Comments:

• Thank you for the open discussion and providing your comments. The best scientific exploration and fact-finding is done through constructive debate and open-mindedness to examining all perspectives. It is nice to see engaged readers and an engaged author.

  -Women’s Health Editor

  Reply

• Thank you for your detailed commentary. First and foremost, I believe most dermatologists, myself included, would agree that further testing of sunscreen filters is absolutely necessary to determine effects of these ingredients on human health and the environment. I also believe that there is little argument regarding the ability of skin to absorb skincare ingredients, including those in sunscreens. With that being said, every scientist and physician should be aware of the concept of dose versus toxicity, that it’s not the chemical that is dangerous, it’s the dose of the chemical. Every chemical has a dose below which no adverse effects or harm occurs, where the benefits of that chemical outweighs the harm. One extra strength Tylenol (500mg) cures a headache, 14 extra strength Tylenol tablets may cause liver failure and death. Yet no one would argue that we should remove acetaminophen from all drug store shelves. It’s the dose that makes the poison, not the chemical itself.

  As for current toxicological data on endocrine disrupting chemicals (EDCs), it is severely lacking. The effects these chemicals have on endocrine pathways is unknown. Yes, some UV filters show endocrine disrupting activity, but so do flaxseeds, alfalfa sprouts and many other plants that we eat every day. Although I certainly agree that more research needs to be done on potential endocrine active substances found in consumer products, including sunscreens, creating an irrational fear of this class of chemicals based on misconceptions about EDCs should be avoided. cosmetics-05-00061.pdf

  Yes, the industry is in need of safe effective UVA ray filters. In the U.S. only avobenzone and zinc oxide can adequately protect against the UVA spectrum. However, there is substantial evidence in the medical literature that concludes the use of broad-spectrum sunscreen reduces both skin cancer risk as well as skin aging. The Skin Cancer Foundation, The American Academy of Dermatology, The Australasian College of Dermatology, The Melanoma Education Foundation, and every major dermatology organization in the United States, Australia, Japan, and the European Union, all of whom base their recommendations on the current scientific literature, concludes that the benefits or wearing sunscreen as part of a comprehensive sun protection program outweighs the risks.

  Melanoma rates are increasing, particularly amongst children, adolescents, and young adults where it has increased more than 250% in the past 4 decades. To blame UVB-biased sunscreens as the cause of this increase is irresponsible and unfounded. Mitsis DKL, Groman A, Beaupin LM, et al: Trends in demographics, incidence, and survival in children, adolescents, and young adults (AYA) with melanoma: A Surveillance, Epidemiology, and End Results (SEER) population-based analysis. 2015 ASCO Annual Meeting. Abstract 9058. Presented June 1, 2015.

  The SEER study commented that in addition to genetic factors, excessive unprotected sun exposure and the growing use of commercial tanning beds were the major culprits of this increase, not the use of sunscreens.

  Thank you for your insights. I believe we share a mutual concern for the well being of planet and each other.

  Reply

  • Thank you for sharing your perspective on the subject … I agree that it is the dose and not the poison that is the problem (this is first rule of toxicology). However, if you have time to review my comments to FDA on the safety of these chemicals … https://www.regulations.gov/docketBrowser?rpp=25&so=DESC&sb=commentDueDate&po=0&s=Joe%2BDiNardo&dct=PS&D=FDA-1978-N-0018, especially the 27 page tox review, I think you might find several references interesting, especially how 6% oxybenzone and 10% octocrylene when used in formulas together produce 78 ppm of benzophenone (a carcinogen that has recently been banned in foods by FDA, listed by IARC and is listed on CA Prop 65 law), concerns that after just one hour of sun exposure with sunscreens allows enough UV into the skin that free radicals are released producing caspases (part of the melanoma pathway) and there are several reproductive effects in humans referenced as well. I believe this is why FDA is requesting carcinogenicity data and reproductive toxicology on the sunscreen actives in questions – especially oxybenzone. There are literally hundreds of publications outlining numerous reactions in many species – aquatic and terrestrial – let’s see if industry will conduct any of the studies requested by FDA. Also, there are many reasons why the melanoma rates have increased significantly all over the world – you can search the WHO 5 continent report, there isn’t a place that melanoma hasn’t increased … I do believe that sunscreens are not enough to protect anyone … sun avoidance/protective clothing are mainly the way to stop the global melanoma epidemic until better products can be developed.

