Cadmium in locally grown rice (Oryza sativa) in Nigeria

Cadmium levels were determined in locally grown rice samples in Nigeria and any potential risk involved in their consumption was assessed. The dried samples were digested with a 1:1 HNO3:HClO4 mixture and analysed with atomic absorption spectrophotometer (AAS). Mean cadmium values (mg/kg) were: Adamawa (0.50 ± 0.02), Benue (0.63 ± 0.05), Nasarawa (0.48 ± 0.10), Taraba (0.48 ± 0.10), Anambra (0.49 ± 0.09), Ebonyi (0.60 ± 0.08) and Enugu (0.59 ± 0.10). All samples exceeded the Codex Alimentarius maximum limit for cadmium in rice. The dietary intake for a 60 kg adult ranges from 235 to 309 µg/week in the northern region and 240-294 µg/week in the south-eastern region. The target hazard quotient (THQ) ranged from 0.54 to 0.71, which is less than 1, indicating that the population will not be exposed to a potential health risk from dietary cadmium. However, the measured cadmium levels in rice should be of concern.