title: Total mercury in wild fish in Guizhou reservoirs, China.
abstract: The health hazard of mercury (Hg) compounds is internationally recognized, and the main pathways for methylmercury (MeHg) intake in humans are through consumption of food, especially fish. Given the large releases of Hg to the environment in China, combined with the fast development of hydropower, this issue deserves attention. Provided similar mobilization pathways of Hg in China as seen in reservoirs in North America and Europe one should expect increased Hg contamination in relation to future hydropower reservoir construction in this country. This study presents total Hg (THg) concentrations in wild fish from six Guizhou reservoirs, China. The THg concentrations in fish were generally low despite high background levels in the bedrock and depositions from local point sources. The over all mean +/- SD concentration of THg was (0.066 +/- 0.078) microg/g (n = 235). After adjusting for among-reservoir variation in THg, there were significant differences in THg among functional groups of the fish, assumed to reflect trophic levels. Predicted THg-concentration ratios, retrieved from a mixed linear model, between the functional groups were 9:4:4:1 for carnivorous, omnivorous, planktivorous and herbivorous fish. This result indicated that MeHg accumulation may prevail even under circumstances with short food chains as in this Chinese water system. No fish exceeded recommended maximum THg limit for human consumption set by World Health Organization and the Standardization Administration of China (0.5 microg/g fish wet weight (ww)). Only six fish (2.5%) exceeded the maximum THg limit set by US Environmental Protection Agency (0.3 microg/g fish ww).
authors.affiliation: State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China. yanhaiyu@vip.skleg.cn
authors.forename: Haiyu
authors.initials: H
authors.lastname: Yan
authors.forename: Atle
authors.initials: A
authors.lastname: Rustadbakken
authors.forename: Heng
authors.initials: H
authors.lastname: Yao
authors.forename: Thorjorn
authors.initials: T
authors.lastname: Larssen
authors.forename: Xinbin
authors.initials: X
authors.lastname: Feng
authors.forename: Ting
authors.initials: T
authors.lastname: Liu
authors.forename: Lihai
authors.initials: L
authors.lastname: Shang
authors.forename: Thrond O
authors.initials: TO
authors.lastname: Haugen
mesh_terms: D000818:Animals; D000835:Animals, Wild; D002681:China; D004784:Environmental Monitoring; D005399:Fishes / Q000378:metabolism*; D008628:Mercury / Q000737:chemistry* / Q000378:metabolism; D008767:Methylmercury Compounds / Q000737:chemistry* / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000378:metabolism
chemical_list: D008767:Methylmercury Compounds; D014874:Water Pollutants, Chemical; D008628:Mercury