Northern Ireland’s rivers are being checked for ‘gender bending’ chemicals that could threaten the future of fish populations.
Environment Minister Edwin Poots has revealed that 85 river sites are being monitored for di-n-butylphthalate, a chemical used to make hard plastics soft and is thought to have an anti-androgenic effect — inhibiting male sex hormones.
Officials are also checking a small number of river sites for female hormones, which have been linked in a number of English rivers to gender changes in fish populations.
Mr Poots said there are no controls on the use of estrogens and anti-androgens but 15 of the largest sewage works in Northern Ireland have been fitted with treatment systems that can partly remove the substances.
However, he warned that there are no sewerage systems in Northern Ireland that guarantee full removal.
The minister was responding to a written Assembly question by Danny Kinahan, who asked what steps are being taken to ensure that estrogens and anti-androgens are now allowed into rivers, particularly the Six Mile Water basin.
Mr Poots said: “In April 2009, Northern Ireland Environment Agency (NIEA) started monitoring rivers for di-n-butylphthalate, a substance that is believed to have an anti-androgenic effect, as part of its Water Framework Directive (WFD) surveillance monitoring programme at 85 river sites throughout Northern Ireland. This includes one on the Green Burn at Millvale, part of the Six Mile Water River Basin. Data on this will be available shortly.”
Mr Kinahan said anglers in the Six Mile Water Trust had raised concerns about levels of female hormone rising in rivers and possibly causing a imbalance with too many female fish.
And Dr Lisa Connolly, who is researching endocrine disruptors at Queen’s University, said the use of di-n-butylphthalate in nail varnish and children’s toys has been banned in the EU as it is believed to be an anti-androgen.
A wide range of natural and synthetic substances have been identified as endocrine disruptors, many having the potential to enter the environment, food chain and drinking water via direct release or through treated sewage.
Angler Michael Martin, of the Six Mile Water Trust, said increased levels of the chemicals in English rivers had been shown to be linked to reductions in fish populations.
“It would be interesting to see whether it is having an effect maybe on Lough Neagh, which has a lot of rivers running into it,” he said.