CADMIUM

Cadmium testing measures cadmium in whole blood (recent exposure, last few months) or urine (cumulative body burden, since cadmium has a 20–30 year body half-life). Whole blood uses trace-element-free royal blue-top tubes; urine is typically spot urine corrected for creatinine or 24-hour collection.

Cadmium accumulates predominantly in the kidney cortex over decades. The earliest clinical effect is renal tubular dysfunction with proteinuria (low-molecular-weight proteins like β2-microglobulin). Chronic high exposure causes osteomalacia and Itai-itai disease — historically a Japanese epidemic from rice grown in cadmium-contaminated water.

India has multiple substantial cadmium-exposure populations. Smokers are a major group — tobacco concentrates cadmium and smokers have 4–5x higher body burden than non-smokers. Occupational exposure is significant in: nickel-cadmium battery manufacture and informal recycling (huge informal e-waste sector in India), electroplating, welding (cadmium-coated steel), pigment manufacture (yellow/red cadmium pigments in plastics and paints), and PVC stabiliser production.

Environmental exposure occurs in communities near smelters, contaminated agricultural soil, and rice grown in contaminated water. NIOH Ahmedabad has documented elevated cadmium in Indian battery and welding workers. Testing supports occupational health surveillance, workup of unexplained tubular kidney disease, and chronic exposure assessment in high-risk communities. It is not appropriate as a routine wellness screen.

Avoid smoking for at least 12 hours before testing to avoid acute-cigarette confounding (chronic body burden will still show). Use trace-element-free royal blue-top tube for blood, trace-metal-free container for urine. Stop multivitamins for 72 hours. For occupational testing, sample end of shift / end of workweek per ACOEM protocols.