SUN PROTECTION MYTHS: FACTS VERSUS FICTION

INTRODUCTION

Media and “experts” continue to misinform consumers about sunscreens and UV protection. Facts need to be separated from fiction. This blog is dedicated to Nikiforos Kollias PhD (biophysicist, photobiologist, medical physicist, bioengineer, Professor of Dermatology at Harvard and UBC). He spent the last 20 years of his life trying to dispel the first myth –  that there is a difference in the way “mineral or natural” and so called “chemical” sunscreens protect against UV radiation.

FICTION

The words “natural” versus “chemical” are used deceptively to imply that some sunscreens are not chemicals, and that a natural or mineral product might be preferable because it acts as a physical barrier  that bends or reflects light, compared to chemical sunscreens that absorb light. This has misinformed the consumer since the last century. It is repeated ad nauseam by every “expert” like a recent CBC program hosted by Heather Hiscox, where another “expert” physician said “physical or barrier” sunscreens reflected or blocked UV radiation and “chemical” products absorbed harmful rays.

FACT

All sunscreens are CHEMICALS – fundamental Chemistry. A chemical is  a  substance in any form : ionic, molecular, organic or inorganic – that is generated by or utilized in a chemical process. Some are organic – meaning carbon based with complex carbon chains and rings in their structure.  Mineral UV filters are inorganic compounds (contain no carbon atoms) like zinc oxide, titanium dioxide, iron oxide, and others. Their individual atoms all occur on the Table of Chemical Elements.

FICTION

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.

FACTS

  • 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 thick mineral  based  make-up will achieve some reflection or a “barrier” effect but all sunscreens absorb photons of light in reducing sun damage.
  • The word chemical is a misnomer as ALL UV FILTERS ARE CHEMICALS. At The Sunscreen Company TM we condemn small Molecular Weight soluble organic filters that reach blood and tissue. Organic does not mean natural or safe – only carbon based. Many of these synthetic filters contain the 6-carbon benzene ring so inimical to humans and the environment. The mineral filters zinc oxide and titanium dioxide ARE STILL CHEMICALS  – albeit inorganic –  made by a geologic system (mother earth) – hence the tendency to think of them as natural.  Mineral filters are now so processed, highly refined, milled, doped and coated that they are really “naturally derived” but so altered that  they are semi-synthetic and hardly natural.
  • New and more efficient nanoscale mineral sunscreens < 1 micron in size only scatter < 10% of incident light. Even older pigment grade forms of zinc oxide and titanium dioxide with larger molecules over 1 micron in size did not reflect more than 15% of the UV rays. All mineral or insoluble UV filters act as semi-conductors and absorb photons with electron shifts to a different valence band, so a harmful wavelength is converted to a less harmful or innocuous wavelength. New particle type filters are synthetic organic compounds that are also insoluble.
  • The only accurate classification of UV filters is soluble versus insoluble and definitely not natural versus chemical. Both types mostly act by absorbing photons. The mechanism of action in mineral UV filters involves the use of photon 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.
  • Filters are safer and preferable not because of “natural” versus “chemical” but Insoluble filters like zinc oxide (inorganic) or bisoctrizole (organic) are safer since  their large size prevents entry through skin into blood, avoiding all the issues with hormone disruption and adverse effects. They are not photocontact allergens like the soluble organic filters. The best UVA filters belong to this group and provide the broad spectrum protection and high UVA shielding required to prevent skin cancer and photoaging.

FICTION

Consumer Reports suggested recently that SPF retesting done by them shows which brand name sunscreens are better. They recommended as best products, several with soluble organic UV filters like avobenzone and oxybenzone, since their tests showed better agreement with the label value for SPF. The same report suggested that mineral based sunscreens like zinc oxide with or without titanium dioxide were not to be recommended as the retest SPF did not meet label claims. This is a dangerous recommendation as it may influence consumers not to use mineral sunscreens. In the right concentrations mineral products are the safest sunscreens for humans and the environment.  Along with other new insoluble UV filters, mineral agents deliver better UVA protection required for truly BROAD SPECTRUM shielding to prevent sunburn, skin cancer, and photoaging.

