title: Half a century of changing mercury levels in Swedish freshwater fish.
abstract: The variability of mercury (Hg) levels in Swedish freshwater fish during almost 50 years was assessed based on a compilation of 44 927 observations from 2881 waters. To obtain comparable values, individual Hg concentrations of fish from any species and of any size were normalized to correspond to a standard 1-kg pike [median: 0.69 mg kg⁻¹ wet weight (ww), mean ± SD: 0.84 ± 0.67 mg kg⁻¹ ww]. The EU Environmental Quality Standard of 0.02 mg kg⁻¹ was exceeded in all waters, while the guideline set by FAO/WHO for Hg levels in fish used for human consumption (0.5-1.0 mg kg⁻¹) was exceeded in 52.5 % of Swedish waters after 2000. Different trend analysis approaches indicated an overall long-term decline of at least 20 % during 1965-2012 but trends did not follow any consistent regional pattern. During the latest decade (2003-2012), however, a spatial gradient has emerged with decreasing trends predominating in southwestern Sweden.
authors.affiliation: Department of Aquatic Sciences and Assessment, SLU, P.O. Box 7050, 750 07, Uppsala, Sweden, staffan.akerblom@slu.se.
authors.forename: Staffan
authors.initials: S
authors.lastname: Akerblom
authors.forename: Anders
authors.initials: A
authors.lastname: Bignert
authors.forename: Markus
authors.initials: M
authors.lastname: Meili
authors.forename: Lars
authors.initials: L
authors.lastname: Sonesten
authors.forename: Marcus
authors.initials: M
authors.lastname: Sundbom
mesh_terms: D000818:Animals; D004781:Environmental Exposure; D004784:Environmental Monitoring; D005399:Fishes / Q000378:metabolism*; D005618:Fresh Water; D008628:Mercury / Q000378:metabolism*; D012621:Seasons; D013548:Sweden
chemical_list: D008628:Mercury