Chromium

Chromium is used worldwide and is an economically very important metal. Many million workers globally are exposed to chromium compounds in chrome plating, welding, dye manufacture and leather processing. Workers in industries that use chromium are at increased risk of chromiums adverse health effects. Exposure is primarily to Cr(VI) via inhalation of aerosols and metal fume. The general population is exposed to chromium by inhaling ambient air, ingesting food, and drinking water containing chromium, typically from nearby waste sites via soluble forms in groundwater and soil. Hexavalent Chromium (Cr(VI) compounds induced DNA damage, gene mutation and chromosomal aberrations in a number of targets Chromium compounds can be sensitizers as well as irritants. When inhaled, chromium compounds are respiratory tract irritants and can cause pulmonary sensitisation. Chronic inhalation of Cr(VI) compounds increases the risk of lung, nasal, and sinus cancer. Severe dermatitis and usually painless skin ulcers can result from contact with Cr(VI) compounds. Cr(VI) is a human carcinogen. Occupational exposure to Cr(VI) compounds in a number of industries has been associated with increased risk of respiratory system cancers and latency for CR(VI) lung cancer can be greater than 20 years.

Some studies indicated that reversible renal tubular damage can occur after low-dose, chronic Cr(VI) exposure. Occupational exposure to Cr(III) does not appear to be associated with renal effects. Cr(VI) compounds can cause mild to severe liver abnormalities. Some Cr(VI) compounds, such as potassium dichromate and chromium trioxide, are caustic and irritating to gastrointestinal mucosal tissue. Oral exposure to Cr(VI) compounds may result in hematological toxicity. Chromate dusts can also produce irritation of the conjunctiva and mucous membranes, nasal ulcers and perforations.Repeated skin contact with chromium dusts can lead to dermatitis. Chromate VI can cause chrome skin ulcers. Contact is occupationally usually the upper extremities especially fingers. The characteristic chrome sore begins as a papule, forming an ulcer with raised hard edges. Ulcers can penetrate deep into soft tissue or become the sites of secondary infection, Lung cancer is the most serious long-term effect . Apart from the carcinogenic potential, prolonged exposure can result in bronchitis, rhinitis, or sinusitis or the formation of nasal mucosal polyps. Besides the lungs and intestinal tract, the liver and kidney are often target organs for chromate toxicity