Fact Sheet: Tannery Operations and Chromium Pollution
Estimated Population at Risk at Identified Sites: 1.8 Million People*
Estimated Global Impact: 2.5 to 4 Million People*
What Is Leather Tanning?
Before leather goods are produced, raw leather hides are tanned to refine the leather and make it durable enough for consumer goods. The tanning process has three general phases: acquisition and pretreatment of raw animal hides; treatment of the hides with a tanning agent; and drying and shining the hides before sending them to product manufacturers. Although tanning is a global industry, waste management processes vary considerably between regions.
How Is Chromium Used during Tanning Operations?
Chromium compounds are applied to hides to make them more durable against moisture and aging. 1 Chromium interacts with fibers in the raw hide during a bathing process, after which the tanned hides are wrung and prepared for finishing. 2
What Are the Human Exposure Pathways for Chromium from Tanning Operations?
Wastewater and solid waste from tanning operations are often improperly discarded, allowing chromium to contaminate local soil, surface water, and groundwater. Humans are typically exposed through ingestion of drinking water and agricultural products.
What Are the Health Risks Associated with Chromium Exposure?
Chromium commonly occurs in two forms. Trivalent chromium (chromium III) occurs naturally and is not dangerous in low concentrations. Hexavalent chromium (chromium VI) is usually created by people and is a human carcinogen. Inhalation of chromium VI can cause cancer of the respiratory system, eye damage, ulcerations, asthmatic bronchitis, and irritation to the throat and nose. Chronic exposure can cause sores in the nose and can lead to holes in the nasal septum. 3 Ingestion of chromium can cause stomach ulcers, and can damage kidney and liver functions. Dermal contact with chromium can cause rashes, sores, and ulcers.
*Population estimates are preliminary and based on an ongoing global assessment of polluted sites.
Footnotes
[1]: Leather Tanning.” U.S. Environmental Protection Agency, 1997. Available at http://www.epa.gov/ttnchie1/ap42/ch09/final/c9s15.pdf.
[2]: Ibid.
[3]: Health Effects of Hexavalent Chromium.” OSHA Factsheet. Occupational Safety and Health Administration. U.S. Department of Labor. July 2006.
Available at http://www.osha.gov/OshDoc/data_General_Facts/hexavalent_chromium.pdf.
