It takes about 250 years for one plastic cup to decompose in a landfill.
Is this supposed to imply a linear relationship? If it takes one plastic cup 250 years to decompose, does it take 100 plastic cups 25,000 years to decompose? Um, I think not (unless there's something I'm missing about the rate of decomposition for large quantities of plastic). This is sensational writing. It would be just as clear and not at all biased to say something like, "The plastic in plastic cups takes 250 years to decompose in a landfill."