  • All of your remarks about dose and toxicity have nothing to do with teratogenicity and hormone disruption in a fetus, particularly at 3-12 weeks. Please suggest how you would ever ethically carry out carry out a study on the effects of EDCs on a developing fetus. You would ask thousands of women to apply not just oxybenzone but combinations of all the PAH filters that all attain blood levels and follow their offspring for 40-60 years, and then their progeny to determine epigenetic effects.

    Human hormone receptor function has nothing in common with rodents and lower species. First, even infinitesimally low levels of exposure— indeed, any level of exposure at all—may cause endocrine or reproductive abnormalities, particularly if exposure occurs during a critical developmental window. Surprisingly, low undetectable doses may even exert more potent effects than higher doses. Second, EDCs may exert non-traditional dose-response curves, such as inverted-U or U-shaped curves. Both of these concepts have been known for hormone and neurotransmitter actions, but only in the past decade have they begun to be appreciated for EDCs.

    Effects of different classes of EDCs may be additive or even synergistic. EDCs may affect not only the exposed individual but also the children and their progeny in subsequent generations. effects may be transmitted not due to mutation of the DNA sequence, but rather through modifications to factors that regulate gene expression such as DNA methylation and histone acetylation. This is a very scary consequence and a risk that most would not wish to take.

    EDCs are proven to have a Non monotonic Dose Response Curve (NMDRC). Low-dose endocrine activity is to be expected. Low dose/response comparisons are impossible, as they occur in cells, tissues, animals and human populations in response to nutrients, vitamins, pharmacological compounds, hormones and endocrine disrupting chemicals (EDCs). Some argue that NMDRCs are not common, are not found for adverse outcomes, and are not relevant for regulation of EDCs. Under the linear dose response model, high dose testing is used to extrapolate to lower doses that are assumed to be ‘safe’ for human exposures. NMDRCs that occur below the toxicological NOAEL would falsify a fundamental assumption, that high dose hazards can be used to predict low dose safety.

    I would suggest reading Diffey’s paper on UVB-BIASED sunscreens (Diffey BL, Osterwalder U, Herzog B. Suntanning with sunscreens: a comparison with sunbed tanning. Photodermatol Photoimmunol Photomed 2015;31:307-314). Unless a sunscreen provides broad-spectrum protection with high UVA-PF values, a 2-week sunbathing vacation that avoids sunburn, using a UVB-BIASED sunscreen, can result in double the UV exposure with a greater health risk than a 10-session sunbed course. This landmark analytic photometric study proves that the wrong sunscreen – UVB-biased – may be more dangerous than tanning bed exposure. Just three days in the sun using a UVB-BIASED sunscreen would be equivalent to two trips to the tanning salon. Both exposures provide asymmetric UVA radiation to your skin. There is another cautionary aspect to this. The 2 week vacation model is extreme but not unrealistic. It is more acute and intense but consider the cumulative everyday exposure from using a UVB-BIASED sunscreen over many years. Many outdoor occupations reach or exceed the vacation exposure. Dermatologists all accept the increased risk for skin cancer from tanning bed exposure- mostly UVA 95% usually – but fail to see the similarity to transmission through a UVB BIASED sunscreens. Tanning bed exposure is mentioned in the SEER study as a factor in increased skin cancer so why not UVB-BIASED sunscreens – there being little difference in the cumulative radiation profiles.

