First assessment of triazoles and other organic contaminants in snow and snowmelt in urban waters, Anchorage, Alaska

摘要

Snow scavenges organic contaminants from the atmosphere and has been shown to retain a variety of contaminants. Concentrated release of organic contaminants during onset of melting due to interstitial melting suggests an immediate transfer of organic contaminants from snow pack to surface water via storm drainages. Urban environments in a climate with extended periods of snow such as Alaska, Maine, Minnesota, Canada, and Northern Europe therefore may experience organic contamination of surface water during snowmelt. This study presents first results on a multidimensional assessment of concentration and changes of organic contaminants, specifically 1H-benzotriazole (BT) and its methylated forms 4- and 5-methyl 1H-benzotriazole (tolyltriazole TT) during snowmelt in an urban creek that passes through Anchorage, Alaska and discharges into Cook Inlet and in two snow dump sites (snow and melt water). Results indicate concentrations up to 310 ng L~(-1) BT and 4490 ng L~(-1) TT during snowmelt. The timing of peak agrees with increasing levels of Na~+ and Cl~- and anthropogenic derived organic material based on fluorescence spectrometry. The concentrations of BT and TT are comparable to those in streams passing through larger industrial Cities in Europe and TT peak concentrations are even higher than those previously determined in streams in Europe and the U.S. In June, after spring melt, while overall DOC increases, concentrations of BT and TT return to levels close to detection limits (e.g. background concentrations) and fluorescence spectrometry indicate that organic carbon becomes more terrestrially derived.