As scientific research on endocrine disruption has advanced, the scope of the research has broadened significantly. The list of hormonally active compounds is longer than anyone had previously imagined in the early days of the research. Not only are more compounds involved, but more hormone systems are now known to be vulnerable. And within each hormonal system, new mechanisms of interaction between compounds and receptor systems are being explored to understand how a compound exerts its effects. Accidental discoveries and systematic testing have revealed a broader array of modern use compounds capable of interfering with the sex steroids hormones.
New results come in regularly, identifying yet another hormonally-active compound.
Bisphenol-A, the basic building block of polycarbonate plastic, not only enters our lives in every objects made from polycarbonate, for example clear plastic baby bottles, it also enters children's mouths when their teeth are coated with polycarbonate to prevent cavities. And, like nonylphenol, bisphenol-A is used as a surfactant in pesticides. The ubiquity of exposure is breathtaking . Concern began to turn to phthalates in the late 1990s after studies showed their potency as a reproductive toxicant during crucial windows a development. The first issues raised were about their use as additives to PVC plastics that make them flexible, and thus useful in children's toys and medical devices, among many uses.