Bandara et al. 2010 — Cadmium in Rice and Chronic Renal Failure, Sri Lanka
This WHO-sponsored investigation established the link between elevated dietary cadmium in Sri Lanka’s North Central Province and an epidemic of chronic renal failure (CRF) affecting agricultural communities. The paper reports extensive Cd measurements in food, water, and biological samples from the affected region.
Key numbers
All concentrations wet weight unless noted.
Cadmium in rice (polished grain, µg/kg wet weight): Range 1.7–92.5 µg/kg; mean 23.356 ± 22.877 µg/kg. Several samples substantially exceeded Codex ML of 400 µg/kg for polished rice (now 200 µg/kg under Codex 2006 revision). The wide range reflects spatial variation in soil Cd across the irrigation zone.
Cadmium in other foods (µg/kg wet weight):
| Commodity | Range | Mean ± SD |
|---|---|---|
| Pulses (Vigna radiata) | 2.1–99.2 | 31.774 ± 28.047 |
| Tilapia niloticus (fish) | 0.5–90.7 | 21.763 |
| Lotus rhizomes (Nelumbo nucifera) | 2.3–271.3 | 46.407 |
Water cadmium (µg/L): Reservoir irrigation water: 0.03–0.06 mg/L (30–60 µg/L), 10–20× above WHO MCL of 3 µg/L. Drinking water (CRF patients’ homes): irrigation/reservoir wells geometric mean 3.174 µg/L (range 0.08–29.14); agro wells 11.18 µg/L (range 2.72–38.8).
Breast milk (µg/L): Range 0.52–75.32 µg/L; mean 18.235 ± 20.74 µg/L. Substantially above values reported in non-affected populations.
Urinary cadmium: Stage 5 CRF patients: 7.6 µg/g creatinine. Asymptomatic farmers: 11.6 µg/g creatinine.
Methods
Not detailed in Marker-converted excerpt. WHO-sponsored field investigation with laboratory analysis. Wet weight basis.
Key finding: Green Revolution fertilizer practices in Sri Lanka introduced Cd through contaminated phosphate fertilizers applied to irrigated rice paddies; Cd accumulates in paddy soil and enters the food chain through rice, pulses, and aquatic foods.
Implications
Certification: Sri Lanka rice Cd mean of 23 µg/kg (range up to 92.5 µg/kg) provides regional context for Cd in rice; demonstrates supply-chain provenance matters. Lotus rhizomes and pulses can carry even higher Cd than rice in contaminated areas.
Courses: Important case study for fertilizer-driven Cd contamination pathway and CRF epidemic.