# Comparative Study of the Presence of Heavy Metals in Edible Vegetable Oils
## 2 Analysis of Publications and Trend of Heavy Metals in Edible Vegetable Oils
### Results of the Analysis of Heavy Metals in Edible Vegetable Oils
#### 2.3.1 Cadmium (Cd)  
Cd is one of the most toxic heavy metals along with Pb and Hg. Although it is associated with different minerals distributed in nature, the human being has contributed to its \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \begin{tabular}{c} **Heavy** \\ **Metals** \\ \end{tabular} & **CX-A 1** & **WHO 2** & **EFSA 3** & \begin{tabular}{c} **Commission** \\ **Regulation** \\ **(EU)** \\ **2021/1317 4** \\ \end{tabular} & \begin{tabular}{c} **Commission** \\ **Regulation (EU)** \\ **2021/1323 5** \\ \end{tabular} & \
\begin{tabular}{c} **CB/T23347-2021** \\ **(China) 6** \\ \end{tabular} &
\begin{tabular}{c} **RD** \\ **308/1983** \\ **(Spain) 7** \\ \end{tabular} \\ \hline Cd & NC 8 & NC/R 9; 10 & NC/R 11 & NA 12 & NC 13 & NC & NC \\ \hline Pb & 0.1 14 & NC/R 15 & NC/R 16 & 0.10 & NA & NC & 0.1 \\ \hline Cu & NC 17 & NC & NC/R 18 & NA & NA & \(\leq\)0.1 & 0.4 \\ \hline Fe & NC 19 & NC & NC & NA & NA & \(\leq\)3.0 & 10 \\ \hline \hline \end{tabular}  
* CX-A, is Codex Alimentarius. 2 WHO, is World Health Organization. 3 ESA, is European Food Safety Authority. 4 Commission Regulation (EU) 2021/1317 of 9 August 2021 amending Regulation (EC) No 1881/2006 as regards maximum levels of lead in certain foodstuffs [65]. 3 Commission Regulation (EU) 2021/1323 of 10 August 2021 amending Regulation (EC) No 1881/2006 as regards maximum levels of cadmium in certain foodstuffs [66]. 6 GB/T2347-2021 (China). Recommended national standard for olive and olive promote oils exported to the Chinese market [67]. 7 Royal Decree (RD) 308/1983 (Spain), the Technical-Sanitary Regulation of edible vegetable oils is approved [68]. 8 NC, not considered in the regulations. 9 NC/R, not considered in the regulations but shows recommendations. 10 Provisional tolerable monthly intake (TMT) of 25 ug/kg body weight [69]. 11 Tolerable weekly intake of cadmium of 2.5 ug/kg body weight [70]. 12 NA, regulation not applicable for this heavy meal. 13 Rapesed 0.15 mg/kg and sunflower seeds 0.50 mg/kg, however the maximum levels do not apply to tree nuts or oiless for crushing and oil refining [66]. 14 [71]. 15 No defined maximum thresholds [72]. 16 Benchmark Dose Lower (BMDL01) of lead at 0.5 ug/kg of body weight per day [73]. 17 A product quality criterion is established with a maximum dose of 0.1 mg/kg for refined oils and 0.4 mg/kg for virgin oils [74]. 18 An adequate intake (AI) is established ranging from 0.4 mg/day for infants to 1.6 mg/day for the adult population of the male gender [75]. 19 A product quality criterion is established with a maximum dose of 1.5 for refined oils and 5.0 mg/kg for virgin oils [74].  
\end{table} 
Table 2: Toxicity thresholds established in current national and international legislation for heavy metals, expressed in mg/kg. dispersal through mining and metallurgical activities [76]. In the edible vegetable oil production and processing sector, its presence may have originated from the organic solvents used in the oil extraction process, which must meet a series of requirements to ensure safety. With this, it is intended to avoid transferring traces to the oil, controlling the presence of Cd in the final product and avoid exposure of this heavy metal to the consumer [77]. In addition to its high toxicity, its problem lies in its long half-life and its ability to accumulate in living beings. Some of the possible health effects from prolonged exposure may be kidney, lung, bone, stomach, and prostate toxicity problems, also developing metabolic syndrome and cancer [78]. More illustratively, Figure 4 represents the mobility of Cd in the soil and plants, and its incorporation through plant consumption [79]. Figure 2 show that Cd is the most analysed heavy metal in the edible vegetable oils collected in this literature review. However, and despite its importance due to the high toxicity it presents, there is no specific legislation for oils regarding the maximum limit allowed for consumption through the ingestion of edible vegetable oils.