This is how long it takes for things to decompose if just out there as litter~ it will never ever break down in a landfill as dirty is put over the trash which does not let any sunlight it to do it's job of breaking things down but the dirty ends up mummifying it! I got this from Keesta.com

Here’s how long it takes for commonly used products to biodegrade, when they are scattered as litter:

cotton rags 1-5 months

paper 2-5 months

rope 3-14 months

orange peels 6 months

wool socks 1 to 5 years

cigarette butts 1 to 12 years

plastic coated paper milk cartons 5 years

leather shoes 25 to 40 years

nylon fabric 30 to 40 years

tin cans 50 to 100 years

aluminum cans 80 to 100 years 

plastic 6-pack shower holder rings 450 years

glass bottles 1 million years

plastic bottles forever