THE HEAVY METAL CONSTITUENTS AND COMPOSITION OF THE SOIL AND MUSHROOMS COLLECTED FROM THE NONG-AUNG PUBLIC FOREST

Abstract

This paper presents the findings of a study conducted to assess the conditions and heavy metal contents of the soil in areas of the Nong-Aung public forest. This study investigates the relationship between the heavy metal contents in soil and the accumulation of heavy metals in naturally occurring mushrooms within the public forest, comparing the components of a waste disposal zone and a general disposal zone. This study employs one-way analysis of variance to analyse variances between groups, with data differences compared using the least significant difference method. The research reveals significant differences (p < 0.05) in the heavy metal contaminants present in soil between the waste disposal zone and the general zone in the public forest. Human activities are found to influence soil properties and heavy metal content. However, it is important to note that the levels of heavy metals in the Nong-Aung public forest do not exceed Thailand’s standards. The study also examines the heavy metal content in various mushroom species, including Mycoamaranthus cambodgensis (Pat.) Trap, Ganoderma applanatum (Pers.ex Wallr.) Patouillard, Heimioporus japonicus (Hongo) E. Horak, Thaeogyroporus porentosus (berk. ET. Broome) and total mushrooms suitable for consumption. The research reveals that the mushrooms have an average Cd content of 0.558 ± 0.908 mg/kg dry weight, with quantities of other elements as follows: Pb 1.740 ± 2.441 mg/kg dry weight, Mn 266 ± 128 mg/kg dry weight, Ni 4.44 ± 2.83 mg/kg dry weight, and As 0.014 ± 0.005 mg/kg dry weight. Importantly, the heavy metal content of mushrooms in the public forest does not exceed the established standards. However, the study highlights concerns regarding the quality of soil in the public forest and its potential impact on the environment and local biodiversity. The paper concludes by emphasising the need for local government and citizen advocacy to impose restrictions on the expansion of waste disposal areas in the public forest.