    Another very instructive paper – a recent study from Godar et al presents intriguing data on the respective roles of UVB and UVA in photocarcinogenesis (Godar DE, Subramanianb M, Merrill SJ. Cutaneous malignant melanoma incidences analyzed worldwide by sex, age, and skin type over personal Ultraviolet-B dose shows no role for sunburn but implies one for Vitamin D3. Dermato-Endocrinology 2017, VOL. 9, NO. 1, e1267077 (12 pages) httpss://dx.doi.org/10.1080/19381980.2016.1267077. There was no correlation of increasing UVR doses, which represent erythemally weighted doses comprised primarily of UVB (290–315 nm) radiation, with increasing melanoma incidence for any skin type anywhere in the world. Even more of a paradox was the significant correlations between increasing melanoma and decreasing UVB dose in Europeans with skin types I-IV. Both Europeans and Americans in some age groups have significant increasing melanoma incidences with decreasing UVB dose, which shows UVB is not the main driver in melanoma and suggests a possible role for lower cutaneous vitamin D3 levels and UVA (315–400 nm) radiation. Melanoma may be initiated or promoted by UVA radiation because people are exposed to it indoors through windows and outdoors through some sunscreen formulations. Another argument to avoid UVB-BIASED sunscreens. All the ultra UVA filters are insoluble large MW filters > 500 Daltons. No permeation, better protection. There are sunscreens using bemotrizinol, bisoctrizole, and zinc oxide with a UVA-PF of 45 measured by HDRS – this is approaching the protection afforded by textiles. Compare this with 3% avobenzone at 8. Mexoryl XL (drometrizole trisiloxane) can attain decent UVA-PF values around 16-18 but it is always used with undesirable PAH filters.

    There is a tendency to focus on extinction as the amount prevented from passing through a sunscreen film. A more useful principle is to quantify the transmission or amount of harmful UV radiation that actually reaches the skin. Clothing has a UV protection Factor of 10-100 or more with uniform attenuation of the entire UVB-UVA spectrum, if made of dense material with medium or deep-color dyes or optical brighteners. Their extinction profile provides the best model for the ideal and maximally effective sunscreen. Many brand name sunscreens using avobenzone or inadequate amounts of zinc oxide that attain the FDA and Health Canada standard of a CW ≥ 370 nm still show considerable UVB bias, and allow transmission of undesirable levels of UVA (mostly UVA1 or the most damaging UV rays). This is best described as a monochromatic protection factor (MPF), defined as the reciprocal value of the transmittance, i.e. 1/T, at a particular wavelength. For a SPF 30 sunscreen the average MPF over the whole UVA I ranges varies from 1 (no protection) to 30 (equivalent to the SPF). Many sunscreens with 3% avobenzone that meet the CW of 370 nm only provide an average protection factor of around 3-5 in the UVA I range for an SPF 30 sunscreen.This means that 1/3 or more (> 33%) of the UVA I radiation is still transmitted onto the skin, whereas < 4% (3.7%)of the UVB radiation (i.e. 1/30) is transmitted through this kind of SPF 30 sunscreen. This is the hallmark of the typical brand name UVB-BIASED sunscreen dominating the market – an extreme UVB protection bias where up to 10 times more UVA than UVB reaches the skin. Asymmetric UVA exposure similar to a tanning bed- less acute and less intense but likely posing the same risks.

    There is a harmony and confluence between the first precept or sacred trust in medicine – “primum non nocere” (first do no harm) and the Precautionary Principle”, when exercised by regulators like the FDA. Eventually, the FDA will develop a regulatory framework and a new Sunscreen Monograph based on the tests that prove safety and efficacy beyond a reasonable doubt. While it evolves, a good place to start would be with a WARNING Label on BIOAVAILABILITY and a CAUTION to pregnant or nursing mothers and others who may be more at risk – young or adolescent children, and couples trying to conceive. This occurs for almost everything that is bioavailable to vulnerable groups and certainly the fetus, even low dose aspirin and many other OTC non-prescription items.

    Since the FDA has provided further proof of bioavailability, industry and their consultants should have no issue with a LABEL WARNING, while they work to meet the requirements to establish safety. This allows the consumer to also share the responsibility and burden of protection against harm with their regulators. An informed choice to use an insoluble mineral sunscreen that is not ordinarily bioavailable, instead of the Category III filters, avoids all the controversy and any risks, including the serious often irreversible effects from hormone disruption, and all the minor self limiting problems like photocontact allergy.

