Talk:Heavy metal (chemistry)

From Wikipedia, the free encyclopedia
Jump to: navigation, search
          This article is of interest to the following WikiProjects:
WikiProject Elements (Rated C-class, Mid-importance)
WikiProject icon This article is supported by WikiProject Elements, which gives a central approach to the chemical elements and their isotopes on Wikipedia. Please participate by editing this article, or visit the project page for more details.
C-Class article C  This article has been rated as C-Class on the quality scale.
 Mid  This article has been rated as Mid-importance on the importance scale.
WikiProject Chemistry (Rated C-class, Low-importance)
WikiProject icon This article is within the scope of WikiProject Chemistry, a collaborative effort to improve the coverage of chemistry on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.
C-Class article C  This article has been rated as C-Class on the project's quality scale.
 Low  This article has been rated as Low-importance on the project's importance scale.
WikiProject Medicine / Toxicology (Rated C-class, Low-importance)
WikiProject icon This article is within the scope of WikiProject Medicine, which recommends that medicine-related articles follow the Manual of Style for medicine-related articles and that biomedical information in any article use high-quality medical sources. Please visit the project page for details or ask questions at Wikipedia talk:WikiProject Medicine.
C-Class article C  This article has been rated as C-Class on the project's quality scale.
 Low  This article has been rated as Low-importance on the project's importance scale.
Taskforce icon
This article is supported by the Toxicology task force (marked as High-importance).

Article of dubious value[edit]

As the article indicates, the meaning of heavy metal is unclear. This article thus joins a collection of similarly dubious articles including toxic metals, gold salts, and now light metals. I am sure that the creation of these articles was motivated by good intentions, but as a chemist, I think that these articles do a net disservice to the readership: they delude readers into thinking that these terms have merit among mainstream chemists. --Smokefoot (talk) 17:17, 4 August 2009 (UTC)

I tend to agree with you (I was the one to add reference #1 and the whole bit about the ambiguity of the term). However, we can't deny that "heavy metal" is used very often by the public (every time there is a news report on Hg or Pb for instance), and is even used by many members of the scientific community who should know better. It is therefore important to have a Wikipedia article that acknowledges this term's existence and explains what people "think" they mean when they use it. The article should make it clear that this term is meaningless. This isn't so clear in the article right now - if anything, the warnings of the first paragraph seem to be ignored by the content of the rest of the article. Time for a re-write. I've moved your comment to the top of the comments section in the hopes that it will inspire someone to work on the article (I hope I haven't committed a faux-pas in doing so!)Nojamus (talk) 19:49, 14 January 2010 (UTC)
I agree with Nojamus -- people use the term "heavy metal" extremely often, and so it is important to have a Wikipedia article on that topic. Even though the term is almost as meaningless as phlogiston or Martian canal or Counter-Earth. I hope that all these articles never delude our readers, but all make it clear that these terms do not have merit. -- (talk) 22:05, 4 May 2010 (UTC)
Agree on the dubious value. Quote: "...these terms do not have merit." Perhaps not from a chemist's perspective, but they do from a linguist's. ...and socially, as do vampires, beauty and GOD. Quote: "Many different definitions have been proposed—some based on density, some on atomic number or atomic weight, and some on chemical properties or toxicity." ...yet the first three or four are mostly ignored. This should be repaired. "PRIMARY MEANINGS OF: heavy metal 1 n, a metal of relatively high density (specific gravity greater than about 5) or of high relative atomic weight (especially one that is poisonous like mercury or lead)" And "Heavy metals (Chem.), the metallic elements not included in the groups of the alkalies, alkaline earths, or the earths; specifically, the heavy metals, as gold, mercury, platinum, lead, silver, etc." RE: the conversation here, scientists should not control this topic any more than they should control the topic of beauty or GOD. I think the Philosophy of Science agrees.
-- (talk) 00:27, 31 January 2012 (UTC)Doug Bashford


With de definition "heavy metals are a group of elements between copper and mercury" you are excluding, for example, the heavy metal lead.


This article doesn't really talk about anything associated with heavy metals The hub 12:08, 21 June 2007 (UTC)

Gold and Tungsten[edit]

Gold is a heavy metal poison also. It is just hard to find soluable compounds of it, but they do exist and will bioaccumulate.

I do not think Tungsten is 'horribly toxic', I think it has a mediocre toxicity, and does not bioaccumulate.

