Peer-reviewed article
Levels of Mercury, Methylmercury and Selenium in Fish: Insights into Children Food Safety
Grazia Barone, Arianna Storelli, Daniela Meleleo, Angela Dambrosio, Rita Garofalo et al. ·
Summary
Written by AI, not yet AICS's view · claude-haiku-4-5-20251001This study measured mercury, methylmercury, and selenium levels in commercially important fish species sold in Italy to assess safety for children. The researchers found that while most fish met European regulatory limits for total mercury, many large predatory fish exceeded US EPA thresholds for methylmercury. Although selenium in fish may help offset some mercury toxicity, the study concludes that children should consume fish in moderation, particularly swordfish and tuna, to avoid exceeding safe weekly intake limits.
Key points
- None of the analyzed fish exceeded European Community regulatory limits for total mercury
- Most large predatory fish species had methylmercury levels above US EPA threshold concentrations
- Estimated weekly intakes of total mercury and methylmercury exceeded safe limits in many cases for children
- Selenium content in fish was sufficient to provide 0.71% to 2.75% of the recommended dietary allowance
- Selenium:mercury molar ratios above 1 suggest selenium may help counteract mercury's toxic effects
Limitations
The study assesses chemical contamination levels and theoretical risk based on intake guidelines, but does not measure actual health outcomes in children or examine real consumption patterns. The analysis is based on commercially available fish species and may not reflect all dietary sources of mercury exposure for children.
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.