Difference between revisions of "Mercury and methyl mercury concentrations in fish"
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| Vendace(inland) | | Vendace(inland) | ||
| − | | 0. | + | | 0.0758 |
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| Vendace(sea) | | Vendace(sea) | ||
| − | | 0. | + | | 0.0758 |
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| Whitefish(inland) | | Whitefish(inland) | ||
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| Pike(inland) | | Pike(inland) | ||
| − | | 0. | + | | 0.3439 |
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| Pike(sea) | | Pike(sea) | ||
| − | | 0. | + | | 0.3629 |
|- | |- | ||
| Perch(inland) | | Perch(inland) | ||
Revision as of 13:21, 21 August 2009
Scope
Mercury and methyl mercury concentrations in fish describes concentrations of mercury and methyl mercury in fish. R↻ Concentrations of sea and freshwater fish species are studied separately.
Definition
Causality
List of parents:
- none
Data
The mercury data includes total mercury concentrations of fish species.[1] The most commonly consumed fish species are described: Farmed salmon, wild salmon, herring, white fish, sprat, perch, flounder, pike-perch, bream, pike, vendace and burbot. Concentration data for imported fish in Finland is not available in many cases. D↷
Unit
Data 1 & Data 2
mg/kg in fresh weight
Formula
Data 1
Analytica_id:
<anacode> Table(Substances,Fishspecies)( (10K*Triangular(1.467,1.577,1.615)),(10K*Triangular(1.467,1.467,1.615)), (10K*Uniform(0.785,1.173)), (10K*Normal(0.783,(0.1*0.783))),(10K*Uniform(0.785,1.173)),(10K*Normal(0.303, (0.1*0.303))), (10K*Normal(0.422,(0.1*0.422))),(10K*Normal(0.406,(0.1*0.406))),(10K*Normal(0.493,(0.1*0.493))), (10K*Normal(0.292,(0.1*0.292))),(10K*Normal(0.751,(0.1*0.751))),(10K*Normal(0.201,(0.1*0.201))), (10K*Triangular(1.467,1.467,1.577)), (10K*Normal(0.783,(0.1*0.783))),(10K*Normal(0.303,(0.1*0.303))), (10K*Normal(0.406,(0.1*0.406))),(10K*Normal(0.493,(0.1*0.493))), (10K*Normal(0.292,(0.1*0.292))), (10K*Normal(0.751,(0.1*0.751))),(10K*Normal(0.201,(0.1*0.201))), (Mercury*Mehg_proportion), (Mercury*Mehg_proportion),(Mercury*Mehg_proportion),(Mercury*Mehg_proportion), (Mercury*Mehg_proportion),(Mercury*Mehg_proportion), (Mercury*Mehg_proportion),(Mercury*Mehg_proportion), (Mercury*Mehg_proportion),(Mercury*Mehg_proportion),(Mercury*Mehg_proportion), (Mercury*Mehg_proportion), (Mercury*Mehg_proportion),(Mercury*Mehg_proportion),(Mercury*Mehg_proportion),(Mercury*Mehg_proportion), (Mercury*Mehg_proportion),(Mercury*Mehg_proportion),(Mercury*Mehg_proportion),(Mercury*Mehg_proportion) ) </anacode>
Narrative description
- There are no separate data for farmed and for wild salmon. Therefore they are assumed to be the same.
- There are no data for vendace(sea), so assumption is that the parameters are the same as vendace(inland)
- There are no data for bream(sea), so assumption is that the parameters are the same as bream(inland)
- There are no data for wild salmon(inland), so assumption is that the parameters are the same as wildsalmon(sea)
First, the mercury data was used to form lognormal distributions for each species with parameters median and geometric standard deviation. Secondly, the proportion of methyl mercury from total mercury was taken into account. Methyl mercury proportion is assumed to follow triangular distribution (author judgement) with parameters (min=0.81, mode=0.93,max=0.98). D↷
Data 2
Narrative description
Probability distributions of the concentration of methyl mercury (MeHg) in various fish species were extracted from [2] where the data on total mercury (Hg) concentration in fish muscle samples of 16 (inland and sea) species was collected. These distributions were obtained in a two step procedure. First, three theoretical distributions were selected to fit the Hg concnetration data, i.e. Weibull, Lognormal and Gamma. Unfortunately, the number of data points for many species listed was too small to give reliable fit results. Therefore, the best fitting distribution was chosen based on the statistical data analysis and goodness-of-fit evaluation performed on a largest set of data points (BS Herring, 35 samples) and then fitted to data of the rest of fish species. The distribution that provides the best fit to the Hg concentration data is Weibull. Finally, information about the proportion of methyl mercury in total Hg concentration (see above: triangular distribution with min=0.81, mode=0.93, max=0.98) was used to determine the probability distribution of MeHg concnetration in fish species chosen.
Moreover, there is no Hg concentration data for Vendace(sea). Therefore the parameters of Weibull distribution here are assumed to be the same as for Vendace(inland). Similarly, the parameters of Weibull distribution for Hg concnetration in Whitefish(sea) are assumed to be the same as for Whitefish(inland).
Result
Data 1
| Fish species | Methylmercury concentration |
|---|---|
| Farmed salmon (sea+inland) | 0.06346 |
| Wild salmon | 0.06347 |
| Herring(sea) | 0.02719 |
| White fish(sea) | 0.02719 |
| Sprat(sea) | 0.01813 |
| Perch(sea) | 0.3082 |
| Flounder(sea) | 0.04533 |
| Pike-perch(sea) | 0.09972 |
| Bream(sea) | 0.05439 |
| Pike(sea) | 0.3626 |
| Vendace(sea) | 0.0725 |
| Burbot(sea) | 0.2358 |
| Wild salmon(inland) | 0.06347 |
| White fish(inland) | 0.07253 |
| Perch(inland) | 0.1269 |
| Pike-perch(inland) | 0.272 |
| Bream(inland) | 0.0544 |
| Pike(inland) | 0.3445 |
| Vendace(inland) | 0.07253 |
| Burbot(inland) | 0.1995 |
Data 2
| Fish species | Mean MeHg concentration |
| Baltic Herring | 0.0259 |
| Vendace(inland) | 0.0758 |
| Vendace(sea) | 0.0758 |
| Whitefish(inland) | 0.0731 |
| Whitefish(sea) | 0.0731 |
| Pike(inland) | 0.3439 |
| Pike(sea) | 0.3629 |
| Perch(inland) | 0.1256 |
| Perch(sea) | 0.339 |
| Atlantic Salmon | 0.0611 |
| Pike-perch(inland) | 0.2702 |
| Pike-perch(sea) | 0.1001 |
References
- ↑ Methyl mercury: EU-kalat elintarvikeviraston julkaisuja 3/2004. Page 13.
- ↑ A.Karjalainen, 2007. http://www.pyrkilo.fi/beneris/index.php/Image:Analytical_data_of_foods-Finland_for_BENERIS_hk_ak.xls
