Talk:Electronic cigarette

A note

I made a few changes to the article (mostly Lead section) today. Most of it was stylistic, merging sentences, rephrasing, moving stuff around, but I hope people will review them for any unintentional errors I might have made. ~Awilley (talk) 21:27, 4 February 2016 (UTC)

Thank you, most of the changes look good. Is there a reason the phrase "but reduced voltage e-cigarettes produce very low levels of formaldehyde" was removed? P Walford (talk) 16:19, 5 February 2016 (UTC)

Thanks for your feedback. On the voltage phrase, I was trying to make it more accessible to normal readers and take out redundancy. So instead of talking about high and low "voltage", which might alienate some readers ("what's a voltage and how do I reduce it?") I put it in terms of high and low "power". The sentence "Using later-generation e-cigarettes on high power can generate more formaldehyde than tobacco does" implies that using them at low power doesn't. It's not necessary IMO to follow that up with "but using e-cigarettes on normal power doesn't generate very much formaldehyde." You can add it back if you want. ~Awilley (talk) 18:25, 5 February 2016 (UTC)

Voltage is more specific than power since higher power may also be caused by an increase in current. Sizeofint (talk) 02:42, 13 February 2016 (UTC)

The increase in voltage is accompanied by an increase in current. The Resistance is fixed, the device can increase the voltage (sometimes displayed as wattage increase but it's the same step up voltage process). It's a power increase and the mechanism usually used is voltage change. That said as here is an interdevice comparison you can have power changes for other reasons and strictly wattage is more closely related to the formaldehyde issue, most directly it's coil temperature. SPACKlick (talk) 02:49, 13 February 2016 (UTC)

@Doc James: Regarding this I did a quick search of the archives and found a lot of RfCs, but I couldn't find the one you're talking about. I don't doubt your word, but would you mind pointing me to this particular one?

On whether Health is more notable than History, I would say that the latter is more important for an encyclopedia, but I can understand why you, in particular, would disagree with that. In any case, I don't think "notable" is a good criteria for determining order. That should be done logically, preferably chronologically, with the reader in mind. To me it makes sense to start with the general introduction, then talk about the history, and then talk about safety, health, cultural impact, etc. I realize all articles will do it differently, but I looked up the most closely related article I could think of (cigarette) and it fits that pattern fairly well.

Last point: If you think that Healthy/Safety is indeed the most important thing, you should be trying to end the Lead section with the paragraph on health/safety, since that's the last thing most visitors will read. See our article on serial position effect for why that might be a good thing. ~Awilley (talk) 04:47, 6 February 2016 (UTC)

It is normal in health-related articles to put History much lower than on many other types, and I think this is absolutely correct. Few readers of pancreatic cancer will be very interested in the history, I suspect. Putting history generally first is a WP tradition, but one I think we overuse, especially when the section is long. Cigarette should probably change too - at present the "Health effects" section begins at (on my m/c) the 16th screen down, which is downright bizarre, but at least that story is no secret. Certainly we should not use that as a model here - I think a very different crowd edits there. I think the RFC the Doc refers to was a general one at the MED project,not specific to this article. Johnbod (talk) 05:53, 6 February 2016 (UTC)

@Awilley There have been a few RFC's on page order. Archive 16, Never closed and archive 17 no consensus and archive 22 no consensus, I may have missed the one DJ is referring to. The topic keeps coming up every so often. I wonder if a list somewhere near the top of all the RFC's this page has had would be helpful to avoid this kind of thing in the future. AlbinoFerret 06:29, 6 February 2016 (UTC)

Thanks Albino for providing the links. The order has been controversial. Doc James (talk · contribs · email) 15:13, 6 February 2016 (UTC)

Good heavens, let's not start that up again. There are more significant improvements that can be made without starting another RfC to change something as mundane as the section order. ~Awilley (talk) 17:03, 6 February 2016 (UTC)

