Would it be accurate to say that any chemical compound not found in nature

[KlatooBNikto]

is,by definition, carcinogenic and not compatibe with human tissue?

I was thinking about this when I read that a compund called Bisphenol A that is used as precursor in a wide array of products has been found to be affecting sexual functions even in very minute quantities. The same kind of toxicity is found in Teflon's precursor.

Any one have any thoughts on this?

[eallen]

1. No. Many synthetic compounds are not carcinogenic.

Compatibility with human tissue is a different question, most of relevance to substances used in surgical prosthetics.

[MADem]

2. "NOT Found in NATURE" is a tricky definition

We may think that things are not found in nature, but then, as our ability to discern things found in nature increases, we find that, indeed, they are found in nature. A lot of heart drugs and other pharmaceuticals have been found off in the Amazon, e.g.

This comment is not particularly helpful to the discussion, but it probably should be gotten out of the way early on!

[luaptifer]

3. it wouldn't be accurate for a number of reasons

including, first, that a chemical is 'carcinogenic' only if it causes cancer or shows evidence of the likelihood to do so. you probably know the root words related to carcino - cancer, and genesis, roughly re 'cause' or 'lead to'. not all 'xenobiotic' chemicals, nor necessarily, even most, cause cancer unless they influence the processes that cause cells to escape the natural regulation that keeps their growth 'under control'. a number of cancers come from mutations in genes that do that sort of regulation.

'compatible with' might be another point of argument (i'm not intending to argue, just explain a couple of things) so that you probably intend, instead, to mean 'not conducive to longterm health'.

take a look at this report for wider arrays of things such as you intend to point out. pthalates or plasticizers are one of the > 100+ nasties found ubiquitously in body fluids of each volunteer donor examined (eg., Bill Moyers): Environmental Working Group: Body Burden

[TreasonousBastard]

4. Asbestos, mercury, radon gas, poisonous alkaloids, snake venom...

are all found in nature.

Many manmade chemical compounds are not only not toxic, but therapeutic.

(This is not to say that we should be dumping benzines and dioxins in the drinking water.)

[Lexingtonian]

5. no

There are plenty of 'natural' carcinogens- aflatoxin B in peanuts, petroleum tar, incompletely burned organic matter such as wood, seafoods, certain kinds of cabbages.

There are a lot of 'unnatural' compounds that are not found in nature but are not carcinogenic. Saccharine, polyethylene and polypropylene plastics, matchstick phosphorous, almost all metals. Most modern antibiotics and other drugs. Most other such materials are either immediately, chemically, toxic or it is for practical purposes impossible to expose oneself in normal circumstance to enough of them for the carcinogenicity to become the primary medical risk- like PVC, polyvinyl chloride plastic, or clothing dyes, or gasoline, or used motor oil. Even stuff like DDT or malathione or 2,3,5-T is not really carcinogenic; the tiny amounts of impurities in them are what is.

Carcinogenic compounds come in at least two or three varieties. One is 'genotoxic' and just plain damages DNA. There are few of these in nature-aflatoxin B is one and 8-benzopyrene (iirc) (the by far principal carcinogen in charred or ash-covered food, wood smoke, tobacco smoke, tar, and gasoline combustion) is another, and the nitrates/nitrites in sea salts when combined with some organic carrier matter a third. Benzopyrene and nitrates/nitrites and radiation, mostly by the sun, probably do cause the great majority of human cancers. By burning so much wood, coal, and petroleum and eating so much nitrate pickled meat or seafood, and living in sunlight levels far higher than befits our skin pigmentation level we're just intensifying what our ancestors did in unhelpful ways. Actually, they probably ate more food that was charred or ash-covered, and may have gotten larger overall carcinogen exposures than we do now, with the possible exception of tobacco smokers and certain kinds of workers.

The second kind is all kinds of relatively sticky (hydrophobic) semicomplex carbon compounds. Relatively few of their hugh variety get through the gut, the lungs, or the skin and into blood or cellular fluids, but then they tend to dissolve into fat and remain there. They don't exist in nature, or only in petroleum, because they are hard to make and bacteria break them down much faster than they are built up on the Earth's surface. No one really knows how these work, except that direct effects on DNA are probably not the case, and they are probably the majority of the "artificial" carcinogens. (They probably do something to proteins and molecular pathways.) We are not adapted to them because the bacteria ate them up too efficiently for billions of years, so they weren't around for vertebrates or even mammals to adapt to. (Tell that to a seal or duck caught in an oil slick....) These compounds are stuff like benzenes, PCBs/dioxins, phorbol esters.

I guess I have to say a little about aging and genetics and cancers. There's an idea that maybe aging means accumulation of carcinogen damage or effects, but it's more complicated than that. Human cell cultures select for cancerous cells when deprived of most of their usual level of oxygen- 90% and 95% levels. Poorly oxygen-fed organ regions do have a way of speeding development of aberrant, dysfunctional, cells. There is also the idea that some continuously renewing cells- of the blood, the liver, the stomach lining- have some kind of cell signalling to achieve renewal that goes more aberrant as it declines with age.