History of Chromium in Drinking Water
Chromium bears Atomic number 24 on the Periodic Table of Elements and is described as a hard brittle gray transition metal. It was discovered by Nicholas Louis Vauquelin in Paris, France in 1797. Chromium is used to make stainless steel. Hexavalent chromium is used for the production of stainless steel, textile dyes, wood preservation, leather tanning, and as anti-corrosion and conversion coatings as well as a variety of niche uses. It is also used in plating for car parts, tools, knives, camouflage paint, stereos, video tapes and lasers. Chromium also gives rubies and emeralds their color. For such a useful metal, it has come to be known as a very carcinogenic material to humans.We are most familiar with Chromium in the hexavalent form. However, Chromium occurs in many forms including Hexavalent Chromium, Trivalent Chromium which is not carcenogenic, pentavalent chromium, chromium trioxide, and various salts of chromate and dichromate. Soluble compounds, like chromic acid, are much weaker carcinogens. The forms vary in levels of dangers to humans with hexavalent chromium leading the way because it is able to enter cells unlike other forms of chromium.
People involved in the production of any of the above products become exposed to Chromium from inhalation, ingestion, or from skin and/or eye contact. Prolonged and repeated exposure can cause lung cancer and when ingested, Chromium can cause stomach cancer and gastrointestinal tumors.
Chromium 6 (hexavalent chromium) was made famous by the movie Erin Brockovich that portrays the real life story of a file clerk in a law office who uncovers a conspiracy by Pacific Gas and Electric (PG&E) to cover up the industrial poisoning of the water of the town of Hinkley, CA.
