Sorry, Chuck, you miss my point. A substance is a human carcinogen,
according to my definition, only if it is proven that normal exposure to
the substance shows a statistical increase of at least one form of
malignant tumour. For example, cigarette smoke (a natural substance) is
carcinogenic. It is extremely misleading and very unscientific if the
"EPA, FDA and other governmental authorities define carcinogens
(mutagens and teratogens, etc.)" based on gavage of acute near-lethal
doses on species with widely different species from humans.
I'll take it down to home territory. I sweeten my tea with chemicals
other than sucrose, as a token effort to control my weight. The
sweeteners I use are verboten in the USA because the FDA has decided
that both active components (saccharine and cyclamates) were
carcinogenic, based on such stupid gavage in rodents. Yet, literally
millions of people in Europe use Huxol, Assugrin and similar sweeteners
of that type, consuming tens of "carcinogenic" pills per week. You can
be certain that there has been wide epidemiological studies and users of
these sweeteners, even in high doses, have not shown any increase of any
cancers. (Saccharine has now been delisted in the USA but cyclamate
salts have not been, although they may be, see
http://www.cancer.gov/cancertopics/factsheet/Risk/artificial-sweeteners/
However, the FDA are now weaselling on that, on the grounds that it may
affect sperm motility, even though an epidemiological study in Spain
amongst workers making the stuff and heavily exposed have proved negative.)
OK, I'll say water is carcinogenic, because there is water in every
tumour. So what?
Brian
Charles Dolci wrote:
> Brian:
>
> You entirely miss the point.
>
> Unlike so many on this and other forums I do not pretend to be an authority - I look to the information from the real authorities, such as Bruce Ames, et al., in this case.
>
> As for the chemicals I cited they ARE carcinogens as the EPA, FDA and other governmental authorities define carcinogens (mutagens and teratogens, etc.). The fact that it takes absolutely absurd and implausible quantities of a chemical to cause tumors in rodents is exactly the point. But that is the standard we have created.
>
> If you define a standard for carcinogenicity for industrial chemicals you can not then argue for using a different standard for "natural" chemicals. We pump laboratory rats full of huge doses of industrial chemicals for most of their brief lives, and then find tumors or other problems when they are cut open. We then wail and moan and groan that these same chemicals in the most minute quantities are going to lead to all sorts of diseases and disorders in man and then legislate to ban their usage. OK I have no problem with that, but then you need to apply the same criteria to natural chemicals.
>
> According to the Food and Drug Administration the standard and near universal way to determine carcinogenicity is with the rodent lifetime tumor bioassay. The maximum tolerated dose (MTD) (i.e. the highest dosage that won't kill the rodent in one shot) for a particular chemical is determined in a dose-range finding study, then doses just below the MTD are administered to male and female rats and mice daily for two years. A statistically significant, chemical-associated increase in tumor count is taken as evidence of carcinogenicity. When they ran these tests using the natural chemicals I described they find that they are "carcinogens".
>
> I don't for a moment believe that they will cause cancer or that they are even harmful, but they ARE "carcinogens" because that is how we have defined the term and that is how we legislate.
>
> BTW, even though safrole and safrole containing sasafras oils were banned from use as food additives by the FDA sassafras root can still be found in health food stores and are used to make tea.
>
> Brian, before you go on these rants I suggest you read the sources I quote. Bruce Ames is one of the world's leading authorities in this field and I am merely quoting his work. Plus there are many other scientists who lists these chemicals as carcinogens. Reread my post. At no time did I say the listed chemicals were harmful, I said they were "carcinogens" which they are.
>
> The point I made is that you can't get all hot and bothered about man-made chemicals because they cause cancers in rats and then ignore the same results from natural chemicals and claim that somehow they are all OK because nature is just so friendly.
>
> Chuck D.
>
>
> Brian Ellis <[log in to unmask]> wrote:
> Chuck
>
> Since when were you an authority on toxicology and epidemiology that you
> dare make unqualified and categorical statements on the carcinogenicity
> of chemicals? Your statements are on a par with Madonna saying that she
> has the way of counteracting radioactivity. Please leave such matters to
> people who know about what they are talking.
>
> Ethanol, per se, is NOT a known carcinogen. It is a known
> trafficaccidentogen, sure. It is surmised by anecdotal evidence that a
> small percentage of alcoholics do develop a cancer, probably due to
> inhibition of the metabolisation of acetaldehyde into acetic acid, but
> this has been observed in persons consuming an average of well over 100
> g ethanol/day. However, most people on this dosage do not develop
> cancers because they are able to metabolise acetaldehyde more rapidly:
> the cancer is therefore due to a combination of continuous heavy alcohol
> consumption and an enzymatic deficiency. Your kind of statement is to be
> deplored because it can mislead ordinary people.
