Abstract: Objective To analyze the contents of heavy metals and harmful elements in earthworms, and to study the association of heavy metals and harmful elements in traditional Chinese medicines with the origins of Chinese medicinal materials. Methods After microwave digestion, the contents of lead, cadmium, arsenic, mercury and copper in earthworms were determined by inductively coupled plasma mass spectrometry (ICP-MS). The safety of samples was evaluated by single factor pollution index method and Nemerow comprehensive pollution index method. Results The average contents of lead, cadmium, arsenic, mercury and copper of 17. batches from 9 places of origins were 8.58, 1.50, 9.86, 0.57 and 27.71 mg/kg, respectively. The results of safety evaluation showed that all batches of earthworms from Shanghai, Jiangsu, Guangxi and Henan were heavily polluted. Earthworms from Guangdong and Zhejiang were moderately polluted, those from Shandong were lightly polluted, those from Anhui were within the safety line, and those from Hainan were safe. The safety evaluation results obtained by single factor pollution index method and Nemerow comprehensive pollution index methods were associated with the origins. Conclusion The study has provided not only reliable data on the relationship between the origin distribution of Chinese medicinal materials and heavy metals and harmful elements, but also reference for safety evaluation, quality control and exploitation of resources of animal medicines.

Key words: earthworm, Pb, Cd, As, Hg, Cu, safety evaluation, heavy metals, harmful elements