The Endometriosis Association has it down pretty darn pat in Toxic Link to Endo:
As explained in books including Our Stolen Future, Dying from Dioxin, and "The Endometriosis Sourcebook", scientists have come to the realization that certain chemical compounds, such as dioxin, have profound immunological and reproductive impacts at exposures far below the level known to cause cancer. These chemicals are known as endocrine disruptors and can mimic hormones and interfere with many physiological processes. Scientists are still researching the mechanisms that are used, but they already know that these man-made chemicals persist in the body for years. PCBs (polychlorinated biphenyls) are a group of dioxin-like chemicals that were used in industry until they were banned in the 1970s. Some PCBs persist in the environment for more than one hundred years.
I expect that one day everything that's wrong with me that's not strictly due to the aging process will be proven to have been caused by some type of environmental pollution. The Fibromyalgia connection is couched in terms of science fiction for now,
but that will change. All in good time. Or bad time, from my perspective.