>
> Caffeic acid has been shown to induce tumours in rodents with a gavage
> of 2% of the substance in their food. This would be equivalent to a
> person of 75 kg drinking over 300 cups of strong coffee per day. There
> is no known epidemiological evidence without confounding factors that
> caffeic acid is toxic to humans, in any way, at normal dosages.
>
> d-Limonene is on FDA's list of synthetic flavoring substances and
> adjuvants that are Generally Recognized as Safe (GRAS). Oxidation
> products of limonene that form during handling and storage, rather than
> limonene itself, are the mediators of irritation and sensitization.
> Although chronic oral administration of d-limonene to rats caused kidney
> damage and kidney tumors in the males, this effect is thought to have no
> human relevance (IARC Group 3). Again, this is unnecessary
> scare-mongering, which is to be deprecated.
>
> Safrole is a known carcinogen in rodents submitted to high-dose gavage,
> more so in mice than rats. The FDA declared it unsuitable for use in
> human foods on the precautionary principle. Its consumption in the USA
> used to be mainly through sassafras root, used in making root beer.
> Betel nut contains relatively high concentrations of safrole and studies
> are being made amongst habitual chewers. However, the areca quid
> contains other chemicals from the betel and from the concomitant impure
> lime used by chewers, which makes identification of the effect of each
> substance very difficult. This is partially compensated by the fact that
> betels from different regions have very different proportions of each
> chemical and statistical studies can more or less judge the effect of
> each. However, the main difficulty in these studies is the bioactivation
> of the tissues due to tobacco smoke. As far as data available to me can
> say, safrole in high doses is a known carcinogen for rodents but there
> is no known evidence that it is carcinogenic for humans, although it may
> be under some circumstances.
>
> This kind of thing is similar to what I have already indicated regarding
> solvents. Trichloroethylene is a known carcinogen for rodents but is
> deemed as non-carcinogenic for humans after extremely long and detailed
> epidemiological studies with cohorts of thousand of persons exposed to
> it. The difference is because the metabolic processes in different
> species can vary considerably. It is therefore very dangerous to
> extrapolate the toxicological findings in one species to another
> species. However, if a substance is found to e.g., induce tumours in one
> species, it can be an indicator where to look in other species.
>
> Toxicology and epidemiology are very complex subjects. As it happens, I
> took a post-grad course in industrial toxicology for engineers 20 years
> or so ago and it really angers me when laymen say that a given substance
> is teratogenic or carcinogenic or whatever without qualification. This
> is like Linda McCartney stating that juvenile milk consumption is the
> cause of obesity.
>
> Sorry if I appear harsh, but science is about turning hypotheses into
> facts, not presupposing that a hypothesis is fact.
>
> Happy New Year!!!
>
> Brian
>
>
> Charles Dolci wrote:
>> Ray, et alia;
>> Interesting. But what are your sources for such statements?
>>
>> Check out http://www.the-scientist.com/article/display/15510/
>>
>> I find your supposition that nature knows enough to just make the right amount of a chemical and no more. I imagine that lends weight to the intelligent design theory of creation. I don't think I have a problem with the claim that "When a living organism produces a chemical it is usually made in small quantities, just enough to meet the needs of the organism" particularly if the purpose of that organism is to kill off another organism that is a threat to it. Such intelligent organisms. But what about those natural chemicals that are not produced by "living organisms" such as chemicals produced in the heat of fires and from volcanoes.
>>
>> But I am not sure I can agree with the notion that natural chemicals are made in such small quantities compared to "industrial quantities". Have you calculated the amount of natural pesticides produced each year by corn crops? Well I haven't either (yet) but I suspect that the world wide production of corn is enough to produce some pretty staggering amount of natural pesticides. What about the huge amount of ethyl alcohol (known carcinogen) contained in alcoholic beverages - oops, Sorry that is man-made isn't it.
>> How about the caffeic acid (carcinogen) in coffee, tomatoes and lettuce or limonene (carcinogen) in oranges, or safrole (carcinogen) in spices. Should I go on?
