Summer, Sun and Sunscreen

Although this is a “cloth diapering” blog, I know that many parents who cloth diaper tend to embrace a more natural approach when it comes to other decisions concerning their children. I thought today, I would stray from diapers a bit and discuss sun safety.

It’s summer and every time we take our tender skinned wee kiddos outside, we consider the implications of the rays emitted by the big glowing orb in the sky. The debates surrounding sunscreen and sun protection rage and many parents are unsure what to do. Do you avoid the sun altogether during the hours of the day when the rays are most dangerous? Can a parent safely lather on the sunscreen to protect their kids? Does sunscreen really protect? Is sunscreen chemically safe? Should a parent allow their child some sun exposure? I definitely cannot answer all of these questions, but will attempt to have a look at the sunscreen issue. I am not a scientist, but what follows includes some of what I have read.

Because I continue to question the safety of sunscreen yet acknowledge the potential harm from prolonged unprotected sun exposure, I advocate for a covering up and reducing the need for sunscreen. My kids are used to heading out in sunny weather with a hat and long sleeves or their NoZone sun suits. They cover up as much as possible, requiring little sunscreen.

Standing in the sunscreen aisle trying to decide which one to buy can be a daunting prospect. When considering a sunscreen what should exactly should a parent look for? Obviously, if it does not protect adequately from the sun’s rays, then it is not worth smearing on your child’s skin, no matter how safe it is. What about that complicated list of ingredients. What do those long words mean? Which ingredients should be avoided and which ones are safe? Are there particular ingredients which provide effective sun protection yet are chemically safe?

The Environmental Working Group provides a list of sunscreen chemicals to avoid. They have recently stated that they can recommend only 8% of 500 sunscreens they reviewed, based on the finding associated with some of the ingredients. They have research excerpts to back up their assertions.

Some Canadian doctors do not agree with the Environmental Working Group’s recommendations. The Canadian Dermatology Association points out that many Canadians are not aware of the dangers of repeated exposure to sunlight. While we worry over the potential carcinogenic effects of sunscreen, we sometimes lose sight of the fact that sunshine too is a carcinogen.

What then is a parent to do? We all must make our own informed choices based on research and review. My choice has been to cover my kids up as much as possible, to apply minimal amounts of sunscreen when necessary, and to use a sunscreen which the EWG rates as effective yet safe. If I need to shop for sunscreen, I actually take a copy of the rather complicated chart shown below, with me to the store. I then look up individual ingredients from sunscreen labels. It's a bit of a labourious process, but important.

This is a copy of the Environmental Working Group’s sunscreen chemical chart. Not included in the chart, but discussed in their essay on the subject, is a form of vitamin A, retinyl palmitate which the Environmental Working Group states data from an FDA study indicate that when applied to the skin in the presence of sunlight, may speed the development of skin tumors and lesions (NTP 2009).

· Human exposure – resulting from sunscreen chemicals penetrating skin and reaching sensitive organs or hormone receptors

· Hormone activity – which can impact the regulation of the reproductive, nervous, thyroid and immune systems, particularly if exposures occur during pregnancy or childhood.

· Other toxicity concerns—including sun-related skin allergy, effects on skin and breakdown products

No ingredient is without concerns; EWG’s rating system for sunscreens takes into account the range of concerns and differences in the weight of the evidence for each active ingredient.

Sunscreen chemical	Percent of U.S. sunscreens containing it	Exposure (skin penetration and biomonitoring)	Toxicity concerns
Sunscreens with highest concern for human exposure and toxicity
4-Methylbenzylidene camphor (4-MBC)	FDA approval pending	Limited skin penetration (1%) in vivo 1-3. Detected in European mothers’ milk at low parts per billion levels 4	Strong evidence of hormone disruption 5-7; 8 9 10; thyroid effects 5; behavioral alterations in female rats 11
Benzophenone-3 (oxybenzone)	60%	1-9% absorbed according to in vivo skin studies 1, 2, 12, 13; detected in volunteers’ urine 14, 15 and in European mothers’ milk 4. Present in 96% of Americans’ urine 16, 17; higher maternal exposures are associated with a decrease in birth weight for girls and an increase in boys 18	Hormone disruption 19-22; reproductive effects and altered organ weights in chronic feeding studies 23. High rates of photo-allergy 24.
3-Benzylidene camphor	FDA approval pending		Hormone disruption 8; in vivoeffects—behavior and estrous cycling 11
Octyl methoxycinnamate (OMC)	40%	Limited skin penetration in vivo <1% 12, urine 1, 2, 14 and in European mothers’ milk at low parts per billion levels.4	Multiple estrogenic effects 5, 6, 19; 21. Thyroid hormone reductions 25; and hormone-mediated immune effects.26Moderate rates of skin allergy. {Rodriguez, 2006 #2683}
Padimate O	1.0%	Limited skin penetration.27 Detected in European mothers’ milk at low parts per billion levels.4	Estrogenic effects 19, 28 8. Damages DNA 29: causes allergic reactions in some people.
Sunscreens with moderate concern for human exposure and toxicity
Octocrylene	49%	Limited skin penetration in vivo 27. Detected in European mothers’ milk.4	Slight to moderate skin irritation.30
Ensulizole	1.2%	Skin penetration measured in vivo, documented concentrations in urine.31	Occasional photoallergic reactions reported.32, 33
Homosalate	45%	Limited skin penetration in vivo <1% 12. Not detected in European mothers’ milk.4	Limited evidence of hormone disruption.8, 19, 22, 28. Toxic metabolites 34
Sulisobenzone (Benzophenone-4)	0.2%	Skin penetration measured 35, estimated at 1%.36	Limited evidence of hormone disruption.37
Zinc Oxide	29%	Very limited skin penetration.38 Estimated at 0.4% in volunteers for nano- and conventional partical sizes. Unknown whether it is in elemental (harmless) or insoluble particle form (toxicologically harmful)39	No photoallergy or hormone disruption. Skin cell study found zinc nanoparticles provoked oxidative stress and DNA damage 40. Coatings may reduce skin reactivity. Zinc inhalation causes lung inflammation.41
Titanium Dioxide	28%	Very limited skin penetration 38: penetration of hairless mouse skin 42: no skin penetration in min-pigs 43.	No photoallergy or hormone disruption. Probable carcinogen when inhaled 44. Inhaled nanoparticles reach organs, cross placenta and enter brain.45-47 Skin damage in vitro48.
Sunscreens with lowest concern for human exposure and toxicity
Avobenzone	50%	Limited skin penetration in vivo 27; and in vitro (0.8%) 3, 49	No evidence of photoallergy or hormone disruption.
Mexoryl SX	Limited approval (4 formulations); broader FDA approval pending	Limited skin penetration in vivo (0.16%).50	No evidence of hormone disruption. Rarely reported skin allergy, more often in children.51
Octisalate	59%	Limited skin penetration in vivo <1%.12 andin vitro (~0.5%).52	Rarely, allergic contact dermatitis.53
Tinosorb M	FDA approval pending	Low skin penetration measured in vitro.54	No in vitro hormone effects. Did not stimulate uterotrophic activityin vivo.55 Allergic reactions uncommon.56
Tinosorb S	FDA approval pending		No in vitro hormone effects; did not stimulate uterotrophic activity.55

4 other ingredients approved in the United States are almost never used in sunscreen, and poorly studied: Menthyl Anthranilate, Benzophenone-8, PABA and Trolamine salicylate