Glanze Redux

Just listened to an interesting 5 mins or so feature on Glanze's recent paper (see above) on today's More or Less (radio programme), a BBC radio programme covering statistics etc. Some of you should be able to pick it up online from the website linked at the article, starts about 5 mins in. Linda Bauld, Ann McNeill, Peter Hajek (co-author of the Cochrane Review - "grossly misleading" he says), Robert West ("mashed together very different studies") - all saying the paper should not have been published, as did an un-named person who peer-reviewed it for the Lancet sub-journal. Glanze & the editor unrepentent. Johnbod (talk) 16:52, 5 February 2016 (UTC)

That's what you get when you mix activism with science. I'm sure it will be straightened out in coming reviews.--TMCk (talk) 18:11, 5 February 2016 (UTC)

Well from a WP stance, as i mentioned earlier[1] its simple: The Glantz paper is a secondary WP:MEDRS review, thus reliable and can be used. The More or Less program is interesting - but cannot really be used. If the paper is flawed then we as WP editors must wait until it gets resolved in the peer-reviewed press. --Kim D. Petersen 09:39, 6 February 2016 (UTC)

Well, the American Legacy Foundation (currently Truth Initiative), which is the largest anti-smoking organisation in the USA, has publicized a systematic review ("The findings were compiled from an in-progress comprehensive systematic review of all published scientific literature on e-cigarettes conducted via a PubMed search through February 19, 2015") which criticizes a pre-published version of Glantz's meta-analysis. Can their findings be reflected in WP?GreyZig 14:37, 16 February 2016 (UTC) — Preceding unsigned comment added by Zvi Zig (talk • contribs)

Diacetyl - toxicology section added to main article. Consensus on moving it to Safety

CFCF has added a section to the page dealing with Diacetyl. This is a toxicology section and IMHO belongs on safety instead of adding it here to a summery section. Opinions? AlbinoFerret 01:23, 8 February 2016 (UTC)

I strongly disagree, this information is florating in the popular press and while this does not give indication to the strength of the information it says a whole deal about its relevance to the main article.

• Wired
• Motherboard
• Washington Post
• National Law Review

The source of the commotion is a new research paper (yes primary, so I chose not to include it) from Harvard claiming: Diacetyl was found in "39 of the 51 flavors tested" [2]

This is not only important as health information for anyone considering buying such e-liquids, but due to recent events also important as a source of proper information in a sea of misinformation, where there are claims that all flavorings are poisonous or even than all ecigs may cause bronchiolitis obliterans. CFCF 💌 📧 06:56, 8 February 2016 (UTC)

• Clearly belongs in the Safety of electronic cigarettes article. And if the material is sufficiently important/pertinent to be summarized from that article, then it should be in that summary. With regards to CFCF's commentary above: You seem to think that Wikipedia should be used to debunk or support what is in the current news-cycle. In other words use Wikipedia as journalism, which is a no go. And finally: Newsmedia coverage does not lead WP:WEIGHT to a MED topic... we are all aware of how wrong media gets medical and science issues - right? --Kim D. Petersen 07:25, 8 February 2016 (UTC)

The above sources have no impact on the weight of the content currently in the article, but they impact its relevance and give an idea about how many readers will come here to inquire about it. It is exactly as you say "we are all aware of how wrong media gets medical and science issues" — but, this is a reason why we should present the facts, instead of leaving to popular speculation. Hiding important and relevant content in sub-articles isn't helpful, and we shouldn't pretend that these get any significant readership (the reason I don't spend any of my limited time working on them), but by all means copy the content there as well. CFCF 💌 📧 21:31, 8 February 2016 (UTC) 

• Doesn't belong anywhere in WP yet, until it is discussed in a secondary source. Jytdog (talk) 07:55, 8 February 2016 (UTC) (striking, I apologize for not having read the actual introduced content Jytdog (talk) 01:10, 9 February 2016 (UTC))

Jytdog It is discussed in secondary sources, the added text is only from secondary sources. This was only justification for it being included in the main article, not in the safety article. CFCF 💌 📧 09:26, 8 February 2016 (UTC)

One of the sources in the article isnt on e-cigs. Its about Diacetyl and popcorn flavourings. AlbinoFerret 11:54, 8 February 2016 (UTC)

Yes, and that source is used to add context that this was how the discovery was made that aerosolized exposure may lead to lung disease. It is absolutely relevant to the section and does not add anything that could amount to synthesis of sources. CFCF 💌 📧 21:31, 8 February 2016 (UTC)

