Understanding the effects of lithium exposure on castor bean (Ricinus communis) plants, a potential bioindicator of lithium-contaminated areas

As lithium (Li) stands out as a crucial component of batteries, the inappropriate disposal of electronic gadgets might drive Li pollution in environmentally sensitive environments, such as dumps, where castor bean (Ricinus communis) plant communities are usually found. The exposure to high Li concentration is potentially harmful to the environment and humans. Therefore, it is opportune to evaluate the potential of bioindicator species to monitor Li contamination. In this scenario, the present study assessed the effects of Li exposure on the development of castor bean plants exposed to lithium chloride at five Li dosages (0, 5, 10, 20, and 30 mg dm^-3). Significant symptoms of phytotoxicity were observed at all doses. Li dosage exhibited increasing impairment effects on plant biometrics, such as stem diameter and the number of leaves, as well as on the SPAD index, nutritional balance, and biomass production. Our findings suggest castor bean as a potential model species for biomonitoring Li-contaminated areas.