Food as the Dominant Pathway of Methylmercury Uptake by Fish

Hall, Britt D.; Bodaly, R. A.; Fudge, R. J. P.; Rudd, John W. M.; Rosenberg, D. M.

doi:10.1023/a:1018071406537

Cited by 421 publications

(120 citation statements)

References 22 publications

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“…In the present study, the methodology employed did not allow quantifying the different Hg forms present in the samples, only the total Hg concentrations. It is assumed, however, that methylmercury is not the predominant form in the analyzed foods, since this organometallic compound is found in fish and other aquatic organisms, in which over 90% of the Hg is in the form of methylmercury 72 , 73 . In most of the analyzed foods, fish by-products or other aquatic organisms were not present, according to what was stated on the labels.…”

Section: Discussionmentioning

confidence: 99%

Toxic element levels in ingredients and commercial pet foods

Zafalon

Pedreira

Vendramini

et al. 2021

Sci Rep

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Nowadays, there is a growing concern about contamination of toxic metals (TM) in pet food due to the great potential for health risks of these elements. TM concentrations in commercial pet foods (n = 100) as well as in ingredients used in their composition (n = 100) were analyzed and compared to the Food and Drug Administration (FDA) maximum tolerable level (MTL), and the TM concentrations found in the different sources of carbohydrate, protein, and fat were compared. The TM concentrations were determined by inductively coupled plasma with optical emission spectrometry (ICP-OES). Concentrations above the MTL for aluminum, mercury, lead, uranium, and vanadium were observed in both dog and cat foods, and the percentage of dog foods that exceeded the MTL of these TM were: 31.9%; 100%; 80.55%; 95.83%; and 75%, respectively, and in cat foods: 10.71%; 100%; 32.14%; 85.71%; 28.57%, respectively. The MTL values of these TMs and the mean values in dog foods (mg/kg dry matter basis) (MTL [mean ± standard deviation]) were: aluminum: 200 (269.17 ± 393.74); mercury: 0.27 (2.51 ± 1.31); lead: 10 (12.55 ± 4.30); uranium: 10 (76.82 ± 28.09); vanadium: 1 (1.35 ± 0.69), while in cat foods were: aluminum: 200 (135.51 ± 143.95); mercury: 0.27 (3.47 ± 4.31); lead: 10 (9.13 ± 5.42); uranium: 10 (49.83 ± 29.18); vanadium: 1 (0.81 ± 0.77). Dry foods presented higher concentrations of most TM (P < 0.05) than wet foods (P < 0.05). Among the carbohydrate sources, there were the highest levels of all TM except cobalt, mercury, and nickel in wheat bran (P < 0.05), while among the protein sources, in general, animal by-products had higher TM concentrations than plant-based ingredients. Pork fat had higher concentrations of arsenic, mercury, and antimony than fish oil and poultry fat. It was concluded that the pet foods evaluated in this study presented high concentrations of the following TM: aluminum, mercury, lead, uranium, and vanadium.

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Section: Discussionmentioning

confidence: 99%

Toxic element levels in ingredients and commercial pet foods

Zafalon

Pedreira

Vendramini

et al. 2021

Sci Rep

View full text Add to dashboard Cite

show abstract

“…Yet there is little direct evidence for how quickly fish MeHg concentrations will decline following reductions in current rates of Hg loading owing, in part, to a range of ecological factors that can influence both the microbial production and the bioaccumulation of MeHg in aquatic food webs 9 , 11 . Further complicating this relationship are human activities such as commercial fishing, introduction of exotic species and enhanced nutrient additions that trigger large-scale trophic disruptions 12 , which can in turn substantially alter fish tissue MeHg concentrations 13 – 15 , because fish acquire most of their MeHg through their diet 16 . Changing climatic conditions can also influence MeHg production 8 , as well as restructure food webs, alter the dominant pathways of energy flow and cause size-dependent changes in fish growth rates that shift population size structure 14 , 17 , 18 .…”

Section: Mainmentioning

confidence: 99%

Experimental evidence for recovery of mercury-contaminated fish populations

Blanchfield

Rudd

Hrenchuk

et al. 2021

Nature

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Anthropogenic releases of mercury (Hg)1–3 are a human health issue4 because the potent toxicant methylmercury (MeHg), formed primarily by microbial methylation of inorganic Hg in aquatic ecosystems, bioaccumulates to high concentrations in fish consumed by humans5,6. Predicting the efficacy of Hg pollution controls on fish MeHg concentrations is complex because many factors influence the production and bioaccumulation of MeHg7–9. Here we conducted a 15-year whole-ecosystem, single-factor experiment to determine the magnitude and timing of reductions in fish MeHg concentrations following reductions in Hg additions to a boreal lake and its watershed. During the seven-year addition phase, we applied enriched Hg isotopes to increase local Hg wet deposition rates fivefold. The Hg isotopes became increasingly incorporated into the food web as MeHg, predominantly from additions to the lake because most of those in the watershed remained there. Thereafter, isotopic additions were stopped, resulting in an approximately 100% reduction in Hg loading to the lake. The concentration of labelled MeHg quickly decreased by up to 91% in lower trophic level organisms, initiating rapid decreases of 38–76% of MeHg concentration in large-bodied fish populations in eight years. Although Hg loading from watersheds may not decline in step with lowering deposition rates, this experiment clearly demonstrates that any reduction in Hg loadings to lakes, whether from direct deposition or runoff, will have immediate benefits to fish consumers.

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“…Metal accumulation in aquatic animals (e.g fishes) either directly uptake from the water using their gills or indirectly absorb from diets by intestine (Oost et al, 2003). In this context, dietary exposure is considered as the main cause of metal accumulation in fishes (Hall et al, 1997;Farag et al, 1999) and the intestine is therefore the primary target of metal accumulation (Bernhoft, 2012).…”

Section: Chromium Concentration In Tissuesmentioning

confidence: 99%

Effects of chronic dietary hexavalent chromium on bioaccumulation and immune responses in the sea cucumber Apostichopus japonicus

Chan

Wang

Shi

et al. 2021

Preprint

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Sea cucumbers Apostichopus japonicus were exposed to five concentrations of dietary hexavalent chromium [0 (control), 100, 200, 400, and 800 mg Cr6+/kg dry weight] amended with K2Cr2O7 for 30 days. The bioaccumulation and immune responses [antioxidant enzymes: superoxide dismutase (SOD) and catalase (CAT); hydrolytic enzymes: acid phosphatase (ACP) and alkaline phosphatase (AKP)] of sea cucumbers were subsequently evaluated. This study found that the order of Cr accumulation in the experimental tissues was respiratory tree > intestine > body wall. Significantly lower SOD activities occurred in the 400 mg/kg group compared to that in the control group. Higher dietary Cr6+ exposure (400 and 800 mg Cr6+ /kg dry weight) did not negatively alter the CAT activities, but significantly inhibited CAT activities in 100 mg/kg group, compared to control group. ACP activities in groups 200, 400 and 800 mg/kg were significantly lower than those in control group, while no significant differences occurred in AKP activities among groups. The present study provides important information into the bioaccumulation and immune responses of the sea cucumber A. japonicus in response to chronic dietary Cr6+ exposure.

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Food as the Dominant Pathway of Methylmercury Uptake by Fish

Cited by 421 publications

References 22 publications

Toxic element levels in ingredients and commercial pet foods

Toxic element levels in ingredients and commercial pet foods

Experimental evidence for recovery of mercury-contaminated fish populations

Effects of chronic dietary hexavalent chromium on bioaccumulation and immune responses in the sea cucumber Apostichopus japonicus

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