>>
>> I am interested to see your source for the statement "It is extremely rare for natural chemicals to be toxic, persistent and to bioaccumulate." That runs counter to the information in the Science article referenced and linked above plus a lot of other research on this issue (see http://www.heartland.org/Article.cfm?artId=9602 )
>>
>> A report by the National Academy of Science stated "
>> Overall, the basic mechanisms involved in the entire process of carcinogenesis-from exposure of the organism to expression of tumors-are qualitatively similar, if not identical, for synthetic and naturally occurring carcinogens. The committee conclud ed that there is no notable mechanistic difference(s) between synthetic and naturally occurring carcinogens. To assess relative potency, the committee compiled and analyzed data on over 200 carcinogens-65 of which were naturally occurring. The data set included agents identified by IARC as having sufficient evidence of carcinogenicity in humans or animals, or by the NTP as known or reasonably anticipated to be human carcinogens. Based in part on this limited sample, the committee concluded that there i s no clear difference between the potency of known naturally occurring and synthetic carcinogens that may be present in the human diet. Of the selected agents tested, both types of chemicals have similar mechanisms of action,
>> similar positivity rates in rodent bioassay tests for carcinogenicity, and encompass similar ranges of carcinogenic potencies. Consequently, both naturally occurring and synthetic chemicals can be evaluated by the same epidemiologic or experimental methods and procedures." (see http://orsted.nap.edu/openbook.php?record_id=5150&page=9 )
>>
>> The statement "Nature has few uses for chemicals that cause genetic mutations or cancer.
>> Many industrial chemicals have these problems." is so far from the facts that it is hard to deal with. The reality is that natural chemicals are just as cancer causing as industrial chemicals - in fact, more so, because they are more pervasive in the environment. Check out any of the numerous articles at http://potency.berkeley.edu/
>>
>> I would like to see some science behind the claims made by Ray.
>>
>> Chuck Dolci
>>
>> Ray Franklin wrote:
>> Chuck,
>>
>> Regarding industrial vs. natural chemicals, there are three important
>> distinctions. And thanks to Brian Ellis for reminding me of persistence and
>> bioaccumulation, which I mistakenly assume everyone understands and takes
>> for granted.
>>
>> When a living organism produces a chemical it is usually made in small
>> quantities, just enough to meet the needs of the organism. Industrial
>> chemicals are made in, well, industrial quantities, and as I pointed out
>> earlier, they are widely dispersed throughout the environment. Because
>> plants and animals are also widely dispersed, some of their chemicals can be
>> widely spread too.
>>
>> It is extremely rare for natural chemicals to be toxic, persistent and to
>> bioaccumulate. It is common for industrial chemicals to have all three of
>> these charactistics. Natural chemicals tend to be broken down or
>> metabolized. Industrial chemicals rarely do this.
>>
>> Nature has few uses for chemicals that cause genetic mutations or cancer.
>> Many industrial chemicals have these problems.
>>
>> I think these distinctions are also partly responsible for the outrage so
>> many people feel around this issue. The presence of PCBs in their bodies is
>> something that was done to them, not by them.
>>
>> Yes, the consumer bought all these products that resulted in the pollution.
>> If business had taken the time to educate customers about all the chemicals
>> used throughout the supply chain that produced the personal computer, then
>> it would be reasonable for business to say "We told you it was bad, but you
>> bought it anyway." To my knowledge, that never happened. RoHS and REACH
>> are now requiring it to happen to some degree.
>>
>> And finally, there are a handful of natural chemicals that resemble
>> industrial chemicals. This Science News article describes some natural
>> chemicals related to DDT and PCB.
>> http://www.sciencenews.org/articles/20061028/fob7.asp They were found in
>> samples of whale oil from 1921. The article also points out that this in no
>> way lets PCB producers off the hook for their pollution. The compounds are
>> not identical to DDT and PCB, just similar. Furthermore, they were produced
>> by natural processes. That is the real value of the discovery: it may be
>> possible to learn how this was done. That is the basis of green chemistry.
>>
>> Regards,
>>
>> Ray Franklin
>> RoHSwell.com
>>
>> -----Original Message-----
>> From: Leadfree [mailto:[log in to unmask]]On Behalf Of Charles Dolci
>> Sent: Friday, December 29, 2006 9:35 PM
>> To: [log in to unmask]
>> Subject: Re: [LF] REACH
>>
>>
>> Ray:
>>
>> I'll buy your distinction of the difference between "industrial" and
>> "natural chemicals", but it is irrelevant. First let me apologize for the
>> imprecise expression of my question. Let me restate it "Can someone tell me
>> the difference between "industrial chemicals" and "natural" chemicals" and
>> their impacts on human health?"
>>
>> Are there any natural chemicals that are harmful to humans such as ... oh,
>> I don't know, let me go out on a limb here... like lead or mercury or other
>> heavy metals. How about arsenic? hemlock? Digitalis from the fox glove
>> plant? Ricin from the castor bean? Mushrooms in your garden after a storm?
>> To suggest that "industrial chemicals" are somehow more dangerous to human
>> health (or anything else for that matter) than "natural chemicals" ignores
>> the reality that the overwhelming majority of the things that harm man are
>> natural.
