Endometriosis and Dioxin Effect
By T. Sadar
Scientists from the University of Wisconsin, Madison, analyzed the prevalence of endometriosis in rhesus monkeys that were chronically exposed to dioxins during a period of about 4 years. 20 animals, divided into 3 groups were followed!
The first group of monkeys was not exposed to dioxins, the second group was exposed to dioxins at a concentration of 5 ppt (parts per trillion), and the third group to the concentration of 25 ppt. Ten years after the exposure to dioxins, scientists tested monkeys for the presence of endometriosis.
In these ten years, three monkeys died, and the autopsy showed, in all three, cases of very widespread endometriosis. All three animals were found dead because of dioxin exposure.
Of the 17 surviving monkeys who were undergoing laparoscopy, in six animals there was no signs of dioxins. In these six monkeys scientists did not found a single case of moderate or severe endometriosis, four animals were completely healthy, two monkeys showed signs of mild endometriosis. The incidence of the disease in the control group was 33%, which corresponds to the overall prevalence of endometriosis (30%) in 304 rhesus monkeys that were not exposed to dioxin.
In the group of animals (7 monkeys) that were exposed to 5 ppt dioxin, medium to severe degree of endometriosis was documented in three of seven animals (43%), and mild endometriosis in one animal.
In the group of animals (7 monkeys) that were exposed to 25 ppt of dioxin in five of seven monkeys (71%) was found moderate or severe degree of endometriosis and in one animal mild degree of endometriosis. Only one monkey from a group of 7 had signs of endometriosis.
The results of this study show a direct effect of chronic exposure to dioxin to the incidence of endometriosis in rhesus monkeys. Disease severity was estimated with standard scoring shows a positive correlation with the daily and cumulative doses of dioxin.