title: Temporal Variation of Chemical Persistence in a Swedish Lake Assessed by Benchmarking.
abstract: Chemical benchmarking was used to investigate the temporal variation of the persistence of chemical contaminants in a Swedish lake. The chemicals studied included 12 pharmaceuticals, an artificial sweetener, and an X-ray contrast agent. Measurements were conducted in late spring, late autumn, and winter. The transformation half-life in the lake could be quantified for 7 of the chemicals. It ranged from several days to hundreds of days. For 5 of the chemicals (bezafibrate, climbazole, diclofenac, furosemide, and hydrochlorothiazide), the measured persistence was lower in late spring than in late autumn. This may have been caused by lower temperatures and/or less irradiation during late autumn. The seasonality in chemical persistence contributed to changes in chemical concentrations in the lake during the year. The impact of seasonality of persistence was compared with the impact of other important variables determining concentrations in the lake: chemical inputs and water flow/dilution. The strongest seasonal variability in chemical concentration in lake water was observed for hydrochlorothiazide (over a factor of 10), and this was attributable to the seasonality in its persistence.
authors.affiliation: Department of Environmental Science and Analytical Chemistry (ACES), Stockholm University, SE-106 91 Stockholm, Sweden.
authors.forename: Hongyan
authors.initials: H
authors.lastname: Zou
authors.affiliation: Department of Environmental Science and Analytical Chemistry (ACES), Stockholm University, SE-106 91 Stockholm, Sweden.
authors.forename: Michael
authors.initials: M
authors.lastname: Radke
authors.affiliation: Department of Environmental Science and Analytical Chemistry (ACES), Stockholm University, SE-106 91 Stockholm, Sweden.
authors.forename: Amelie
authors.initials: A
authors.lastname: Kierkegaard
authors.affiliation: Department of Environmental Science and Analytical Chemistry (ACES), Stockholm University, SE-106 91 Stockholm, Sweden.
authors.forename: Michael S
authors.initials: MS
authors.lastname: McLachlan
mesh_terms: D019985:Benchmarking / Q000379:methods*; D017753:Ecosystem; D004784:Environmental Monitoring; D006207:Half-Life; D060106:Lakes / Q000737:chemistry*; D011786:Quality Control; D012621:Seasons; D013548:Sweden; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification
chemical_list: D014874:Water Pollutants, Chemical