Suchergebnisse

AbstractReuse of oilfield‐produced water (OPW) for crop irrigation has the potential to make a critical difference in the water budgets of highly productive but drought‐stressed agricultural watersheds. This is the first peer‐reviewed study to evaluate how trace metals in OPW used to irrigate California crops may affect human health. We modeled and quantified risks associated with consuming foods irrigated with OPW using available concentration data. The probabilistic risk assessment simulated OPW metal concentrations, crop uptake, human exposures, and potential noncancer and carcinogenic health effects. Overall, our findings indicate that there is a low risk of ingesting toxic amounts of metals from the consumption of tree nuts, citrus, grapes, and root vegetables irrigated with low‐saline OPW. Results show increased arsenic cancer risk (at 10−6) for adult vegetarians, assuming higher consumption of multiple foods irrigated with OPW that contain high arsenic concentrations. All other cancer risks are below levels of concern and all noncancer hazards are far below levels of concern. Arsenic risk concerns could be mitigated by practices such as blending high‐arsenic OPW. Future risk assessment research should model the risks of organic compounds in OPW, as our study focused on inorganic compounds. Nevertheless, our findings indicate that low‐saline OPW may provide a safe and sustainable alternative irrigation water source if water quality is adequately monitored and blended as needed prior to irrigation.

The extraction of unconventional oil and gas—from shale rocks, tight sand, and coalbed formations—is shifting the geographies of fossil fuel production, with complex consequences. Following on the natural science survey of the environmental consequences of hydraulic fracturing (Jackson et al. 2014), this review examines social science literature on unconventional energy. After an overview of the rise of unconventional energy, the review examines energy economics and geopolitics, community mobilization, and state and private regulatory responses. Unconventional energy requires differing frames of analysis than conventional energy because of three distinct characteristics: increased drilling density; low-carbon and "clean" energy narratives of natural gas; and differing ownership and royalty structures. This review points to the need for an interdisciplinary approach to the resulting dynamic, multi-level web of relationships that implicate land, water, food, and climate. Further, the review highlights how scholarship on unconventional energy informs the broader energy landscape and contested energy futures.