Ladies, stop taking the pill!

Ethinyl Estradiol 2 (EE2) is a synthetic hormone, that is a bioactive oestrogen, used commonly in medication (the contraceptive pill for example), as well as livestock (to improve the productivity). EE2 is also used in aquaculture, to farm single-sex populations of fish.

A conceptual diagram of how EE2 enters the acquatic system through various sources

It is of growing concern to the environment because of its ability to be absorbed into organic matter, concentrate in biota, and accumulate in sediments. They enter the environment generally through wastewater systems, and by manure.
I mentioned how EE2 can be used in aquatic systems, to control the growth and population of farmed species. The problem with this, is there's a lot of 'waste' that spills into surrounding areas of water. Approximately 70% of the chemical 'spills' out due to over feeding of fish; this also triggers areas around the world where EE2 is more commonly found in the water. This translates to local freshwater being contaminated, a problem because humans drink this water- it has been found but not confirmed that the chemical can cause a decrease in fertility, and may cause cancer.

Many past studies concluded that these EE2 hormones can be highly toxic to exposed aquatic species. These are some of the effects:
-An increase of plasma vitellogenin (a gene) in male and female fish
-An increase of intersex fish
-A decrease in egg and sperm production
-A reduction in gamete quality
-Male fish changing sex
-Reduced fertility
It also has the ability to change the behaviour of a species. Reyhanian et al. (2011) proved that EE2 affected the shoaling behavior in adult male zebra fish. Those that were exposed to higher concentrations had a greater reduction in swimming activity, and spent a lot of time near the surface, compared to fish exposed to much smaller doses.
Amphibians and mammals have also been proven to be affected by EE2. The Northern leopard frog was seen to have altered sex ratios of tadpoles, with a dominance of females. The metamorphism process was also delayed by up to two weeks. Controlled experiments on mice led to the conclusion of a retardation in their growth.

EE2 has the ability to be absorbed into organic matter, so there are often higher concentrations of the hormone found at the bottom of water systems, in the sediments. They can actually encourage the EE2 to settle due to the hydrophobic properties of the sediments, with concentrations being 1000 times higher than levels recorded at the surface of the water. This is problematic, because it also means that the hormone can stay in the environment for a longer period of time, especially if sediments deposit on top, creating beds. Benthic invertebrates are left extremely vulnerable because of this. Labadie and Hill (2007)

So we know that EE2 can be some what problematic to the environment, but it's not that easy to get rid of it. We cannot just ban them, because they have become an important factor in everyday lives. Studies have found that EE2 can be removed from the environment completely, by the use of microbes and bacteria, by the process of biological degradation.  But it's not easy to introduce a bunch of bacteria into water systems without complications- this would be expensive, and we do not know what the long term effects are. Filter systems can be put in place in sewage systems, but this too is costly, not to mention the amount of energy that would be used to do so. I think it's important to study the sediments of water basins; if they hold much higher concentrations of EE2, finding a way to clean them may help reduce the amount of EE2 dramatically.