chemical u use like detergent etc. gas, coal and other energies. furniture and housing deforesting killing our supply and the animals that support nature. most chemical companies u use dump chemicals in water sources and get away with it for years with the epa. basically the reason why we dont lower our source on pollutions is greed we bribe the senators and the presidents to get more money from the consumer and the companies say its their freedom or its unamerican to stop them from getting wealthy.