Introduction

There are three clinical scenarios that can face the physician dealing with a patient with excessive cadmium exposures.

• The complex picture of the respiratory injuries that inhalation of cadmium fumes can cause.
• The insidious development of cadmium-related renal disease and the secondary effects on bone that can accompany excessive chronic cadmium exposure.
• Increased risk of certain cancers due to chronically heavy cadmium exposures.

History and Presentation - Acute High-Dose Exposure

Acute inhalation

The history taken after acute cadmium inhalation usually involves signs and symptoms in the respiratory system. The first symptom, often throat irritation, may not be sufficient to cause exposed workers and others to leave the contaminated area.

More striking signs and symptoms, which may be delayed by four to ten hours include

• pleuritic chest pain,
• dyspnea,
• cyanosis,
• fever,
• tachycardia, and
• nausea.

Depending on the extent of exposure, sustained fever and noncardiac pulmonary edema may develop. Death has occurred in 20% of cases with pulmonary edema (Newman-Taylor 1998). Inhalation exposure can also result in acute hepatic and renal injury.

Acute oral

In the past, acute cadmium intoxication occurred after oral ingestion of acidic foods or beverages sstored in cadmium-plated containers, with symptoms of:

• abdominal cramps,
• diarrhea,
• salivation,
• severe nausea, and
• vomiting.

In humans, single lethal oral doses of soluble cadmium salts have ranged from 30-40 mg. (ATSDR, 1999; Drebler, 2002)

Physical Examination of the Acutely Exposed Patient

The physical examination of the patient acutely exposed via inhalation to cadmium should emphasize respiratory signs of acute respiratory injury such as cough and the development of crackles indicating the serious complication of pulmonary edema. In cases of oral ingestion, the status of the gastrointestinal tract as well as the hepatic and renal systems should be monitored.

Approach to the Chronically Exposed Patient

Adverse effects of excessive chronic cadmium exposure may include

• chronic obstructive pulmonary disease (inhalation only),
• chronic renal failure,
• kidney stones,
• liver damage (rare),
• lung cancer,
• osteomalacia,
• possibly hypertension,
• prostatic cancer, and
• proteinuria.

Chronic cadmium exposure has been reported to cause mild anemia, anosmia, and yellowing of teeth.

Exposure History for the Chronically Exposed

Detailed questioning about occupations and hobbies is the key to including chronic cadmium poisoning in the differential diagnosis.

Subjects for some of these questions include

• industrial hygiene,
• use of personal protective equipment including respirators or face shields, and
• eating or drinking in the work place or in hobby areas where exposure to cadmium could occur.

The history should also cover tobacco smoking as well as the use of nephrotoxic medications. The review of systems should pay special attention to the renal, cardiovascular, musculoskeletal and respiratory systems as well as eliciting any reproductive concerns (Lewis, 1997). For more information on taking a detailed environmental exposure history, please see ATSDR's Case Study on Environmental Medicine Taking an Exposure History ( www.atsdr.cdc.gov/csem/csem.asp?csem=17&po=0).

In the general population, ingestion of cadmium-contaminated food is more likely to occur than inhalation of cadmium particles. Today, acute cadmium ingestion is unlikely to be a clinically significant source of exposure in North America. Chronic ingestion, however, is still possible in certain populations, such as children with pica who ingest contaminated soil.

Physical Examination for the Chronically Exposed

Low-level exposure among the general population produces few early physical findings on examination. Among those occupationally exposed or exposed to high levels in the environment, examination of the respiratory, musculoskeletal and genitourinary systems is indicated (Lewis 1997).

Progress Check