FACTS

  • The laboratory SPF test with a solar lamp emitting a limited light spectrum compared to sunlight is useless in predicting how a sunscreen performs in Real Life sunlight for many reasons. Studies confirm  products labelled SPF 50-100 tested in sunlight are actually SPF 10-15. Professor Brian Diffey – a physicist – showed that based on laws of  biometrics and physics – most sunscreens cannot achieve a SPF above 25. FDA and Health Canada have been advised by scientists that SPF lab tests and others are accurate for lotion formulations using soluble organic filters, but are erroneous for products containing particulates like zinc oxide or titanium dioxide. The tests require modifications to accurately assess the true performance of these and other particulates. Ask any consumer if they have ever had a sunburn with mineral sunscreens using proper concentrations like 22-25% zinc oxide or 15-20% zinc oxide with a filter like titanium dioxide 7.5% or special particle dispersions. Yet 70% of fair skinned consumers may return from vacation with sunburn after applying high SPF brand name sunscreens using soluble organic filters, despite re-application every 2-3 hours and label claims of water resistance. The SPF is a fallacious test and bears no relation to outdoor performance in actual sunlight– repeating it in a different lab and comparing values just gives another useless result and cannot be used to assess the quality of a product.
  • This Consumer Report suggesting  that the best sunscreens are those using  soluble organic filters is untrue and detrimental to the consumer. The ability to prevent sunburn is one thing and the SPF may be a rough guide, but the prevention of skin cancer and photoaging depends on UVA shielding. The soluble small sized filters all enter your blood, including oxybenzone,  just banned in Hawaii because of the toxicity to coral and marine wildlife leading to severe reef degradation. The entire group are suspected hormone disruptors and may be linked to some cancers like thyroid and prostate. Worse, they give UVB-BIASED protection where the sunscreen transmits 10 times or more UVA than UVB radiation.  The UVA filter used in most sunscreens is avobenzone. It is not photostable, has a similar structure to the Hawaii banned oxybenzone – likely has similar effects – and at 3-4% in a SPF 30-50 sunscreen has a UVA-PF (UVA Protection Factor) < 10 , inadequate to prevent sun damage.
  • Proper protection approaching indoor shade and dense textiles comes from the degree of UVA protection – a UVA-PF > 10.  Higher is better and high UVA shielding usually means high UVB as well, but not vice versa. Use zinc oxide in the right concentrations and in CLEAR particle dispersions for the best UVA and BROAD SPECTRUM protection available in N. America.

THE BEST SUNSCREENS TO PREVENT SKIN CANCER AND PHOTOAGING

Safety is the prudent first principle in selecting a sunscreen. Use ONLY combinations of these filters where  available :

  • Zinc oxide, titanium dioxide, encapsulated octinoxate, ecamsule (Mexoryl SX™), bemotrizinol (Tinosorb S™), bisoctrizole (Tinosorb M™), polysilicone -15 (Parsol SLX™), iscotrizinol, octyl triazone, and bisdisulizole disodium (Neo Heliopan AP™). None are hormone disruptors and only octyl triazone is a photoallergen.
  • Avoid them if they are combined with “undesirables” – oxybenzone, avobenzone, homosalate, octisalate, octocrylene, regular octinoxate (not encapsulated), and 4-methyl benzylidene camphor – all small molecular weight filters that pass into blood, are suspected hormone disruptors, photocontact allergens, and likely degrade coral through hormone disruption.

Good filters like bemotrizinol, bisoctrizole, ecamsule, drometrizole, and bisdisulizole are of limited availability in Canada and the USA, and even abroad are usually combined with the “undesirables” and best avoided. Adequate filter levels is the second selection principle to ensure enough UVA protection and truly BROAD SPECTRUM protection.  Zinc oxide is the only safe and effective UVA filter widely available in N. America. Look for 15-25% with or without UVB filters like encapsulated octinoxate or titanium dioxide. Any sunscreen with < 15% zinc oxide hardly achieves the UVA shielding needed to prevent skin cancer and photoaging. My next blog describes:

  • How to ensure your sunscreen has good UVA protection
  • Why high UVA shielding mimics ideal protection from indoor shade and tightly woven clothing.
  • Why high UVA shielding will prevent skin cancer and photoaging.
  • Why CyberDERM sunscreens provide the best UVA shielding in very transparent esthetic products with the best sensory feel on your skin.

© Denis K. Dudley MD 2018. All Rights Reserved.

