Cadmium in Drinking Water: Health Risks

Cadmium is a toxic heavy metal that can enter drinking water through industrial discharge, mining and smelting activities, battery manufacturing, phosphate fertilizers, and corroded galvanized pipes. When cadmium levels exceed drinking-water standards, both acute and chronic health effects become a serious concern.

At high concentrations, short-term exposure can cause nausea, vomiting, abdominal pain, diarrhea, and in severe cases shock and organ failure. However, the greater public health threat comes from long-term exposure to lower, sustained levels.

The kidney is the primary target organ. Cadmium accumulates in the renal cortex, where it damages proximal tubular cells and impairs reabsorption. This can lead to proteinuria, glucosuria, aminoaciduria, and progressive loss of kidney function. Because cadmium has a biological half-life of decades, repeated exposure allows it to build up over a lifetime.

Bone health is also affected. Cadmium interferes with calcium and vitamin D metabolism, contributing to osteoporosis, osteomalacia, bone pain, and increased fracture risk. The classic example is Itai-itai disease in Japan, caused by long-term cadmium-contaminated water and rice.

Cardiovascular effects have been reported as well. Cadmium exposure is associated with hypertension, atherosclerosis, and increased risk of cardiovascular disease. It may also disrupt the endocrine system and reproductive function, with studies linking it to reduced sperm quality and developmental effects.

Cadmium is classified as a human carcinogen. Chronic exposure has been linked to lung, prostate, and kidney cancers, and possibly other types. Vulnerable groups include children, pregnant women, the elderly, smokers, and people with existing kidney disease, since they are more susceptible or may absorb cadmium more readily.

Prevention is essential. Drinking-water sources should be monitored regularly, and contaminated supplies should be treated using reverse osmosis, distillation, or ion-exchange systems. Reducing smoking and maintaining adequate iron, calcium, and zinc status can also lower cadmium absorption and toxicity.

In conclusion, cadmium exceeding drinking-water standards poses significant risks to the kidneys, bones, cardiovascular system, and potentially cancer. Even low-level chronic exposure should not be ignored. Prompt monitoring, source control, and effective water treatment are necessary to protect public health.