Bioaccumulation and Health Risk Assessment of Nickel Uptake by Five Wild Edible Saprotrophic Mushroom Species Collected from Croatia

The current study investigates the bioaccumulation potential of the heavy metal nickel (Ni) in five edible saprotrophic mushroom species (Agaricus campestris L., Armillaria mellea (Vahl) P.Kumm., Clitocybe inversa (Sowerby) Vizzini, Clitocybe nebularis (Batsch), P.Kumm., and Macrolepiota procera (Scop.) Singer) collected from seven forest locations (Trakoscan, Medvednica, Petrova gora, Skrad, Krk, Labinstina, and Motovun) of Croatia. For this purpose, forest soil and mushroom samples (cap and stipe) were collected from January to December 2021 and analyzed using inductively coupled plasma optical emission spectroscopy (ICP-OES). The results showed that all soil samples showed an occurrence of Ni, ranging from 1.62 to 3.55 mg/Kg. On the other hand, the cap parts of all five mushroom species showed a higher Ni content as compared to those in the stipe parts. Overall, there is a substantial positive association between soil Ni availability and the mean Ni concentration (mg/Kg) in the cap and stipe parts of A. campestris (3.08 and 2.22), A. mellea (2.59 and 1.55), C. inversa (2.38 and 1.75), C. nebularis (2.56 and 1.91), and M. procera (2.94 and 1.94). Multivariate analyses using principal component analysis (PCA) and hierarchical cluster analysis (HCA) showed that the Skrad and Petrova gora locations had the highest Ni contents in the selected mushroom species. Moreover, the estimated daily intake of Ni from consuming these mushrooms was below the threshold limits as suggested by dietary intake modeling (DIM) and health risk index (HRI) values. Therefore, this study emphasizes the importance of examining the Ni bioaccumulation potential of wild edible mushrooms, as well as the health hazards associated with their consumption, which are useful for food safety rules and recommendations.

Automated summary

This study investigates the bioaccumulation potential of the heavy metal nickel in five edible saprotrophic mushroom species collected from seven forest locations in Croatia. The results show a positive association between soil nickel availability and nickel concentration in the cap and stipe parts of the mushrooms. The highest nickel content was found in mushrooms from Skrad and Petrova gora locations. The estimated daily intake of nickel from consuming these mushrooms was below the threshold limits.