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THE LABEL SPF CANNOT BE USED TO ESTIMATE SAFE SUN EXPOSURE TIME

North American consumers should not rely on label claims – whether it is the SPF or claims of UVA and Broad spectrum protection. Most of our brand name sunscreens would not pass European or Australian criteria for UVA-PF (UVA- Protection Factor) and their better standards for Broad Spectrum coverage. Proper and adequate UVA protection may be the most essential property for a sunscreen to actually prevent skin cancer and photoaging. The global market, particularly in North America is dominated by UVB- BIASED sunscreens with inadequate UVA protection, despite label claims saying ‘BROAD SPECTRUM’ UVA/UVB. Even the EWG (Environmental Working Group) recognizes this reality in their 2017 Sunscreen Report. More on this in my next BLOG.
There are over 25 stakeholder and professional coalitions with Comprehensive Cancer Control (CCC) plans  that publicise a prevention strategy. Language may differ but they all focus on key elements of sun avoidance, never burn or tan from UV exposure, wearing protective clothing with a tight weave, wear UV protective sunglasses, and generously apply a sunscreen with sun protection factor (SPF) 15 or higher and both UVA/UVB protection. Sunscreen use is the weakest link in the protocol. Rising cancer rates show that the current approach has failed and critical analysis argues that ineffective UVB-BIASED sunscreens dominating the N.American market are a driving factor.  Australia where balanced sunscreens using better UVA filters are plenty,  are actually seeing skin cancer rates levelling off or falling in certain provinces. Two landmark studies from Australia show that effective sunscreens applied daily can potentially reduce all forms of skin cancer. In N. America the grim reality is otherwise:

 

  • Skin cancer is now the most common cancer in the United States with the incidence essentially doubling for all skin cancers in 40 years,  and they now account for more than 50% of all human cancers – i.e. skin cancer cases outnumber all other cancers combined.
  • In 2017, over 160,000 Americans are expected to be diagnosed with melanoma, which is the leading cause of cancer death in women ages 25-30 and the second leading cause in women ages 30-35.  In ages 15-29, melanoma is the second most commonly diagnosed cancer. From 1970 to 2009, the incidence of melanoma increased by 8-fold among young women and 4-fold among young men. In the USA, one person dies of melanoma every 54 minutes (almost 10,000/year).  4000 Americans die in a year from Squamous Cell Cancer (SCC) .

 

