I know a lot of people on here are from London/the UK in general. So perhaps you might want to know that a new study has further linked both estrogenic and anti-androgenic chemicals to declining male fertility in fish in UK rivers.

When it comes to affecting male fertility, there are two major types of compounds that might have strong, negative impacts: estrogenics and anti-androgenics. Estrogenics, as the name implies, are pseudo-estrogens or estrogens, and tend to feminize males of a species. They are sought to derive from human sources like birth control pills. While they have not been shown to have as profound an effect on human males, they are generally considered responsible for most wildlife reproductive changes. In contrast, anti-androgenics, which change male reproduction by directly blocking testosterone, have been strongly linked to affects in humans, but have been less linked to natural outbreaks and effects. These include the less regulated bisphenols and phthalates (found in plastics, for example).

This study, published in Environmental Health Perspectives, sought to look at both compound types and their effects on male fish in UK river systems. Because anti-androgens are less linked to wildlife problems, they are generally considered to be at low enough levels not to bother humans. Therefore, if anti-androgens were found to have profound effects on fish, it would mean that the river systems in the UK are chock full of emasculating compounds at levels which are probably high enough to worry people, too.

And, of course, they did. Many areas had a hodgepodge of compounds, whose combined effects were synergistic. These effects included oocytes in the fish’ testes, increased levels of feminine hormones, and intersex fish. The combination of compounds far more accurately predicted feminization than each group alone, meaning that there are fewer differences between the reproductive disruption in fish and humans as previously thought.

What this means for you British boys is that your water ain’t as safe as you might think. Of course, the UK is hardly unique in their levels of these compounds – they’re just the most recently tested. And some of these compounds, like those used in plastics, aren’t well regulated – though studies like this will hopefully start to change that. In the mean time, I suggest thinking a bit more carefully before microwaving food in plastic tubs and drinking any ’ole water…

Susan Jobling, Robert W. Burn, Karen Thorpe, Richard Williams, Charles Tyler (2009). Statistical Modelling Suggests That Anti-Androgens in Wastewater Treatment Works Effluents are Contributing Causes of Widespread Sexual Disruption in Fish Living in English Rivers Environmental Health Perspectives DOI: 10.1289/ehp.0800197