    With the FDA proposal, I would humbly suggest that all physicians begin to advise patients that permeation occurs when using A PAH filter, particularly if expectant or nursing mothers, parents of young or adolescent children, and couples trying to conceive are involved. To the skeptics about how serious the toxicity from PAH filters is likely to be, I would encourage them to exercise caution for their families and patients, and err on the side of caution to spare them the serious consequences of rubbing on these congeners of petrochemicals, DDT, BPA, and human estrogen. Health and lifestyle decisions are personal. I will exercise the Precautionary Principle every time where my grandchildren are concerned. For patients, I will continue to sustain the first precept in medicine – Primum non Nocere (first do no harm). A lot of adjectives are being thrown around – irresponsible, unfounded, irrational. Everyone is entitled to their opinion – those who are confident that there is no need for the FDA to invoke the Precautionary Principle and no need to counsel patients on permeation, should feel free to continue using PAH filters personally and professionally. Most patients elect to use insoluble filters when given the information on PAH filters.

• I am married to a dermatologist. She is also a photobiologist and sub-specialist in cutaneous laser surgery & medicine. In 2008 CDC in the USA reported that 96.8% of Americans had benzophenone (oxybenzone) in urine from its pervasive use in sunscreens and cosmetics She stopped recommending sunscreens using Polycyclic Aromatic Hydrocarbon (PAH) since then, when it also became apparent from earlier European studies that several of the group – oxybenzone, octocrylene, homosalate, and 4-methyl benzylidene camphor had hormone disrupting effects in animals and humans. In the EU, 85.2% of nursing mothers had at least one UV filter in breast milk (Schlumpf et al Chemosphere 2010), and oxybenzone was found in the urine (99%) and amniotic fluid (61%) of patients having amniocentesis (Philippat et al Environ Health Perspect 2013). Our review of the literature over 2 decades suggests that 6-11% of the amount applied to skin is absorbed into blood. FDA data now confirms permeation through human skin does occur, and even ecamsule with a borderline MW around the 500 Dalton mark was able to do so at a low level still exceeding the FDA threshold for toxicity testing.

  No further studies are needed in our opinion. We believe in the first precept – Primum non nocere – First do no harm. Particularly since it is now very likely that these PAH sunscreens do not have the requisite UVA protection to inhibit the UVA mutagenesis and the disabling of the repair p53 gene essential to prevent cancer. There are over 15 papers in contemporary literature that show a primary role for UVA (particularly UVA1) in the genesis of skin cancer (and photoaging). UVA also may be crucial in melanoma. Godar et al (Dermato-Endocrinology 2017) established this by showing was no correlation between UVB exposure and increasing melanoma incidence, and in some cases, there was an inverse relationship (certain ages and skin types in Europe/Italy/America). There was no difference in the incidence of melanoma between outdoor and indoor workers who are exposed to UVA through clouds, auto and window glass, and UVB-BIASED sunscreens. It explains why most UVB-BIASED sunscreens have failed to prevent melanoma. Decreasing vitamin D levels that could be a factor as it helps to kill both virally infected cells and cancer cells. This argues for more sunscreens with better UVA coverage.

  The FDA is applying the Precautionary Principle for the first time with respect to PAH UV filters. The risks from any PAH filter is shown by over 100 studies in peer-reviewed literature. Where efficacy is concerned – just look at cancer statistics in the 5 decades where these PAH filters and their UVB-BIASED products dominated global markets. Melanoma rates in the United States tripled between 1975 and 2014. Skin cancer is now the most common cancer in the USA and in N. America, and accounts for more than 50% of all human cancers. Data from the Global Burden of Disease Study 2015 reported that from 2005 to 2015 there was a 27.2% and 42.9% increase in the global death rate from melanoma and NMSC respectively.

