Bisphenol A, or BPA, as its close friends call it, is a chemical used to create plastics. It's included in a ton of great stuff—water bottles, tooth fillings, sports equipment—because it's cheap and shatterproof. It also kills sperm.
A new report by Kaiser Permanente only scares us shitless about BPA even more, saying that elevated exposure to the stuff makes men two to four times more likely to have less, worse sperm. And some of the sperm you do have will be dead. All of these things are not qualities you want your sperm to possess, if you are planning on populating the earth anytime soon (or ever). And, just in case you thought you were safe because you're not rolling around on the floor rubbing plastics across your face—everyone involved in the study was within the exposure levels the EPA has deemed safe. Thanks, EPA!