Showing posts with label Endocrine disruption. Show all posts
Showing posts with label Endocrine disruption. Show all posts

Thursday, November 17, 2011

Estrogen and Progesterone in Waterways

In the last post, I was speculating about how estrogens from effluent might end up in way water ways and end up increasing the incidence of prostate cancer. I wondered if the problem (if it there is anything more than a chance association) might be progesterone from birth control pills rather than estrogen. Progesterone is markedly non-soluble in water so it seemed unlikely at first thought. Poking around a little, progesterone might end up in sewage effluent after all. The three studies below report on fecal and/or urinary progesterone, conjugated progesterone or "progesterone metabolites" in animals. So . . . maybe progesterone contamination of water might be relevant. And, not all sewage is filtered and treated. I recently watched someone emptying a truckload of portapotties into one of our local creeks. (Yes, I called the police, who told me it was not their problem.) Don't know if anyone has looked at this or not. If you know, please have at it in comments.
deCatanzaro D, Muir C, Beaton EA, & Jetha M (2004). Non-invasive repeated measurement of urinary progesterone, 17beta-estradiol, and testosterone in developing, cycling, pregnant, and postpartum female mice. Steroids, 69 (10), 687-96 PMID: 15465115Kinoshita K, Inada S, Seki K, Sasaki A, Hama N, & Kusunoki H (2011). Long-term monitoring of fecal steroid hormones in female snow leopards (Panthera uncia) during pregnancy or pseudopregnancy. PloS one, 6 (5) PMID: 21559303Brown JL, Wasser SK, Wildt DE, & Graham LH (1994). Comparative aspects of steroid hormone metabolism and ovarian activity in felids, measured noninvasively in feces. Biology of reproduction, 51 (4), 776-86 PMID: 7819459google-site-verification: googleaa234ad89e44d776.html

Wednesday, November 16, 2011

Response to a friend on significance of Triclosan in drinking water

Sorry Friend. That was a poor response to your question about the significance of Triclosan following news of the chemical as an androgen blocker in water.




Triclosan is a thyroid disruptor and according to recent reports, an androgen blocker. As an anti-androgen, exposure could be important to male fetuses, since it could potentially interfere with development of the genito-urinary system, which could mean birth defects like hypospadias, small phallus, or non-obvious problems like changes in numbers and proportions of cells that would, later in life, produce sperm and testosterone. Thyoid inhibition has its own effects on development of the male reproductive system as well. So there might be some interesting interactive effects if both thyroid hormones and androgens are impacted. If that would occur you'd see reduced fertility. In an adult lowered testosterone would lead to other problems.

Blocking androgens, on the upside, might lead to less prostate cancer. It would be interesting to see if Dial Soap or other triclosan-containing products use this as a marketing point. "protects against body odor, gingivitis AND prostate cancer" Let's guess not.

Lastly, there was also an article out recently that associates rates of prostate cancer with presumed levels of estrogen (presumably from urine from women on birth control) in water supplies (Margel & Fleshner 2011). This was unexpected to me, until I thought about the pathway through which testosterone is produced. Testosterone can be synthesized from Progesterone, which is also present in birth control pills. So, it may be the progesterone, rather than estrogen, that is causing the problem. Progesterone is not water soluble, so its unlikely to be found in water systems unless conjugated to something else or incorporated in something else, so this is just speculation on my part.

Back to Triclosan. You can find some basic information on what kinds of products contain Triclosan at the Environmental Working Group Website. Its dated 2008, but the basic information may be useful.

For all of this, note that, for Triclosan, the picture is far from clear, as recent papers also report Triclosan enhancing androgenic activity in vitro (Christen et al. 2010) and as having estrogenic activity (Jung et al. 2011). Neither of those qualities is desirable in an environmental contaminant.
Best wishes,

Margel, D., & Fleshner, N. (2011). Oral contraceptive use is associated with prostate cancer: an ecological study BMJ Open, 1 (2) DOI: 10.1136/bmjopen-2011-000311

Christen V, Crettaz P, Oberli-Schrämmli A, & Fent K (2010). Some flame retardants and the antimicrobials triclosan and triclocarban enhance the androgenic activity in vitro. Chemosphere, 81 (10), 1245-52 PMID: 20943248

Jung EM, An BS, Choi KC, & Jeung EB (2011). Potential estrogenic activity of triclosan in the uterus of immature rats and rat pituitary GH3 cells. Toxicology letters PMID: 22062131

Rostkowski, P., Horwood, J., Shears, J., Lange, A., Oladapo, F., Besselink, H., Tyler, C., & Hill, E. (2011). Bioassay- directed identification of novel antiandrogenic compounds in bile of fish exposed to wastewater effluents. Environmental Science & Technology DOI: 10.1021/es202966c