Various forms of cadmium poisoning have been documented in the literature. Acute poisoning, depending on the mode of exposure, can cause life-threatening respiratory or gastrointestinal symptoms in the absence of immediate supportive therapy, while chronic toxicity, mostly through occupational exposure may lead to renal failure, osteomalacia and increase the risk for cardiovascular disease. Patient history and laboratory studies are vital for the diagnosis.
Cadmium is used for various industrial purposes, including plastic and battery manufacturing, smelting, pigment production, metal-plating, but also in the production of tobacco, suggesting that a wide range of workers are at risk of exposure    . Cadmium poisoning can occur either by inhalation or ingestion and in both settings, poisoning may be acute or chronic, depending on the amount of cadmium introduced into the body and the rate of exposure     :
The diagnosis of cadmium poisoning must be made promptly, especially if the overall condition of the patient suggests acute poisoning. A detailed patient history is vital in order to determine the potential source of symptoms - whether the patient was exposed to cadmium in the industrial setting (in the case of respiratory symptoms), or if "suspicious" food was eaten prior to the onset of complaints. After a thorough clinical examination to assess breathing, cardiac function and vital signs, an immediate laboratory workup comprised of serum electrolytes, renal function tests (blood urea nitrogen and creatinine), a complete blood count (CBC) and liver enzymes (alanine and aspartate aminotransferases, or ALT and AST, respectively) must be performed  . If poisoning through inhalation is suspected, a chest X-ray, arterial blood gas (ABG) measurements, and oxygen saturation are also necessary. Regardless of the mode of exposure or severity of symptoms, cadmium can be detected in both serum and urine, and levels of > 5 μg/dL in serum will be present in the setting of acute poisoning  . In addition to urine testing for cadmium (which will show >100 nmol/L and a markedly increased creatinine), levels of β2-microglobulin in urine will be markedly elevated in this patient population, whereas N-acetyl-α-D-glucosaminidase (NAG) and retinol-binding-protein (RBP) are also excreted in higher amounts in these patients. All three compounds are useful when cadmium is the presumed cause of symptoms, as their increased excretion occurs as a result of impaired proximal tubule reabsorption   .