Occurrence of PCBs in raw and finished drinking water at seven public water systems along the Hudson River

Polychlorinated biphenyls (PCBs) were measured in raw and finished drinking water at seven Public Water Systems (PWSs) along the Hudson River as part of a baseline monitoring program prior to the extensive sediment dredging of the Upper Hudson River. Water samples were either analyzed using an Aroclor method (based on USEPA Method 508) or a congener method (Modified Green Bay Mass Balance Method). Using the congener-based method, raw water concentrations ranged from <9.3 to 164.3 ng/L and finished water concentrations ranged from <9.3 to 186.6 ng/L. Using the Aroclor method, finished water concentrations ranged from <5.0 to 200.9 ng/L. Most finished water samples above 73.0 ng/L were from a PWS with wells drilled near the river. Excluding the well data, total PCB concentrations in raw water at systems in the Upper River were similar to concentrations at systems in the Lower River, though the congener patterns differed. Paired comparison of total PCB concentrations using the two analytical methods showed good agreement, although raw water showed a different relationship than finished water.     

Spatially resolved detection of luminescence: a unique tool for archaeochronometry

Archaeochronometry uses luminescence dating to reveal ages of sediments and artefacts. Uncertainties in luminescence ages are partly related to the dating procedure, which uses grain separates. This is particularly true for stone surfaces, which require an imaging method for luminescence detection. Here we present the development of a novel luminescence device with high spatial resolution as well as signal-to-noise ratio and data processing software that now allows us to determine palaeodoses and potentially the dose-rate for cut sections of rocks and artefacts. The determination of the luminescence age of single mineral grains within sections and even of selected zones within grains becomes feasible, opening up a wide field of new applications.