Preventing sunburn (early effect) or UVA damage (early and late effects), and damage to the genetic and immune apparatus of the skin is the essence of effective photoprotection. The label SPF is supposed to quantify a sunscreen’s ability to prevent that early sign of sun damage. The SPF as measured by FDA and Health Canada mandated tests give a poor estimate of the sunscreen’s actual performance in sunlight.
The premise that SPF can be used to plan your exposure time is based on several invalid assumptions. Recent studies confirm that the lab or label SPF is inaccurate, when compared to the real life value obtained in sunlight. The lamp used in calculations for label purposes, only emits 290-400 nm based on the false assumption that the erythema reaction was mediated only by UVR (UVB and UVA). Visible Light (VL at 400-740 nm)) and Infra-red (IR at beyond 740 nm)) could be responsible for up to 20-30 % of the erythema response. Sunlight has more UVA (up to  5X ) than the testing lamp emission. Industry and physicians continue to advise consumers that the SPF can be used to calculate the safe exposure time for protected skin outdoors. We know differently –  fair individuals mostly get sunburned with prolonged outdoor exposure or during tropical vacations, despite using high SPF sunscreens and stringently following all the re-application instructions.   Media reports in 2015-2017 from Consumer Reports, the BBC in the UK, CBS, NBC, and CNN in the USA, have all presented data that up to 50% of brand name sunscreens fail to achieve even 50% of their labelled SPF values.
Science now confirms this travesty. The label SPF is inaccurate when compared to the real life value obtained in sunlight. A landmark study  presented at the 26th Annual Meeting of The Photomedicine Society (Orlando, Florida, February 2017), showed that  50 commercially available sunscreens with label SPF 50 or more had SPF values of 6-10  when measured in sunlight (Hughes S. and  Cole C.). No wonder, as testing lamp emission spectrum is far removed from that of actual terrestrial radiation, and the intensity used in testing is different from sunlight. The compliance factor also adds another real life problem as most  users apply < than the 2 mg/cmas done for the lab test. Scientists also now provide the principles in physics that explain why the SPF test cannot be accurate (Diffey B, Osterwalder U, 2017).  They report that labelled SPF, determined by in vivo assay using a UV solar simulator, overestimates the SPF that would be expected in natural sunlight.  Products labelled SPF50+ may not be able to achieve a protection against sunlight of more than 25-fold., or SPF 25. The popular interpretation of the SPF to mean how much longer skin covered with sunscreen takes to burn in sunlight compared with unprotected skin, can no longer be defended.
Any falsely high SPF reading can be further  manipulated by adding anti-redness agents (similar to aspirin) that artificially increases the MED (Minimal Erythema Dose) used to determine the SPF, for the sunscreen containing these anti-inflammatory chemicals. Sunscreens are replete with SPF boosters- bisabolol, niacinamide, salicylate compounds, and numerous others. This may be very harmful to a consumer. The false (often high SPF 50-100) values distort the reality of what protection to expect. If you are very fair – Type 1- always burns never tans- you may actually burn within 5 minutes with extreme sun exposure. An SPF 30 conveys the impression that it is safe to stay out for up to 150 minutes and SPF 50 for up to 250 minutes. A real life SPF 10 in sunlight means you should multiply your 5 minute burn time by only 10 for a safe 50 minute exposure, then get out the sun or re-apply your sunscreen liberally if you stay out longer. A boosted SPF is falsely elevated by interfering with the biologic endpoint or early warning signal of redness, the first sign of sunburn. It is no longer commensurate to the amount of radiation being prevented from reaching your skin,  but related to delayed redness. You are actually burning but have no way of knowing this as your early warning signal has been blunted. This false sense of security may make you remain outdoors i/o seeking shade. You will experience more sun damage and incur the risks of skin cancer and photoaging. This  is only related to UVB exposure – think of the damage resulting from the more harmful UVA radiation that you are now receiving in high levels, particularly since most N. American sunscreens have inadequate UVA-PF values.
  • Use no more than half the label  SPF when calculating your outdoor exposure time, and if you are redhead or extremely fair use a factor of 10.
  • It is better to use the other elements of a photoprotection strategy – avoid sun exposure, wear UV protective clothing, wear head gear and UV protective sunglasses etc. – to the extent you can, and use a sunscreen with a safe UVA filter like zinc oxide in adequate concentrations.
  • The particle type sunscreens that use zinc oxide, titanium dioxide, encapsulated octinoxate, drometrizole trisiloxane (Mexoryl XL™), terephthalylidene dicamphor sulfonic acid (Ecamsule or Mexoryl SX™),  biscotrizole (MBBT or Tinosorb M™), bemotrizinol (BEMT or Tinosorb S™),  and others are large in size, sit on the skin avoiding any entry into blood and the various attendant risks. Only the first five are available in Canada. Mexoryl XL™ and SX™ are patented to L’Oreal and regrettably are usually combined with undesirable soluble hydrocarbon filters, which should be stringently avoided. All except titanium dioxide and encapsulated octinoxate are UVA filters, and when mixed with other safe UVB filters achieve dispersions of spectral homeostasis (balanced UVA/UVB protection). In this situation where a sunscreen behaves like a neutral density filter, the label SPF may be closer to the Real Life SPF value in sunlight.  Look for products that have > 20% zinc oxide alone, or 15 % with 7.5% titanium dioxide or encapsulated octinoxate.
  • For maximum protection and to avoid all the controversy on hormone disruption and environmental hazards, use only sunscreens  with particle based or large molecular weight filters in the right combination. The high UVA protection achieves that flat balanced protection where the ratio UVA-PF/SPF approaches 1, and the label SPF comes closer to the Real Life value in sunlight. Strictly avoid all small molecular weight soluble hydrocarbon filters – avobenzone, oxybenzone, homosalate, octisalate, octocrylene, regular octinoxate, and 4-methylbenzilidene camphor. All may enter blood and only avobenzone has any UVA attenuation. It still gives a significant UVB bias where up to 30% of UVA between 340-400 nm – the most damaging UV rays are transmitted to your skin.
© Denis K. Dudley MD, October 2017. All rights reserved.

SOLUBLE UV SUNSCREEN FILTERS ARE A PRIMARY ROUTE OF EXPOSURE TO HORMONE DISRUPTORS

Hormone disruptors or Endocrine Disrupting Chemicals (EDCs) have been in the news again. At The Endocrine Society Meeting  (2016) , a Danish study (Skakkebaek et al) confirmed that 13/30 UV filters tested or 45%  had direct effects on human sperm cells explaining the male infertility associated with sunscreens. They imitated the hormones progesterone and prostaglandin, not estrogen, as is usual. They disrupted numerous functions required for fertility by simulating hormonal signals controlling the CatSper ion channel for calcium flux – a very specific mechanism for human sperm cells. Eight  of the 13 offending sunscreen agents are still used widely in N. America.

