Should a canary be mandatory in your kitchen?

[Master Splinter]

Using a canary as an indicator relies on assuming that there is a one-to-one mapping between substances (and quantities) that are toxic to canaries and things that are toxic to humans.

So if you tested say, funnelweb spider bite toxin on a canary, you'd label it as non-toxic - it's only fatal to primates. And while the average human can scarf down chocolate with relative impunity, dogs and cats metabolise the theobromine in chocolate much, much more slowly so it presents a serious health risk to them. Again, humans (even babies) can process N-propyl disulphide (from garlic and onions) in breathtaking quantities, but it can cause liver failure in cats.

Birds have very efficient respiratory systems; this means that airborne toxins can be built up rapidly, at rates faster than their body can process them out.

[Bushmiller]

Master S

You have a very valid point regarding the different susceptibilities of species.

Canaries were traditionally used in underground mines to give early warning of concentrations of gases toxic to humans such as carbon monoxide, methane and, in excessive quantities, carbon dioxide (to the exclusion of oxygen). These were gases that affected both humans and birds.

The tests in the case of Teflon have only involved canaries and rats. At this stage there have been no volunteers from the human contingent .

Having said that, in 1981 (Dupont have been aware of the potential for problems since at least 1961) Dupont conducted a study to see if there were any birth defects amongst babies born to women who had been exposed to PFOA. They did this because rats exposed to PFOA showed marked problems with their progeny.

Dupont chose eight women. Not a a very convincing test, none of the usual control groups and a dismally small sample, I know, but bear in mind this came from Dupont themselves. They had a criteria that if one birth defect appeared they would chalk it up as coincidence even though that ratio was well out of the norm. If two or more birth defects occured they would know they had a problem.

Two women had babies with birth defects. Not only were the defects similar, but they were identical to the defects to the testing on the rats of eye and facial problems. Dupont transferred the women to different departments, shut down the health studies and continued with business.

Just back on the subject of canaries, one of my many jobs was working at the BHP steelworks in Newcastle. They had stopped using canaries because the birds had developed a tolerance to the poisonous gases. They had been breeding the birds in the vicinity of the blast furnace!

Regards
Paul

[jimbur]

[QUOTE=Master Splinter;1696873]Again, humans (even babies) can process N-propyl disulphide (from garlic and onions) in breathtaking quantities.
Love that.

[Bushmiller]

Again, humans (even babies) can process N-propyl disulphide (from garlic and onions) in breathtaking quantities, but it can cause liver failure in cats.

Master S

I grew garlic commercially for a while. That was another of my mistakes in life. However, I asked a herbalist friend to tell me about the qualities of garlic. He said " Have you got a spare week?" I don't think I ever did get to hear exactly what the qualities were.

Other animals may be affected by the N-propyl disulphide such as horses and cattle. Worms definitely don't like it and that might be why it is used as drenching compound.

I know I stunk of garlic for nearly a year even if I wasn't eating it. It is a very intrusive aroma.

All extra support for your statement regarding relative susceptibilities across animal species.

Thanks for alerting me to the existence of N-propyl disulphide. I just thought garlic had a pungent odour, but I suspected I was missing something and life might not be quite that simple .

Regards
Paul

[Master Splinter]

If you want garlic pong, you should actually try jumping down the column in the periodic table; selenium compounds can apparently leave you with garlic breath for several months after ingestion.

I always find this blogger's posts well worth reading - Eight Toxic Foods: A Little Chemical Education. In the Pipeline:

[jimbur]

I like the idea of canaries developing immunity and singing happily as the humans cark it. The future could be yellow and feathered.

[Bushmiller]

If you want garlic pong, you should actually try jumping down the column in the periodic table; selenium compounds can apparently leave you with garlic breath for several months after ingestion.

I always find this blogger's posts well worth reading - Eight Toxic Foods: A Little Chemical Education. In the Pipeline:

Master S

A good read. Well reasoned and thought out.

He mentions the animals used in experiments. Do any of you recall that in the Hitchhikers Guide to the Galaxy the mice are the masters of the universe? Arthur protests that humans only use them for experiments to shape the way we behave......

Regards
Paul