Heavy Metal Content in Medicinal Plants Grown in Hydroponics and Forest Soil in the Central Part of Western Siberia

Abstract

The Khanty-Mansi Autonomous Okrug-Yugra, situated within Russia’s Far North, has undergone substantial industrialization and economic development. However, it is confronted with considerable environmental challenges, notably soil contamination. This study examines the presence of heavy metals (lead, cadmium, copper and zinc) in medicinal and berry plants from the forest ecosystem of this region. The following plant species were analyzed: Hypericum perforatum, Rubus arcticus, Origanum vulgare and Thymus vulgaris. The samples were taken from both open ground and hydroponic cultivation under artificial lighting. The findings indicate that the levels of lead present in all samples remain below the permissible limit of 10 mg/kg. Cadmium levels exhibited variability, with hydroponically grown plants containing 0.01 to 0.5 mg/kg and open ground Hypericum and Rubus perforatum containing up to 0.8 mg/kg. The combination of hydroponic cultivation and specific lighting conditions has been demonstrated to reduce lead and cadmium accumulation by a minimum of 1.6 times in comparison to open ground cultivation. The copper content of the samples ranged from 3 to 8 mg/kg, while the zinc content was 1.2–1.5 times higher in the plants grown in the open compared to those grown hydroponically. Notwithstanding these variations, the heavy metal content of all plant samples remains below the threshold values, thus rendering them safe for harvesting and utilization. This research serves to illustrate the environmental impact of industrial activities and to identify hydroponics as a potential strategy for their mitigation.