All of these are consistent with chronic cadmium toxicity. The patient is also a smoker. Chronic cadmium exposure primarily affects the kidneys and skeleton. Renal dysfunction in this patient is indicated by the laboratory findings. The stooped posture, waddling gait, lumbar pain, and pain induced by spinal percussion are the result of skeletal changes and deformities.
Most of your questions will probably center on the patient’s hobby, as this is the greatest potential source of cadmium exposure. Typical questions would include the following:
What types of materials and metals are used in making jewelry? What are the ingredients of all composite products?
On a weekly basis, how many hours are spent fabricating jewelry in the basement?
What type of face shield is used? Why is respiratory protection not used during grinding and soldering operations?
Is the work area kept clean and free of dust? How?
Does she wash her hands before eating in the work area and are attempts made to keep food and cigarettes from becoming contaminated by dust and particulates?
Does she shower and change her clothes before leaving the work area?
It is also important to investigate smoking habits.
The most useful diagnostic test for cadmium exposure is a 24-hour urinary cadmium excretion standardized for creatinine: ß2-microglobulin levels, in conjunction with cadmium excretion, will aid in evaluating subclinical renal dysfunction. The following tests also may be helpful in evaluating the patient: urinary protein and glucose, LDH, SGPT or ALT, and SGOT or AST. A chest X ray and pulmonary function test should be obtained if cadmium inhalation is a factor.
The patient is experiencing renal dysfunction, as evidenced by the 3+ level of proteinuria and glycosuria. When proximal tubular damage occurs, cadmium excretion can result from two sources; breakdown of the tubular epithelium and decreased reabsorption. Under these conditions, urinary cadmium levels are likely to be markedly increased and no longer reflect body burden. Exposed workers can excrete several hundred micrograms of cadmium per gram of creatinine; urinary cadmium levels in an unexposed population are typically between 1 and 10 µg cadmium/g creatinine. The patient therefore would be expected to have a urinary cadmium level of several hundred micrograms of cadmium per gram of creatinine, depending on her most recent exposure.
There is no effective treatment for cadmium toxicity; chelation therapy has no role in cadmium poisoning. Removal from the source of exposure and patient education to significantly reduce exposure are important, particularly before the condition has progressed to irreversible renal dysfunction. Supportive measures to alleviate symptoms should be provided.
The neighbors should be evaluated and educated. Even if they do not use the fertilizer from the wastewater treatment plant or water from the same irrigation source, runoff from the patient’s land may contaminate their soil or well water. Consultation with the local or state health department is advisable if a potential public health hazard exists.