Concentration of heavy metals in various children's herbal tea types and their correlations

Abstract

This investigation was undertaken to determine the concentrations of cadmium, lead, mercury, zinc, copper and magnesium in six tea types used as children's tea. Six types of tea of different herbal composition used for children's consumption (T1, T2, T3, T4, T5 and T6) were analyzed in three subsequent collections. The analysis of cadmium showed that the concentration was very similar in all types of children's tea, ranging from 0.233 to 0.369 mg/kg. Lead concentrations were in the range of 0.340-1.564 mg/kg without any significant differences. The analysis of mercury detected very low concentration of this metal in all samples (0.002-0.004 mg/kg). In zinc, the values ranged from 36.633 to 71.711 mg/kg, with significant differences (p < 0.001) according to tea type. Copper concentration was 10.089-30.178 mg/kg with the highest value in T4. The concentration of magnesium was significantly higher in tea T1 and T2 (102.311 and 129.422 mg/kg) in comparison with other tea types where the level was 19.811-37.411 mg/kg. The maximum tolerable limit determined by Codex Alimentarius was not exceeded in any sample. In general, correlation analysis detected high positive correlation between cadmium and lead (r = 0.89), cadmium and mercury (r = 0.92) and between lead and mercury (r = 0.77).

Determination of multi element levels in leaves and herbal teas from Turkey by ICP-OES

“…In the literature, Cu levels in tea samples consumed have been reported in the range of 15.7 and 34 µg/g [20]. The range of Cu concentration in the black tea samples has been reported as 24.07±2.25 µg/g [17] and a range from 10.089 and 30.178 µg/g in children's herbal tea.…”

“…Görür et al reported in 2011 Zn levels of 23.6 to 120.5 µg/g in the digestion and from 2.8 to 18 µg/g in the infusion of the Turkish tea market. Haban et al have reported ranges from 36.6 to 71.7 µg/g Zn concentrations in children's herbal tea samples [17,30].…”

“…The pollution is then accumulated within the body of organisms. These metals are toxic materials when they are in excessive doses [17]. The heavy metals (Al, Ba, Cr, Cu, Fe, Mn, Ni, Sr and Zn) content in 18 herbal teas (some consumed as leaves or as flowers) purchased from local markets were determined by ICP-OES.…”

“…It is vital for many biological functions and plays a very important role in more than 300 enzymes in the human organism [17]. In the present study on the herbal tea leaves Zn levels were found to be 14.0±0.3 and 27.0±0.7 µg/g in the digestion and 1.0±0.1 to 17.0±0.8 µg/g and 5.0±0.2 and 103.0±0.4 µg/g in the digestion and 1.0±0.1 to 90.0±0.4 µg/g in the infusion.…”

Determination of Rare Earth Elements in Some Flower Herb Teas and their Infusions

“…Due to the importance of heavy metal present in herbs, several studies have been carried out to determine their levels. [4][5][6][7] By comparison with heavy metal, the levels of rare earth elements (REEs) in herb tea receive little concern. Some evidences show that excessive exposure to rare earth oxides (REOs) is harmful to human health such as leukemia.…”