Effects of cadmium, lead, mercury, chromium, and selenium co-treatment on egg quality and fatty acids.

This study aimed to reveal the effect of selenium (Se) and heavy metals (chromium (Cr), cadmium (Cd), lead (Pb), and mercury (Hg)) on the quality, fatty acids, and 13 kinds of ions in the egg yolk and albumen. Four experimental groups were established, including a control group (control; basal diet), Se group (basal diet + Se), heavy metals group (basal diet + CdCl2 + Pb(NO3)2 + HgCl2 + CrCl3), and Se + heavy metal (HM) group (basal diet + Se + CdCl2 + Pb(NO3)2 + HgCl2 + CrCl3). Se supplementation significantly increased the experimental egg yolk percentage since Se accumulation mainly occurred in the yolks of the eggs. The Cr content in the yolks of the Se + heavy metal groups decreased at 28 days, while a significant reduction was evident in the Cd and Hg levels of the Se + heavy metal yolks compared to the heavy metal group at 84 days. The complex interactions between the elements were analyzed to determine the positive and negative correlations. Se displayed a high positive correlation with Cd and Pb in the yolk and albumen, while the heavy metals minimally affected the fatty acids in the egg yolk.

Health risk assessment of heavy metals contamination in selenium-enriched eggs.

This study aims to quantify the amount of selenium (Se) generally consumed in the Chinese diet via Se-enriched eggs, as well as the levels of lead (Pb), arsenic (As), cadmium (Cd), chromium (Cr), and mercury (Hg) in such eggs, and to assess the health risks associated with their consumption in China. As would be expected, Se was found to present significantly higher geometric mean levels in the Se-enriched eggs (0.464 mg/kg) than in normal eggs (0.304 mg/kg); however, Se concentrations were also closely related to the Cr and Pb in the eggs, with the Pb levels found to exceed the Chinese standard limit. Therefore, the quantity of Pb in Se-enriched eggs requires attention. According to estimated daily intake (EDI) evaluations of Se and heavy metals, levels were found to be highest via children for all metals in the eggs, In adults, the total target hazard quotient (TTHQ) for Se, Pb, Cd, As, Hg, and Cr contamination in eggs were calculated to be below the standard limit of 1, thus confirming that Se-enriched eggs may be considered safe for consumption by adults. However, the THQ of as was higher than 1 in the children aged of 2-4 years, and the TTHQ values were higher than 1 in boys aged 2-9 and girls aged 2-8, indicating a significant non-carcinogenic health risk due to the intake of maximum metals in the eggs samples. Thus, the safety of selenium-enriched eggs for children should be of wide concern. In conclusion, while Se-enriched eggs offer high levels of selenium, their health safety is concerning.

Benefit-risk assessment of dietary selenium and its associated metals intake in China (2017-2019): Is current selenium-rich agro-food safe enough?

Dietary consumption of selenium-rich agro-food is an effective way to avoid selenium deficiency diseases, however, over consumption of selenium-rich agro-food will result in potential risk of selenosis and problems with associated metals. In this study, we measured the concentrations of selenium and its associated metals in 2756 common and 4894 selenium-rich agro-food samples in 10 regions of China. We found that selenium-rich rice, flour, edible fungi and algae, meat, and tea contain higher levels of associated metals than other selenium-rich agro-food samples. Increasing the consumption of selenium-rich agro-food could make the actual intakes (AIs) of selenium for all population to meet respective recommended daily intakes (RDIs). Benefit-risk assessment results indicated that increasing the consumption of selenium-rich agro-food make AIs of selenium for all populations meet RDIs, chromium intakes for people under 18 years old exceed provisional tolerated daily intake (PTDIs), while arsenic and cadmium intakes are close to PTDIs. The main dietary contributors of selenium, chromium, arsenic and cadmium were meat, edible fungi and algae, rice, and rice, respectively. The study supported the consumption of selenium-rich agro-food for effective selenium supplement, but also emphasized potential risk from associated metals in selenium-rich agro-food, especially chromium.

Determination of Selenium in Common and Selenium-Rich Rice from Different Areas in China and Assessment of Their Dietary Intake.

In this study, 41 common rice varieties and 211 selenium-rich rice varieties from ten representative areas in China were collected in 2017-2019. The selenium contents of rice were analyzed with optimized inductively coupled plasma mass spectrometry (ICP-MS). Selenium concentrations of common rice and selenium-rich rice ranges were 0.81-7.26 and 0.76-180.73 µg/100 g, respectively. The selenium contents in selenium-rich rice from different areas were significantly different (p < 0.001) while those in common rice from different areas were not. The selenium-rich rice in Harbin and Keshan showed the lowest selenium level and those from selenium-rich areas (Enshi and Ankang) were highest. Based on the estimation of the risk assessment software @risk7.0 (Palisade Corporation, New York, NY, USA), the consumption of selenium-rich rice can effectively increase dietary selenium intake for the population. However, the risk index of P95 (Percentile 95) selenium exposure at the tolerable upper intake level for children at 2-14 years old exceeded 100%, with potential risk currently. Therefore, the consumption of selenium-rich rice should be properly monitored for young children and adolescents.