| Abstract
| - The study of organic contaminants at high altitudes ismotivated by the potential risk that they pose to humansliving in, or depending on resources derived from, mountains,and to terrestrial and aquatic ecosystems in alpineareas. Mountains are also ideal settings to study contaminanttransport and behavior along gradients of climate andsurface cover. Information on organic contaminants inmountains is compiled from the literature and synthesized,with a focus on atmospheric transport and deposition,contaminant dynamics in alpine lakes and aquatic organisms,and concentration differences with altitude. Diurnalmountain winds, in connection with enhanced depositionat higher elevations caused by low temperatures and highprecipitation rates, conspire to make mid-latitudemountains become convergence zones for selectedpersistent organic chemicals. In particular, the more volatileconstituents of contaminant mixtures seem to becomeenriched, relative to the less volatile constituents at higheraltitudes. For selected contaminants, concentrationinversions (i.e., concentrations that increase with elevation)have been observed. A notable difference between coldtrapping in high latitudes and high altitudes is the likelyimportance of precipitation. High rates of snow depositionin mid- and high-latitude mountains may lead to a largecontaminant release during snowmelt. Regions above thetree line often have little capacity to retain the releasedcontaminants, suggesting the potential for a highly dynamiccontaminant fate situation during the snow-free seasonwith significant revolatilization and runoff. The chemical andenvironmental factors that control the orographic coldtrapping of organic contaminants should be examined furtherby measuring and comparatively interpreting concentrationgradients along several mountain slopes with widelydifferent characteristics. Future efforts should further focuson the bioaccumulation and potential effects of contaminantsin the upper trophic levels of alpine food chains, onmeasuring more water-soluble, persistent organiccontaminants, and on studying how climate change mayaffect contaminant dynamics in mountain settings.
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