Heavy Metal Pollution Analysis and Health Risk Assessment of Two Medicinal Insects of Mylabris

Mylabris is the dried body of the Chinese blister beetle (Mylabris sp.), which has been used in traditional Chinese medicine and achieved significant positive effects in the treatment of cancer including liver cancer, lung cancer, and rectal cancer. However, heavy metal pollution and accumulation of Mylabris insects could pose threat to human health. This study was carried out to assess levels of different heavy metals like Cu, As, Cd, Hg, and Pb, along with soil–plant-insect system and health risks using two representative Mylabris insects from the Hasi Mountains of Gansu Province, China. The results showed that the heavy metal concentration of plants and insects followed the order Cu > Pb > As > Hg > Cd. Compared with soil and plants, the content of Cu in insects was the highest, reaching 45.65 mg/kg. Cu was the main element that caused insects to absorb and accumulate. The quantitative risk analysis implied the two Mylabris insects had carcinogenic risks, with the contribution of As providing 63% and 60.7%, respectively. This kind of carcinogenic risk that the human body could bear was not easy to cause side effects to normal people, but it was difficult and dangerous for cancer patients. Thus, the evaluation of health risk lays the foundation for pollutant risk monitoring.