Medicinal source:

Nawab, J., Khan, S., Shah, M.T., Qamar, Z., Din, I., Mahmood, Q., Gul, N. & Huang, Q. (2015). Contamination of Soil, Medicinal, and Fodder Plants with Lead and Cadmium Present in Mine-Affected Areas, Northern Pakistan. Environ Monit Assess. 187: 605.