Perfluorooctanoic Acid (PFOA) persists in the environment and does not break down. It is toxic and carcinogenic to animals. In vivo studies have found that exposure to PFOA increases the risk of certain tumours of the liver, testes, mammary gland (breast) and pancreas. The substance is irritating to the eyes, skin and respiratory tract. May be carcinogenic to humans. May cause toxicity to human reproduction or development. PFOA has been detected in the blood of more than 98% of the general U.S. population at levels in the low and parts per billion range, with higher levels in chemical plant employees and surrounding subpopulations. Exposure has been associated with elevated cholesterol and uric acid levels, and elevated serum PFOA levels have recently been found to be associated with an increased risk of chronic kidney disease in the general U.S. population, consistent with earlier animal studies.