Talk:Phthalate

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[edit] How do I finish the equation...

C8H5O4K + NaOH → ??? —Preceding unsigned comment added by 72.139.119.165 (talk • contribs) 2006-06-06 00:26:17 (UTC)

Is the response above sarcastic? The article seems to point out that pthalates are definitely not a huge hazard that can be replicated. However, scientists can't guarantee there are no risks associated with it. RMartinez

Reading the scientific evidence does not lead to a conclusion that phthalates are safe. Reading the many peer-reviewed journal studies of phthalates' effects on health at, for example, OurStolenFuture.org, offers a pretty clear picture that phthalates are not safe, and that their effects on health (the effects we know of) are very serious. University student 09:49, 15 April 2007 (UTC)

[edit] Serious?

Not a scientist here, but many of these chemicals are studied by the NIEHS's National Toxicology Program-Center for the Evaluation of Risks to Human Reproduction. The CERHR appears to establish so-called "expert panels" that review the literature in a public forum and provide conclusions.

So far expert panels have reviewed:

  • Butyl Benzyl Phthalate
  • Di-n-Butyl Phthalate
  • Di-(2-Ethylhexyl) Phthalate
  • Diisodecyl Phthalate
  • Diisononyl Phthalate
  • Di-n-Hexyl Phthalate
  • Di-n-Octyl Phthalate

Their findings can be located at the resources page of their website. I have only looked at a couple of these reports. The phrases I have seen used in reference to ordinary usage are 'negligible concern,' 'minimal concern,' and 'some concern.' The phrase 'serious concern' only showed up in one case that I saw and was in reference to infants undergoing serious surgical procedures. I have the impression that these groups use a standard terminology and that the phrase selected may have a precise meaning. Perhaps someone knows? --Bob Herrick 21:52, 21 August 2007 (UTC)

I was reading over the article, Follow-Up Study of Adolescents Exposed to Di(2-Ethylhexyl) Phthalate (DEHP)

as Neonates on Extracorporeal Membrane Oxygenation (ECMO) Support, that was reference as [5]. I could not find anything that supported the italicized portion of the quote

Upon birth of the children whose mother's urine had been previously measured, the genital features and anogenital distance were measured and correlated with the residue levels in the mother's urine. In boys, the highest levels of residue were seven times more likely to have a shortened anogenital distance.[5]There was also a correlation between heightened residue levels and smaller penis sizes. Boys with smaller penises were more likely to have testes that didn't descend properly into the scrotum.

I am going to remove it as it is not true as there was no correlation found. —Preceding unsigned comment added by JHarman16 (talk • contribs) 03:07, 2 October 2007 (UTC)

[edit] Health effects section

Please look at it, something wrong with the syntax.... —Preceding unsigned comment added by Christian75 (talk • contribs) 01:20, 28 October 2007 (UTC)

[edit] Endocrine effects

Not one mention of endocrine effects/disruption? Isn't this one of the primary health effects that has been noted? Badagnani (talk) 07:01, 28 November 2007 (UTC)

No. The effects have been claimed, based on large doses in in-vitro animal studies. There is very little evidence that phthalates cause any effect in humans, in the amounts found in the environment.Pustelnik (talk) 00:21, 12 February 2008 (UTC)
As with most human environmental exposures, scientists have to grapple with the question of dose. As the saying goes, "dose makes the poison". Because it is unethical to expose a human to a potentially hazardous agent, scientists use animal models for phthalate exposure studies. Most phthalate studies examining reproductive effects use dose levels on the order of 100 to 500 mg phthalate/kg body weight/day; the average human is exposed to about 1000 times less. The issue is do the obvious reproductive malformations seen at the higher dose levels in animal studies occur in humans at human exposure levels. The answer is we don't know. Humans could be more susceptible than animals to phthalates because of different physiology. Furthermore, there are epidemiological data (noted in the wiki) associating higher human phthalate levels to changes in endocrine-sensitive reproductive endpoints. This all points to the need for additional research before a definitive answer can be reached. Kajohnso (talk) 21:40, 27 February 2008 (UTC)

