more on mercury pollution in our environment - IMPORTANT FOR ALL TO READ

[Guest guest]

Since the genetic issue has come up lately in the news with new

findings of a genetic link I wanted to share this article with all of

you which points out that " Increasing levels of toxic substances in

our environment may be triggering genetic mutations and may be

contributing significantly to the increasing diagnoses of autism. "

this is not simple a genetic epidemic - i don't believe in such a

thing something has triggered this and this article has something here

http://autisminnb.blogspot.com/2007/10/autistic-children-canaries-in-

coal-mine.html

Sunday, October 07, 2007

Autistic Children - Canaries In The Coal Mine?

The classic example of animals serving as sentinels is the " canary in

the coal mine " . Well into the 20th century, coal miners in England

and the US brought canaries into coal mines as an " early warning

signal " for toxic gases including methane and carbon monoxide. The

birds, being more sensitive, would become sick before the miners, who

would then have a chance to escape or put on protective respirators.

- Wikipedia

Is the dramatic rise in the diagnoses of autism solely a result of

changed diagnostic criteria and enhanced public awareness? Or are

environmental factors also involved? Are children suffering

increasingly from developmental disorders, including autism, because

of degradation of the world environment? Like the canaries in the

coal mines do the increasing numbers of autistic children also serve

as a warning of serious environmental decay?

The thimerosal/vaccine theories have occupied much public attention

over the past several years but have they also distracted from other

potential environmental factors? Few would deny the very important

role of genetics in autism. The Unified Theory of Autism and the

concept of genetic mutation, however, suggest that genetic mutations

associated with autism may arise from environmental triggers.

Vaccines are not the only human source of mercury which can also be

found in thermometers, dental fillings, fluorescent light bulbs, and

other consumer products. Environment Canada has a web page called

Mercury and the Environment which illustrates how mercury,

particularly methylmercury, concentrates in in the environment, and

in living organisms.

Some mercury compounds are more easily absorbed by living organisms

than elemental mercury itself. When atmospheric mercury falls to

earth, it may be altered by bacterial or chemical action into an

organic form known as methylmercury. Methylmercury is much more toxic

than the original metal molecules that drifted in the air, and has

the ability to migrate through cell membranes and " bioaccumulate " in

living tissue. Bioaccumulation is the process by which a substance

builds up in a living organism from the surrounding air or water, or

through the consumption of contaminated food. Bioaccumulation will

vary for different species and will depend on emission sources as

well as local factors like water chemistry and temperature.

In the following figure, the concept of accumulated methylmercury is

illustrated by the red dots, however the dots are not to scale.

The bioaccumulation of methylmercury in natural ecosystems is an

environmental concern because it inflicts increasing levels of harm

on species higher up the food chain. This occurs through a process

known as " biomagnification " , whereby persistent substances like

methylmercury will increase in concentration from microorganisms, to

fish, to fish eating predators like otters and loons, and to humans.

Elevated methylmercury levels may lead to the decline of affected

wildlife populations and may affect human health when people consume

significant quantities of fish or other contaminated foods.

The Environment Canada site states that the amount of mercury in the

air arising from human activities has increased by a factor of 2 to 4

since industrialization. In addition to mercury there have been

frequent recalls of toy products containing lead. A recent California

study suggested a causal connection between some pesticides and

autism rates.

With the significant environmental degradation taking place today it

seems entirely possible that the increasing prevalence of autism

amongst children may be due to more than changes in diagnostic

criteria and public awareness. Increasing levels of toxic substances

in our environment may be triggering genetic mutations and may be

contributing significantly to the increasing diagnoses of autism.

Autism research should pursue all possible factors, genetic and

environmental. To help our autistic children - and to more thoroughly

understand what we are doing to our environment and ourselves.