The response from the dermatology/industry alliance was swift and predictable. Many dermatologists appearing in the  media, are consultants for the sunscreen industry. A NYU dermatologist and consultant for Johnson & Johnson immediately proclaimed that this was not science, as it was done in a test tube. That is so absurd- many studies are done in vitro and there are already  numerous studies in vitro and in vivo in animals and humans that identify several UV-filters as endocrine disrupting chemicals. There is already enough science implicating hormone disruptors in human endocrine disorders that any human study would never be ethical. He also said that dermatologists must only pay attention to the “known science”. “The most important thing to remember is we do this experiment with tens of millions of people every summer [as they wear sunscreen on our beaches and outdoors], and we’re not seeing effects that would be predicted by a study like this.”  This is even more bizarre. As a physician, I am embarrassed at these ridiculous statements. These consumers are not being followed over a lifetime with semen analysis and epidemiologic studies looking for all the possible effects like fibroids, endometriosis, uterine cancer, breast cancer, diabetes, obesity, and several childhood disorders.  A definitive study would require  a large number of participants from pregnancy through childhood to adult ages- followed over a lifetime to see what the differences in reproductive and cancer outcomes were. Such a study is obviously impossible.

The Danish study also showed that the effect began at very low doses of the chemicals, below the levels of some UV filters found in people after whole-body application of sunscreens. It  provides a context and an explanation for a prior report from the National Institute of Health that men with high exposure to UV filters like oxybenzone had a 30 percent reduction in fecundity, the biological ability to reproduce. Lower fecundity may result in a longer time to pregnancy. “Our next step is to figure out how these particular chemicals may be affecting couple fecundity or time to pregnancy—whether it’s by diminishing sperm quality or inhibiting reproduction some other way.” said Germaine Louis, Ph.D., director of the Division of Intramural Population Health Research at the Eunice Kennedy Shriver National Institute of Child Health and Human Development. The data came from the Longitudinal Investigation of Fertility and the Environment (LIFE) study, established to examine relationships among fertility, lifestyle factors, and exposure to environmental chemicals.

Most dermatologists like the J&J consultant, are either unaware of, or choose to ignore  the WHO and Endocrine Society positions and the prior NIH report. The WHO published a 250 page evidence based review entitled “ State of the Science of ENDOCRINE DISRUPTING CHEMICALS 2012 “ representing a broad scientific consensus among the leading experts in related fields, confirming how things have changed in just over a decade. In 2002 the scientific consensus was that there was only weak evidence for causal links existed but that careful study and observation was necessary.  Ten years later the WHO/UNEP report cite numerous examples of human and wildlife effects that call for focused action on this growing problem. “Of special concern are effects on early development of both humans and wildlife, as these effects are often irreversible and may not become evident until later in life.

For the past 10 years, I have urged physicians and patients to realize that sunscreens and cosmetics represent the major source of exposure to hormone disruptors for most urban dwellers in N. America. Consider my deductive but evidence based argument outlined below. I respectfully submit it is persuasive. Consider it in the context of the level of caution you exercise where the health of your children is concerned.

 Soluble UV filters definitely reach human blood, tissue, and regulatory brain centers through the skin

This is not theoretical as stated by dermatologists in The Globe and Mail newspaper. Basic science tells us that any fat soluble chemical with a molecular weight (MW) < 500 Daltons will pass through the skin very rapidly. The soluble filters still used in most sunscreens in this category include: avobenzone, oxybenzone (benzophenone), homosalate, octisalate, octocrylene, octinoxate (non-encapsulated), and 4-methyl benzilidene camphor (enzacamene). No study is needed  to tell me that all of these are more likely than not to enter our bodies, and reach the unborn at every stage of pregnancy. No study is needed to know that the entire group are hormone disruptors, based on the principle of isoform function, where chemicals with similar structure bind to the same endocrine receptor and produce the same effects. Since  oxybenzone and homosalate are proven hormone disruptors, so are avobenzone and octisalate. The Danish study (2016) on altered sperm function indicted all of the above plus a few others.

  • 8 studies I know of  confirm  that UV filters of this type attain blood levels in humans, not from animal studies. They come from diverse populations in the USA, France, Denmark,  Switzerland, and Sweden. A few especially refute the propaganda from the dermatology/industry alliance:
  • The CDC study from 2008 (Calafat et al) that showed 97% of 2517 Americans, age 6-70, of both genders had oxybenzone in their urine, and also found Bisphenol A (BPA) in 93.8% of these urine samples.
  • An EU study from Krause et al (2012) showing that 85.2% of European mothers had various UV filters in breast milk . 100% of the breast milk samples had pesticide residues- persistent organochlor pollutants (POPs), i.e., organochlor pesticides and metabolites, polybrominated diphenylethers and polychlorinated biphenyls (PCBs). This tells us that human contamination is related to the route of exposure. Pesticides contaminate the environment, water, and our food chain. Everyone is susceptible in certain countries. Not everyone uses a cosmetic or a sunscreen – hence the lower rate of breast milk contamination.
  • Zhang et al (2013) showed that benzophenones appear in paired urine and blood samples in adults , children, and pregnant women. Matched maternal and fetal cord blood showed that benzophenones crossed the placenta.

