Occurrence and Health Risk Assessment of Heavy Metals in Lychee (Litchi chinensis Sonn., Sapindaceae) Fruit Samples

This study aimed to assess the occurrence of eight heavy metals in lychee (Litchi chinensis Sonn.) fruit samples collected from orchards of the Dehradun and Haridwar districts in Uttarakhand, India. Lychee fruit samples were collected from ten (10) sampling locations from May to June 2023 and analyzed using inductively coupled plasma optical emission spectroscopy (ICP-OES). Results showed that lychee fruit samples showed varying levels of selected heavy metals, i.e., Cd (0.009-0.095 mg/kg), Cr (0.079-0.960 mg/kg), Cu (0.095-0.258 mg/kg), Fe (0.254-0.531 mg/kg), Pb (0.000-0.011 mg/kg), Mn (0.862-1.903 mg/kg), Ni (0.166-0.310 mg/kg), and Zn (0.076-0.149 mg/kg). It was observed that lychee fruit sampling sites near urban and industrial areas had higher concentrations of heavy metals as compared to those in rural and agricultural areas. In addition, principal component analysis (PCA) and clustered heatmap dendrogram results showed that several sites had significant similarities in terms of heavy metal availability. Overall, the levels of all heavy metals were below the safe limits as suggested by health risk studies. The selected indices such as daily intake of metals (DIM), health risk index (HRI), and target hazard quotient (THQ) did not exceed the standard limit which indicated consumption of lychee fruit was safe at all sampling sites. The results of this study emphasize the need to regularly monitor lychee heavy metal levels and implement sustainable agricultural and environmental practices to reduce contamination sources.