Sewage changes sexuality of fish

SEX HORMONES in sewage can cause sexual changes in trout and carp, according to government- commissioned research.

It provides the first firm evidence for something scientists have long suspected - that the huge quantities of synthetic hormones used over the past 25 years could be having an effect on life downstream.

The hormones are in the urine and faeces of women who take contraceptive pills. Similar but less potent hormone-like chemicals can also be formed when household and industrial detergents break down.

Scientists are uncertain whether one, or both of the two sources act on fish. Fish share some genetic elements with humans so can absorb the hormones.

The Department of the Environment funded the research after hermaphrodite roach were found next to a large sewage outfall a decade ago. For years the work was kept secret at the insistence of the now privatised water authorities, which met some of the costs.

Scientists at Brunel University in Uxbridge, west London, and at the Ministry of Agriculture's fisheries laboratories put caged carp and trout in rivers next to outfalls from 28 sewage works around Britain. Some or all of the fish died at several of these sites.

At 15, where the fish all survived, male fish and immature females began producing vitellogenin, a protein found in the yolk of fish eggs. It was roughly equivalent to a man beginning to lactate. The studies are continuing, and scientists recently found fish were being affected up to half a mile downstream of outfalls.

The scientists also exposed fish in the laboratory to different concentrations of a synthetic oestrogen hormone used in contraceptive pills, 17 alpha ethynyloestradiol, mixed into the tank water. They found that extraordinarily low concentrations of under one part in a million million affected fish in the same way as the sewage effluent. Even the most advanced chemical analysis techniques cannot detect the hormones at these levels.

The hormones are also likely to be finding their way into drinking water, but at much lower concentrations. Fish exposed to tap water showed no sexual changes.

PROMOTED VIDEO
Have you tried new the Independent Digital Edition apps?
News
ebooksAn unforgettable anthology of contemporary reportage
News
Bourgogne wine maker Laboure-Roi vice president Thibault Garin (L) offers the company's 2013 Beaujolais Nouveau wine to the guest in the wine spa at the Hakone Yunessun spa resort facilities in Hakone town, Kanagawa prefecture, some 100-kilometre west of Tokyo
i100
Voices
Oscar Pistorius is led out of court in Pretoria. Pistorius received a five-year prison sentence for culpable homicide by judge Thokozile Masipais for the killing of his girlfriend Reeva Steenkamp
voicesThokozile Masipa simply had no choice but to jail the athlete
Arts and Entertainment
James Blunt's debut album Back to Bedlam shot him to fame in 2004
music

Singer says the track was 'force-fed down people's throats'

News
i100
Life and Style
The Tinder app has around 10 million users worldwide

techThe original free dating app will remain the same, developers say

Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

IT Project Manager

Competitive: Clearwater People Solutions Ltd: Our client based in Chelmsford a...

Business Intelligence Specialist - work from home

£40000 per annum: Ashdown Group: An established and growing IT Consultancy fir...

Business Intelligence Specialist - work from home

£40000 per annum: Ashdown Group: An established and growing IT Consultancy fir...

IT Manager

£40000 - £45000 per annum + pension, healthcare,25 days: Ashdown Group: An est...

Day In a Page

Two super-sized ships have cruised into British waters, but how big can these behemoths get?

Super-sized ships: How big can they get?

Two of the largest vessels in the world cruised into UK waters last week
British doctors on brink of 'cure' for paralysis with spinal cord treatment

British doctors on brink of cure for paralysis

Sufferers can now be offered the possibility of cure thanks to a revolutionary implant of regenerative cells
Let's talk about loss

We need to talk about loss

Secrecy and silence surround stillbirth
Will there be an all-female mission to Mars?

Will there be an all-female mission to Mars?

Women may be better suited to space travel than men are
Oscar Pistorius sentencing: The athlete's wealth and notoriety have provoked a long overdue debate on South African prisons

'They poured water on, then electrified me...'

If Oscar Pistorius is sent to jail, his experience will not be that of other inmates
James Wharton: The former Guard now fighting discrimination against gay soldiers

The former Guard now fighting discrimination against gay soldiers

Life after the Army has brought new battles for the LGBT activist James Wharton
Ebola in the US: Panic over the virus threatens to infect President Obama's midterms

Panic over Ebola threatens to infect the midterms

Just one person has died, yet November's elections may be affected by what Republicans call 'Obama's Katrina', says Rupert Cornwell
Premier League coaches join the RSC to swap the tricks of their trades

Darling, you were fabulous! But offside...

Premier League coaches are joining the RSC to learn acting skills, and in turn they will teach its actors to play football. Nick Clark finds out why
How to dress with authority: Kirsty Wark and Camila Batmanghelidjh discuss the changing role of fashion in women's workwear

How to dress with authority

Kirsty Wark and Camila Batmanghelidjh discuss the changing role of fashion in women's workwear
New book on Joy Division's Ian Curtis sheds new light on the life of the late singer

New book on Ian Curtis sheds fresh light on the life of the late singer

'Joy Division were making art... Ian was for real' says author Jon Savage
Sean Harris: A rare interview with British acting's secret weapon

Sean Harris: A rare interview with British acting's secret weapon

The Bafta-winner talks Hollywood, being branded a psycho, and how Barbra Streisand is his true inspiration
Tim Minchin, interview: The musician, comedian and world's favourite ginger is on scorching form

Tim Minchin interview

For a no-holds-barred comedian who is scathing about woolly thinking and oppressive religiosity, he is surprisingly gentle in person
Boris Johnson's boozing won't win the puritan vote

Boris's boozing won't win the puritan vote

Many of us Brits still disapprove of conspicuous consumption – it's the way we were raised, says DJ Taylor
Ash frontman Tim Wheeler reveals how he came to terms with his father's dementia

Tim Wheeler: Alzheimer's, memories and my dad

Wheeler's dad suffered from Alzheimer's for three years. When he died, there was only one way the Ash frontman knew how to respond: with a heartfelt solo album