Thats mixing apples and oranges. There is no source that links the type of exposure in a industrial popcorn factory to the exposure in e-cigs. AlbinoFerret 00:15, 9 February 2016 (UTC)

Actually, the first source in the section, the one you cited ([3]) does. — page 4
Actually the very sentence above the one you cited

Some ENDS solutions contain harmful flavoring molecules, diacetyl and acetyl propionyl, used to add a buttery taste to the vapor and are known to cause bronchiolitis obliterans. These chemicals have been demonstrated to be present in higher concentrations in ENDS than is recommended by the National Institute of Occupational Safety and Health [33].

CFCF 💌 📧 00:35, 9 February 2016 (UTC)

Content in question

Flavorings

Diacetyl is commonly found at lower levels in e-cigarettes than in traditional cigarettes. Certain flavorings may contain harmful substances such as diacetyl and acetyl-propionyl which give a buttery taste. Diacetyl has previously been connected to bronchiolitis obliterans when breathed in as an aerosol by popcorn manufacturers, known then as Popcorn lung. A 2015 review urged for specific regulation of diacetyl and acetyl-propionyl in e-liquid, which are safe when ingested but harmful when inhaled. Both diacetyl and acetyl-propionyl have been found in concentrations beyond those recommended by the US National Institute for Occupational Safety and Health.

A 2015 class-action lawsuit is pending in Orange County over claims connecting the specific e-liquid flavorings containing diacetyl and acetyl propionyl and incidences of the lung disease bronchiolitis obliterans.

References

To clarify this is the added text, it is not related to the above popular press and primary sources. As you can see — this is all sourced to secondary sources, all of which are MEDRS-compliant or unrelated to medicine. CFCF 💌 📧 21:36, 8 February 2016 (UTC)

The first paragraph of that content is fine WP content. My apologies again for my earlier sloppy reaction. With regard to the second paragraph, I have a strong preference to not discuss ongoing litigation until it is resolved, unless the litigation itself causes big changes (in this case, if companies stopped using it because of the litigation, per reliable sources. I'll address the WEIGHT question - whether this belongs here - in a moment, when I read some more. Jytdog (talk) 01:13, 9 February 2016 (UTC)

In a main article like this, which has spawned sub-articles, I am a firm believer that content should be added first to the relevant spun-off articles, evaluated as to whether it is important enough to make the lead of that article, and if it does, modify the lead of that article, and only then added to the main article. That is all per WP:SUMMARY and WP:SPLIT. I have removed the content from this article and have added it to the body of the safety article and blended it in this series of diffs. I did remove the litigation information. I think we will need more information on how prevalent diacetyl is in e-cig liquids in order to decide if it rises to the importance of making the lead of that article; there is not enough information in hand to decide that right now. Jytdog (talk) 01:40, 9 February 2016 (UTC)

I agree with all that. Johnbod (talk) 09:49, 9 February 2016 (UTC)

effect on immune system genes

I just came across this--leaving it here for other people to possibly decide to use.

• http://arstechnica.com/science/2016/02/e-cigs-shut-down-hundreds-of-immune-system-genes-regular-cigs-dont/

173.228.123.101 (talk) 19:20, 13 February 2016 (UTC)

Yu et. al.

I have seen several stories in the national press in the UK covering Yu et. al.: [4]. Since this is from November 2015 I presume it has already been discussed, which archive should I look in please? Guy (Help!) 11:18, 15 February 2016 (UTC)

For clarity the article is doi:10.1016/j.oraloncology.2015.10.018 (the link did not work for me)—but no, it has not been discussed. We stick almost entirely to secondary sources for these articles, and while that source is without question very interesting, it is so in the same way that Ars Technica – E-cigs shut down hundreds of immune system genes—regular cigs don’t is interesting—the evidence is only preliminary and it is better if Wikipedians are removed from trying to interpret it. CFCF 💌 📧 12:22, 15 February 2016 (UTC)

Agreed. We stick to secondary sources entirely. --Kim D. Petersen 15:02, 15 February 2016 (UTC)

Also agree, we do not lack for secondary sources in this article. Its best that we stick to secondary sources. AlbinoFerret 20:06, 15 February 2016 (UTC)

Why all the refs in the lead?

