Researchers have identified 15 chemicals that may be linked to earlier menopause. Women with the highest levels of these chemicals in their bodies went through menopause anywhere between two and four years earlier than women with the lowest levels, the team at Washington University in St. Louis found. The 15 chemicals most likely to be in either the blood or urine of women who had earlier menopause include pesticides, a batch of now-banned chemicals called PCBs, and two phthalates in a group called DEHPs. Those last two phthalates are used in many common household products, however. They're used to make plastic more flexible and are found in tablecloths, floor tiles, upholstery, shower curtains, garden hoses, swimming pool liners, rainwear, baby pants, dolls, some toys, medical tubing, and blood storage bags.