Metal concentrations of Chinese herbal medicine products in the United States

Abstract

SUMMARY We determined arsenic, lead, mercury and cadmium concentrations in Chinese herbal medicinessold in the United States by medical use parts. 54 kinds of herbal products including 9 medicaluse parts (radix, rhizoma, cortex, pericarpium, fructus, lignum, semen, folium, and herba) wereanalyzed using inductively coupled plasma-mass spectrometry for arsenic, lead and cadmium,and using mercury analyzer for mercury. Arsenic (median concentration, 0.25 mg/g), mercury(0.20 mg/g), lead (3.78 mg/g) and cadmium (0.39 mg/g) were detected in 71%, 54%, 35%, and18% of 143 herbal medicine samples, respectively. A total of 27% and 12% of 143 productsanalyzed contained mercury and cadmium above the regulatory standards. Herba and folium(leaves of herbal plants) were the most contaminated parts from metals, whereas pericarpium,lignum and semen (outer layers and seeds) were less contaminated. This study suggests thatmetal contamination is different by medical use parts. Our findings provide further evidence thatefforts to protect people using traditional remedies from metal intoxication should be made toenforce the regulatory standards.Key words: Chinese herbal medicine; Metals; Toxicity