Hormone disruptors are definitely affecting the health of this and the next generation.

Drs Dudley and Laughlin
Dr. Dudley and Dr. Sharyn Laughlin at a company event

 

I am married to dermatologist/ photobiologist Dr. Sharyn Laughlin (www.laserderm.ca). We share the concern of the WHO, the United Nations Environmental Program, The Endocrine Society, The European Pediatric Society, The European Commission and others, that hormone disruptors are now strongly linked to adverse reproductive outcomes, endocrine cancers, and neurological disorders like ADHD, possibly Autism Spectrum disorder, Parkinson’s disease and Alzheimer’s, asthma, obesity, and diabetes.

Consider the statement from a 2009 review from The Endocrine Society : The evidence for adverse reproductive outcomes (infertility, cancers, malformations) from exposure to endocrine disrupting chemicals is strong, and there is mounting evidence for effects on other endocrine systems, including thyroid, neuroendocrine, obesity and metabolism, and insulin and glucose homeostasis.

Their recent warning (September 2015) is even more ominous:

  • Unborn children are particularly at risk when exposed to endocrine disrupters, according to the society.
  • The new statement corroborates earlier findings, linking endocrine disrupters — in addition to their impact on obesity and diabetes — to effects on male and female reproductive health, hormone-related cancers, prostate conditions, thyroid disorders, and neuro-developmental issues.
  • Andrea Gore, PhD, Professor and Vacek Chair of Pharmacology at the University of Texas at Austin, and Chair of the Task Force that developed the statement, said the group is highlighting obesity and diabetes this time because the evidence for effects on these diseases is much stronger than it was 5 years ago. She advises that not just endocrinologists, but general practitioners, pediatricians, obstetrician-gynecologists, and fertility doctors should emphasize reduction of exposure to these disrupters when they talk to their patients.

 My comment:  Dr. Gore, like the WHO and others, has  also missed  that dermatologists and sunscreens are at epicenter of the problem. Given the patterns of exposure and the way EDCs intersect with our daily lives, sunscreen filters and cosmetic chemicals are the likely primary source of exposure for most of us in a developed society.

Why sunscreens and cosmetics are the main exposure to EDCs for most urban residents in N.America.

Over a 1000 chemicals are now identified as EDCs. Most have never been studied for their effects on humans. The ones that likely intersect with our lives include:

  • Persistent organochlor pollutants (POPs) in pesticides and flame retardants in furnishings
  • Bisphenol A (BPA) and phthalates in cans, plastics and the ink on some receipts
  • Soluble sunscreen filters and cosmetics
  • Metalloestrogens: aluminium, cadmium, antimony, selenium, tin, copper, lead, arsenite, nickel, copper, lead, cobalt, antimony, and arsenite
  • Various phytoestrogens – flavones, soy, isoflavones, favonols

Many are weak and of less significance than pesticides and UV filters. Some contaminate our food and water supply. However, the principle of multiplication is an increasing issue where an individual may be exposed to several sources. Bisphenol A  (BPA) and phthalates in plastics and tins, and produce sprayed with pesticides are publicised as a source of human EDC exposure by ingestion. This exposure is more tangential than sunscreen or cosmetic chemicals. The liver may metabolize and ameliorate the effects of EDCs ingested. Sunscreen chemicals absorbed through the skin obtain direct access to tissues and the brain and bypass this protective mechanism. Logical and critical thinking leads you to the unavoidable conclusion that sunscreen and cosmetic chemicals are the most important source of EDC exposure in a first world society.  They may be used one or more times daily in combinations of products, applied to a part of or the whole body, passing directly into the blood and brain. Soluble filters do require re-application every few hours for outdoor exposure and swimming. They wash off more easily and as they are absorbed into blood they require replacement on the skin. Particle type insoluble filters have no percutaneous entry and can be made into bioadhesive dispersions that may  not require re-application.

