PFAS River Export Analysis Highlights the Urgent Need for Catchment-Scale Mass Loading Data

Source apportionment of per-and polyfluoroalkyl substances (PFAS) requires an understanding of the mass loading of these compounds in river basins. However, there is a lack of temporally variable and catchment-scale mass loading data, meaning identification and prioritization of sources of PFAS to rivers for management interventions can be difficult. Here, we analyze PFAS concentrations and loads in the River Mersey to provide the first temporally robust estimates of PFAS export for a European river system and the first estimates of the contribution of wastewater treatment works (WwTWs) to total river PFAS export. We estimate an annual PFAS export of 68.1 kg for the River Mersey and report that the yield of perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) in the catchment is among the highest recorded globally. Analysis of river and WwTW loads indicates approximately one-third of PFOA emitted from WwTWs is potentially stored in the catchment and approximately half of PFOS transported by the River Mersey may not originate from WwTWs. As governments move toward regulation of PFAS in WwTW effluents, our findings highlight the complexity of PFAS source apportionment and the need for catchment-scale mass loading data. This study indicates that strategies for reducing PFAS loading that focus solely on WwTW effluents may not achieve river water quality targets

Synoptic sampling and principal components analysis to identify sources of water and metals to an acid mine drainage stream

Combining the synoptic mass balance approach with principal components analysis (PCA) can be an effective method for discretising the chemistry of inflows and source areas in watersheds where contamination is diffuse in nature and/or complicated by groundwater interactions. This paper presents a field-scale study in which synoptic sampling and PCA are employed in a mineralized watershed (Lion Creek, Colorado, USA) under low flow conditions to (i) quantify the impacts of mining activity on stream water quality; (ii) quantify the spatial pattern of constituent loading; and (iii) identify inflow sources most responsible for observed changes in stream chemistry and constituent loading. Several of the constituents investigated (Al, Cd, Cu, Fe, Mn, Zn) fail to meet chronic aquatic life standards along most of the study reach. The spatial pattern of constituent loading suggests four primary sources of contamination under low flow conditions. Three of these sources are associated with acidic (pH <3.1) seeps that enter along the left bank of Lion Creek. Investigation of inflow water (tracemetal and major ion) chemistry using PCA suggests a hydraulic connection between many of the left bank inflows and mine water in the Minnesota Mine shaft located to the north-east of the river channel. In addition, water chemistry data during a rainfall-runoff event suggests the spatial pattern of constituent loading may be modified during rainfall due to dissolution of efflorescent salts or erosion of streamside tailings. These data point to the complexity of contaminant mobilisation processes and constituent loading in mining-affected watersheds but the combined synoptic sampling and PCA approach enables a conceptual model of contaminant dynamics to be developed to inform remediation

Natural attenuation can lead to environmental resilience in mine environment

Four streams flowing in the Iglesiente and Arburese mine districts (SW Sardinia, Italy), exploited for zinc (Zn) and lead (Pb) extraction from sulphides and secondary non-sulphide mineralization (calamine ores), have been studied combining investigations from the macroscale (hydrologic tracer techniques) to the microscale (X-ray powder diffraction, scanning electron microscopy, X-ray absorption spectroscopy). In the investigated area, concerns arise from release of metals to water during weathering of ore minerals and mine-waste. Specifically, Zn is observed at extremely high concentrations (10s of mg/L or more) in waters in some of the investigated catchments. The results from synoptic sampling campaigns showed marked differences of Zn loads, from 6.3 kg/day (Rio San Giorgio) to 2000 kg/day (Rio Irvi). Moreover, natural attenuation of metals was found to occur i) through precipitation of Fe compounds (Fe oxy/hydroxides and “green rust”), ii) by means of the authigenic formation of metal sulphides promoted by microbial sulphate reduction, iii) by metal intake in roots and stems of plants (Phragmites australis and Juncus acutus) and by immobilization in the rhizosphere, and iv) by cyanobacterial biomineralization processes that lead to formation of Zn-rich phases (hydrozincite and amorphous Zn-silicate). The biologically mediated natural processes that lead to significant abatement and/or reduction of metal loads, are the response of environmental systems to perturbations caused from mine activities, and can be considered part of the resilience of the system itself. The aim of this study is to understand the effect of these processes on the evolution of the studied systems towards more stable and, likely, resilient conditions, e.g. by limiting metal mobility and favouring the improvement of the overall quality of water. The understanding of how ecosystems adapt and respond to contamination, and which chemical and physical factors control these natural biogeochemical barriers, can help to plan effective remediation actions

Selective blockade of interferon-α and -β reveals their non-redundant functions in a mouse model of West Nile virus infection

Although type I interferons (IFNs) were first described almost 60 years ago, the ability to monitor and modulate the functional activities of the individual IFN subtypes that comprise this family has been hindered by a lack of reagents. The major type I IFNs, IFN-β and the multiple subtypes of IFN-α, are expressed widely and induce their effects on cells by interacting with a shared heterodimeric receptor (IFNAR). In the mouse, the physiologic actions of IFN-α and IFN-β have been defined using polyclonal anti-type I IFN sera, by targeting IFNAR using monoclonal antibodies or knockout mice, or using Ifnb-/- mice. However, the corresponding analysis of IFN-α has been difficult because of its polygenic nature. Herein, we describe two monoclonal antibodies (mAbs) that differentially neutralize murine IFN-β or multiple subtypes of murine IFN-α. Using these mAbs, we distinguish specific contributions of IFN-β versus IFN-α in restricting viral pathogenesis and identify IFN-α as the key mediator of the antiviral response in mice infected with West Nile virus. This study thus suggests the utility of these new reagents in dissecting the antiviral and immunomodulatory roles of IFN-β versus IFN-α in murine models of infection, immunity, and autoimmunity

Assessment of origin and fate of contaminants along mining-affected Rio Montevecchio (SW Sardinia, Italy): A hydrologic-tracer and environmental mineralogy study

Hydrologic tracer techniques were applied to Rio Montevecchio (SW Sardinia, Italy), a stream affected by mine drainage, allowing the calculation of discharge and contaminant loads. Discharge along the stream showed a constant increase throughout the 2.7 km-long study reach, up to 13.6 l/s at the last synoptic point. Calculated loads of mine-related constituents were large, reaching values of 1780 kg/day for, 340 kg/day for Zn, 47 kg/day for Fe, and 50 kg/day for Mn. The difference of the cumulative instream metal loads between the first and the last synoptic sampling points indicated gains of 421 kg/day for Zn, 2080 kg/day for, 56 kg/day for Mn, and 50 kg/day for Fe. The source areas critical for contaminants loading were almost all concentrated in the first 800 meters of the stream, with the exception of Pb, whose loading occurs evenly along the whole study reach. Precipitation of secondary minerals along the streambed was responsible for a very high attenuation of Al and Fe loads (66% and 77%) and affected also and Zn loads, though less effectively. Rio Montevecchio has the second highest metal load among the rivers investigated with tracer techniques in SW Sardinia. In comparison with Rio Irvi, which has one order of magnitude higher metal loads, natural attenuation processes limit the loads in Rio Montevecchio. Results are useful to clarify the hydrogeochemical paths involved in the release and attenuation of pollutants, improving our understanding of stream responses to contamination and aiding development of site-specific remediation actions

One-dimensional transport with inflow and storage (OTIS) : a solute transport model for streams and rivers /

Shipping list no.: 98-0326-P.Includes bibliographical references (p. 72-73).Mode of access: Internet