Talk:Potential health risks of sunscreen/Archive 1

POV concerns
In response to, it seems to me that this is an obvious and blatant WP:POVFORK and/or pitch to potential class action plaintiffs. If it can't be integrated into the main article it definitely needs some balance brought to it, including a rename. At this stage the article makes a statement and then proceeds to demonstrate its falsity. If "There are many claims that sunscreen use protects against skin cancer" then surely these claims and the evidence for them needs to be included in this article as well?

At the moment the article may as well read like this


 * Government and evil corporations claim that sunscreen causes helps prevent cancer. However, here is the evidence that they are lying and potentially damaging your health. If you are concerned please see these class action suits currently taking place that may be of interest to you.

Note I have no opinion or even interest in the topic (although for the record I do wear sunscreen) however if this is a "controversy" both sides should be represented. -- Mattinbgn\talk 10:50, 29 March 2008 (UTC)


 * Holy POV, Batman! This isn't an encyclopedia article, it's a laundry list of under-qualified claims pieced together with informal text. The heavy reliance on primary sources (single studies) invites a boatload of WP:SYNTH violations here...I don't have an opinion on the efficacy of sunscreen in the prevention or promotion of melanoma, but it's clear that there's WP:UNDUE issues here. Judging from the merge discussion, this article needs to go...pull out anything useful before it's up at AfD. (Which I may be doing myself in the near future.) &mdash; Scientizzle 23:45, 18 April 2008 (UTC)

grouping skin cancers together is missleading
The above statements (POV concerns) originates from the undifferentiated discussion of all forms of skin cancer together. There are three forms of skin cancer: squamous cell carcinom, basal cell carcinom, and malignant melanom. Importantly the first two forms are caused by one mechanism (direct DNA damage) and the last one is caused by another mechanism (indirect DNA damage = free radicals). From a mechanistic viewpoint it is therefore easily possible to understand that the first two forms are prevented by sunscreen use, and the last one is amplified. This agrees with the epidemiological results. Importantly the malignant melanom is responsible for 75% of all skin cancer related death cases. It is rare, but the mortality rate is many times higher than the mortality rates for squamous cell carcinom and basal cell carcinom. It is crucial to distinguish the different forms of skin cancer for this discussion.Gerriet42 (talk) 09:49, 8 April 2008 (UTC)

Link farm
The external links appeared to be a link farm and so I have removed them all here for group review and concensus building to determine which meet the external link policy. Add your comments in the section below. GundamsЯus (talk) 04:25, 20 April 2008 (UTC)

Issues of fact
Note for the record that I am totally aware that sunscreen has been shown in some cases to be useless or harmful. Whatever is published in the scientific literature, I of course accept. This article, however, contains a number of claims that are not supported by its own sources. The first, which I am going to change, is a false quote supposedly from the FDA. What the FDA actually said on page 49079 is "For all these reasons, FDA has tentatively concluded that the available evidence fails to show that sunscreen use alone helps prevents skin cancer or premature skin aging." (bolding mine)

Here are some further worrying things here: The highest frequency of BRAF mutations is in malignant melanoma. This does not seem to be related to the effects of ultraviolet light, the only known environmental risk factor for this disease. The T right arrow A change at nucleotide 1796, which accounts for 35 of 38 (92%) of BRAF mutations in melanoma, is distinct from the CC right arrow TT or C right arrow T changes associated with pyrimidine dimer formation following exposure to ultraviolet light—these changes are commonly found, for example, in the TP53 gene in non-melanoma skin cancers. If I am reading this correctly, this is saying something rather different than the article claims.
 * The link "Kerry Hanson skin penetration" says "The researchers note that the additional ROS are generated only when the UV filters have penetrated into the skin and, at the same time, sunscreen has not been reapplied to prevent ultraviolet radiation from reaching these filters." This only says that sunscreen is harmful when improperly used.
 * The study "Mutations of the BRAF gene in human cancer" does not mention the term "indirect DNA damage," as this article claims. The study does contain the "92%" here:
 * In multiple places, the page alleges a conspiracy of the medical community and cosmetic industries. This serious allegation needs some serious evidence if it is to be placed here.
 * There has been only one person writing this article, Gerriet42.

