These materials are known to, or supsected of, causing health problems in people in animals. These problems include: damage to the brain and nervous system; behavioral problems; damage to kidneys and other organs; anemia; pregnancy risks; reproductive problems; increased potential for allergies; damage to the liver, and are, or suspected to be, carcinogenic. These materials can enter the system through water or air. For these reasons, some local and national governments and eco-labeling programs have limited and banned these materials.