[edit] Rational Skepticism

The Rational skepticism tag for this article has been deleted. Comment at RS portal. The "health effects' section is definitely a case for a rational skepticism tag in my opinion, and probably a weasel words tag as well. Pustelnik (talk) 00:17, 12 February 2008 (UTC)

I'll admit that I am not a member of Wikiproject Rational Skepticism and had not even been aware of the project until User:Pustelnik placed {{Rational skepticism |class=start |importance=}} at the top of this page. But having had a long look at the project page, and at Scientific skepticism I'm convinced this is not within the scope of the project:
  1. Firstly, this is an article about a chemical, and as a far as I tell, no other chemical pages are part of the project (except Bisphenol A and a few others also added by Pustelnik)
  2. According to the project page, a topic's inclusion in the Skeptic's Dictionary is grounds for inclusion in the project. Phthalates and endocrine disruption in general are not included in the Dictionary.
  3. Another project goal is "To identify cases of fraud and other unethical/illegal activities undertaken by religious and quasi-religious organizations, as they often go unreported." There is no fraud or illegal activity here, nor is there a religious or quasi-religious element.
  4. Finally, if the term 'rational skepticism' has a meaning other than simply "a scientific topic about which there is debate/controversy" then it should not be applied to any old topic about which there is debate within the academic/scientific community. I posit that there has to be something more than the mere existence of debate/controversy for the term 'rational skepticism' to apply.
If inclusion in the project only had implications for the project itself and its members, I wouldn't care about this. But unfortunately for the rest of us, it does have implications beyond the project, because it associates phthalates and the attendant health controversy with such pseudo-scientific topics as UFOs, reflexology, Clairvoyance, etc. Adding this tag to a talk page is similar, though not as extreme, as adding {{Category:Pseudoscience}} to an atricle page.
In short, while controversty certainly exists around the health effects of phthalates (and more generally the endocrine disruptor hypothesis), there is difference between this kind of controversy and rational skepticism. If the topic was just as irrational as those included in the project, there wouldn't be hundreds of papers published on it, with probably dozens of new ones coming out every month in peer reviewed scientific journals. The EPA wouldn't be putting together and endocrine disruptor screening program, etc, etc. Pustelnik may have his doubts, but that doesn't relegate the topic to ranks of dowsing, electronic voice phenomenon, and Magick. Yilloslime (t) 01:23, 12 February 2008 (UTC)
The US government, and a few others, have had projects to look into UFO's and remote viewing as well. The EPA looking into endocrine disruptors is similar. I would not object to moving the "health effects' section to endocrine disruptor. I think that the endocrine disruptor theory fits very well into the company of the phenomena you mention. The Rational Skepticism portal does not require that the topic be included in the Skeptic's Dictionary. A Rational skepticism tag means that the poster "Questions the veracity of claims lacking empirical evidence". Document that phthalates have health effects in humans, and in doses that are possible to get through unintended use. This tag is a challange to improve the article. Fraud? The author of one prominent paper in the field was sanctioned for scientific misconduct. Quasi-religious? I'll leave that one to the experts, but the endcrine disruptor movement does appear to have its own sacred scripture and saints. Pustelnik (talk) 02:10, 12 February 2008 (UTC)
The project page decribes the project as "Dedicated to creating and adding to articles related to science and philosophy, while checking the POV currently present in various Wikipedia articles dealing with such topics as psychics, magick, "alternative" medicines, etc." emphasis my own. The phthalates controversy—while perhaps overstated and sometimes misrepresented in the mainstream media—is none-the-less a legitimate scientific and medical controversy, and not pseudoscientific quackery along the lines of "psychics, magick, "alternative" medicines, etc."
I don't see where the project pages says that the "A Rational skepticism tag means that the poster 'Questions the veracity of claims lacking empirical evidence,'" but I do see where it says "In practice, a scientific skeptic generally focuses on critically examining claims and theories which they believe to be far beyond the mainstream of science." with the underlined linking to pseudoscience. The idea that low doses of phthalates may cause adverse effects in humans is certainly a testable hypothesis, and thus beyond the practical focus of rational skepticism stated above. Phthalates cause adverse effects in experimental animals; in in vitro assays, some phthalates interact with human hormone receptors; and most humans are exposed to phthalates in utero and throughout their life. Therefore, it's not unreasonable and it's certainly not pseudoscience to hypothesize that this exposure may adversely effect human health, nor is it unreasonable to suggest that we try to limit our exposure while we wait for the epidemiological studies that will test the hypothesis to be designed, carried out, analyzed, published, and then replicated. In the end, it may turn out that there was nothing to worry about, but we definitely don't know that yet. Yilloslime (t) 05:29, 12 February 2008 (UTC)