I unfortunately do not have access to the scientific journals that are referenced, which severely hinders my ability to criticize the article. I think the existing inaccuracies demand a review from someone who has access to those resources. Judging by some of the content, I have my doubts that those studies actually say what it is claimed that they do. This is not an issue of whether or not I support the sunscreen industry or whatever, this is an issue of whether or not the article is supported by facts. Hopefully this conflict can be resolved by recourse to the resources. BecauseWhy? (talk) 02:05, 21 April 2008 (UTC)


 * Nobody is claiming a conspiracy!! This page is about the discrepancy between the public perception of sunscreen and the discussion of photocarcinogenic effects that is going on in the scientific literature.
 * If anyone needs access to the original literature I will be happy to send them via email. Just leave a message on my talk page. Gerriet42 (talk) 12:29, 12 May 2008 (UTC)

Uncited Claim
The following submission was made to a social bookmarking site

Title:How come I didn't know this? Your chances of catching malignant melanoma (which killed my uncle), responsible for 75 % of all skin cancer deaths, are amplified by the use of sunscreen.

http://reddit.com/info/6gh1q/comments/

It appears to be based on this uncited claim in the article: "Even though it is rare, malignant melanoma is responsible for 75 % of all skin cancer related death cases"

Is there a citation for this claim?

Wageslave (talk) 02:32, 21 April 2008 (UTC)
 * Well, that statistic is also in the article melanoma, and this source is given:
 * http://www.aafp.org/afp/20000715/357.html
 * The AAFP is a legitimate source, as far as I know. I will be adding the citation to the article. BecauseWhy? (talk) 02:47, 21 April 2008 (UTC)

Apparent misquoting of FDA
Gerriet42 apparently changed the FDA quotation from its original "...evidence fails to show that sunscreen use alone helps prevents skin cancer..." to "...evidence fails to show that sunscreen use prevents skin cancer..." with removal of the words "alone helps". The change was made at 13:36, 9 April 2008 (http://en.wikipedia.org/w/index.php?title=Sunscreen_controversy&oldid=204446890).66.67.47.120 (talk) 17:45, 22 April 2008 (UTC)
 * If sunscreen use alone does not protect against skin cancer, then the protective effect of using protective clothing AND sunscreen stems from the protective clothing - not from the sunscreen. Unless of course you believe in synergistic effects. Synergistic effects are possible only in medicines that act together and have a bigger effect than the sum of each effect alone. But I think that a synergistic interaction between clothing and sunscreen can be excluded. What do you guys think? are synergistic effects possible, or is the contribution from the sunscreen always a non-protective one?? Gerriet42 (talk) 12:35, 12 May 2008 (UTC)

WP:SYNTH
See WP:SYNTH policy: Gerriet42 isn't following it.66.67.47.120 (talk) 18:01, 22 April 2008 (UTC)

rename to "sunscreen discrepancy"
I think, that this article is describing the large DISCREPANCY between the scientific knowledge about sunscreen and all the critisizm that it gets from photochemsists and photobiologists on the one side and the information that is given to the public on the other side. Therefore I suggest to rename the article to "sunscreen discrepancy" Gerriet42 (talk) 06:58, 15 May 2008 (UTC)


 * A better option is to just merge the article to Sunscreen. And even if that does not get done, the article Sunscreen discrepancy, should it exist, should be moved and/or merged here. The term "sunscreen discrepancy" suggests that sunscreen is a type of data. --Blanchardb- Me • MyEars • MyMouth -timed 07:18, 15 May 2008 (UTC)

I am still unhappy with the title "sunscreen controversy". The article is describing the large gap between the scientific information and the popular believe. This has to be obvious from the title. So how about  "sunscreen desinformation"  or maybe   "sunscreen information-gap". (I am just brainstorming here, please make alternative suggestions.) Gerriet42 (talk) 07:26, 15 May 2008 (UTC)


 * Given the reason why you want a better title, "sunscreen controversy" is the best possible title. All other suggestions here will only serve to create confusion. --Blanchardb- Me • MyEars • MyMouth -timed 08:09, 15 May 2008 (UTC)

This should be merged with the main sunscreen article, not renamed. There is no reason for important information like this to be segregated to its own article. —Preceding unsigned comment added by 71.167.60.210 (talk) 16:52, 24 May 2009 (UTC)

Concerns...
I think the article currently reads like a research paper rather than an encyclopedia article; it makes numerous claims that may be inappropriate original synthesis...since the article is large, my time is currently limited, and I don't have access to all the listed research articles, I've only done a cursory investigation into the claims here.