  For safety, perhaps reading toxicology and endocrinology literature provides a different perspective that reproductive organs and central nervous system represent sensitive targets for developmental effects of endocrine active xenobiotics. Contemporary studies document widespread effects in human and wildlife from PAH UV filters and their structural analogues like DDT, BPA, and other EDCs. A review of 85 scientific papers in humans and lower species concluded that aromatic hydrocarbon UV filters are generally involved in the disruption of the hypothalamic–pituitary–gonadal system. More recent studies confirm that UV hydrocarbon filters, and other phenols like parabens, clearly change levels of virtually sex, pituitary, thyroid hormones, and certain growth factors in both pregnant and non-pregnant women. A change in a hormone level is evidence of HORMONE DISRUPTION. The numerous clinical consequences are another matter, and may not be evident for up to 40 years or more. A very recent publication showed evidence that the PAH UV filters can affect the timing of puberty in boys and girls. Neonatal effects are also being reported – urinary levels of benzophenone in early and late pregnancy may delay fetal growth – girls more than boys ; Hirschsprung’s Disease, a neonatal intestinal abnormality that is derived from a failure of enteric neural crest cells migration during embryogenesis (5 – 12 weeks) is linked to oxybenzone exposure in pregnancy; and other neural tube defects like spina bifida are associated with maternal PAH exposure. Toxicity to human reproductive function is also a major concern.

  It is impossible to perform definitive studies on toxicity,mutagenic or epigenetic effects, or to assess the NOAEL (No Observed Adverse Effect Level) in a fetus. In the situation with PAH UV filters, the Benefit Risk Assessment equation has only risk to the fetus and no intended benefit. The industry will never provide evidence of human safety for PAH UV filters – for the simple reason they are not.

  Everyone should use a sunscreen as a part of overall sun protection strategy. First rule. Avoid every filter that could pollute your body. Second rule. Select one with the better UVA filters from the insoluble group- zinc oxide, bisoctrizole, bemotrizinol (both approved in Canada and the rest of the world), and drometrizole trisiloxane (Mexoryl XL).

  Permeation and bioavailability is now an established fact in humans. There is a common pathway for toxicity to humans and the marine eco-system. First PERMEATION then HORMONE DISRUPTION, DNA mutation and genotoxicity. If we humans use only large sized insoluble filters we protect human health and likely protect the coral as well.

  Not everything needs a study. Basic science can instruct us. The 500 Dalton rule establishes the probability of permeation into humans. Over the past 20 years (and now the FDA) many studies have confirmed the basic physiologic premise. All 12 Category III and ecamsule will permeate. There is another instructive often forgotten first principle from basic endocrinology – isoform function – chemicals with the same structure will act at a cellular level in a similar manner, and bind to the same receptors. Hence if oxybenzone exhibits endocrine disrupting properties, the entire group should be considered as doing so, and the Precautionary Principle applied.

  This article talks about true versus untrue. Yet it perpetuates a 20 y/o falsehood. Mineral filters DO NOT reflect and scatter UVR to any degree. Even the larger sized older pigment grade zinc oxide never physically impeded > 10-15% of incident radiation. Nikiforos Kollias PhD (biophysicist, photobiologist, medical physicist, bio-engineer, Professor of Dermatology, Harvard and University of British Columbia), spent the last 20 years of his life trying to dispel the myth – that there is a difference in the way “mineral or natural” and so called “chemical” sunscreens protect against UV radiation. The labels physical and chemical as applied to sunscreens are inappropriate (Professor N. Kollias, Archives in Dermatology, Feb 1999). Minerals like titanium dioxide (TiO2), zinc oxide (ZnO), and others, remain as particles in a sunscreen because of low solubility. These substances are ‘physical’ since they have a predetermined particulate size but are chemicals by any definition. Even soluble organic filters will form physical crystals as the carrier base evaporates. Consumers are blitzed with the fallacy that “natural” (mineral) filters reflect or bend light like a barrier- whereas the so-called chemical agents absorb light in a chemical reaction. Photoprotection from scattering or reflection of light occurs only if a very thick optical barrier prevents light from passing through to the skin, similar to a thick coat of paint not seen in commercially available sunscreens. This would not be acceptable to any consumer. A thicker mineral based make-up will achieve some reflection or a “barrier” effect but all sunscreens absorb photons of light in reducing sun damage. All UV filters, hydrocarbon or mineral absorb photons and use the energy to excite electrons. For example, rutile TiO2, has a band gap energy of 3.06 eV corresponding to a wavelength of 412.5 nm. Light at or below this wavelength will have enough energy to excite electrons from the valence band to the conduction band. Any photon with a wavelength longer than the band gap will not be absorbed by the sunscreen. Each substance has its unique semiconductor properties and band gap, accounting for the filtering activity at different wavelengths. Harmful rays are converted to more benign spectra – usually heat.

