Levels of Mercury, Methylmercury and Selenium in Fish: Insights into Children Food Safety

Abstract

Total mercury (THg), methylmercury (MeHg), and selenium (Se) concentrations were measured in various commercially important fish species. The benefit–risk binomial associated with these chemicals was assessed in children through the probability of exceeding the provisional tolerable weekly intakes (PTWIs) of the contaminants and the Se recommended dietary allowance (RDA). The Se:Hg molar ratios, selenium health benefit values (HBVSe), and monthly consumption rate limits (CRmm) for each species were also calculated. THg and Se were analyzed by atomic absorption spectrophotometer (Shimadzu, Milan, Italy), while MeHg was determined by Trace Ultra gas chromatograph connected with a PolarisQ MS (Thermo Fisher Scientific, Waltham, MA, USA). None of the analyzed fish had Hg levels above the European Community regulatory limits, while most large predators had MeHg levels over the threshold concentration set by US EPA. The estimated weekly intakes of THg and MeHg exceeded in many cases the PTWIs and the Se estimated daily intakes were provided from 0.71% to 2.75% of the RDA. Se:Hg molar ratios above 1 and positive HBVSe index suggested that Se in fish could be enough to alleviate the potential toxic effect of Hg. However, high-risk groups as children should consume fish in moderation because a large consumption pattern, especially of swordfish and tunas, might be of concern for health.

Bioaccumulation of Toxic Metals in Commercially Valuable Fish from the Western Region of Ghana

“…Selenium mean concentration in the study ranged from 2.06 to 8.13 mg/kg. The concentration of Se in this study is in line with the finding of [51] who reported values of 0.15 µg g −1 to 0.58 μg g −1 from the Mediterranean area. However, the concentration of Se in this study is higher than the findings of [52] who reported concentration of 0.27 mg/kg to 0.56 mg/kg in Gadus morhus and Sebastes spp respectively.…”

Determination of Mercury, Methylmercury and Selenium Concentrations in Elasmobranch Meat: Fish Consumption Safety

“…With respect to skates, Barone et al [ 15 ] in a recent paper measured concentrations from 0.58 to 0.67 μg g −1 w.w. in different species from the Mediterranean Sea. Nicolaus et al [ 60 ] find levels between 0.02 and 1.8 μg g −1 w.w. with an average of 0.43 μg g −1 w.w. in Leucoraja circularis from Celtic Sea.…”

“…Concerning batoids, the published data are scarce or even non-existent, as in the case of torpedinids. The few studies on skates seem to indicate that consumption of these species provide far more Se than Hg to the consumer [ 15 , 57 , 68 ]. This suggestion is in an agreement with the findings of the current study, which shows a healthy profile of these species and provides a clear example of integration between Se-specific nutritional benefits and the potential Hg-exposure risks.…”

“…Additionally, often, consumers are unaware that they are ingesting shark meat because it is mislabelled as other types of elasmobranch or teleost fish, e.g., smooth dogfish, yellow-tailed gurnard, “corvina”, or even swordfish to increase the price. Despite this, poorly understood is the human risk associated with elasmobranch meat consumption in the general Italian population [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ]. Similarly, there is a paucity of publications that include Se measurements when assessing Hg exposure risks from fish [ 15 , 24 , 25 , 26 , 27 ].…”

“…Despite this, poorly understood is the human risk associated with elasmobranch meat consumption in the general Italian population [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ]. Similarly, there is a paucity of publications that include Se measurements when assessing Hg exposure risks from fish [ 15 , 24 , 25 , 26 , 27 ]. In this overall picture, the present study reports a set of data on THg, MeHg and Se concentrations in a wide range of elasmobranch fish, with a special focus on sharks.…”