To start, a recent review indicates that sunscreen use in general, and larger SPF numbers specifically, leads to greater sun exposure. Additionally, "It is well known that the majority of sunscreen users apply only a fifth to a third of quantities of sunscreens used in laboratory for testing their SPF"..."Observational studies did not perform adjustment of their results on natural sun sensitivity of study participants. Hence, the higher number of sunburns among (high SPF) sunscreen users in observational studies could have been due to greater sun sensitivity." This single review alone presents an obvious hypothesis regarding malignant melanoma: sunscreen use = higher overall UV exposure =?= more malignant melanoma.

This article doesn't appear to deal with that at all, instead focusing on photocarcinogenicity and such...

Other important notes from my cursory research:
 * "Use of common sunscreen formulations that absorb UVB almost completely, but transmit large quantities of UVA, may contribute to risk of melanoma in populations at latitudes >40 degrees."


 * "Meta-analyses of observational case-control studies have demonstrated no association between sunscreen use and the development of malignant melanoma...It is not surprising that case-control studies have failed to find any association between sunscreen use and the risk of melanoma when consideration is given to the sunscreens in common usage at the time and the way in which sunscreen is applied in practice. Modern high Sun Protection Factor, broad-spectrum sunscreens, on the other hand, can be expected to be an effective measure in helping to prevent melanoma compared with sunscreens typical of those used 10-20 years ago."


 * "No association was seen between melanoma and sunscreen use. Failure to control for confounding factors may explain previous reports of positive associations linking melanoma to sunscreen use. In addition, it may take decades to detect a protective association between melanoma and use of the newer formulations of sunscreens."

Bottom line: the reliance of this article on primary sources (single research articles) from which to draw conclusions invites OR problems...coverage of this topic should be shifted towards the use of reviews and meta-anlyses in order to reduce this issue. There is plenty of room, I believe, to simply improve the sunscreen article's coverage of some of these issues. Finally, this isn't really a "controversy" (no media coverage of one is presented at least) but really a collection of criticisms (again, more appropriate for the main article, I think) that aren't tightly associated, some of which may have been addressed by more recent research.

Comments? &mdash; Scientizzle 22:35, 15 May 2008 (UTC)


 * Yes. Here's a comment. Read this revision. All subsequent edits were made by a single individual. --Blanchardb- Me • MyEars • MyMouth -timed 00:39, 16 May 2008 (UTC)
 * I would go further back.TheRedPenOfDoom (talk) 00:44, 16 May 2008 (UTC)

I found this interesting (in layman's terms, reaches the same conclusions as some of Scientizzle's sources): LEF.org/magazine/mag2005/jun2005_report_sunscreen_01.htm —Preceding unsigned comment added by 76.212.134.98 (talk) 08:56, 28 May 2008 (UTC)

There are several different contributions to the increased melanoma risk among sunscreen users: 1) the absence of UVA filters combined with a longer exposure time of the sunscreen user 2) free radical generation of sunscreen chemicals that have penetrated into the skin  3) less vitamin D generation in sunscreen users

I am well aware of these three different explanations. I guess all of them contribute to the problem. The larger amount of ROS that has been measured in sunscreen treated skin (Kerry Hanson) definitely shows, that contribution number 2) is a relevant one. The epidemiological data will never be able to disentangle these three contributions. However the mechanistic considerations and the laboratory measurements do have the capacity to measure the size of contribution 2) in an isolated fashion.Gerriet42 (talk) 03:49, 16 May 2008 (UTC)

I was suggesting to rename the article to "sunscreen discrepancy" or similar (see above). This was exactly because the article is describing the large gap between research articles and the public perception of sunscreen. There is a lot of critisizm in the scientific literature about the use of sunscreen (in photochemistry and photobiology literature), but this is not represented in the popular press at all. That discrepancy is exactly what this article is supposed to describe. What would be a good name for the article? Gerriet42 (talk) 03:57, 16 May 2008 (UTC)


