The most common source of exposure to cadmium is through:

Cadmium exposure primarily occurs through ingestion, making it the most common source of exposure in the general population. This can happen through the consumption of contaminated food and water, as cadmium can accumulate in soil and crops. For example, agricultural practices using cadmium-containing fertilizers can lead to higher levels of cadmium in food crops, which are then consumed by humans.

While inhalation is a source of exposure, particularly for workers in certain industries such as battery manufacturing, smelting, or welding, it is not as prevalent in the general population. Absorption and inoculation are less relevant in the context of cadmium, as they do not represent typical routes of exposure for the public. Therefore, ingestion is identified as the most common source when considering the broader population and day-to-day exposures.