The most common occupational exposure to mercury is through:

Inhalation is the most common route of occupational exposure to mercury, particularly in industries that utilize or process mercury. This is primarily due to the fact that mercury is often present in vapor form at room temperature. When mercury is heated or during certain industrial processes, mercury vapor can be released and easily inhaled by workers, leading to respiratory exposure.

This exposure through inhalation can result in significant health risks, as elemental mercury can be absorbed through the lungs and enter the bloodstream, potentially affecting the nervous system and other organs. In environments such as dental offices, chlor-alkali plants, and some mining operations, employees are at a higher risk of inhaling mercury vapors as a result of their work activities.

The other routes of exposure, such as absorption, ingestion, or inoculation, while possible, do not occur as frequently in occupational settings involving mercury. Absorption of mercury through the skin is less common, and ingestion typically involves accidents or improper handling rather than a typical occupational exposure. Inoculation might occur in very specific industrial contexts but is not a primary concern in relation to mercury exposure. Therefore, inhalation stands out as the most prevalent method of exposure in occupational scenarios.