Wildlife Health and Populations
Environmental Estrogens in Minnesota
The Effect of Environmental Estrogens on Mens Health
Some of the first adverse human health effects postulated to be connected to environmental estrogen exposure were disorders of the male reproductive tract. Nearly simultaneous reports of falling sperm counts, increased testicular cancers, and increased birth defects of the male genitalia suggested to scientists that all three conditions were caused by exposure to excess estrogen. A likely source of these exposures was environmental estrogen. Unfortunately, it has proven difficult definitively prove this hypothesis, as dangerous estrogen exposures can be very small (and thus hard to detect) and effects of exposure are not manifest for years (or sometimes decades) after exposure. Using animal models, DES babies (children exposed to large doses of environmental estrogen in utero as their mothers were given DES to prevent miscarriage), and new techniques to measure small amounts of estrogens in blood, scientists have undertaken many studies to try to understand the effect of exposures to environmental estrogens (both in utero and after birth) on the reproductive health of men.
Here are concise results of some recent studies in the area of environmental estrogens and mens health. Click on the link to get more information.
- Environmental Estrogens and E.D.-- Adaikan PG and Srilatha B. reported in 2003 that when estrogen was administered to mature male rats, they began to suffer erectile dysfunction. This study suggests that exposure to environmental estrogens could cause impotence in mature men. Adaikan PG, Srilatha B. Oestrogen-mediated hormonal imbalance precipitates erectile dysfunction. Int J Impot Res. 2003 Feb;15(1):38-43.
- Environmental Estrogens and male fertility A research group reported in 2002 that PCBs were found in the semen of infertile men, but not in the semen of fertile men. Also, the concentration of phthalate esters was much higher in infertile men than in fertile men. The authors hypothesized that PCB and OE exposure may have come, from some extent, to fish consumption. This report suggests that some male infertility is due to exposure to environmental estrogens after birth. Rozati R, Reddy PP, Reddanna P, Mujtaba R. Role of environmental estrogens in the deterioration of male factor fertility. Fertil Steril. 2002 Dec;78(6):1187-94.
- Environmental Estrogens and Prostate Cancer A research group found in 2003 that men with prostate cancer had increased levels of PCB in their blood, compared to men without prostate cancer. This result suggests that environmental estrogen exposure after birth can lead to prostate cancer. Ritchie JM, Vial SL, Fuortes LJ, Guo H, Reedy VE, Smith EM. Organochlorines and risk of prostate cancer. J Occup Environ Med. 2003 Jul;45(7):692-702.
- Environmental Estrogens and Testicular Cancer, Defects of the Male Reproductive Tract and Related Infertility -- Increasingly, testicular cancer, cryptorchidism and hypospadias (birth defects involving undescended testicles and malformation of the penis), and some types of infertility are being grouped together into one syndrome called testicular dysgenesis syndrome (or TDS). A great deal of evidence has been collected suggesting that this disorder has been increasing in the past 50 years. In addition, evidence from rat and mouse models shows that exposure to environmental estrogens in utero, causes TDS-like syndromes in both animals. Taken together, these studies implicate environmental estrogens in the etiology of TDS. In 2003, Sharpe RM published a paper summarizing the results of many studies on TDS and estrogen. Sharpe RM. The 'oestrogen hypothesis'- where do we stand now? Int J Androl. 2003 Feb;26(1):2-15.