>>
>> I do not doubt that there are more obese people today than ever before.
>> But I would not call it an epidemic. We all know that people are also taller
>> now than ever before - are we going to call that a height epidemic? We are
>> living longer than ever before - are we going to call that a vitality
>> epidemic? There are more medical interventions now than ever before - are we
>> going to call this a health epidemic?
>>
>> The reality is that society today makes fewer physical demands on people
>> and rich foods are cheaper and more abundant than ever before. Increased
>> obesity is the result of a life style that is prevalent in Western society.
>> Let's step aside for a minute and look at reality. If the spread of
>> "industrial chemicals" is as widespread as we are told then how come this
>> obesity "situation" is not a problem in China, Asia, or Africa? Why is it
>> only evident in the affluent industrial countries. I have neighbors who
>> drive half a mile each evening to buy a cup of latte, mocha, frappe
>> super-whipped coffee (or whatever it is they buy) from Starbucks, then come
>> home just in time to pay the pizza delivery man who brought dinner for the
>> family. Who among us has/had a grandmother who would have thought of having
>> dinner brought in by a vendor? Why did our parents and grandparents tell us
>> of their walking three miles to school every day in the snow? - because they
>> did it.
>>
>> Since we are eating a lot more and doing a lot less physical activity why
>> is anyone suprised that we are becoming more obese? Why does anybody, other
>> than a Ph.D. candidate looking for a dissertation topic, have to look for
>> obscure and arcane reasons for such a thing? Even if some of those putative
>> causes for obesity are valid, what are their contributions to the problem?
>> If the presence of some industrial chemical accounts for .0001% of a
>> person's excessive weight gain then what is gained by eliminating that
>> chemical. So rather than being 600 pounds the person would only weigh 599
>> pounds. If people today eat like pigs and move like sloths then why are we
>> looking for obscure and insignificant contributors to the obesity problem?
>> Or maybe the chemical just triggers a reaction in the body - if it wasn't
>> for the endocrine disruptors we could still eat three times as much as ever
>> before, never lift a finger all day and still look like Twiggy.
>>
>> You say that "A large number of scientific studies began with the
>> observation of a coincidence, or correlation, a term you mentioned later."
>> Absolutley, no argument there - but let us not lose sight of the fact that
>> determining a correlation is only the beginning of the inquiry - not the
>> end.
>>
>> You say "As engineers we must constantly make design decisions in the face
>> of
>> incomplete and faulty data. I see nothing wrong with doing the same in
>> politics, public health and environmental protection. I also think
>> policy should be based on science. And I accept the emergence of trends as
>> sufficient evidence for decisions. I do not require irrefutable proof,
>> or even reasonable proof. Rather, I trust in a decision-making system
>> that is less than perfect and has demonstrated an ability to learn and
>> correct
>> mistakes." - Fine, but that completely ignores the reality of politics.
>> Politicians are not interested in science or doing good - they are merely
>> concerned with currying favor with the right groups and financial sources.
>>
>> I don't disagree with your ultimate goal - however, I require a higher
>> level of proof (i.e. presentation of evidence and facts) before I commit
>> resources to some new fad. It is axiomatic that all resources are scare and
>> have alternative uses. If we piss away scarce human and monetary resources
>> on the latest political/scientific fad de jour which yields no measurable
>> benefit that means resources were not invested in truly worthy ventures -
>> such as my retirement on a quiet Mediterranean island.
>>
>> By the way - to pursue a more amusing and entertaining academic exercise
>> (perhaps on another forum) - I was just watching a program on one of the
>> science channels and it was talking about the rather alarming number of
>> large near earth objects (NEOs) that could actually slam into the earth,
>> and, if big enough, wipe out all life on Earth. The program mentioned that,
>> at present, the US is the only country spending any money on research to
>> find and track these NEO's and come up with ways to deflect or destroy one
>> should it be determined to be on a collision course.
>>
>> Let us assume, for the sake of argument, that this is true. Let's say that
>> the US gov't approaches the other nations of the world and asks them all to
>> contribute something to this effort. They all say "No". Let's also say that
>> a few years from now a NEO is found and monitored and it is determined that,
>> in fact, it is on a collision course with earth - but it will hit somewhere
>> in Asia or Eastern Europe and that North America will be the least impacted
>> by the adverse consequences of this event. The US has the technology to
>> deflect or destroy the NEO before it comes too close. Since all other
>> countries elected not to participate in the effort to avoid such disasters,
>> what should America's response be?
>> I know what my response would be.
>> Chuck Dolci
>>
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