  To comment on all questionable aspects of this article is not possible with the format, which creates a largely one-way discourse to the advantage of the writer. If regulators apply the Precautionary Principle and physicians practice the first precept the entire issue may be resolved. Insoluble UV filters with MW > 500 Daltons (G/mol) avoid all the controversy in humans, provide higher UVA protection against skin cancer, and may be a better choice for the coral, marine life, and the environment in general.

  Reply

  • The author is currently on vacation without access to WiFi. She will respond when she returns. Thank you for this informative comment. Pat Salber (Editor)

• The article was supposed to clarify truth versus misinformation Material here is dated and does not reflect the current body of science but contains the same platitudes from the dermatology/industry alliance. “Sunscreens prevent cancer”. Earlier studies supported the belief that intensive use of sunscreens increased the risk of skin cancer (Haywood et al J Invest Dermatol 2003). Possible explanation never discussed by dermatologists: Early sunscreens used UV filters with UVB and some UVA2 extinction but with minimal or no UVA1 filtering. These UVB-BIASED sunscreens still dominate the global sunscreen market. They prevent UVB effects like sunburn to varying degrees but offer inadequate protection against the most damaging and deeper penetrating UVA1 rays. Global skin cancer rates have doubled and tripled in some countries since 1960. Hardly surprising, as contemporary science suggests that UVA plays a primary role [24]. Autier from the International Agency for Research on Cancer, Lyon, France, warned in 2009 about the implications of intentional sun exposure using sunscreens with low UVA attenuation ability, to extend the duration of sun exposure. He called this ‘sunscreen abuse’ as it allowed outdoor behavior that would not be otherwise possible. Polycyclic Aromatic Hydrocarbon (PAH) UV filters even with avobenzone can only give UVB-BIASED protection. They have little chance of preventing the UVA mediated cascade of DNA mutations – 94% UVA versus 6% UVB – and most importantly protecting the repair p53 gene from being disabled by UVA.

  Whatever the reason for banning Polycyclic Aromatic Hydrocarbon (PAH) sunscreens to protect coral, there is little dispute about prohibiting their use in HUMANS. If there is little benefit to using the typical sunscreen with combinations of the proposed Category III UV filters, the whole Benefit Risk Assessment (BRA) paradigm takes on a different perspective, where any level of risk, however low, may be unacceptable.

  Earlier studies suggest that reproductive organs and central nervous system represent sensitive targets for developmental effects of endocrine active xenobiotics. Contemporary studies document widespread effects in human and wildlife from PAH UV filters and their structural analogues like DDT, BPA, and other EDCs like parabens. A 2016 review of 85 scientific papers in humans and lower species concluded that PAH UV filters are generally involved in the disruption of the hypothalamic–pituitary–gonadal system. More recent studies in 2017-2019 confirm that UV hydrocarbon filters, and other phenols (like the preservative parabens), clearly change levels of virtually every sex hormone, pituitary hormones, thyroid hormones and certain growth factors in both pregnant and non-pregnant women. A change in a hormone level is evidence of HORMONE DISRUPTION. In one of several recent studies in healthy premenopausal women, various phenols, including oxybenzone and parabens changed the levels of key reproductive hormones – FSH (Follicle Stimulating Hormone), (LH) Luteinising Hormone, estradiol, and progesterone. The numerous clinical consequences are another matter, and may not be evident for up to 40 years or more. A very recent publication showed evidence that the PAH UV filters can affect the timing of puberty in boys and girls. Neonatal effects are also being reported. Maternal urinary levels of benzophenone in early and late pregnancy appear to delay fetal growth with more pronounced effects in girls compared to boys. Hirschsprung’s Disease, an uncommon neonatal problem from a failure of enteric neural crest cells migration during embryogenesis from 5 to 12 weeks.has been linked to oxybenzone exposure in pregnancy. Neural tube defects like spina bifida have been reported to be associated with maternal PAH exposure. Toxicity to human reproductive function is also a major concern.

