Evaluation of vulnerability of Suillus variegatus and Suillus granulatus mushrooms to sequester mercury in fruiting bodies

ABSTRACT

This work determined the mercury (Hg) contents and bioconcentration potential of two Suillus mushrooms, and the probable dietary intake of this element from a mushroom meal. The determination of total Hg content of fungal and soil samples was performed using cold-vapour atomic absorption spectroscopy by a direct sample thermal decomposition coupled with gold wool trap of Hg and its further desorption and quantitative measurement at a wavelength of 253.7 nm. The median values of Hg contents (mg kg⁻¹ dry biomass) in 213 specimens of S. variegatus from 12 background areas varied widely from 0.087 to 0.51 for caps and from 0.041 to 0.24 for stipes. In 52 specimens of S. granulatus, the Hg contents ranged from 0.30 to 0.41 for caps and from 0.058 to 0.14 for stipes. Both species could be classified as moderate accumulators of Hg and the median bioconcentration factor values ranged from 7.0 to 14 (caps) and 2.1 to 13 (stipes) for S. variegatus and 9.5 (caps) and 1.3 (stipes) for S. granulatus. The estimated intake rates of Hg with the consumption of 300-g caps were from 0.0026 to 0.015 per capita or from 0.000037 to 0.00022 mg kg⁻¹ body mass and this do not indicate any cause for concern associated with eating a meal once or more in a week during the mushrooming season.

KEYWORDS:

• Food
• forest topsoil
• fungi
• mercury, heavy metals
• organic food
• nutrition

Acknowledgments

Technical support by Michał Bajerowicz, Katarzyna Bargłowska, Anna Dryżałowska, Grażyna Jarzyńska, Danuta Kocieniewska, Edyta Kułdo, Wojciech Makowiec, Ewa Monkiewicz, Aleksandra Mostrag, Katarzyna Słowikowska, Aleksandra Stefańska, Katarzyna Strupińska, Joanna Szubstarska, Justyna Wenta and Joanna Ziółkowska is acknowledged.