Overview
The authors bought palm weevil larvae and winged termites from market vendors at 12 sites in Anambra State, Nigeria, and measured ten elements by flame atomic absorption spectrometry. They report one mean per species on a dry-weight basis and a target hazard quotient assessment, which found all hazard indices below 1. Arsenic was not detected in either insect.
Key numbers
- Palm weevil larvae: lead 0.133 ± 0.013, cadmium 0.031 ± 0.006, mercury 0.375 ± 0.125 mg/kg; arsenic ND (Table 1).
- Termites: lead 0.112 ± 0.311, cadmium 0.375 ± 0.021, mercury 0.155 ± 0.026 mg/kg; arsenic ND (Table 1). The text gives termite cadmium as 0.037 mg/kg, which conflicts with the table.
- Hazard index 2.9E-01 for palm weevil and 1.8E-01 for termite (Table 2).
Methods (brief)
Insects were digested in nitric and perchloric acid (4:1) and analyzed by flame AAS (Varian AA240). Quality control used a water-matrix reference material (NIST 1640) with recoveries of 90 to 99.5%. Results are given in mg/kg dry weight with a stated detection limit of 0.001 mg/kg.
Evidence Fitness
Direct market data for edible insects, but each species is summarized by a single mean of triplicates with no per-site values, and the harvest origin of the insects is unknown. Mercury and arsenic by flame AAS are weak (the authors say so), the reference material is a water matrix, and the termite cadmium value differs tenfold between the table and the text. Treat it as indicative.