Beryllium included as a heavy metal[edit]

I don't think beryllium, the second lightest metal and the fourth lightest element, should be included in the definition of heavy metals. However, mentioning that light, but toxic, metals are sometimes incorrectly called heavy metals would be fine. -- Kjkolb 02:03, 18 December 2005 (UTC)

Beryllium or Potassium as Second-Lightest Metal[edit]

I'm sorry, I am confused, a search of wikipedia will aid you to discover that both beryllium and potassium are (as labeled according to other wikipedia users) the "second lightest metals" since I doubt this is true, could someone who knows please verify which one of these two entries is true, following is the link to the Potassium article. Thanks for your help.

The article says that potassium is the second lightest by density (at least it does now). Beryllium has a lower atomic mass, so it is lighter on a per atom basis. Density is mass divided by volume, though (they're not talking density on a single atom basis, which beryllium would win). If a light element packs its atoms closely together, then a solid piece or a cupful of the element may be heavier than a heavier element with atoms spaced farther apart. -- Kjkolb 10:36, 16 August 2006 (UTC)

Heavy metal poisoning[edit]

A request for the above separate page was put on the Expansion page.

A minor point for the article on creation - the use of heavy metals in "detective fiction poisoning" - Arsenic and Old Lace, and thallium in Agatha Christie's The Pale Horse. Jackiespeel 17:20, 14 June 2006 (UTC)

Page title[edit]

Shouldn't the title of this page be Heavy metal rather than Heavy metals, by Wikipedia:Naming conventions? ―Wmahan. 06:32, 3 October 2006 (UTC)

Heavy metal is also a musical genre,so maybe it's better to keep it the way it is right now.

Heavy metals in food sources[edit]

I got to this page from a link from Omega-3_fatty_acid, in particular, am interested in which foods have a high risk of heavy metals (such as certain fish... which ones?), and in what magnitudes?

  • Generally fishes and sea food - the larger, the more mercury poisoned may they be; sea salt; kelp; other. — Preceding unsigned comment added by Ozrev (talkcontribs) 22:55, 15 December 2013 (UTC)

I'm searching for information on how to artificially increase a metal's physical weight to indefinitive amounts.[edit]

Friday, 10-6-06; Portland, OR; 12:04pm West Coast Pacific Time

Is there an expert on this "Talk:Heavy metals (comment)" page who knows how to artificially increase the physical weight of a small piece of metal (say the size of a 1/2 inch diameter galvanized steel washer)? Is this only theory, or has this concept actually been proven? bear in mind, that I wish to affect only the weight of this size and not the physical dimensions of this size; in other words: Is it possible to artificially increase the weight of a 1/2 inch diameter steel washer to an indefinite weight such as, for example, 50 lbs., 100 lbs., 150 lbs., 200 lbs., 500 lbs., or even to a weight of 1,000 lbs.? Why would I want to try this? For a private science project I'm cogitating.

--MyPresentCPUisTooSlow 19:33, 6 October 2006 (UTC)MyPresentCPUisTooSlow

You would either have to compress it and add more metal to it, or turn it into a different substance entirely. There is no way to keep the same substance and change the weight, exempting splitting the atom. And that just decreases the weight. —The preceding unsigned comment was added by User: (talkcontribs).
There is, of course, one very obvious way to keep the same metal and increase its weight: subject it to a stronger gravitational field. The weight of a particular mass of metal varies depending upon local gravity. However, I'm thinking this isn't the answer that you're after. Cheers, --Plumbago 09:10, 11 January 2007 (UTC)
You could bombard the metal with neutrons, and sometimes in some cases some metals would absorb them into their nuclei, yielding heavier isotopes of the same metal element (say, steel, as in your given example). It wouldn't be more than a marginal weight (mass) increase. Not up to the orders of magnitude of increase that you're after. Under most conditions, you would "split atoms" with your neutrom beam, like was saying, though he was wrong to say that you'd be left with the same metal (no more steel). Atom splitting yields different elements. Good luck with your private science project. 18:07, 21 August 2007 (UTC)
I think the density increases that you're after are not attainable (not in this century and on this planet anyway ;-). If you really want the same steel item to significantly increase it's density, it can hardly be done in a reasonable way. Neutron bombardment, as outlined above, is of course not for do-it-yourself science projects. And even if you attempted that (which would be dangerous and possibly illegal), all you could reasonably hope for is to convert all iron atoms into iron-58 isotopes (the heaviest stable iron isotope) which whould yield a density increase of only 4% over the original item. Much easier would be to use directly an item made from a more dense steel alloy, e.g. a tungsten steel alloy, but that of course is then a different item. So I think it is safe to say, your desired goal is not even within the realms of fringe science, but total science fiction.-- (talk) 12:27, 9 April 2008 (UTC)