Direct quote from tne pseudoscience article: "Those labled as practicing or advocating a "pseudoscience" normally reject this classification. Pseudosciences have been characterized by the use of vague, exaggerated, or untestable claims, over-reliance on confirmation rather than refutation, lack of openness to testing by other experts, and a lack of progress in theory development." Pustelnik (talk) 12:18, 12 February 2008 (UTC)
That is a poor argument, as it can apply equally well to any topic, regardless of whether the topic is pseudoscientific or not. Imagine if we were talking about chemistry and a skpetic said, "Chemistry is psuedoscience," and a chemist retorted, "Actually, chemical hypotheses are testable....." to which the skeptic replied "Those labled as practicing or advocating a 'pseudoscience' normally reject this classification." The argument boils down to: "If I say it's pseudoscience, then it's pseudoscience," and that's about as non-scientific of an argument as they come... —Preceding unsigned comment added by Yilloslime (talk • contribs) 16:14, 12 February 2008 (UTC)
OK, take the Sheela Sathyanarayana article in Pediatrics. "Vague and exaggerated claims" of health effects in infants, even at lower doses than adults, although the study in question did not measure any health effects in infants or adults! The claims are "testable", but in the 16 years since Theo Colborn used the term "endocrine disruptor", they have rarely been tested. Over-reliance on confirmation rather than refutation speaks for itself. Lack of progress in theory development is also evident, in that the people claiming that these chemicals all are or "might" be dangerous have not looked for non-endocrine mechaniasm of toxicity, and in fact, rarely even measure hormones, but still claim that these affect the endocrine system. If you want to show that this is not pseudoscience, show me a specific statement in the form that X chemical causes Y in humans, in doses found in the environment. Then show where an experiment or epidemiologic study that could potentially disprove this was done, and did not disprove the effect. It is definite not a "he says, she says" situation. Claims that "more study is needed' are evidence that so far, the studies that have been done are not convincing. You don't need "more studies" to show that penicillin kills many bacteria, but you sure do to show that environment phthalates have any endocrine effect in humans. Pustelnik (talk) 00:42, 28 February 2008 (UTC)
The Sathyanarayana study is just an assessment of exposure, it's not meant to be an epidemiological study that would look for associations between exposure and health outcomes. True, after 16 years we don't have conclusive proof that humans can be adversely affected by environmentally relevant concentrations of chemicals interacting with the endocrine system. But that's irrelevant--there's no time limit on proving a hypothesis, and 16 years is certainly not a long time anyway. The wheels of science spin slowly. How long did it take to prove that benzene causes cancer, or that CO2 leads to climate change, or that trans-fats are bad for you? And those wheels spin especially slowly when the subject of investigation is the human body, since we can't just use people as guinea pigs to directly test hypotheses. Instead, we've got to wait around for an accidently exposed population to be identified, or in recruit pregnant women, test them for X, then follow their offspring looking for adverse effects, ect... Yilloslime (t) 06:51, 28 February 2008 (UTC)
This is pseudo-science because the claim is made that these substances are harmful in humans, without supporting evidence. It is what Richard Feynman called "cargo cult science". It has all the forms and trappings of science, but the aim of the research is not to prove or disprove a theory, it is to persue another non-scientific agenda, the banning of certain classes of chemicals. Pustelnik (talk) 02:49, 18 April 2008 (UTC)
You have any references for this characterization? Yilloslime (t) 03:39, 18 April 2008 (UTC)
See the WSJ article on 'Why I left Greenpeace" by one of its founders, listed below. There is ample evidence to re-instate the "Rational Skepticism" tag. The claim of adverse health effects is basicly a political move by environmental activists, and not a finding supported by scientific research.Pustelnik (talk) 11:10, 25 April 2008 (UTC)
The day that a mountain of studies in the scientific literature and risk assessments by various governments can be scientifically rebutted an Op-Ed in the WSJ (a notoriously poor source for scientific information) by a controversial non-scientist like Patrick Moore (environmentalist) is a sad day for wikipedia. Yilloslime (t) 16:00, 25 April 2008 (UTC)

