It's depressing how much **** can end up in the river, but at least they appear to be doing something about it.
Gender-bending fish problem in Colorado creek mitigated by treatment plant upgrade

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[I]"The fish and I were both stunned and disbelieving to find ourselves connected by a line." William Humphrey in "The Armchair Angler"[/I]

"Gay" trout eh? Is that why rainbows have pink flush down their flanks?

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How poor a thing, sometimes I find,
Will captivate a greedy mind - Isaac Walton.

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Argh! This **** has been pretty much completely disproved. Fish gender and behaviour is disrupted by high levels of nitrates present in *any* sewage and slurry. You don't need oestrogens/pharmaceuticals etc. to have the same effect. Fish gender-bending is not primarily due to any pharmaceuticals in waste waters it's down to the nitrates. This fallacy was massive in the 80's apparently the intersex fish were an indicator that we were all going infertile from drinking contaminated water... years on it's apparent that fertility rates are unchanged and the main causes are better understood. Still this **** gets printed again from time to time.

Bad Science!

lol, maybe you should read the article and look into who did the work before you play armchair scientist!

Its not nitrates (they cause enrichment and algal blooms). What actually happens is that it is a whole cocktail of things (including pharmaceuticals, detergent breakdown products, plasticising chemicals etc. etc.) cause the effect. They tend to be molecules made of long (and often branched) chains of carbon atoms and just by chance happen to fit inside the receptor for hormones which control the production of either male or female characteristics.

The problem of the "cocktail" effect is that it is very difficult to put in place a single measure that will reduce the overall "gender-bending" effect. That a company has invested in reducing at least some components of the cocktail is a good thing - and they should be recognised for that.

The Salmon and Trout Association have published an easily read summary of the effect of endocrine disruptors on fish, a subtle form of pollution that spreads from the rivers to impact on estuarine and sea life. Don't drink the water.

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Musha rig um du rum da

I did. Whether or not pharmaceuticals at the dilutions present in rivers make a difference is still debateable but even if they do the fact that nitrates cause sexual defects is well-proven and the levels at which they have an effect is well known.

How much do you know about treated sewage effluent such as that in the article Big Jim? I happen to know a lot about it professionally. I can assure you that the concentrations of nitrate are significant while the concentrations of pharmaceuticals are much less so.

If the article had stated that "the nitrates were removed from the waste water before dosing the test fish" then the conclusions that the pharmaceuticals in the waste water were a significant factor would be plausible. (Knowing about the effects of nitrates I looked to see whether this sort of step had been taken or that there had been some "control" for the effects of the waste water constituents other than pharmaceuticals). However this does not appear to have been accounted for - so the research left massive doses of a known fish sex-disruptor in the effluent and then appears to have ignored that and attributed the changes solely to trace doses of other sex-disruptors.

These traces may have played a part but reporting them as the only or main causes of abnormalities is frankly unsupportable, sensationalist and wrong. I can assure you that the levels of nitrates in treated and untreated sewage effluents, and agricultural effluents in our rivers are a far greater problem and a far greater cause of such abnormalities.

Also 50% dosing of fish in the effluent is not something that is ever likely to occur real world let alone the 100% scenario in the experiment.

I think that ignoring major causes is bad science and failing to report these in an article is at least misdirection or worse by the journos. It is understandable that a scientist who has spent a while on research and found an effect might be keen to publicise it, but it is very common for scientists to ignore whether the effect is significant in the real world. They might not get further funding...

PS. I've read around the subject and that's my opinion at present. I'll be happy to revise it if I see evidence that the effects of phamacueticals are significant, or if we ever reduce the other causes to the point that they become significant. Meanwhile I'd prefer we focus on the fire so to speak.

I don't know exactly what hyper nitrated water does to humans long term - I don't think anybody else does either .

I do wish they'd got some form of strictures on those and other allowable nasties and especially the ones the main water companies have been allowed freely to discarge under the 1989 consents - withdrawals of the which they appear to have been spending rather a lot of money opposing of late.

As I see it , me and most of you are currently testbeds on the long term effects , cocktailed as well , of a variety of substances that I'd rather not be ingesting long term , if it's all the same to the Water Powers that Be .

I am also of the view that Directors of Water Companies and the scientists who advise them should be given 12 months law and then forced to consume water of the same quality as their own worst discharges . I reckon this simple approach would have a startling effect on water quality for customers like you and me !

But I live in mental fairyland !

Must get out more

Steve P

Wrongfoot - my own professional background is in academic research into the effects of pollutants on animals in river systems (Freshwater Ecotoxicology). I've also done some first hand research examining the stimulation of female egg yolk protein (vitellogenin) in male trout by detergent breakdown products (4-nonylphenol).

Your own assessment of the news item reported is, unfortunately, far more biased and less objective than the actual news item itself.

Without getting too far into technical definitions, the problem of tackling endocrine disruption (innappropriate stimulation of the hormone receptors of animals) is deeply complicated by the issue of "chemical synergy" as well as "potency".

Potency is how big an effect you get from a given concentration of a chemical (in the case of ethynylestrodiol in the contraceptive pill - it is highly potent at concentrations of nanograms per litre or 1 part per TRILLION). Therefore, you can't just simply look at the relevant concentration of each potential pollutant and tackle those at higher concentrations- you have to look at potency.

To further complicate matters - the overall effect of a mixture of "gender bending" chemicals can be the same as the sum of all the tiny individual potencies.....This is called additivity (where the overall potency of the mixture equals the additive potency of each individual component). It has also been reported that some mixtures may be "synergistic" or, in other words, the effect of the mixture is GREATER than the additive sum of individual potencies....

There are a great many rivers which are >90% treated effluent (e.g. the river Lea in Greater London where much of the pioneering fieldwork on this subject was done by Prof John Sumpter and Dr. Sue Jobling of Brunel University in the early 1990's) so a 50% dilution is actually a little conservative in that case!!

Even so - the fact that the treatment procedure of the effluent significantly delayed the onset of feminisation shows that it is having a significantly protective effect on the quality of effluent released.

Some references here:
A variety of environmentally persistent chemicals, including some phthalate plasticizers, are weakly estrogenic.
Exposure of Juvenile Roach (Rutilus rutilus) to Treated Sewage Effluent Induces Dose-Dependent and Persistent Disruption in Gonadal Duct Development - Environmental Science & Technology (ACS Publications)
Relative Potencies and Combination Effects of Steroidal Estrogens in Fish - Environmental Science & Technology (ACS Publications)
Accurate Prediction of the Response of Freshwater Fish to a Mixture of Estrogenic Chemicals

---------- Post added at 02:43 PM ---------- Previous post was at 02:39 PM ----------

Synergistic (greater than additive) effects here:

Synergistic activation of estrogen receptor with c... [Science. 1996] - PubMed result

Blimey !!! I also get depressed when I realise how little I know, compared to others on the forum.
Excellent input thanks.

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[I]"The fish and I were both stunned and disbelieving to find ourselves connected by a line." William Humphrey in "The Armchair Angler"[/I]