Humans generally accumulate cadmium extremely slowly throughout their lives. Cadmium concentrations are higher among cigarette smokers than nonsmokers, but even tobacco use does not explain this patient's scenario.
Occupational exposures to cadmium occur primarily in certain industries involving soldering, welding, or other processes with cadmium-containing metal products. This patient's occupation as a construction contractor does not easily fit this description, however.
The patient's hobbies, if any, are unknown to us. Even if his hobbies included metal work, it is still unlikely that these activities could have produced cadmium concentrations in the ranges found in this case.
It is possible that one or more of the nutritional supplements could have contributed to the cadmium poisoning. Under federal law, products marketed as dietary supplements are explicitly not regulated by the US Food and Drug Administration. Some dietary supplements have occasionally been the source of poisoning by heavy metals or other toxic substances. However, we have no information that more strongly implicates the dietary supplement, which was not tested for cadmium, so the link remains circumstantial at best. Furthermore, if the patient's death was due only to contaminated dietary supplements, we would expect others to have been sickened also.
The blood and tissue concentrations were extremely high, and the reported symptoms apparently progressed in the week preceding his presentation for care. Both their acuity and severity suggest acute poisoning.
Was the patient the victim of malicious poisoning by someone with access to cadmium? A few milligrams of cadmium or even less than a milligram of a cadmium salt may be enough to produce fatal toxicity.
With the limited available information, the exact manner of the fatal cadmium exposure remains undetermined.
Author Contributions: All authors confirmed they have contributed to the intellectual content of this paper and have met the following 3 requirements: (a) significant contributions to the conception and design, acquisition of data, or analysis and interpretation of data; (b) drafting or revising the article for intellectual content; and (c) final approval of the published article.
Authors' Disclosures or Potential Conflicts of Interest: No authors declared any potential conflicts of interest.
- Received for publication June 28, 2011.
- Accepted for publication July 13, 2011.
- © 2011 The American Association for Clinical Chemistry