Introduction

For the average American, low levels of cadmium exposure occur through diet. Currently, these background exposures through diet are not believed to cause adverse health effects.

However, there are groups within the United States who suffer higher than average exposures to cadmium because of occupation, hobby, or personal habits such as smoking.

Additionally, there are certain regions of the globe, such as Japan, which are contaminated with high levels of cadmium in the environment. Because local food crops, such as rice, pick up high levels of cadmium, local people are exposed to cadmium through their diet.

Direct Occupational Exposure

In the United States in the 1990s, approximately 297,000 workers were estimated to be at greatest risk of cadmium exposure (NIOSH, 1990). There are no more recent estimates. The types of workers potentially exposed include

• alloy makers,
• aluminum solder makers,
• ammunition makers,
• auto mechanics,
• battery makers,
• bearing makers,
• braziers and solderers,
• cable and trolley wire makers,
• cadmium alloy and cadmium-plate welders,
• cadmium platers,
• cadmium vapor lamp makers,
• ceramic and pottery makers,
• copper-cadmium alloy makers,
• dental amalgam makers,
• electric instrument makers,
• electrical condenser makers,
• electroplaters,
• engravers,
• glass makers,
• incandescent lamp makers,
• jewelers,
• lithographers,
• lithopane makers,
• metal sculptors,
• mining and refinery workers,
• municipal solid waste recovery workers,
• paint makers,
• paint sprayers,
• pesticide makers,
• pharmaceutical workers,
• photoelectric cell makers,
• pigment makers,
• plastic products makers,
• smelterers,
• solder makers, and
• textile printers.

Smokers

Effects of cigarettes and smoking on cadmium exposure.

• A cigarette contains approximately 2.0 μg of cadmium, 2-10% of which is transferred to primary cigarette smoke (Mannino et al. 2004).
• Of the cadmium in the primary inhaled cigarette smoke, nearly 50% is absorbed from the lungs into the systemic circulation during active smoking (Satarug et al. 2003; Jarup  2002).
• Smokers typically have cadmium blood and body burdens more than double those of nonsmokers (Waalkes et al. 2003).
• Clinicians should be aware that smokers have a higher urinary cadmium levels than nonsmokers (Mannino et al. 2004).

Background Exposures

Background levels of cadmium in food, water, and ambient air are not a health concern for the general North American population. Typical dietary intake is about 30 micrograms per day (μg/day), (Satarug et al. 2003) but normal individuals absorb only a small proportion of an orally ingested dose (1-10%) (Horiguchi et al. 2004).

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