The lead section of a Wikipedia article is supposed to summarize the article's contents, so inline citations (which make it look like the material was added to the lead first) should be kept to a minimum. And yet somehow this article's lead has over forty!? Also, the lead is enormous... just saying...

Hijiri 88 (聖やや) 09:58, 22 February 2016 (UTC)

Most leads on medical articles are referenced, and should be. Most leads are also much too short, and this is a long article on a complex topic. The lead now has 5 paras, one more than WP:LEAD suggests, but personally I think that's ok. Johnbod (talk) 12:45, 22 February 2016 (UTC)

Can you cite tge PAG that says "Most leads on medical articles should be referenced"? This seems counter-intuitive to me. The body should be thoroughly referenced, but the lead should comprise a summary of the body. It should be based on the content of the article itself, not on external reliable sources. Hijiri 88 (聖やや) 13:58, 22 February 2016 (UTC)

Can you provide a PAG that says that the lede should not be referenced? AlbinoFerret 14:08, 22 February 2016 (UTC)

WP:LEDE states that ”[t]he lead serves as ... a summary of [the article's] most important contents”. It does say that the lead's contents should be verifiable (a given), but this in my experience more usually interpreted as meaning that the lead should summarize the sourced contents of the article body. The only things it says need citations are contentious statements. The enormous number of citations in this article's lead (some of them not cited anywhere else in the article!) implies it was composed independently of the rest of the article, which would be a clear violation of the project norm. Hijiri 88 (聖やや) 22:59, 22 February 2016 (UTC)

I take that as a no, you do not have a PAG that says the lede should not be referenced. AlbinoFerret 23:16, 22 February 2016 (UTC)

The relevant section is WP:LEADCITE, which doesn't prohibit going overboard with cites (that's left to editorial judgement). Common practice is to avoid citation clutter in the lead as, per MOS:INTRO, it is "a concise version of the article" meant to "briefly summarize the most important points covered in an article" (where the cites are mandatory and thus redundant in the lead). Cites in the lead interfere with its readability, particularly when they are numerous. This lead is a particularly ugly example, but I won't comment on whether it's justified. Curly Turkey 🍁 ¡gobble! 23:46, 22 February 2016 (UTC)

@AlbinoFerret: So let's get this straight: I post an OP comment accurately summarizing the PAG that says that leads should summarize body contents, and another user shows up and makes a bizarre claim that articles on medical topics usually have more sources in the lead than other articles. This "PAG" does not appear anywhere on-wiki. When I ask the user to quote the PAG, you show up and dodge the question, insisting that I quote the PAG that I already quoted. I do this, and then you promptly ignore the PAG that I quoted at you. But still no Wikipedia PAG has been provided that says "Most leads on medical articles should be referenced". MOS:MED actually says the opposite: Adding sources to the lead is a reasonable practice but not required as long as the text in question is supported in the body of the article. So why are there some sources cited in the lead that aren't cited in the body? Does the material they support in the lead not appear in the body? If so, that is an explicit violation of the core principle of WP:LEDE that The lead should ... summarize the body of the article with appropriate weight.. Hijiri 88 (聖やや) 04:49, 23 February 2016 (UTC)

To say, as I did, "Most leads on medical articles are referenced" will only seem a "bizarre claim" to someone who has never looked at any of our developed medical articles. Johnbod (talk) 13:55, 23 February 2016 (UTC)

There are statements in the lead that aren't cited in the body? That's a straight-up violation. Are you sure they weren't in today's addition (the one that added a fifth paragraph) that has since been reverted? Curly Turkey 🍁 ¡gobble! 05:06, 23 February 2016 (UTC)

I can respond to Hijiri88 by stating that no PAG supports this either way, and LEADCITE allows for a fully cited lede. That medical articles normally have fully cited ledes doesn't mean any PAG requires them to have citations, but that the community of editors has come to realize that it is very helpful—it may at some point be added to a PAG, but for now that hasn't been done as it is not required. WP:MEDRS gives an indication as to why medical statements are sensitive, not only because of their impact on lives, but also because of the controversy surrounding any single statement.

