What is the basic of pollution. Earths outher shell is build up of the most lightest materials from earth. The most heavy materials found on the crust are those from impacts from space. All materials with a higher density then lava are from space or are digged up. Coal, oil, gas and other fossile materials are burned and release heavy gasses which remain at the bottom of the atmosphere sufficating all live that needs propper air. The seas are made of light materials, all heavy materials sink to the bottom to stay there. Plastics and other human made metarials do not belong in this environment and making a tick soup out of it instead of the light biological materials and oxygen for live.

So our main task should be to not use heavy materials on the surface of the earth but to use them only below a certain dept or in high orbit so that it can not fall back to earth. Second we should start to clean up earth and remove all heavy + particles from water, air and ground. Next thing to do would be not to use any atoms created by men wich have a negative impact on earth but to use them only far away from earth in space. I can go on like this for a long time but the most important should come first so that it has a major effect towards a cleaner earth.