Endocrine disruptors and human health - Is there a problem? An update

It has been hypothesized that environmental exposure to synthetic estrogeni c chemicals and related endocrine-active compounds may be responsible for a global decrease in sperm counts, decreased male reproductive capacity, and breast cancer in women. Results of recent studies show that there are larg e demographic variations in sperm counts within countries or regions, and a nalyses of North American data show that sperm counts have not decreased ov er the last 60 years. Analyses of records for hypospadias and cryptorchidis m also show demographic differences in these disorders before 1985; however , since 1985 rates of hypospadias have not changed and cryptorchidism has a ctually declined. Temporal changes in sex ratios and fertility are minimal, whereas testicular cancer is increasing in most countries; however, in Sca ndinavia, the difference between high (Denmark) and low (Finland) incidence areas are not well understood and are unlikely to be correlated with diffe rences in exposure to synthetic industrial chemicals. Results from studies on organochlorine contaminants (DDE/PCB) show that levels were not signific antly different in breast cancer patients versus controls. Thus, many of th e male and female reproductive tract problems linked to the endocrine-disru ptor hypothesis have not increased and are not correlated with synthetic in dustrial contaminants. This does not exclude an endocrine-etiology for some adverse environmental effects or human problems associated with high expos ures to some chemicals.