Mercury Exposure
Mercury exposure in the workplace
Mercury is a metal, and a natural component of the ocean and earth’s crust. It is the only metal that is in the liquid state at room temperature. Although we are all exposed to mercury to some degree, mercury is not essential to any bodily functions. It is desirable to avoid exposure when possible, as it is a protoplasmic poison that is hazardous to all forms of life.
Approximately 70,000 workers are exposed to mercury every year. Recent applications include:
- Use as a germicide and preservative
- Paper pulp production
- Chemical processes such as alkaline-chlorine plants
- The manufacture of medical and scientific instruments
- Vinyl manufacturing
Food (such as fish) serves as the major source of exposure for the general population.
In 1665, mercury had the distinction of being the first substance to give rise to legislation dealing with the occupational disease it caused; the workday in mercury mines in Idria (now Slovenia) was reduced from the 14 hours prevalent at the time to six hours a day.
Mercury and its compounds exist in three general forms:
- Elemental (or metallic): Also known as liquid silver or quicksilver. Exposure to elemental mercury occurs predominantly through inhalation of the vaporized metal.
- Inorganic: Mercury can combine with other elements (mainly chlorine, sulfur and oxygen) to form inorganic mercury compounds. Ingestion is the primary route of toxicity for inorganic mercurial salts.
- Organic: Mercury may combine with carbon or carbon-containing substances to make organic mercury compounds. These organic compounds are further divided between alkyl (carbon-chain) and aryl (aromatic ring) groups. Organic mercurials are used chiefly as preservatives and antiseptics. Methyl, ethyl and phenyl compounds are used as seed dressings to inhibit fungal growth and delay germination. Exposure is primarily dietary.