Actually, he has a Phd in environmental science. Why do you call him a non-scientist?Pustelnik (talk) 17:03, 30 May 2008 (UTC)

Having earned a PhD in a scientific discipline in the past does not automatically mean someone is a scientist today. Practicing science in a professional capacity makes one a scientist. To make an analogy: Hillary Clinton has a JD, but she's not currently a lawyer. Yilloslime (t) 18:09, 30 May 2008 (UTC)
I just checked the Wikipedia article on Hillary Clinton, and she is listed as a lawyer in several categories. I would say that a few Wikipedia editors disagree with your categorizations. You just deleted a reference disputing the scientific value of the Sathyanarayana article in Pediatrics. Does this mean that you are not a scientist? That was not scientific behavior. On the other hand, maybe it means that she is not a scientist, as the article claimed that health effects were greater in infants, even though it did not measure any health effects! Pustelnik (talk) 02:49, 31 May 2008 (UTC)
Hilary Clinton has a JD; she's not currently a practicing lawyer. She once lived in Arkansas; she no longer does. What to make of the Category:Arkansas lawyers? Anyways, this is hair splitting, and I think I've proven my original point: scientists are people who practice science.
WRT the material about Sathyanarayana you want to include, I have two problems: The first is that you are making a straw-man argument. The point of the study was only to assess exposure, and it's clear both in the study itself and in what we've written about it here at WP that it did not attempt to measure adverse effects. So criticizing the article for not looking at health outcomes falsely impugns its value. Second, the letters to the editor that you want to cite don't appear to be publicly available--they don't seem to be online yet, even with a subscription (or they weren't yesterday when I reverted, I haven't checked today), and the print issue isn't out yet either, so per WP:V they can't be used as sources for anything. Yet. I realize this argument will be moot soon, if it isn't already. Yilloslime (t) 17:08, 31 May 2008 (UTC)
I had my copy when I added it. Most journals and magazines are "available" before their official publication date. You miss the point, now added to the article. If your study does not measure adverse effects (actually, no effects at all were measured), it is pseudoscience to claim that the effects are greater in infants. You need to proove your assertions, just like you need to prove thay something "might" be harmful. Pustelnik (talk) 21:47, 3 June 2008 (UTC)
The Sathyanarayana article does not claim to provide any new information about possible adverse effects of phthalate exposure. It's only an exposure assessment. The authors' statement that "Young infants are more vulnerable to the potential adverse effects of phthalates given their increased dosage per unit body surface area, metabolic capabilities, and developing endocrine and reproductive systems" is, I assume, intended to put their work in perspective and explain why their results are relevant and of interest. Putting the results of one's research into broader context is not pseudoscience, but rather a requirement of most journals that publish original research. While I agree that the "assertion" is not proven by the Sathyanarayana article itself, it is backed-up by the twenty-odd sources they cite in the intro section, and the statement is a reasonable summary of that literature. Or at least the editors of Pediatrics and the article's reviewers thought so, otherwise it wouldn't have been published. [Also, please properly indent your comments to make the discussion easier to follow.] Yilloslime (t) 22:36, 3 June 2008 (UTC)
May also be worth remembering that having a Ph.D. does not make one an expert on all fields of human knowledge. Ph.D.'s are generally awarded for highly focused work in a specific sub-discipline. They reflect a level of accomplishment and expertise in that discipline. However, without commenting on the specifics here, the world is overfull of people who leverage their degrees or accomplishments in one field to make pronouncements in another where they lack expertise. MastCell Talk 18:39, 30 May 2008 (UTC)
You won't get a disagreement from me on that, but a PhD in environmental science probably gives your opinion on environmental issues more credibility than someone with, say, a Masters of Science in chemistry. Pustelnik (talk) 02:55, 31 May 2008 (UTC)
You should be careful with that. I've got pretty thick skin, but a lot of folks around here would consider that comment a violation of WP:NPA. Yilloslime (t) 17:08, 31 May 2008 (UTC)
Just refering to Dr. Science. He has a masters degree. Pustelnik (talk) 00:56, 1 June 2008 (UTC)
In the spirit of WP:AGF I'll take your word for it, but since my userpage says I have a MS in Chemistry, you can see how one could interpret your comment as a reference to me. Yilloslime (t) 01:02, 1 June 2008 (UTC)
I posted to their main page, that if I had wanted to view articles by the Skeptical Inquirer, I would had gone to their website not Wikipedia. This is in my opinion, bizzare that they are allowed to post their template to Every article that appears in their dictionary. As I said before, If I wanted to read about articles in their Dictionary, I would had gone to the Skeptical Inquirer site. Not Wikipedia. In many of their so-called rational edits the meaning of the article has substantially changed in my opinion, to read like articles from the Skeptical Inquirer, thus the original meaning of the articles have been changed and I object to that greatly.Magnum Serpentine (talk) 21:43, 4 June 2008 (UTC)

