	url = {https://apps.webofknowledge.com/InboundService.do?product=WOS\&Func=Frame\&DestFail=http\%3A\%2F\%2Fwww.webofknowledge.com\&SrcApp=search\&SrcAuth=Alerting\&SID=8AkJOJLKFU3j5nkGaRI\&customersID=Alerting\&mode=FullRecord\&IsProductCode=Yes\&AlertId=4d48b20a-7d27-4fa2-},
	author = {Nghiem, Athena A. and Shen, Yating and Stahl, Mason and Sun, Jing and Haque, Ezazul and DeYoung, Beck and Nguyen, Khue N. and Thi Mai, Tran and Trang, Pham Thi Kim and Pham, Hung Viet and Mailloux, Brian and Harvey, Charles F. and van Geen, Alexander and Bostick, Benjam{\'\i}n C.}
}
@article {2725,
	title = {Tropical peatland carbon storage linked to global latitudinal trends in peat recalcitrance},
	journal = {Nature Communications},
	volume = {9},
	year = {2018},
	month = {Jan-12-2018},
	abstract = {Peatlands represent large terrestrial carbon banks. Given that most peat accumulates in boreal regions, where low temperatures and water saturation preserve organic matter, the existence of peat in (sub)tropical regions remains enigmatic. Here we examined peat and plant chemistry across a latitudinal transect from the Arctic to the tropics. Near-surface low-latitude peat has lower carbohydrate and greater aromatic content than near-surface high-latitude peat, creating a reduced oxidation state and resulting recalcitrance. This recalcitrance allows peat to persist in the (sub)tropics despite warm temperatures. Because we observed similar declines in carbohydrate content with depth in high-latitude peat, our data explain recent field-scale deep peat warming experiments in which catotelm (deeper) peat remained stable despite temperature increases up to 9 {\textdegree}C. We suggest that high-latitude deep peat reservoirs may be stabilized in the face of climate change by their ultimately lower carbohydrate and higher aromatic composition, similar to tropical peats.},
	doi = {10.1038/s41467-018-06050-2},
	url = {http://www.nature.com/articles/s41467-018-06050-2},
	author = {Hodgkins, Suzanne B. and Richardson, Curtis J. and Dommain, Ren{\'e} and Wang, Hongjun and Glaser, Paul H. and Verbeke, Brittany and Winkler, B. Rose and Cobb, Alexander R. and Rich, Virginia I. and Missilmani, Malak and Flanagan, Neal and Ho, Mengchi and Hoyt, Alison M. and Harvey, Charles F. and Vining, S. Rose and Hough, Moira A. and Moore, Tim R. and Richard, Pierre J. H. and De La Cruz, Florentino B. and Toufaily, Joumana and Hamdan, Rasha and Cooper, William T. and Chanton, Jeffrey P.}
}
