Coll, C; Lindim, C; Sobek, A; Sohn, MD; MacLeod, M: Prospects for finding Junge variability-lifetime relationships for micropollutants in the Danube river, Environmental Science: Processes & Impacts, 21(9), 1489-1497 (2019), doi:10.1039/C9EM00283A [Link]

Persistence of chemical pollutants is difficult to measure in thefield. Junge variability-lifetime relationships,correlating the relative standard deviation of measured concentrations with residence time, have been usedto estimate persistence of air pollutants. Junge relationships for micropollutants in rivers could provideevidence that half-lives of compounds estimated from laboratory andfield data are representative ofhalf-lives in a specific system, location and time. Here, we explore the hypothesis that Jungerelationships could exist for micropollutants in the Danube river using: (1) concentrations of sixhypothetical chemicals modeled using the STREAM-EU fate and transport model, and (2) concentrationsof nine micropollutants measured in the third Joint Danube Survey (JDS3) combined withbiodegradation half-lives reported in the literature. Using STREAM-EU, we found that spatial andtemporal variability in modeled concentrations was inversely correlated with half-life for the fourmicropollutants with half-lives#90 days. For these four modeled micropollutants, we found Jungerelationships with slopes significantly different from zero in the temporal variability of concentrations at88% of the 67 JDS3 measurement sites, and in the spatial variability of concentrations on 36% out of 365modeled days. A Junge relationship significant at the 95% confidence level was not found in the spatialvariability of nine micropollutants measured in the JDS3, nor in STREAM-EU-modeled concentrationsextracted for the dates and locations of the JDS3. Nevertheless, our model scenarios suggest that Jungerelationships might be found in future measurements of spatial and temporal variability ofmicropollutants, especially in temporal variability of pollutants measured downstream in the Danube river.

last modified 2019-11-05