Humans depend on nature to dispose of the waste products. Our oceans, rivers, lakes and lands have become the dumping yards for society's industrial and organic waste. Pollutants entering our environment travel through the food web and end up in the tissues of the living things they come into contact with. Large numbers of population overwhelm the Earth's capacities to absorb, transform or break down these materials. Some materials take thousands of years to decay, and many become more toxic as they decompose, resulting in long-term environmental damage.