 * I'm not convinced a re-name would solve the underlying issue: WP:SYNTH concerns. As I've noted, claims should be primarily drwan from relevant secondary sources when discussing a scientific controversy. Popular coverage isn't needed if there is sufficient academic literature from which to properly create an article.
 * The question becomes: when claims relying heavily on interpretation of primary sources are edited to reflect the secondary sources, is there enough substantive content and coverage to justify this article rather than merging the content into the main sunscreen article. I don't know...but I think we need to figure that out. &mdash; Scientizzle 17:07, 22 May 2008 (UTC)

the temporal design of experiments
There are sufficient references to the scientific literature in this section. I think the tag for more references is unjustified. Gerriet42 (talk) 11:44, 19 May 2008 (UTC)
 * As the tag says, those are all primary sources and need analysis from secondary or tertiary sources. TheRedPenOfDoom (talk) 13:28, 19 May 2008 (UTC)

What would be a secondary source? Gerriet42 (talk) 17:42, 19 May 2008 (UTC) The article is supposed to describe the large discrepancy between the scientific knowledge, and what is beeing said in the public press. For that it is necessary to go into the scientific literature. Gerriet42 (talk) 17:42, 19 May 2008 (UTC)
 * A secondary source would be a source that makes analysis based on the primary research sources. For example a book or article that quotes the studies that you have provided. Wikipedia is here to report what others have said, not put forthanalysis of the material ourselves that comes up with new information that is being covered up in the public press. TheRedPenOfDoom (talk) 21:45, 19 May 2008 (UTC)
 * This article is describing the controversy that is going on in the primary literature. It will take another 3-5 years before secondary literature is available. I still think the tag should be removed. Gerriet42 (talk) 15:08, 22 May 2008 (UTC)

The reporting of scientific data in Wikipedia can be a tricky subject...on controversial topics, it's paramount to report the literature appropriately. I frequent other topics on which there's substantial primary literature (individual published studies) with wide variability in quality, results, and impact; in general, any broad claims based on the scientific literature should be drawn from secondary sources such as literature reviews and meta-analyses wherever possible. These do exist (I cited some above), so they should be the main sources from which almost all information is cited for this topic. [Single research articles are certainly relevant and appropriate for highly specific, caveat-tempered claims requiring careful & reasonable editorial discretion.] If reviews and meta-analyses haven't covered a topic, it's very easy to fall into WP:SYNTH problems by linking primary sources. Are there any secondary sources that address the temporal design of experiments? &mdash; Scientizzle 17:02, 22 May 2008 (UTC)

So where is the data?
So where can I actually go and find out how much UVA my particular brand of sunscreen really blocks? I am not seeing this information in the article. —Preceding unsigned comment added by 71.190.204.107 (talk) 19:22, 15 July 2008 (UTC)
 * Because UVA blocking is not regulated by the FDA, there isn't a convenient number like the SPF (which tells you how much UVB a sunscreen blocks). Manufacturers would just prefer to put "NOW PROTECTS AGAINST UVA" on the package and omit other information. Testing protocols for UVA blocking are also not very well-developed as yet. The best you can do is to look up the list of ingredients known to protect against UVA and look for at least one of them when buying sunscreen. Inhumandecency (talk) 16:29, 18 July 2008 (UTC)

The relevant problem with sunscreen is not that it is transparent to UVA, but it is that it penetrates into the skin over time! —Preceding unsigned comment added by 217.142.144.126 (talk) 11:52, 21 July 2008 (UTC)

Bot report : Found duplicate references !
In the last revision I edited, I found duplicate named references, i.e. references sharing the same name, but not having the same content. Please check them, as I am not able to fix them automatically :) DumZiBoT (talk) 17:22, 13 August 2008 (UTC)
 * "Treffel" :
 * "Mosley2007" :
 * "Hayden1997" :
 * "Mosley2007" :
 * "Hayden1997" :
 * "Hayden1997" :
 * "Hayden1997" :

Is PABA banned in the US as a sunscreen?
I believe Europe banned PABA in sunscreens (although manufacturers weren't interested anyway). I cannot find info on whether PABA has ever been banned in the US. I believe it is not. EtherDoc (talk) 19:15, 27 September 2009 (UTC)
 * Try to ask at WT:PHARM, there someone should know. --ἀνυπόδητος (talk) 15:13, 29 September 2009 (UTC)