Added Wikify Tag[edit]

I'm not sure if that was the appropriate tag, but this article does not read like an encyclopedic entry should. I don't currently have the knowledge to update the article properly, so hopefully this tag will draw someone in. Maghnus 05:39, 5 March 2007 (UTC)

Free radicals?[edit]

The paragraph about free radicals and their link with heavy metals seems to be unmitigated pseudoscience. In particular, it's contradicted by a lot of the article on Chelation therapy. Also, eating foods rich in fibre is hardly going to "wisk metals out of the digestive tract", and stating that phytonutrients have "an extra electron which is used to deactivate free radicals" would offend any semi-knowledgeable biology student, not least because the term "phytonutrients" encompasses a huge variety of different compounds. I'm deleting the paragraph entirely as there's very little there to salvage. Kupos 20:06, 10 April 2007 (UTC)

I concur. That one about the extra electron was a doozie. A lot of information and theory out there is propagated without wide replication and peer review. Does the experiment mean what it seems to mean? I hav no trouble with promoting vejtable consumption, but phytonutrient is too jeneral a term in the context and I am sick and tired of hearing about vejtables that react to the atmosphere.
I'm a free radical. BrewJay (talk) 10:29, 21 March 2008 (UTC)

Depleted Uranium[edit]

Is depleted Uranium classified as a heavy metal? Would it be an acceptable example (it is quite dense, it is a metal, so I would be hard pressed to deny that it is a heavy metal).

read referece #1 and your question will be answered C.wolke (talk) 21:13, 4 October 2008 (UTC)

List of Common Problematic Heavy Metals[edit]

It would be prudent to list some of the common problems associated with certain heavy metals – including, for example : 1)Mercury 2)Lead 3)The list could go on – but you get the picture.

Some metals are already mentioned - but I was hoping more for a systematic list (say, a list of all metals in the periodic table, together with comments concerning the MANY different alloys of them which are present in industrial society and how alloying can affect toxicity, etc...).

Common symptoms which both “major” exposure are associated with, as well as “minor” exposure (ie: low level background exposure for prolonged time periods).

Common methods of detection (some simple, scientific, “back garden” methods of detecting and calibrating concentrations of heavy metals in water and food supplies sounds like a good idea here).

It is worth adding the comment that even minor amounts of heavy metal, when they find themselves in body tissue, have the effect of negatively affecting nervous cells, etc....- but this is probably too obvious to mention.

MrASMafmo (talk) 21:02, 11 March 2008 (UTC)

read referece #1 and you will know that a list of heavy metals will include ALL elements of the PSE except H - therefore such a list would be meaningless C.wolke (talk) 21:15, 4 October 2008 (UTC)
So, what do they make bone plates, bone pins, and tooth fillings out of? Toxic substances! I knew our doctors/dentists were trying to kill us!!
The public must assume that some things are reasonably benign. And some things are not (which is why they're banned (eg: lead paint/pipes, asbestos, mercury thermometers, etc))
I don't think MrASMafmo is unreasonable to want to find a list of the biggest culprits of widespread disorders. Which is kinda the whole linguistic purpose behind the unscientific term 'heavy metals'.
~ender 2014-10-14 1:53:AM MST
The article toxic metal already exists, but the situation isn't resolved, both in reality and on Wikipedia. --Vuo (talk) 11:06, 5 October 2008 (UTC)

One Decision[edit]

Heavy metal, in most cases, is pejorative, so I've long understood it to exclude essential minerals. Then again, I see that balance is important, so I can understand some authors including Zinc. Beryllium is a hard case, since it's lighter than many inevitable elements of biology (carbon, nitrogen, and phosphorus). Lead is clearly in the category. So are Tin and antimony. I mean to avoid saying "Heavy Metal" without excluding transition metals. I've got this tap water dechlorinator that says on the bottle that it removes Heavy Metals. I'm not going to believe that until I see a precipitate. BrewJay (talk) 10:02, 21 March 2008 (UTC)

read referece #1 and your question will be answered C.wolke (talk) 21:13, 4 October 2008 (UTC)

