Pollution triggers bizarre behaviour in animals (human animals too)

[Guest guest]

When we go to the doctor with symptoms of toxic load poisoning we are

usually told that they can't find anything or that it is psychological

based and if treated they will usualy give something that suppresses

the symptoms but in doing so will actually make greater the toxic load

and the resultant damage. F.

 

 

http://www.newscientist.com/news/news.jsp?id=ns99996343

 

Pollution triggers bizarre behaviour in animals

 

16:45 03 September 04

 

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Hyperactive fish, stupid frogs, fearless mice and seagulls that fall

over. It sounds like a weird animal circus, but this is no freak show.

Animals around the world are increasingly behaving in bizarre ways,

and the cause is environmental pollution.

 

The chemicals to blame are known as endocrine disruptors, and range

from heavy metals such as lead to polychlorinated biphenyls (PCBs) and

additives such as bisphenol A.

 

For decades, biologists have known that these chemicals can alter the

behaviour of wild animals. And in recent years it has become clear

that pollutants can cause gender-bending effects by altering animals'

physiology, particularly their sexual organs.

 

But now two major reviews have revealed that the chemicals are having

a much greater impact on animal behaviour than anyone suspected. Low

concentrations of these pollutants are changing both the social and

mating behaviours of a raft of species. This potentially poses a far

greater threat to survival than, for example, falling sperm counts

caused by higher chemical concentrations.

 

 

Snails and quails

 

The two research teams have independently collected evidence revealing

the effects on egrets and gulls, snails, quails, rats and macaques,

minnows, mosquito fish, falcons and frogs. Behaviours altered include

mating and parenting, nest building, learning, predator avoidance,

foraging, activity levels and even balance.

 

In one study, for instance, male starlings exposed to dicrotophos

insecticide decreased their singing, displaying, flying and foraging

activities by 50%. And newts exposed to low levels of the pesticide

endosulfan found it harder to sniff out the attractive pheromones of

potential mates.

 

Researchers have also shown that increasing numbers of male western

gulls hatched from eggs exposed to DDT attempt to mate with each

other. In recent years, scientists have also found that lead affects

the balance of gulls, while atrazine makes goldfish hyperactive and

the chemical TCDD makes the play behaviour in macaques rougher.

 

Despite this wealth of evidence, these effects have gone largely

unnoticed by toxicologists, says Ethan Clotfelter of Amherst College

in Massachusetts, lead author of one of the reviews, published in

August 2004 in Animal Behaviour (vol 68, p 465).

 

 

Missing a trick

 

Not only are we failing to acknowledge the scale of the problem caused

by endocrine disruptors, but toxicologists may be missing a trick:

changes in animal behaviour could be an early warning that certain

chemicals are harmful. " You might see behavioural effects long before

you see a population crash, " Clotfelter says.

 

Dustin Penn and Sarah Zala of the Konrad Lorenz Institute of

Comparative Ethology at the Austrian Academy of Sciences in Vienna

agree. They have just published a second review of the effects of

endocrine disruptors in the same journal (DOI:

10.1016/j.anbehav.2004.01.005). " The most important point is the

incredible amount of evidence that this is a widespread problem, " Penn

says.

 

Both research groups say that biologists must wake up to the fact that

endocrine disruptors might explain bizarre behaviour in wild animals.

And both reviews reveal that different concentrations of chemicals can

have unexpected effects.

 

Male mice exposed to low doses of some pesticides increase their

scent-marking behaviour, for instance, but decrease it when exposed to

higher concentrations.

 

 

Damaging doses

 

" Pollutants that have been considered safe when tested at medium doses

could have damaging effects at lower doses, " Penn and Zala warn in

their review. And conversely, toxicologists might exaggerate the risks

posed by higher doses.

 

Other behavioural biologists back the authors' call for biologists and

toxicologists to work more closely to determine the scale of the

problem. " It's been decades since the first evidence appeared that

chemicals in the environment can influence behaviour, " says John

McCarty of the University of Nebraska in Omaha, who researches the

impact of pollutants on birds.

 

" It seems to me that this body of evidence was pushed to the

background while most environmental scientists and regulators focused

on mortality and cancer rates [caused by endocrine disruptors and

other pollutants]. "

 

The US Environmental Protection Agency says it cannot provide a

detailed comment on the research, but promises it will investigate

further. " We'll review these two scientific articles as we continue to

develop an endocrine screening and testing programme, " a spokeswoman

told New Scientist.

 

Geoff Brighty, ecosytems science manager at the UK Environment Agency,

agrees that studying the effects of chemicals on animal behaviour

should be given a higher priority. " It is becoming recognised that

behaviour is important to look at to make sure a chemical is safe, and

we ignore it at our peril. "

 

 

Andy Coghlan