[edit] EU risk assessments...

I have commented out[1] the paragraph in the health effects section about the EU's Risk Assessments (RAs) of DINP and DIDP for the following reasons:

  • It's unclear to me why we are singling out these two specific phthalates--do the EU RAs of other phthalates reach the similar or different conclusions?
  • The two RAs cited were published in 2003, and were based on literature published only up to 2001. Since then, a lot of new studies have come out, so holding these RAs up as definitive documents seems to muddle, rather than clarify, the picture.
  • The cited documents are hosted on www.phthalates.com, a phthalate manufacturer sponsored website. The actual EU RAs, hosted here[2] reach somewhat different conclusions and don't support what was written in this article's text, at least for DIDP which is the only one I've checked so far. For consumers, that report concluded "There is a need for limiting the risks; risk reduction measures which arealready being applied shall be taken into account. This conclusion applies in case DIDP should be used as a substitute for other phthalates in toys because of concerns for hepatic toxicity as a consequence of repeated exposure of infants and newborn babies arising mainly by the oral route from mouthing and sucking toys and baby equipment. Pertaining to reduced offspring survival, due to the uncertainty related to the relevance of this end point for newborns and infants and to the lack of experience in this particular field of transgenerationaleffect, no formal conclusion could be drawn."[3]

Yilloslime (t) 05:40, 13 February 2008 (UTC)

[edit] discussion of phthaltes in 'why i left greenpeace' article

Just stumbled across this interesting piece, http://online.wsj.com/article/SB120882720657033391.html by a "Patrick Moore, co-founder and former leader of Greenpeace", citing concern about phthaltes as an example of modern eco-irationality... Anyone care to integrate a mention to it? DanBri (talk) 21:29, 22 April 2008 (UTC)

[edit] orthophthalic acid

As discussed at phthalic acids, the ortho-isomer is called phthalic acid; the meta-, isophthalic acid; and the ortho para-, terephthalic acid. Furthermore, there are only 9,400 google hits] for "orthophthalatic acid", whereas there are some 408,000 hits for "phthalic acid." Finally, my Merck Index (12 Ed.) indexes the cmpd as "phthalic acid" and does not even list "orthophthalic acid" as a synonym. Yilloslime (t) 18:34, 25 April 2008 (UTC)

[edit] Can someone add an IPA or even better soundfile as to pronunciation???

Simple question: How the --- do you pronounce phthalate??? could someone add an ogg file for the non scientists?? Japan-man (talk) 08:19, 2 May 2008 (UTC)

I don't know IPA or how to make an ogg, but I can tell you the leading ph is not (generally) pronounced. So just pretend it's no there. "thal" rhymes with the names "al" or "val" and then "ate" is like, well, "ate". Yilloslime (t) 15:19, 2 May 2008 (UTC)