#Toxins: Toxic chemicals are used in industry, agriculture, laboratories, hospitals, waste management systems and even residential homes, and include chlorofluorocarbons, heavy metals, pesticides, herbicides, toxic waste, PCB, DDT, bioaccumulation, endocrine disruptors, asbestos. These can also arise from poorly implemented hazardous waste management. These can be solid, liquid or gaseous and can pollute air, water and soil. When they enter the food-chain, they pose a health risk especially for children and elderly people according to National Geographic.