Determination of the Concentration of Heavy Metals and Their Assessment of Related Potential Health Risk for Dry Black Teas in Kashan, Iran

Document Type: Original Article


1 MA,Department of Environmental Health Engineering, Faculty of Health, Kashan University of Medical Sciences, Kashan, Iran

2 Associate Professor in Department of Environmental Health Engineering, Faculty of Health, Kashan University of Medical Sciences, Kashan, Iran

3 Associate Professor in Department of Biostatistics and Public Health, Faculty of Health, Kashan University of Medical Sciences, Kashan, Iran

4 Full Professor in Department of Environmental Health Engineering, Faculty of Health, Kashan University of Medical Sciences, Kashan, Iran



Tea is one of the most popular beverages being widely used by all families, especially among Iranians. Thus, the presence of any contaminants in tea can be dangerous for the health of consumers. The present study aimed to evaluate the concentration of heavy metals and their potential health risk in the dry black teas available in Kashan shops. This cross-sectional study was carried out on 31 brands of dry black tea purchased randomly from shops in Kashan, Iran in 2019. After the preparation of samples, the concentration of some heavy metals was determined by ICP-OES (Inductively Coupled Plasma/Optical Emission Spectrophotometer)based on the procedure described in the Standard Method. The evaluation carcinogenic risk was performed using related formula. Based on results of this study, the mean concentration of Fe, Zn, Cu, Ni, Cr, Pb, As and Cd was 83.42, 21.47, 19.46, 4.04, 0.72, 0.66, 0.4 and 0.04 Mgkg-1 of dry black tea, respectively. According to their associated potential health risk assessment, THQ of some heavy metals including As, Cu, Cr, Ni, Pb, Fe, Zn and Cd was 0.064, 0.023, 0.011, 9.76×10-3, 9.11×10-3, 5.76×10-3, 3.46×10-3 and 1.88×10-3 Mgkg-1day-1 and HI was less than one (0.129). Regarding the findings, it can be concluded that, the concentration of Cu, Ni and Cr in all samples of dry black tea was compatible with the Iranian and WHO standard level, while for Cd, Pb, As, Zn and Fe in some samples were more than the Iranian and WHO standard level. In addition, risk assessment analysis indicated that the consumption of the studied black tea had no carcinogenic potential risk for consumers.


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