Linda Marsi in the October 2015 issue of MORE magazine and experts like Dr. Gore talk about reducing your exposure by avoiding storage or microwaving food in plastic containers with known EDCs, not handling receipts where ink contains phthalates, avoiding household exposures from flame retardants and stain or water repellants. Every precaution is worthwhile, but these are mostly low level and extraneous sources. Any benefit  from these precautions are negated if you ignore the greater exposure that comes from applying a cosmetic or sunscreen to large areas of skin. Many experts warn about avoiding EDCs but the silence on EDC exposure from soluble sunscreen filters is deafening:

  • After the NIH reported the data from the LIFE study on the link between infertility and benzophenone type sunscreens, infertility experts expressed concern that BPA and phthalates are a concern to all couples wishing to conceive, with the caveat that the growing body of evidence that EDCs adversely affected reproductive capacity was  “ preliminary”. Dr. Ruth Lathi, a researcher and director of Stanford’s Recurrent Pregnancy Loss Program and Dr. Linda Giudice, president of the American Society for Reproductive Medicine and a professor of reproductive sciences at the University of California at San Francisco recommended the half-measures that couples wishing to conceive should not store or microwave food in plastic containers with BPA.
  • Germaine Louis , Ph.D., director of the Division of Intramural Population Health Research at the Eunice Kennedy Shriver National Institute of Child Health and Human Development was involved with the LIFE study. She said “Our next step is to figure out how these particular chemicals may be affecting couple fecundity or time to pregnancy—whether it’s by diminishing sperm quality or inhibiting reproduction some other way.” Dr. David Adamson, founder and CEO of Advanced Reproductive Care, Inc. (ARC), the largest network of fertility specialists in the United States and a pioneer in reproductive medicine joined Dr. Louis in advising that  men concerned about fertility should reduce their use of benzophenone UV filters—and  by washing after returning indoors.

The analysis and advice in these statements is incomplete. I repeat that no one, including couples hoping to have a child, needs to moderate their use of sunscreens. The proper advice is to avoid all soluble filters. Everyone should use sunscreens with safe insoluble particle based filters that actually provide better balanced UV attenuation with higher UVA protection. Washing off benzophenone or any soluble filter at the end of the day is ineffective and illogical. Absorption is rapid, peaking  at about 10% of the applied amount, 1-2 hours after each application. If  tangential exposure from BPA and phthalates in cans and plastics pose a level of exposure to be considered, then  daily recurrent exposure from soluble UV filters and cosmetics is a greater concern. Most city dwellers in N. America have little if any exposure to pesticides, unlike the third world where indiscriminate pesticide use may explain higher rates for precocious or early puberty in girls as young as age 6-7.

My Final Thoughts

The WHO, UNEP, European Commission, European Pediatric Society, The European Environmental Agency, The Endocrine Society and The Pediatric Endocrine Society USA based), all agree the evidence for adverse reproductive outcomes (infertility, cancers, malformations) from exposure to endocrine disrupting chemicals is strong, and there is mounting evidence for effects on other endocrine systems, including thyroid, neuroendocrine, obesity and metabolism, and insulin and glucose homeostasis:

  1. In Females- uterine fibroids, endometriosis, uterine and breast cancer, infertility, polycystic ovarian syndrome (PCOS), precocious puberty, and premature menopause.
  2. In Males: prostate cancer, feminization syndromes (testicular dysgenesis).
  3. In children: asthma, learning/behaviour disorders (ADHD, autism spectrum disorder).
  4. In both genders: thyroid cancer, type 2 diabetes, obesity, cardiovascular disease, Alzheimer and Parkinson disease.

The dermatology/industry alliance cites irrelevant studies that the toxic doses in rats or mice would not ordinarily be attained in humans from the usual pattern of everyday use. The Danish researchers (Skakkebaek et al) in their 2016 study, found that 13, or 45 percent, of the 29 UV filters tested induced calcium ion influxes in the sperm cells, thus interfering with normal sperm cell function. “This effect began at very low doses of the chemicals, below the levels of some UV filters found in people after whole-body application of sunscreens said. Some studies in animals do suggest that UV filters are not harmful. It is difficult to prove a negative. What is needed is proof that they are safe in humans, as we are not large rodents. Mothers with high levels of oxybenzone in their bodies were more likely to give birth to underweight or small for gestational age baby girls (Wolff 2008).  This is not a perfect study but consider if it should be ignored because a study on uterine weight in mice suggested no hormonal effects from UV filters. Most of the data from animal studies suggest that UV filters affect a variety of reproductive and other hormones. The most blatant flaw in the industry disingenuous position is that endocrine receptor function in humans is different from lower animals. Consider the potential effects on a 10-week old human embryo from even a few hormone disruptors binding to even a few receptors. The effects at this critical period of human development on endocrine function and imprinting, or on neural signaling mechanisms that are hormone sensitive, could be very profound and usually permanent.

