Feminized Fish – Hormonal Disruption as a Development Issue

Some time in the 1990s, I started hearing stories of lesbian gulls and fish turning female. These were, it seemed, apocryphal tales of a world in which all that was masculine was slowly, surely, being transformed. They lingered with me, the stuff of science fiction. But this was not fiction. Fast forward twenty years and there are rivers in Britain in which not a single fish born male retains their sex; and, research by environmental toxicologist Elizabeth Hill and her team at Sussex University reveals, the reason lies in our kitchen cupboards and on our bathroom shelves.

Late capitalism offers us a panoply of chemical cleaning agents that have made their way across the world as transnational corporations have expanded their consumer markets. Brightly packaged products balance nimbly in market places and line supermarket shelves from Brighton to Bujumbura to Bangkok. Their cocktail of chemicals is complemented with the synthetic hormones that find their way into bloodstreams and groundwater courtesy of family planning programmes supported by USAID and other international agencies. The disruptive effects of chemicals commonly found in cleaning products, shampoo and toothpaste and the contraceptive pill is not just a matter for the global north, even if their effects on the bodies and lives of those in the global south remain to be documented.

Back in the UK, Hill’s research began with the finding of high proportions of intersex fish in river sites where there was higher concentrations of sewage. These fish had started their lives as male. But something had happened to their reproductive systems. Amidst the sperm cells were a growing mass of egg cells, squeezing shut their sperm tracts and rendering them unable to produce sperm of good enough quality to reproduce. What was happening? Why were these fish “turning female”? Hill and her team set about investigating what was in our rivers that could be producing such a dramatic effect.

What they found, initially, was chemicals related to female hormone-altering medicines: traces of the main chemical in the combined contraceptive pill, ethinylestradiol, the naturally-occurring hormone estradiol from women’s and men’s urine, and horse oestrogen, the key ingredient in the hormone replacement therapy (HRT) given to menopausal women. This cocktail of oestrogens was part of the story. And it was a story confirmed by colleagues elsewhere in the UK, whose risk map of oestrogens in Britain’s rivers paints a worrying picture: the nearer to a city that we live, the more we might expect our rivers – and our ground water – to carry sufficiently high concentrations of hormones to bring about these changes in fish. It only takes a small leap of the imagination to begin to see the possible connections with worrying falls in human male sperm counts and the steady rise in testicular cancer that has been observed over recent decades.

But, Hill and her team discovered, these oestrogens were only part of the story. Some of the low risk sites, where oestrogens were in relatively low concentration, still had intersex fish. They went back to testing the river water, looking not for chemicals that they knew were there, but to try to find out what else was in the water. This was no easy task. Sewage contains more than 40,000 chemicals.

The story was more complex than they had anticipated. Using a sophisticated test to isolate anti-androgenic compounds – that is, compounds that could act to block the body’s capacity to take up hormones that enable the body to develop and remain at normal levels of functioning as male – they found that there were literally dozens of chemicals in the water that had an anti-androgenic effect. Some of them were extremely powerful: one, a widely used agricultural fungicide present in river water, propiconazole, was found to be 120 times more potent than medication used to achieve similar effects in the treatment of prostate cancer. Experiments explored the effect of the oestrogens and anti-androgens on fish, separately and in combination.

A sample of fish was introduced into water very similar to the dozens of rivers in the UK where levels of sewage are high, and where a mix of synthetic and naturally occurring oestrogens and a range of anti-androgens is present. Most started off male. Not a single fish retained its sex. They all turned female.

What Hill and her team were beginning to show was that it was the combination of oestrogens and anti-androgens that was the problem. By this point, you might be wondering: does the government know about this, and if so, what are they doing? They were not the only scientists to find these effects. Numerous studies have shown the risks to wildlife and humans of hormone-altering chemicals – what are known as “endrocrine disruptors”. Last year, the World Health Organization and the United Nations Environment Programme published a paper calling for more research into the worrying effect of the presence of these chemicals in environmental pollution. And yet the UK government is barely even contemplating EU legislation to remove oestrogens from sewage, let alone addressing the co-presence of what Hill estimates to be almost 100 anti-androgenic compounds.

Where are these compounds coming from? 3.5 million British women currently take the combined contraceptive pill, almost a quarter of the entire female population of reproductive age. HRT is also widely used. But these synthetic oestrogens are, as Hill has shown, only a relatively small part of the problem. It has long been known that certain plastics have an endocrine disrupting effect; worryingly, traces of them can be found in just about everyone’s urine. What about the anti-androgens? Hill and her team isolated a number of highly potent chemicals, and traced them back to products that are used not just in farming, but in homes all over the UK. Triclosan, for example, is commonly found in toothpaste, soap and mouthwash. Micronazole can be found in many a medicine cabinet, in creams used to treat athlete’s foot. Many cosmetics contain chlorophene. And there are many, many others, found in cleaning products, cosmetics and sun creams, as well as in plastics and pesticides.

Fish turning female is one thing, but what is all this doing to humans? What we know about human reproduction is that as the foetus grows, hormones in the womb have a decisive effect on the baby’s sex: if between 8 and 15 weeks, that baby receives sufficient androgenic hormone, it will become male. If there isn’t enough of that hormone, it will become female – or will suffer from the abnormalities of the testes that are increasingly being reported. These abnormalities are strongly linked with testicular cancer in later life, and with impaired male fertility. Since the mid 20th century, sperm counts in this country have been falling by 1-2% a year; 20% of young men in Europe are now affected by low sperm counts, and there’s a high level of abnormal sperm cells. One study, Hill reports, found that some 67% of Danish men have less than 9% of normal sperm cells. Testicular cancer has doubled in the last 25 years in the UK, a shocking increase that hints at an emerging health crisis.

Some EU countries are urging women to take precautions and to avoid or limit exposure to cosmetics and cleaning products if they’re planning to become pregnant and during the first two trimesters of pregnancy. The UK government has done little to make the public aware of these risks, nor to seek to avert them.

It has been environmental scientists, like Elizabeth Hill and her team, who have waded in muddy rivers collecting samples of sewage-laced water and who have developed ever more sensitive tests to determine just what is in it. Their work has found not just endocrine-disrupting chemicals, but also a host of other medications – mood altering drugs, anti-clotting agents, painkillers – with potentially harmful effects on fish and wildlife, as well as on humans. The next time there is a drought in the UK, and river water is pumped into reservoirs, we will be treated to a cocktail of chemicals even more concentrated than the dose we are receiving through the tap.

Time perhaps to press our government to do something about improve the capacity of sewage works to remove these chemicals and make consumers aware of what they’re putting into their bodies and our rivers and ground water – if not for us, for the next generation. And time, too, to put the environmental hazards of the unregulated expansion of transnational corporations peddling these products to ever more remote markets under the spotlight for the hidden costs that this may bring with it.

This piece was written after attending a Professorial Inaugural Lecture given by Dr Elizabeth Hill at Sussex University on May 28, 2013. Watch Dr Hill’s lecture here. All errors of understanding and interpretation are mine alone. 


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