Impact of agricultural chemicals on selected heavy metals accumulation in herb plants

Abstract

The aim of this paper is to determine cadmium, lead and nickel concentration in different herb plants and in the soil collected in the areas close to winter wheat and grain maize fields. The following herbs were analyzed: Achillea millefolium, Cichorium intybus L., Equisetum arvense, Polygonum persicaria, Plantago lanceolata L., and Plantago major L. They were sampled one and ten meters away from the edge of the fields. The plants, 70 of each species, were collected during the flowering stage from 1 to 20 July 2014. At the same places soil samples were taken. Cadmium, lead and nickel concentration was determined with inductively coupled plasma-atomic emission spectrometry. All the herbs growing near the wheat field, except for Cichorium intybus L., had lead concentration above the limit. For other metals the concentration was below the limits set for dried herbs. Herbs plants growing close to the wheat field had a higher concentration of heavy metals than the same plants growing near the grain maize field. The average concentration of cadmium, lead and nickel in the soil around the fields was much lower than the concentration of the same metals in average, non-contaminated soil. In the soil-plant system the highest accumulation coefficient of heavy metals was for cadmium, then for nickel while the lowest was for lead.