Yesterday was the first time I even heard of this issue ( on TV). The news show said the government( and it appears some others) had known about this for at least 10 years. Wow, this one was kept off the mainstream media teleprompters quite well for some time. No warning label,discussion, etc, probably for our own good as they say. Wonder if the rich have been using something else - my quick research on this sems to be that no sunscreen is the best option ( really bad stuff in the stuff that the hoi-poi buys and you need the sun anyway ( lack of sunlight on your skin may cause cancer,etc even without considering the chemicals you massage onto yours kids' backs). Thanks Bill, George and Barack. 159.105.80.141 (talk) 11:18, 25 May 2010 (UTC)
 * There's no good evidence that lack of sun causes cancer (and we don't usually spend uor lives in cellars anyway – a few minutes of sunlight a day produces enough vitamin D). On the other hand, there is good evidence that too much sun causes cancer. --ἀνυπόδητος (talk) 12:05, 25 May 2010 (UTC)

Article section "2010"
My problem is that, while the copyvio has been mended by rephrasing, the fact that this is a controversial claim with no reliable source cannot, or only with a lengthy explanation to put the claims in context. Per WP:RSMED, popular press like AOL isn't a reliable source, nor is the controversial Environmental Working Group unless their study is published in a (preferably peer-reviewed) journal. We can discuss the claims if you like; to begin with: how much vitamin A (or derivatives) is contained in sunscreens? Certainly much less than 0.05% which is the concentration in Retin-A, which causes the skin to get dry, to itch and peel, often without UV exposure. Such a sunscreen would be unsellable. And 0.05% is only one tenth of the higher concentration used in the study. And it wasn't combined with a sunscreen. And it was done in lab animals, not humans. All this relativises the claim, which right now reads as if there was direct evidence for sunscreens to cause cancer. Similar considerations would be needed for the other claims, but I know too little about the situation in America to do it and suspect it wouldn't be worth the trouble anyway – if we discussed every claim raised in the popular press, the article would soon exceed 100K. [Note: Copied message from User talk:12.7.202.2, where it was deleted with the edit summary ''Messages rec'd., but "Per WP:RSMED, popular press like AOL isn't a reliable source, nor is the controversial Environmental Working Group unless ..." is without support.'' I'll place a disputed tag for now, but independent views on the reliability and notability of this claim would be welcome.] --ἀνυπόδητος (talk) 06:28, 26 May 2010 (UTC)

Copyright problem removed
One or more portions of this article duplicated other source(s). Infringing material has been rewritten or removed and must not be restored, unless it is duly released under a compatible license. (For more information, please see "using copyrighted works from others" if you are not the copyright holder of this material, or "donating copyrighted materials" if you are.) For legal reasons, we cannot accept copyrighted text or images borrowed from other web sites or published material; such additions will be deleted. Contributors may use copyrighted publications as a source of information, but not as a source of sentences or phrases. Accordingly, the material may be rewritten, but only if it does not infringe on the copyright of the original or plagiarize from that source. Please see our guideline on non-free text for how to properly implement limited quotations of copyrighted text. Wikipedia takes copyright violations very seriously, and persistent violators will be blocked from editing. While we appreciate contributions, we must require all contributors to understand and comply with these policies. Thank you. Moonriddengirl (talk) 17:11, 1 June 2010 (UTC)
 * What about this rewrite?

2010
According to researchers at Environmental Working Group, "only 39 of the 500 products are safe and effective to use." Their report states sun protection factor (SPF) numbers are unreliable, because the chemical oxybenzone is hormone-disrupting and penetrates the skin, entering the bloodstream, SPF numbers are presented with unreliable claims of performance, and the Food and Drug Administration's regulation and oversight is inadequate. "Most alarming" is that vitamin A and chemical relatives, retinol and retinyl palmitate, may "accelerate" the very cancers sunscreen use is expected to protect against. About half of the 500 products the EWG tested contained these compounds.

-12.7.202.2 (talk) 16:06, 3 June 2010 (UTC)


 * Despite your repeated deletion of my messages, AOL still isn't a reliable source per WP:RSMED. Nor is the National Ledger, I suspect. Nor is the Environmental Working Group. --ἀνυπόδητος (talk) 16:29, 3 June 2010 (UTC)


 * I was asked about this rewrite at my talk page. First, if that first quotation is meant to come from the AOL article, it would need a citation immediately afterward. But, if so, it's inaccurate. WP:NFC requires that quotes be verbatim as well as directly cited. You can omit some language, but need to note that you have done so, as with ellipses. And you need to note who you're actually quoting, which in this case is Andrew Schneider (since he is not himself quoting). That might look like this:


 * The next sentence is pretty good. The last sentence again suggests that you are quoting the Environmental Working Group, when you are quoting Andrew Schneider. And where did you get the word accelerate, in quotes there? The actual sentence, from the source, seems to be: "But the most alarming disclosure in this year's report is the finding that vitamin A and its derivatives, retinol and retinyl palmitate, may speed up the cancer that sunscreen is used to prevent." You might present that something like this:


 * None of this, of course, addresses the question of reliability of the source. I'm solely addressing the use of non-free content within Wikipedia's policies & guidelines. --Moonriddengirl (talk) 16:40, 3 June 2010 (UTC)
 * Use of non-free content is what I'd like you to address. That is how the fellow above seems determined to remove this, but his oft-stated reasons seem to be lack of scientific validity, not something editors at WP should take upon themselves. RS challenges to scientific validity are, of course, permitted additions. He ignores "accelerate" in the ref cit title. Please render an opinion on any copy-vio by the paragraph above, and if he doesn't like it, let him present a coherent rewrite below. Thanks, 12.7.202.2 (talk) 17:07, 3 June 2010 (UTC)
 * I did address use of non-free content. As explained above, the paragraph is in violation of WP:NFC. --Moonriddengirl (talk) 17:08, 3 June 2010 (UTC)
 * The proposed rewrite complies, does it not? -74.162.148.8 (talk) 19:54, 19 June 2010 (UTC)

2010
Andrew Schneider of AOL News reports that researchers at Environmental Working Group found "only 39 of the 500 products they examined...safe and effective to use." Their report states sun protection factor (SPF) numbers are unreliable, because the chemical oxybenzone is hormone-disrupting and penetrates the skin, entering the bloodstream, SPF numbers are presented with unreliable claims of performance, and the Food and Drug Administration's regulation and oversight is inadequate. Schneider found "most alarming" the report's statement that "cancer that sunscreen is used to prevent" may actually be accelerated by vitamin A and chemical relatives, retinol and retinyl palmitate, which are added to sunscreens to help reduce the appearance of aging. About half of the 500 products the EWG tested contained these compounds.

Requested move

 * The following discussion is an archived discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section. 

The result of the move request was: moved Dpmuk (talk) 12:56, 15 March 2011 (UTC)

Sunscreen controversy → Potential health risks of sunscreen — This page move was suggested in the recent deletion discussion. There was concerns that the current title doesn't meet POV requirements. D O N D E groovily  Talk to me  08:01, 5 March 2011 (UTC)
 * Support: A more NPOV article title. –CWenger (talk) 03:18, 15 March 2011 (UTC)
 * The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

Sunscreen prevents tanning
The article Skin Biology: A Healthy Tan? by Ingrid Wickelgren, Science, 2 March 2007, Vol. 315, no. 5816, pp. 1214-1216 claims that sunscreen prevents tanning. Tanning protects against melanoma, and sunscreen does not. Thereby sunscreen promotes melanoma. Since melanoma is deadly, whereas the other two types of skin cancer are not, using sunscreen may be harmful and dangerous. Mateat (talk) 20:07, 6 June 2011 (UTC)


 * Here's the citation, ready for use:
 * Mateat, it's important to note that the incidence and prevalence of the carcinomas versus melanoma make a the cost-benefit calculations regarding sunscreen complicated; it's certainly not established that "using sunscreen may be harmful and dangerous" is really an accurate descriptor of the associated risk trade-offs... &mdash; Scientizzle 22:55, 6 June 2011 (UTC)
 * Mateat, it's important to note that the incidence and prevalence of the carcinomas versus melanoma make a the cost-benefit calculations regarding sunscreen complicated; it's certainly not established that "using sunscreen may be harmful and dangerous" is really an accurate descriptor of the associated risk trade-offs... &mdash; Scientizzle 22:55, 6 June 2011 (UTC)

Health risk of titanium dioxide nanoparticles
I take issue with this paragraph: "Studies have found that titanium dioxide nanoparticles cause genetic damage in mice, suggesting that humans may be at risk of cancer or genetic disorders resulting from exposure.[41]" - These particles won't penetrate human skin (see original research), so their use in sunscreens (possibly excl. spray-on lotions) poses no health risk. Can I delete this paragraph? --Jofo.wiki (talk) 11:50, 15 May 2012 (UTC)
 * The referenced study describes high doses given orally to rats. The relevance to lower doses applied to the skin of humans in unclear, and the study's authors make no such connection.  I think it is reasonable to remove the paragraph.  -- Ed (Edgar181) 12:41, 15 May 2012 (UTC)