TEGA-Öfen erhitzen die Proben bis auf 1000 Grad Celsius (NASA/JPL/University of Arizona/Texas A&M)[edit] (talk) 15:17, 7 June 2008 (UTC)


Bismuth is not stable.Tailsfan2 (talk) 22:30, 13 January 2009 (UTC)

Lead is not a transition element[edit]

The article says: One source defines heavy metal as one of the "common transition metals, such as copper, lead, and zinc. Well, that source isn't worth citing as whoever wrote it doesn't know that lead is not a transition metal - it's a group 4 element. (talk) 13:23, 28 July 2009 (UTC)

Don't know if the source actually said that, but it was erroneous/confusing ... removed. Vsmith (talk) 15:57, 28 July 2009 (UTC)


Arsenic (As) is not a metal at all. I suggest to remove As completely from the text as this element being listed here is even more misleading than the term "heavy metal" itself. C.wolke (talk) 20:43, 12 February 2010 (UTC)

I removed the sidebar link to the Latin article since that article deals with Heavy Metal music and not with chemistry. — Preceding unsigned comment added by (talk) 19:52, 2 November 2013 (UTC)

Clarification needed[edit]

@Smokefoot: You added a 'clarification needed' tag to the opening sentence, which currently reads: "A heavy metal is any metal or metalloid of environmental concern." Could you elaborate as to what clarification you were looking for? Sandbh (talk) 09:55, 24 April 2015 (UTC)

Well it reads like a student essay or op-ed,. Where are the books on "heavy metals". Is there a field of study recognized by some university course or research institute? IMHO, good articles begin with a topic that is well defined and then discuss the components of that topic. On the other hand, this thing is a form of "hippie science", a topic concocted by naive editors, well intentioned no doubt. Toxic metals is another one. I guess we could write an article on light metal ... oops we have one! --Smokefoot (talk) 13:29, 24 April 2015 (UTC)
Hmm, I hope it stacks up better than a student essay in the eyes of other readers! I can see a coherent structure viz., definitions > contamination sources > entry routes > detrimental effects > historical reports > remediation > benefits. I also see content that is supported by what appear to be reliable sources, including several books such as Heavy Metals in the Environment (Wang et al. 2009). And it wasn't my intent to turn the article into an op-ed so if it comes over that way, please elaborate. As far as universities etc go I presume the topic of heavy metals is subsumed within, say, Environmental Science; Chemistry; Toxicology; Botany; or Geochemistry. I did find mention of a Centre for Heavy Metals Research, within the School of Chemistry at the University of Sydney although I wasn't able to locate details of its charter. Curiously, I also found mention of a 1992 Monash University PhD thesis, Chemistry of the heavy metals, by Cant, but am not yet sure of its coverage.
I cannot accept the hippie science categorisation. Clearly, the term "heavy metal/s" and its meaning is used in scientific writing by scientists, even if it is a fuzzy concept—indeed, notions or definitions that suffer from fuzziness (e.g. atomic radius, electronegativity, metallic bond, organometallic chemistry, transition metals) pervade chemistry to some extent. Searching Royal Society of Chemistry Journals, for example, yielded 14,694 hits for the phrase, "heavy metals". As to toxic metals, Wikipedia doesn't have an article by this name; I presume you were referring to the metal toxicity article. I'm not a fan of the light metals article in its current form although there would probably be no shortage of potential source material. Deming, writing in Fundamental chemistry (1940, 1947) devoted a chapter to light metals, which he defined as the alkali and alkaline metals and aluminium (a category instead referred to as 'pre-transition metals' by some other authors); metallurgically there is Smithell's light metals handbook (1998); a search of American Chemical Society journals generated 391 hits for the phrase "light metals"; and the The Minerals, Metals & Materials Society has a Light Metals Division organised to "serve professionals in both the traditional (aluminum, magnesium, beryllium, titanium, lithium, and other reactive metals) and emerging light metals (composites, laminates, etc.) fields." I included a link to this article in the hope of prompting another editor to see if they could improve it. Sandbh (talk) 06:14, 26 April 2015 (UTC)

Origin of the term[edit]

The lede says "The term originated with reference to the harmful effects of metals like ..." but the second paragraph of § Definitions says "The origin of the term is not clear." Seems like one of these needs to be changed a bit. YBG (talk) 04:14, 1 May 2015 (UTC)

Changed the second one, thanks. Sandbh (talk) 08:03, 1 May 2015 (UTC)