  It is impossible to carry out definitive studies or to assess the NOAEL (No Observed Adverse Effect Level) in a fetus. for toxicity, and mutagenic or epigenetic effects. In the situation with PAH UV filters, the BRA equation has only risk to the fetus and no intended benefit. The Precautionary Principle as integrated into various jurisdictions, recognizes that the absence of full scientific certainty shall not be used as a reason for postponing decisions where there is a risk of serious or irreversible harm. The application of precaution is distinctive within science-based risk management and is characterized by three basic tenets: the need for a decision, a risk of serious or irreversible harm and a lack of full scientific certainty. The precautionary principle permits decision makers to take decisions in the absence of scientific certainty if there is a sufficiently serious risk. So it requires the exercise of judgement, in other words it is a principle of policy making.

  I will leave the debate about taking a precautionary approach for the marine habitat to the divided group of coral scientists and marine biologists. The skeptics in the marine world can afford to ignore the Precautionary Principle. I cannot. As a physician, I march to a more exacting drummer – the sacred trust in medicine – “primum non nocere” or first do no harm.

  Reply

  • The author is currently on vacation without access to WiFi. She will respond when she returns. Thank you for this informative comment. Pat Salber (Editor)

• Sorry, one more point. The only thing that is laughable about sunscreens harming coral is that the damage is only caused by one thing – “global warming”. Corals have been bleaching in Hawaii at 3 to 6 degrees Fahrenheit below what is normally seen with global warming. A study just published a few days ago demonstrated that nitrogen run-off plays a very important role in coral bleaching/death https://link.springer.com/article/10.1007/s00227-019-3538-9 … many sunscreen products contain nitrogen as well and too many tourists in an area can also be problematic … the list goes on. Also, it’s not just coral, many aquatic species are negatively impacted by these chemicals. No one that I have ever conducted research with ever said “if we ban sunscreens the coral will all come back”… remember doubt is the $10 billion sunscreen industry’s way of continuing to make money!

  We need to do as much as we can, as soon as we can to stop the environmental damage that is occurring everywhere on our planet … banning damaging sunscreens is just the start and it is something we can all do NOW.

  Reply

  • Joe Dinardo is exactly right. Permeation and bioavailability is now an established FACT in humans. There is a common pathway for toxicity to humans and the marine eco-system. First PERMEATION then HORMONE DISRUPTION, DNA mutation and genotoxicity. Coral has an epidermis similar to human skin but less complex. The finding of PAH filters in rivers, lakes, remote estuaries, coral reefs, and even in the surface and coastal waters of the Arctic, with further contamination of fish and other marine food sources, should concern all of us. It may also be a secondary route for human contamination.

    The FDA is applying The Precautionary Principle at long last, to these petrochemicals that are structural analogues to DDT, BPA, human estrogen, and numerous phenols. Physicians are remiss in not advising patients about permeation even if there was no risk of harm.

    The physicians (who are now on every media platform) denouncing the FDA Proposal, appear to ignore the fact that many EDCs are proven to have a Non monotonic Dose Response Curve (NMDRC). Low-dose endocrine activity is to be expected. Low dose/response comparisons are impossible, as they occur in cells, tissues, animals and human populations in response to nutrients, vitamins, pharmacological compounds, hormones and endocrine disrupting chemicals (EDCs). Some argue that NMDRCs are not common, are not found for adverse outcomes, and are not relevant for regulation of EDCs. Under the linear dose response model, high dose testing is used to extrapolate to lower doses that are assumed to be ‘safe’ for human exposures. NMDRCs that occur below the toxicological NOAEL would falsify a fundamental assumption, that high dose hazards can be used to predict low dose safety. Furthermore, the fact that a substance with endocrine biological activity is accepted for pharmaceutical use does not imply that its effect can be used as a comparison for other chemicals or mixtures. A substance with similar or even much lower effects on the reproductive cycle should still be regarded as an EDC when used outside an intended therapeutic purpose. While a substance that blocks reproduction may be viewed as safe as an ingredient for a contraceptive, it is clear that a reduction or loss of fertility should be interpreted as an “adverse effect” when resulting from a mixture not specifically designed for this, such as a cosmetic, PAH UV filter, or a drug with another purpose.

