In 2014 the Journal “Endocrinology” published a paper on fracking and so called “gender benders”. In a really very nice piece of research they took water samples from both fracking and reference sites outside the fracking area. They then tested the water for endocrine disrupting chemicals (“gender benders”). To explain the science. The authors looked for chemicals found in the water samples and which exhibited androgenic, anti-androgenic, estrogenic or anti-estogenic properties. A n androgen is a chemical (usually a steroid) that promotes male characteristics in vertebrates. Estrogens have the same function in women (and a lot of other biological functions in both sexes). Confusingly men have low concentrations of estrogens and women androgens. The best known and strongest estrogen is 17β-estradiol and the best known androgen is testosterone, although there are a variety of other closely related steroids with lower biological effects.
There have been concerns about “gender benders” for years. These concerns fall into two areas. The first source of concern is steroids such as progesterone and estradiol and their analogues entering water supplies from oral contraceptives. Basically women urinate them out. They are at low concentration and are relatively resistant to breakdown by bacteria. The second worry is that of is chemicals added to plastics (such as pthalate esters) to give them specific properties such a hardness, malleability etc. Of course we now know plastic is now widely distributed in the environment as micro particles. Again these chemicals are at low concentration and relatively resistant to biological breakdown. In principle both sources are easy to deal with in drinking water by the use of activated charcoal. This binds all organic matter in the water. This is an expensive solution however and not all water companies have done so for example in the UK.
Its easy to see why having the female contraceptive pill in drinking water may not be a good idea but what about the other “gender benders”? Hormones bind to and activate specific proteins. Protein binding takes place by specific 3D arrangement of molecules that bind to binding sites on the protein. Surprisingly the gender benders can mimic the hormone molecules’ 3D shape even though their overall structure is often totally different from a steroid. The presence of all these chemicals even at a tiny concentration can unbalance certain parts of our metabolism. Nothing is proven but there is evidence that reproductive problems such as rising levels of infertility, cancers such as testicular cancer and other reproductive cancers could be linked to these chemicals.
It seems that a variety of such “gender benders” are being used in the fracking process. What the authors did was sample water from inside and outside the fracking areas in Colorado. They extracted the fairly insoluble “gender benders” into an organic phase (methanol) dried and concentrated them. These concentrated stocks were then diluted to make a final experimental concentration of 4x or 40x the concentration they were sampled at. Human cell lines were genetically modified to express the main androgen and estrogen receptor genes linked to a gene from fireflies. Adding samples or androgen/estrogen controls of known amounts led the chemicals to bind to the genes of interest and make the firefly genes fluoresce, allowing a comparison between the natural and mimicking chemicals. This fluorescence was then measured and gave a measure of the androgenic, anti-androgenic, estrogenic or anti-estrogenic properties of the chemicals. In addition chemicals known to be used in fracking were also tried using this biological assay method.
Antiestrogenic, antiandrogenic, and strong estrogenic effects were found in the chemicals and waters tested. Most of the sites tested had at least some biological effects and effects were were found in two separate river samples. What does this mean? Obviously the levels tested were concentrated compared to the original samples but this discrepancy would be overcome by constant low exposure and low exposure does seem to be an issue. Another objection is that people are not directly drinking the water. In the rural US many people are not on mains water. More worrying is that the effects were found in river water. This will supply cities downstream and without proper treatment these chemicals will be entering the water supply. What is surprising is that when you look the chemical structures of some of the chemicals used in this study online their structures are nothing like steroids. Is this an argument against all fracking? No not in of itself, but it does add to the other arguments and begs the question with gender benders being a considerable problem already do we want to add to it?
Original paper can be seen here.