There must be a lot we don't know about the effects of pollution on wildlife. Here's one for our resident chemist.
Mercury Poisoning Makes Birds Act Homosexual
Male birds that eat mercury-contaminated food show "surprising" homosexual behaviour, scientists have found.
An effect of mercury poisoning on birds
- Neil Fitzgerald
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Re: An effect of mercury poisoning on birds
There could be an interesting connection here with Freddie Mercury!
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Re: An effect of mercury poisoning on birds
Do you mean me?Neil Fitzgerald wrote:There must be a lot we don't know about the effects of pollution on wildlife. Here's one for our resident chemist.
Well what immediately strikes me from the first line of the abstract is the lack of chemical rigour by the authors:
"Methylmercury (MeHg) is the most biologically available and toxic form of mercury, and can act as a powerful teratogen, neurotoxin and endocrine disruptor in vertebrates."
- Methyl mercury is not univalent but divalent, and is charged, viz [HgCH3]+.
Unfortunately I can't read the full paper at the moment. But I would like to know how they eliminated the possibility of all the other endocrine disruptors in the environment having this effect. Of course it's well known that endocrine disruption can have significant negative effects: DDT caused alligators to have smaller penises, western human males now have lower sperm counts due to soy, while eastern human males now have lower sperm counts due to milk. As well as some beneficial ones. It seems more likely to me that the methylmercury would interact with selenium- or sulphur-rich proteins, rather than bind to the oestrogen receptors itself (it is the wrong size and shape). Could that effect feeding behaviour, with a greater intake of xenoestrogens? Don't male caged birds show a greater tendency towrads effeminancy anyway? - I recall a report which stated that when rats are put under stress they exhibit some female behaviour.
What also strikes me is the sample size is very small - 160. Well small to a chemist who is using to do things with samples of at least 1,000,000,000,000,000,000,000 individuals. I would like to know whether their conclusions are statistically valid.
As they state "However, mechanisms of endocrine impairment [by methylmercury] and net effects on demography of biota are poorly understood.". They don't appear to have added anything to that understanding. So at the moment I remain to be convinced by their conclusions. There are many more powerful and more abundant endocrine disruptors in the environment than methylmercury. And if Nilmini Jayasena is female (it is a girl's name) then that would be a good source of oestradiol, which is, of course, a very potent binder to the oestrogen receptors.
I'll try to find the paper in the university library.
- No, we don't subscribe to it.