    Eventually, the FDA will develop a regulatory framework and a new Sunscreen Monograph based on the tests that prove safety and efficacy beyond a reasonable doubt. While it evolves, a good place to start would be with a WARNING Label on BIOAVAILABILITY and a CAUTION to pregnant or nursing mothers and others who may be more at risk – young or adolescent children, and couples trying to conceive. This occurs for almost everything that is bioavailable to vulnerable groups and certainly the fetus, even low dose aspirin and many other OTC non-prescription items. There is a harmony and confluence between the first precept or sacred trust in medicine – “primum non nocere” (first do no harm) when applied by physicians and the Precautionary Principle”, when exercised by regulators like the FDA.

    Not everything in clinical medicine needs a study. Fundamental physiology and first principles are instructive. All of the Category III filters share common properties. They are low Molecular Weight (MW) soluble chemicals that will be absorbed through human skin, at different rates and perhaps to different peak levels. The 500 Dalton rule establishes this probability (Bos & Meinardi 2000) and over the past 20 years many studies have confirmed the basic physiologic premise.

    The FDA proposal questions 40 years of policy. We should let consumers make their own informed choice on the fact of permeation into blood, breast milk, and crossing into our brains and the unborn. The golden rule in endocrinology is “isoform function”, same structure – same actions – where permeation and hormone disruption are concerned. For over two decades, I have said that if oxybenzone reaches blood, all PAH filters will take varying times to attain steady state and peak levels. The FDA did their own permeation and bioavailability studies, which confirm that all in the group (including avobenzone) attain blood levels. This led to their new proposals when they also decided that the sunscreen issue was very similar to that of BPA.

    Think of the enormity of this : there is no other OTC, drug, pollutant, or pesticide that is found in 96.8% of humans tested, in the breast milk of 85.2% of nursing mothers tested, is present in global municipal wastewater, found in coastal waters around resorts and in remote estuaries, in rivers all over the world, in most swimming pools and hot-tubs of most resort or public pools – from North America, to Japan to Switzerland to Australia, even the Arctic – literally the entire globe when looked for, as is the case for oxybenzone and other hydrocarbon UV filters. All of this for UVB-BIASED sunscreens – that cannot and as statistics show – DO NOT prevent skin cancer to any useful degree.

  • The author is currently on vacation without access to WiFi. She will respond when she returns. Thank you for this informative comment. Pat Salber (Editor)

• These are all very important points to consider: however, currently FDA has changed what is “approved”. Only Zinc Oxide and Titanium Dioxide are currently consider safe and effective for human use (Category I). PABA and Trolamine Salicylate have been removed from the FDA list because they are not considered safe and effective (Category II). The remaining 12 chemicals FDA is requesting additional testing (Category III), specifically, human absorption, what happens to the chemical when it enters your body, can it cause cancer and can it cause effects to unborn babies. These points have come up because scientists from all over the world have already published several studies that demonstrate that these risks are possible. The question is will the $10 billion a year sunscreen industry spend the money to show FDA that these 12 chemicals are safe (this is required by law, our tax $ are not supposed to be used). Short answer – NO; they hardly ever do and it is highly unlikely they will do it now. Industry will more than likely continue to cast doubt on the issue with phrases like “?sunscreens save lives?” “?sunscreens prevent skin cancer” and alike confusing as many people as possible for as long as they can, in order to make as much money selling these products before they are told to remove them from the store shelves!

  Should you use a sunscreen? If you do, you should minimize your exposure to them as much as possible by applying them to only the exposed areas! Until then, PLEASE avoid direct sun exposure when possible – especially at peak hours (10 AM – 3 PM), wear protective clothing – including hats and sunglasses, if going to the beach use a beach umbrella or cabana and LASTLY apply a non-nano zinc oxide or titanium dioxide (Category I) sunscreen to any areas exposed to sunlight.

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