Now, this may be going to in depth for this discussion, but most of our readers (especially on medical articles) do not read past the lede, and having sources present there is very useful for that group. (I will not provide data for this here, but it exists). Also worthy of notice is how certain editors and even IPs will tag any statement without a directly visible source in medical articles with a {{cn}}-tag, regardless if it is in the lede or in the body.

So, lets move this discussion from the unproductive to the productive. We identified that the prior 5-paragraph lede had 6 citations for a single statement – which is CITATIONOVERKILL – and normally a sign of dubious statements. I can not see any similar issues with the current content — does anyone else? CFCF 💌 📧 07:28, 23 February 2016 (UTC)

There are statements in the lead that are cited to sources that are only cited once, in the lead. Admittedly, on a brief inspection the one I found was attached to a sentence that also cited two other sources, which means either that it is redundant or that the sentence includes information taken from all three sources, and some of that information does not appear in the body of the article. I don't have a serious problem with a fully-cited lead (though I think it is ugly and gives the wrong impression, and would never do it myself -- this attitude is not required by PAG, but it is encouraged), but unique citations in the lead are definitely a problem, as they are either redundant and give the wrong impression, or they are being used to include information in the lead that does not appear in the article proper. A slightly more thorough examination revealed that there are at present three such sources (currently numbered 15, 29 and 37); of these, only the last is not accompanied by other citations, and appears to be used to support the statement that "In the United States e-cigarettes are used by a significant percentage of ... adults". ("e-cigarettes are used by a significant percentage of youth" is attributed to another source that is used in the following section for "up to 13% of American high school students had used them at least once in the last month", but this difference in wording is not really a problem.) I don't have time to read the entire article at the moment, much less the tens of thousands of words of talk page archives, but has this sentence in the lead been discussed? Does it accurately and duly summarize some point that is made in the article? Summarizing "3.4% of American adults" as "significant" seems dubious... Hijiri 88 (聖やや) 08:12, 23 February 2016 (UTC)

The more controversial an article subject is, the more citations you will see in the lede. That follows per WP:V. If someone could question the statement, then it must be cited. --Kim D. Petersen 21:47, 22 February 2016 (UTC)

The more controversial an article subject is, the more citations you will see in the lede—not true. Richard Nixon (a Featured Article) is the subject of considerable controversy, yet there isn't a cite in his entire lengthy lead (even, surprisingly, for the statement "he is historically ranked as among the worst U.S. presidents"). Citations are allowed in the lead for particularly contentious individual statements, but never are they required in the lead, as any statement in the lead must be in the body, where it must be cited. Curly Turkey 🍁 ¡gobble! 23:50, 22 February 2016 (UTC)

• I tend to agree with the OP that the Lead does have a case of WP:Citation overkill. The 1st sentence of paragraph 2 has 6 citations! As a side note, I'm not sure when it grew a 5th paragraph. It only had 4 the last time I checked. ~Awilley (talk) 01:32, 23 February 2016 (UTC)

This poorly constructed and undiscussed edit inserted the 5th paragraph just a few hours ago: https://en.wikipedia.org/w/index.php?title=Electronic_cigarette&diff=706352255&oldid=706329637 CFCF 💌 📧 01:45, 23 February 2016 (UTC)

(edit conflict)Pinging User:Zvi Zig who seems to have added the 5th paragraph just today [5] ~Awilley (talk) 01:46, 23 February 2016 (UTC)

Have restored it to 4 paragraphs. Refs in the lead are fine. Doc James (talk · contribs · email) 02:31, 23 February 2016 (UTC)

Sorry I've not known the 4 paragraph lede rule...

Unfortunately, my edits have been reverted by talk. The concerns that I tried addressing in my reverted edit were...

1. The opening lede statement on health asserting all-embracing uncertainty is redundant vague. The direct statements on health risks and cessation, convey their respective degrees of certainty.

2. As a review by Cancer Research UK states, that "there is a consensus that e-cigarettes are almost certainly much safer than tobacco smoking". A wide range of sources concur on this point, as I have referenced in my edit which talk reverted. The phrase, "e-cigarettes are probably safer", doesn't reflect this point.