 The developing fetus and young or pubescent children are the most vulnerable humans, since infinitesimally low or undetectable, indeed any level of exposure may cause hormonal reproductive defects, particularly at these critical times of development. The existing animal model data and human evidence taken together, suggest that exposure to EDCs during these critical times plays a role in the increased incidences of the human diseases listed above. The definitive human study over a lifetime can never be done, given the complexity imposed by varying effects due to different ages at exposure, a latent period that could be 20-50 years, multiplication from exposure to several EDCs, transgenerational  effects through altered enzymes that affect genes, confounding factors like other causes of these diseases, and the ethical dilemma since there is already strong evidence of adverse effects. We believe in The Precautionary Principle, as mandated under Canadian law, to err on the side of caution, since it meets our personal approach to medical practice and the first precept in medicine- primum non nocere or “first do no harm”. Physicians have a duty of care to advise patients that soluble filters enter blood, particularly in pregnancy, just as they do for any medication, even aspirin. Every expectant or nursing mother and parent, deserves to make their own informed choice:

  • Either: use a sunscreen with filters and chemicals that give incomplete protection, contaminate your body, and are strongly linked to serious permanent disorders, other temporary problems like photocontact allergy in humans, are harmful to lower species and damage the coral reefs as they wash off swimmers.
  • Or: exercise an abundance of caution or the precautionary approach by selecting a sunscreen with filters that remain on the skin, give arguably better or balanced protection, never attain blood, fetal, or brain levels, and have no risk for even minor adverse effects like photocontact allergy, or pose any risk to animals or the environment.

As a former obstetrician, I appreciate the persuasive simplicity that anything safe to use in pregnancy is safe to use for everyone. Dr. Laughlin describes an effective sunscreen as one that actually prevents skin cancer and photoaging. Coming from Maternal Fetal Medicine, I define a safe sunscreen as one that is safe to use in pregnancy. Soluble filters operate almost exclusively in the UVB and shortwave UVA2 wavelengths. Only avobenzone has any UVA1 attenuation. The usual combination of soluble filters provide a potent mix of hormone disruptors while providing UVB-biased protection that hardly lowers the risk of skin cancer and photoaging- mediated mostly by UVA1. Rising cancer rates are related to these UVB-biased sunscreens that dominate the N. American market. Particle based sunscreens with zinc oxide alone, or with titanium dioxide or encapsulated octinoxate meet both objectives- safety and efficacy. It is ironic that the sunscreens with soluble filters have limited benefits while probably exposing you to harm. The prudent choice seems rather obvious, but most consumers are never given the relevant information. Physicians have a duty of care to advise you that soluble filters enter your blood, particularly if you are pregnant or the parent of young or pubescent children.

The Precautionary Principle considers the limits of science and errs on the side of caution, so that action in the public interest is not delayed until the damage is done. Regulators at the FDA and Health Canada, often act only when there is incontrovertible evidence of harm, which is too late. This policy is illogical since it is criminal or unethical to do definitive studies on humans, particularly in pregnant women and children. This shifts the burden of protection against harm through caution, from the government to you. BPA was justifiably banned under The Precautionary Principle as a carcinogen and hormone disruptor. I believe The Precautionary Principle is being ignored where soluble sunscreen filters are concerned. The case for banning them is much stronger than that of BPA.

Can Using a Sunscreen Be Worse than Using a Tanning Bed? The Health Implications of a UVB Biased Sunscreen.

The Role of Long Wave UVA in Skin Cancer

There is an unrelenting rise in skin cancer rates in North America with an annual increase around 2-3 % over the past 3 decades. Continue reading Can Using a Sunscreen Be Worse than Using a Tanning Bed? The Health Implications of a UVB Biased Sunscreen.

9 Reasons Why Oxybenzone Might be One of the Most Dangerous Chemicals in Your House

As a former specialist in Maternal Fetal Medicine (MFM) and Reproductive Endocrinology, I believe the Endocrine Disrupting Chemicals (EDC’s) are already affecting human health and I stopped exposing my family some 30 years ago. Continue reading 9 Reasons Why Oxybenzone Might be One of the Most Dangerous Chemicals in Your House