Temporal Changes in Lead and Cadmium Levels in Amanita muscaria Samples Collected in Poland

In recent years, an increasing popularity of consuming Amanita muscaria has been observed in Poland, aimed at reducing various medical symptoms. However, there is a lack of data regarding the impact of variations in the content of toxic elements, such as cadmium (Cd) and lead (Pb), in Amanita muscaria collected during late summer and mid-fall. The aim of this study was to determine the concentrations of Pb and Cd in Amanita muscaria samples collected at different times of the year, compare the concentrations of these elements in samples with and without cap skin, and compare the obtained values to permissible limits in dietary supplements. A total of 44 Amanita muscaria samples were collected during three different harvesting periods (August, September, and October 2023) from Puszcza Biała, located approximately 80 km from Warsaw. The mushrooms were subjected to mineralization using concentrated nitric acid and hydrogen peroxide, followed by the determination of Pb and Cd concentrations using an atomic absorption spectrometer. Significant statistical differences were found in the Pb concentrations of samples collected in three different seasons (η² = 0.67, p < 0.001), with the concentration increasing progressively, reaching its highest value in October. Similarly, the Cd concentration also increased in the later collections, although the effect of time was weaker (η² = 0.13, p = 0.03). No significant differences were observed in Pb and Cd concentrations between samples with and without cap skin. The average Cd concentrations in mushrooms were significantly higher than the permissible levels in dietary supplements; they were four times higher in August (p < 0.001), six times higher in September (p < 0.001), and nine times higher in October (p < 0.001). The Pb concentration in the October samples was close to the permissible limit but did not exceed it in a statistically significant manner (p = 0.85). Due to the high Cd concentrations and potentially hazardous levels of Pb, the consumption of Amanita muscaria carries a significant risk of toxicity, which may lead to serious health hazards, particularly in the context of prolonged exposure.