3. 95% less harmful estimate by Public Health England and others should be reflected in the lede -- "safer" is not quantified. The Pisinger review conclusion that "no firm conclusions can be reached..." should also be reflected, for balance. ZviZig/GreyZig 12:03, 23 February 2016 (UTC)

You are missing the numerous less than positive reports, it has taken time to find the balance that now exists between positive and negative sources. CFCF 💌 📧 13:41, 23 February 2016 (UTC)

• I've started Wikipedia_talk:WikiProject_Medicine#.22Adding_sources_to_the_lead_is_a_reasonable_practice_but_not_required_as_long_as_the_text_in_question_is_supported_in_the_body_of_the_article.22 - if we don't have a "PAG" (?!) explicitly stating what we normally do in medical articles, then we should. Johnbod (talk) 14:57, 23 February 2016 (UTC)

The original premise in this discussion is flawed. Our manual of style gives this guidance on the lead: "The lead serves as an introduction to the article and a summary of its most important contents." and "It should identify the topic, establish context, explain why the topic is notable, and summarize the most important points, including any prominent controversies." (my emphases), which is not the same as assuming that it must be solely a summary of the rest of the article and nothing else. Not every topic can be properly introduced through sources that already exist in the rest of the article, and that may be especially true of articles dealing with controversial topics. It is perfectly reasonable for a source that gives a broad introduction to a topic to be a good choice for referencing part of the lead, and yet not be sufficiently detailed to act as a good choice as a citation within a complex discussion later in the article, where more specialised sources are more appropriate. These sort of judgements belong to discussion in individual articles and it is necessary to seek a consensus in these cases. Apart from direct quotations, there's no rule that dictates whether citations appear in the lead or not; nor is there a rule that proscribes the use of a citation in the lead that does not appear elsewhere. --RexxS (talk) 18:53, 23 February 2016 (UTC)

You're not seriously suggesting the lead can be loaded up with information not in the body, are you? Curly Turkey 🍁 ¡gobble! 23:12, 23 February 2016 (UTC)

Are you seriously suggesting that the lead must only contain information in the body? I've linked the PAG pages that show how you have failed to understand that the lead performs more functions than just summary of the body. You are simply wrong when making false claims like "any statement in the lead must be in the body" - which is patent nonsense. The balance between the functions of introduction, establishing notability, providing context, and summarising the body is a matter for consensus between editors at the article, not by dictat from a non-existent policy. --RexxS (talk) 23:47, 24 February 2016 (UTC)

I'm seriously suggesting that serious justification is required for anything in the lead not appearing in the body. How do you justify keeping such information out of the body if it's important enough to be in the lead? How does that not violate WP:WEIGHT, for one instance? Curly Turkey 🍁 ¡gobble! 02:06, 25 February 2016 (UTC)

• Hijiri88 - please read WP:CITELEAD. It says that if anything in the lead is challenged, editors should provide in-line citations. You may not be aware that almost every line of this article has been fought over; there is nothing that hasn't been challenged. Because of that, I hope you can see that it is completely appropriate to have citations in the lead. In my view, the lead is probably about the right length as this is a long article. It could possibly be condensed more but doing so will probably be very costly in terms of volunteer time to negotiate that. There is nothing alarming in the lead that I can see, and nothing to really argue about. This has nothing to do with MEDMOS - that is a red herring. It is plain old WP:LEAD at work here. Jytdog (talk) 19:52, 23 February 2016 (UTC)

I am indeed aware of the controversy surrounding the article. I even discussed it with Curly Turkey some time ago, and the latter user pointed out how much more controversial this article apparently is on Wikipedia than, say, the State of Palestine. It frankly baffles me. But this article's lead currently appears to contain information not found in the body, or at best a dubious summary of what's in the body (3.4% became ”a significant percentage”, which is WP:WEASEL at best). This can happen as a good faith mistake when the lead is independently of the body, rather than based directly on the body. Any time the lead cites sources not cited in the body it should be a cause for concern. Hijiri 88 (聖やや) 06:05, 24 February 2016 (UTC)

I agree that nothing should be in the lead that is not the body. Why not try to just fix it (as conservatively as you can!!) and see how that goes? I would suggest that you understand what is driving the dispute before you get involved so that you don't walk into propeller blades. I'll drop a note on your talk page. Jytdog (talk) 08:35, 24 February 2016 (UTC)

Break

There is general agreement that Lead sections can have citations (nobody has argued otherwise) and that this particular Lead section should have citations. The problem that seems to be getting ignored in some of the arguments above is that this Lead section has too many citations. For instance, we have the following completely uncontroversial sentence with 4 (!) citations.

The e-liquids used in e-cigarettes usually contains a mix of propylene glycol, glycerin, nicotine, and flavorings.^{[17][19][23][24]}

There is also this beast with 7 citations:

The vapor can contain small amounts of toxins, including traces of heavy metals detected at levels permissible in inhalation medicines,^[16][27][6] and some potentially harmful chemicals not found in tobacco smoke^[28] at levels permissible by workplace safety standards.^[27][29][30]

I think the best way forward would be for somebody to judiciously prune some of these citations so we have no more than about 1-2 per sentence, and certainly no more than 1 per clause. If we find long sentences like my second example that can't be sourced to 1-2 sources it might be a good reason to break them up or look for possible WP:SYNTH. I could do this, but I don't know the literature as well as most of you regulars here so it would take me 5x as long. Volunteers? ~Awilley (talk) 19:46, 24 February 2016 (UTC)

That may be possible, but some sentences have been combined and the citations moved to the end. In that case it may be necessary to keep them. But the main components of ejuice is probably non controversial. AlbinoFerret 20:52, 24 February 2016 (UTC)

You don't need to remove cites; you can bundle them. That still leaves the issue of material in the lead that's not in the body, though. Curly Turkey 🍁 ¡gobble! 21:19, 24 February 2016 (UTC)

I now removed some extra references relevant to the sentence I edited on heavy metals. I also left only most authoritative sources in the sentence on e-juice (Cochrane and AACR reviews).GreyZig 21:46, 24 February 2016 (UTC)

Bundling is a good idea, but I'm not sure if it's compatible with the current reference system of naming the references and re-using them in the article. Reference 6 (Grana 2014) is currently being cited in 26 different sentences throughout the article. Bundling all the instances of multiple citations could lead to a lot of redundancy. Another option might be to convert the references using {{Harvard citation}} with short citations that link to the full citations in a References section, but that's a lot of work. ~Awilley (talk) 22:33, 24 February 2016 (UTC)

Well, if someone wants to do it, it would save a lot of headaches in the long run and make the article more pleasant to read. Still, that leaves the issue of material in the lead that's not in the body. Curly Turkey 🍁 ¡gobble! 22:59, 24 February 2016 (UTC)

Repeating that there is material in the lede that doesn't exist in the body is all good—but you haven't actually presented anything that argues for this. Like RexxS says — we don't necessarily need the same sources, but for the lede to be a summary of the article's major points. The only substantive argument in this entire mass of verbiage is that 3.4% of the adult American population isn't significant — but since that includes nearly 10 million people it damn well is significant. Now I'm going to paraphrase Jytdog (though somewhat less elegantly) and ask you and Hijiri 88 to either come with constructive suggestions or stop wasting everyone's time on petty semantics and nit-picky interpretation of policy. CFCF 💌 📧 23:05, 24 February 2016 (UTC) 

but you haven't actually presented anything that argues for this—you're right, but my point was that the issue was raised but hadn't been addressed. If there isn't material in the lead that isn't in the body, then somebody should say so.

but since that includes nearly 10 million people it damn well is significant—you have an empirical measure of "significant"? Curly Turkey 🍁 ¡gobble! 23:24, 24 February 2016 (UTC)

On that note, I'm still trying to find the place in the body that says "a significant percentage of American adults"... Hijiri 88 (聖やや) 01:37, 25 February 2016 (UTC)

So you're arguing that we should consider random musings of unengaged individuals? If you aren't going to take an effort to understand the underlying issues I am going to ignore you from now on, and I suggest others do so as well—per WP:Don't feed the troll(s). As for having "an empirical measure" of significant I suggest you brush up on what linguistics is, and why words are by definition intangible. CFCF 💌 📧 03:17, 25 February 2016 (UTC)